JP4278600B2 - Plant control device - Google Patents

Description

  The present invention relates to a plant control apparatus in which mutual interference exists between a plurality of control inputs and a plurality of control amounts.

  Conventionally, what was described in patent document 1 is known as a control apparatus which controls a polishing robot. In this control apparatus, a polishing robot is controlled as follows by a sliding mode non-interference control algorithm that combines a sliding mode control algorithm and a non-interference control algorithm.

  First, a polishing apparatus including a polishing robot has two control inputs for driving powers fmx and fmy in the x and y directions of the polishing robot, and controls two positions Px and Py in the x and y directions of the workpiece. And a plant in which mutual interference exists between these two control inputs fmx and fmy and the two control amounts Px and Py. Next, as a plant model, a continuous time system model that represents the relationship between the control input fmx and the control amount Px and a continuous time system model that represents the relationship between the control input fmy and the control amount Py are used.

  The control inputs fmx and fmy are determined by the sliding mode control algorithm so that the control amounts Px and Py converge to the two target values, respectively, and at the same time, the two control inputs fmx and fmy are determined by the non-interference control algorithm. And the two control amounts Px and Py are determined so as to eliminate mutual interference. That is, with the sliding mode non-interference control algorithm, while the mutual interference existing between the two control inputs fmx and fmy and the two control amounts Px and Py is eliminated, the control amounts Px and Py are set to two target values, respectively. Control inputs fmx and fmy are determined so as to converge, whereby the polishing robot is controlled.

JP-A-10-301602

  In the above conventional control device, since a continuous time system model is used as a plant model, it is difficult to directly identify the model parameters of the plant model from the experimental data of the plant. Therefore, as a specific identification method, a continuous-time system model must be approximated to a discrete-time system model, and model parameters must be identified based on this. It will decline. Furthermore, since the discrete-time system model must be approximated again to the continuous-time system model, the use of such two approximate transformations increases the modeling error of the plant model. As a result, it is necessary to keep the controller gain low in order to ensure a stable control margin, and there is a problem in that controllability and control accuracy are reduced.

  In addition, when a continuous-time system model is used, the differential value of the controlled variable is used as a variable constituting the switching function. Therefore, when the control cycle is shortened, such a differential value changes in the controlled variable. The speed is not shown, and the state becomes close to the noise component. As a result, the robustness that is a feature of the sliding mode control is lost, and the controllability and control accuracy are further reduced.

  The present invention has been made in order to solve the above-described problem. In the case where a plurality of control amounts are controlled while eliminating mutual interference existing between a plurality of control inputs and a plurality of control amounts, the controllability is improved. And it aims at providing the control apparatus of the plant which can improve control accuracy.

In order to achieve the above object, the invention according to claim 1 includes a plurality of control inputs (target throttle valve opening TH_cmd and target valve lift Liftin_cmd, target intake pipe pressure PB_cmd and target EGR lift Legr_cmd) and a plurality of control amounts ( The control devices 1B and 1C of the plants 90 and 404 in which mutual interference exists between the intake pipe pressure PB and the intake air amount Gcyl, the intake air amount Gcyl and the EGR amount Gegr). Target value setting means (ECU2, target value calculation units 100, 400) for setting a plurality of target values (target intake pipe pressure PB_cmd, target intake air amount Gcyl_cmd, target intake air amount Gcyl_cmd and target EGR amount Gegr_cmd), Model a plant as a discrete-time model A predetermined control algorithm including a combination of a predetermined response designating control algorithm and a predetermined non-interference control algorithm based on the plant model [Equations (19), (100)] [Equations (2) to (9), ( 41) to (50), (64), (66) to (74)] to eliminate mutual interference for causing a plurality of control inputs to follow a plurality of control amounts to a plurality of target values, respectively. Non-interacting input calculating means for calculating as a plurality of non-interacting inputs (ECU 2, response specifying type controller 101, freedom degree response specifying type controllers 201, 301, 401, non-interacting controllers 102, 202, 302, 402) When the Bei example, a plant model [equation (19), (100)], a plurality of non-interacting parameter for defining the relationship between the control inputs and a plurality of controlled variables The non-interacting input calculating means includes a plurality of non-interacting input calculation means according to at least one of a plurality of non-interacting parameters and a plurality of control amounts, according to a predetermined control algorithm. Interfering inputs are calculated, and a plurality of non-interacting parameters are respectively calculated, a plurality of non-interacting inputs, a plurality of control variables and plant internal variables (engine speed NE, atmospheric pressure PA, valve timing HI.VT, LO . VT, exhaust pipe internal pressure Pex) according to at least one of the identification means (ECU2, on-board identifiers 303, 403) for further identification, further comprising a plurality of non-interacting inputs, a plurality of controls A plurality of decoupling parameter reference values Fth_base, Flf_base, Rcp depending on the quantity and at least one of the plant internal variables base, Scp_base, Heg_base are calculated, and a plurality of correction values (corrected terms dFth_hat, dFlf_hat) are determined by a predetermined sequential identification algorithm according to at least one of a plurality of non-interacting inputs, a plurality of controlled variables, and an internal variable of the plant. , dRcp_hat, dScp_hat, dHeg_hat), and by correcting the reference values of the plurality of non-interacting parameters with the plurality of correction values, respectively, to identify the plurality of non-interacting parameters.

  According to this plant control apparatus, a plurality of predetermined control algorithms including a combination of a predetermined response designating control algorithm and a predetermined non-interference control algorithm based on a plant model obtained by modeling a plant as a discrete-time system model. Control inputs are calculated as a plurality of non-interacting inputs that eliminate mutual interference to cause a plurality of control amounts to follow a plurality of target values, respectively. It is possible to cause the plurality of control amounts to follow the plurality of target values with high accuracy while eliminating the mutual interference between the two. Furthermore, since a discrete-time system model is used in the calculation of a plurality of non-interacting inputs, modeling errors can be reduced compared to the conventional case using a continuous-time system model, thereby increasing the controller gain. While setting a high value, it is possible to secure a control stability margin. In addition to this, since the discrete time system model is used, unlike the conventional case using the continuous time system model, it is not necessary to use the differential value of the controlled variable as a variable constituting the switching function, so that the control cycle is short. Even in this case, it is possible to ensure the robustness that is a feature of the response specification type control algorithm such as the sliding mode control. As described above, controllability and control accuracy can be improved.

The plant model also includes a plurality of non-interacting parameters for defining a relationship between a plurality of control inputs and a plurality of control amounts, and the plurality of non-interacting inputs include a plurality of non-interacting parameters and a plurality of controls. A plurality of non-interacting parameters are respectively calculated as at least one of a plurality of non-interacting inputs, a plurality of control amounts, and an internal variable of the plant. In response, they are identified sequentially. In this way, since non-interacting parameters that can be direct modeling errors of the plant model are sequentially identified, a plurality of non-interacting inputs can be calculated while compensating for the modeling error quickly and appropriately. . As a result, even if modeling errors occur due to aging and variability among individuals in a plant where the degree of mutual interference between multiple control inputs and multiple controlled variables is considerable, modeling is possible. The error can be compensated quickly and appropriately, thereby ensuring good controllability and control accuracy.

Furthermore, in a plant in which mutual interference exists between a plurality of control inputs and a plurality of control amounts, a plurality of control inputs and a plurality of control amounts are generally in a complex mutual interference relationship. Therefore, when identifying non-interacting parameters sequentially as in this control device, such a tendency becomes prominent when there is a large modeling error immediately after the start of identification. May be misidentified. On the other hand, according to this plant control apparatus, reference values for a plurality of decoupling parameters are calculated in accordance with at least one of a plurality of decoupling inputs, a plurality of controlled variables, and an internal variable of the plant. A plurality of correction values are calculated by a predetermined sequential identification algorithm in accordance with at least one of a plurality of non-interacting inputs, a plurality of control variables, and an internal variable of the plant, and a plurality of decoupling parameter criteria A plurality of non-interacting parameters are identified by correcting each value with a plurality of correction values. Therefore, immediately after the start of identification, a plurality of non-interacting parameters are identified as values close to the reference value, so that erroneous identification can be avoided and the identification accuracy can be improved. In addition, for example, when a predetermined forgetting effect is added to the correction value, a plurality of non-interacting parameters are identified in a state where they are constrained in the vicinity of the reference value. Identification as a value can be prevented (that is, drift of a non-interacting parameter can be prevented), whereby stability of the control system can be ensured and identification accuracy can be improved.

The invention according to claim 2 includes a plurality of control inputs (target throttle valve opening TH_cmd and target valve lift Liftin_cmd, target boost pressure PB_cmd and target EGR lift Legr_cmd) and a plurality of control amounts (intake pipe pressure PB and intake air amount). Gcyl, intake air amount Gcyl, and EGR amount Gegr) are control devices 1A to 1C of plants 90 and 404 in which mutual interference exists, and a plurality of target values (targets) that are targets of a plurality of control amounts. Target value setting means (ECU2, target value calculation units 100 and 400) for setting the intake pipe internal pressure PB_cmd, the target intake air amount Gcyl_cmd, the target intake air amount Gcyl_cmd and the target EGR amount Gegr_cmd), and a plant model that models the plant [ Based on equations (19), (100)] A predetermined control algorithm including a combination of a predetermined target value filter type two-degree-of-freedom control algorithm and a predetermined non-interference control algorithm [Expressions (41) to (50), (64), (66) to (75)] Thus, the non-interacting input calculation means (ECU2, ECU2) respectively calculates the plurality of control inputs as a plurality of non-interacting inputs for eliminating mutual interference for causing the plurality of control amounts to follow the plurality of target values, respectively. A two-degree-of-freedom response designating type controller 201, 301, 401 and a non-interacting controller 202, 302, 402), and the predetermined target value filter type two-degree-of-freedom control algorithm is a predetermined target value filter algorithm [formula (48) to (49), (73) to (74)] and a predetermined feedback control algorithm [Expressions (41) to (47), (66) to (7) Characterized in that) and a two-degree-of-freedom feedback control algorithm target value filter type that combines.

According to this plant control apparatus , a plurality of predetermined control algorithms including a combination of a predetermined target value filter type two-degree-of-freedom control algorithm and a predetermined non-interference control algorithm based on a plant model obtained by modeling a plant, These control inputs are calculated as a plurality of non-interacting inputs for eliminating mutual interference for causing a plurality of control amounts to follow a plurality of target values, respectively. The predetermined target value filter type two-degree-of-freedom control algorithm is a target value filter-type two-degree-of-freedom feedback control in which a predetermined target value filter algorithm and a predetermined feedback control algorithm are combined. Input can increase disturbance suppression capability by a predetermined feedback control algorithm and suppress a decrease in controllability due to modeling error, and at the same time, the response of the control amount to the target value is moderated by the predetermined target value filter algorithm Can be calculated as As a result, it is possible to calculate a plurality of non-interacting inputs as values with small change amounts and change speeds while ensuring high disturbance suppression capability, and as a result, control amounts due to errors in the non-interference control algorithm. Even when a deviation between the target value and the target value occurs, the amount of change and the speed of change can be held at a small value, and an increase in the deviation can be appropriately suppressed by a high disturbance suppression capability. As described above, while eliminating mutual interference between a plurality of control inputs and a plurality of control amounts, a plurality of control amounts can follow a plurality of target values with high accuracy, thereby improving controllability and control accuracy. be able to.

The invention according to claim 3 is characterized in that, in the plant control devices 1A to 1C according to claim 2 , the predetermined feedback control algorithm is a predetermined response assignment control algorithm.

According to this plant control apparatus , a plurality of input values are calculated by a target value filter type two-degree-of-freedom response specification type control algorithm that combines a predetermined target value filter algorithm and a predetermined response specification type control algorithm. Therefore, compared with the case of using a target value filter type two-degree-of-freedom feedback control algorithm that combines a general feedback control algorithm and a target value filter algorithm, the behavior of the deviation between the control amount and the target value is exponential. As a result, the disturbance suppressing ability can be further enhanced. Thereby, the ability to suppress the deviation between the control amount and the target value can be further enhanced.

The invention according to claim 4 includes a plurality of control inputs (target throttle valve opening TH_cmd and target valve lift Liftin_cmd, target intake pipe internal pressure PB_cmd and target EGR lift Legr_cmd) and a plurality of control amounts (intake pipe internal pressure PB and intake air amount). Gcyl, intake air amount Gcyl, and EGR amount Gegr) are control devices 1B and 1C of plants 90 and 404, and are plant models that model the plant [Equations (19) and (100) ] Based on predetermined control algorithms [Formulas (41) to (49), (64), Formulas (66) to (75)] including a predetermined non-interference control algorithm [Formulas (64) and (75)] , Non-interacting input calculation that calculates multiple control inputs as multiple non-interacting inputs that eliminate mutual interference Means (ECU2, two-degree-of-freedom response designation type controllers 301 and 401, non-interacting controllers 302 and 402), and the plant model defines a plurality of non-intervals for defining a relationship between a plurality of control inputs and a plurality of control amounts. Including non-interacting parameters Fth, Flf, Rcp, Scp, and Heg, and the non-interacting input calculating means uses a predetermined control algorithm according to at least one of the plurality of non-interacting parameters and the plurality of control amounts. A non-interacting input is calculated, and a plurality of non-interacting parameters are respectively calculated, a plurality of non-interacting inputs, a plurality of controlled variables and plant internal variables (engine speed NE, atmospheric pressure PA, valve timing HI.VT, Identification means (ECU2, onboard identifier 30) for sequential identification according to at least one of LO.VT and exhaust pipe internal pressure Pex) , E further Bei 403), identification means (ECU 2, the onboard identifier 303, 403) includes a plurality of non-interacting inputs, according to at least one internal variables of the plurality of control amounts and the plant, a plurality of non Interference parameter reference values Fth_base, Flf_base, Rcp_base, Scp_base, Heg_base are calculated, and a predetermined sequential identification algorithm is used according to at least one of a plurality of non-interacting inputs, a plurality of controlled variables, and an internal variable of the plant. By calculating a plurality of correction values (correction terms dFth_hat, dFlf_hat, dRcp_hat, dScp_hat, dHeg_hat) and correcting the reference values of the plurality of non-interacting parameters with the plurality of correction values, respectively, It is characterized by identifying.

  According to this plant control apparatus, a plurality of non-interfering signals that eliminate a mutual interference by a predetermined control algorithm including a predetermined non-interfering control algorithm based on a plant model obtained by modeling the plant. Each of them is calculated as an input. The plant model includes a plurality of non-interacting parameters for defining a relationship between a plurality of control inputs and a plurality of control amounts. The plurality of non-interacting inputs include a plurality of non-interacting parameters and a plurality of control amounts. Each of the plurality of non-interacting parameters is calculated according to at least one of a plurality of non-interacting inputs, a plurality of control variables, and an internal variable of the plant, respectively. Sequentially identified. In this way, since non-interacting parameters that can be direct modeling errors of the plant model are sequentially identified, a plurality of non-interacting inputs can be calculated while compensating for the modeling error quickly and appropriately. . As a result, even if a modeling error occurs in a plant where the degree of mutual interference between a plurality of control inputs and a plurality of control amounts is considerably large due to aging and variation among individuals, Modeling errors can be compensated quickly and appropriately, thereby ensuring good controllability and control accuracy.

In addition, in a plant in which mutual interference exists between a plurality of control inputs and a plurality of control amounts, a plurality of control inputs and a plurality of control amounts are generally in a complex mutual interference relationship. Therefore, when identifying non-interacting parameters sequentially as in this control device, such a tendency becomes prominent when there is a large modeling error immediately after the start of identification. May be misidentified. On the other hand, according to this plant control apparatus, reference values for a plurality of decoupling parameters are calculated in accordance with at least one of a plurality of decoupling inputs, a plurality of controlled variables, and an internal variable of the plant. A plurality of correction values are calculated by a predetermined sequential identification algorithm in accordance with at least one of a plurality of non-interacting inputs, a plurality of control variables, and an internal variable of the plant, and a plurality of decoupling parameter criteria A plurality of non-interacting parameters are identified by correcting each value with a plurality of correction values. Therefore, immediately after the start of identification, a plurality of non-interacting parameters are identified as values close to the reference value, so that erroneous identification can be avoided and the identification accuracy can be improved. In addition, for example, when a predetermined forgetting effect is added to the correction value, a plurality of non-interacting parameters are identified in a state where they are constrained in the vicinity of the reference value. Identification as a value can be prevented (that is, drift of a non-interacting parameter can be prevented), whereby stability of the control system can be ensured and identification accuracy can be improved.

According to a fifth aspect of the present invention, in the control device 1A , 1B of the plant 90 according to any one of the first to fourth aspects, the plurality of control amounts are the pressure in the intake passage of the internal combustion engine 3 (intake pipe internal pressure PB). And a plurality of control inputs are values for controlling the throttle valve opening TH of the internal combustion engine 3 (target throttle valve opening TH_cmd) and the lift Liftin of the intake valve 4 of the internal combustion engine 3. It is a value for control (target valve lift Liftin_cmd).

  According to the control device of this plant, the value for controlling the lift of the intake valve and the value for controlling the throttle valve opening are mutually interfered with the intake pipe internal pressure and the intake air amount of the internal combustion engine. Therefore, the intake pipe internal pressure and the intake air amount can be controlled independently of each other and with high responsiveness secured. As a result, normally, by suppressing the degree of negative pressure in the intake pipe, it is possible to reduce pumping loss and improve fuel efficiency, as well as required for brake pressure control and evaporated fuel control (purge control). The negative pressure in the intake pipe can be appropriately secured as necessary.

The invention according to claim 6 is the plant control apparatus 1C according to any one of claims 1 to 4 , wherein the plurality of control amounts are the intake air amount Gcyl and the EGR amount Gegr of the internal combustion engine 3, The inputs are a value for controlling the supercharging pressure PB of the internal combustion engine 3 (target supercharging pressure PB_cmd) and a value for controlling the EGR amount of the internal combustion engine 3 (target EGR lift Legr_cmd). To do.

  According to this plant control device, the value for controlling the supercharging pressure and the value for controlling the EGR amount cancel the mutual interference between the supercharging pressure and the EGR amount of the internal combustion engine. Since it is calculated as a correct value, the supercharging pressure and the EGR amount can be controlled in a state of being independent from each other and ensuring high responsiveness. As a result, fuel consumption and exhaust gas characteristics can both be maintained in good condition by EGR control, and at the same time, the intake air amount for generating the required driving force can be secured freely and with high responsiveness by supercharging pressure control. Can do. As a result, it is possible to achieve both good fuel consumption and exhaust gas characteristics and good drivability.

  Hereinafter, a control device according to a first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 2, the control device 1 includes an ECU 2. As will be described later, the ECU 2 performs variable mechanism control processing or the like according to the operating state of the internal combustion engine (hereinafter referred to as “engine”) 3. The control process is executed.

  As shown in FIGS. 1 and 3, the engine 3 is an in-line four-cylinder gasoline engine having four sets of cylinders 3a and pistons 3b (only one set is shown), and is mounted on a vehicle (not shown). The engine 3 is provided for each cylinder 3a, and opens and closes an intake valve 4 and an exhaust valve 7 for opening and closing an intake port and an exhaust port, an intake camshaft 5 and an intake cam 6 for driving the intake valve 4, and an intake valve 4, respectively. A variable intake valve mechanism 40 for driving, an exhaust camshaft 8 and an exhaust cam 9 for driving the exhaust valve 7, an exhaust valve mechanism 70 for opening and closing the exhaust valve 7, and the like are provided.

  The intake valve 4 has a stem 4a slidably fitted to a guide 4b, and the guide 4b is fixed to the cylinder head 3c. Further, as shown in FIG. 4, the intake valve 4 is provided with upper and lower spring seats 4c, 4d and a valve spring 4e provided therebetween, and is attached in the valve closing direction by the valve spring 4e. It is energized.

  Further, each of the intake camshaft 5 and the exhaust camshaft 8 is rotatably attached to the cylinder head 3c via a holder (not shown). An intake sprocket (not shown) is coaxially fixed to one end portion of the intake camshaft 5, and is connected to the crankshaft 3d via the intake sprocket and a timing belt (not shown). As a result, the intake camshaft 5 rotates once every time the crankshaft 3d rotates twice. In addition, the intake cam 6 is provided for each cylinder 3a on the intake camshaft 5 so as to rotate integrally therewith.

  Furthermore, the variable intake valve mechanism 40 opens and closes the intake valve 4 of each cylinder 3a as the intake camshaft 5 rotates, and changes the lift of the intake valve 4 steplessly, thereby The amount is changed, and details thereof will be described later. In the present embodiment, “the lift of the intake valve 4 (hereinafter referred to as“ valve lift ”)” represents the maximum lift of the intake valve 4.

  On the other hand, the exhaust valve 7 has a stem 7a slidably fitted to a guide 7b, and the guide 7b is fixed to the cylinder head 3c. Further, the exhaust valve 7 includes upper and lower spring seats 7c and 7d and a valve spring 7e provided therebetween, and is urged in the valve closing direction by the valve spring 7e.

  The exhaust camshaft 8 includes an exhaust sprocket (not shown) integrated with the exhaust camshaft 8 and is connected to the crankshaft 3d via the exhaust sprocket and a timing belt (not shown). One rotation for every rotation. Further, the exhaust cam 9 is provided for each cylinder 3a on the exhaust camshaft 8 so as to rotate integrally therewith.

  Further, the exhaust valve mechanism 70 includes a rocker arm 71. The rocker arm 71 rotates with the rotation of the exhaust cam 9, thereby opening and closing the exhaust valve 7 against the urging force of the valve spring 7e. To drive.

  The engine 3 is provided with a crank angle sensor 20 and a water temperature sensor 21. The crank angle sensor 20 outputs a CRK signal and a TDC signal, both of which are pulse signals, to the ECU 2 as the crankshaft 3d rotates. The CRK signal is output at one pulse every predetermined crank angle (for example, 10 °), and the ECU 2 calculates the engine speed (hereinafter referred to as “engine speed”) NE of the engine 3 based on the CRK signal. The TDC signal is a signal indicating that the piston 3b of each cylinder 3a is at a predetermined crank angle position slightly before the TDC position of the intake stroke, and one pulse is output for each predetermined crank angle.

  On the other hand, the water temperature sensor 21 includes a thermistor attached to the cylinder block 3e of the engine 3, and outputs a detection signal representing the engine water temperature TW, which is the temperature of the cooling water circulating in the cylinder block 3e, to the ECU 2. .

  The intake pipe 10 of the engine 3 is provided with an air flow sensor 22, a throttle valve mechanism 11, a throttle valve opening sensor 23, an intake pipe internal pressure sensor 24, a fuel injection valve 12, and the like in order from the upstream side. The air flow sensor 22 includes a hot-wire air flow meter, and outputs a detection signal representing the flow rate of air flowing in the intake pipe 10 (hereinafter referred to as “air flow rate”) Qin to the ECU 2. Based on the air flow rate Qin, the ECU 2 calculates an intake air amount Gcyl estimated to be actually taken into the cylinder 3a, as will be described later.

  The throttle valve mechanism 11 includes a throttle valve 11a and a TH actuator 11b that opens and closes the throttle valve 11a. The throttle valve 11a is rotatably provided in the middle of the intake pipe 10, and changes the intake air amount by the change in the opening degree associated with the rotation. The TH actuator 11b is a combination of a motor connected to the ECU 2 and a gear mechanism (both not shown). The TH actuator 11b is driven by an opening control input Uth from the ECU 2 to thereby reduce the opening of the throttle valve 11a. Change.

  The throttle valve 11a is provided with two springs (both not shown) for urging the throttle valve 11a in the valve opening direction and the valve closing direction, respectively. Due to the urging force of these two springs, the throttle valve 11a, as will be described later, when the opening control input Uth is set to the value 0 or when the opening control input Uth is not input to the TH actuator 11b. The predetermined initial opening is maintained. This initial opening is a value close to the fully closed state, and it is possible to appropriately perform idle operation and engine start while stopping, and at the same time secure an intake air amount that can maintain a low-speed driving state during driving. A possible value (for example, 6 °) is set.

  Further, in the vicinity of the throttle valve 11a of the intake pipe 10, there is provided a throttle valve opening sensor 23 composed of, for example, a potentiometer. The throttle valve opening sensor 23 outputs a detection signal representing the opening TH (hereinafter referred to as “throttle valve opening”) TH of the throttle valve 11 a to the ECU 2.

  On the other hand, a portion of the intake pipe 10 on the downstream side of the throttle valve 11a is a surge tank 10a, and an intake pipe internal pressure sensor 24 and an intake air temperature sensor 25 are provided in the surge tank 10a.

  The intake pipe internal pressure sensor 24 is constituted by a semiconductor pressure sensor, for example, and outputs a detection signal representing the pressure (hereinafter referred to as “intake pipe internal pressure”) PB in the intake pipe 10 to the ECU 2. The intake pipe internal pressure PB (pressure in the intake passage) is detected as an absolute pressure. The intake air temperature sensor 25 outputs a detection signal representing the temperature TA of the air flowing through the intake pipe 10 (hereinafter referred to as “intake air temperature”) TA to the ECU 2.

  Further, the fuel injection valve 12 is driven by a drive signal corresponding to the fuel injection amount from the ECU 2 and injects fuel into the intake pipe 10.

  On the other hand, a spark plug 13 (see FIG. 2) is attached to the cylinder head 3c of the engine 3. The spark plug 13 is connected to the ECU 2 via an ignition coil (not shown), and is discharged when a drive signal (voltage signal) from the ECU 2 is applied at a timing according to the ignition timing. To burn.

  The engine 3 is provided with an evaporated fuel processing device 18. The evaporative fuel processing device 18 is for preventing the evaporative fuel generated in the fuel tank 18c from being released to the atmosphere side, and a canister 18a for temporarily adsorbing the fuel component in the evaporative fuel, A negative pressure introduction pipe 18b for connecting the canister 18a and the intake pipe 10 is provided. In the evaporative fuel processing device 18, the fuel component in the evaporative fuel is temporarily adsorbed by the canister 18a, then desorbed from the canister 18a due to the negative pressure in the intake pipe 10, and is taken into the intake pipe via the introduction pipe 18b. 10 is introduced into the combustion chamber together with air.

  Further, the engine 3 is provided with a master back 19, and this master back 19 is connected to the intake pipe 10 via a negative pressure introduction pipe 19b. In the negative pressure chamber (not shown) in the master back 19, the negative pressure in the intake pipe 10 is introduced and stored through the introduction pipe 19b. When the brake pedal 19a is depressed, the master back 19 generates assist force for assisting braking force using the negative pressure stored in the negative pressure chamber as a power source. The assist force is configured to have a larger value as the negative pressure stored in the negative pressure chamber is larger, that is, as the pressure in the negative pressure chamber is lower.

  Next, the variable intake valve mechanism 40 described above will be described. As shown in FIG. 4, the variable intake valve mechanism 40 includes an intake camshaft 5, an intake cam 6, a variable valve lift mechanism 50, and the like.

  This variable valve lift mechanism 50 opens and closes the intake valve 4 as the intake camshaft 5 rotates, and changes the valve lift Liftin steplessly between a predetermined maximum value Liftin_H and a predetermined minimum value Liftin_L. This includes a four-bar linkage type rocker arm mechanism 51 provided for each cylinder 3a, and a lift actuator 60 (see FIG. 5) for simultaneously driving these rocker arm mechanisms 51.

  Each rocker arm mechanism 51 includes a rocker arm 52 and upper and lower links 53 and 54. One end portion of the upper link 53 is rotatably attached to the upper end portion of the rocker arm 52 via the upper pin 55, and the other end portion is rotatably attached to the rocker arm shaft 56. The rocker arm shaft 56 is attached to the cylinder head 3c via a holder (not shown).

  A roller 57 is rotatably provided on the upper pin 55 of the rocker arm 52. The roller 57 is in contact with the cam surface of the intake cam 6 and rolls on the intake cam 6 while being guided by the cam surface when the intake cam 6 rotates. As a result, the rocker arm 52 is driven in the vertical direction, and the upper link 53 rotates about the rocker arm shaft 56.

  Further, an adjustment bolt 52a is attached to the end of the rocker arm 52 on the intake valve 4 side. When the rocker arm 52 moves up and down with the rotation of the intake cam 6, the adjust bolt 52a drives the stem 4a up and down to open and close the intake valve 4 against the urging force of the valve spring 4e.

  Further, one end portion of the lower link 54 is rotatably attached to the lower end portion of the rocker arm 52 via the lower pin 58, and the connecting shaft 59 is rotatable to the other end portion of the lower link 54. It is attached. The lower link 54 is connected to a short arm 65 (to be described later) of the lift actuator 60 via the connecting shaft 59.

  On the other hand, the lift actuator 60 is driven by the ECU 2 and includes an electric motor 61, a nut 62, a link 63, a long arm 64, a short arm 65, and the like as shown in FIG. The electric motor 61 is connected to the ECU 2 and disposed outside the head cover 3 f of the engine 3. The rotating shaft of the electric motor 61 is a screw shaft 61a on which a male screw is formed, and a nut 62 is screwed onto the screw shaft 61a. The nut 62 is connected to the long arm 64 via the link 63. One end of the link 63 is rotatably attached to the nut 62 via a pin 63a, and the other end is rotatably attached to one end of the long arm 64 via a pin 63b. .

  The other end of the long arm 64 is attached to one end of the short arm 65 via a rotation shaft 66. The rotating shaft 66 is formed in a circular cross section, passes through the head cover 3f of the engine 3, and is rotatably supported by the rotating shaft 66. As the rotation shaft 66 rotates, the long arm 64 and the short arm 65 rotate integrally therewith.

  Further, the connecting shaft 59 is attached to the other end portion of the short arm 65, whereby the short arm 65 is connected to the lower link 54 via the connecting shaft 59. In addition, a minimum lift stopper 67a and a maximum lift stopper 67b are provided in the vicinity of the short arm 65 with a space between each other, and the two arms 67a and 67b allow the short arm 65 to move within its rotation range. Are regulated as described later.

  Next, the operation of the variable valve lift mechanism 50 configured as described above will be described. In this variable valve lift mechanism 50, when a later-described lift control input Uliftin from the ECU 2 is input to the lift actuator 60, the screw shaft 61a rotates and the long arm 64 and the short arm 65 are moved by the movement of the nut 62 associated therewith. While rotating about the rotation shaft 66, the lower link 54 of the rocker arm mechanism 51 rotates about the lower pin 58 as the short arm 65 rotates. That is, the lower link 54 is driven by the lift actuator 60.

  As shown in FIG. 5A, when the short arm 65 rotates counterclockwise in the drawing, the short arm 65 contacts and is locked to the maximum lift stopper 67b. As a result, the lower link 54 is also locked at the maximum lift position indicated by the solid line in FIG. On the other hand, as shown in FIG. 5B, when the short arm 65 rotates in the clockwise direction in the drawing, the short arm 65 comes into contact with and is locked to the minimum lift stopper 67a. Thereby, the lower link 54 is also locked at the minimum lift position indicated by a two-dot chain line in FIG.

  As described above, the rotation range of the short arm 65 is regulated between the maximum lift position shown in FIG. 5A and the minimum lift position shown in FIG. 5B by the two stoppers 67a and 67b. Thereby, the rotation range of the lower link 54 is also regulated between the maximum lift position indicated by a solid line in FIG. 4 and the minimum lift position indicated by a two-dot chain line in FIG.

  When the lower link 54 is at the maximum lift position, in the four-bar link constituted by the rocker arm shaft 56, the upper and lower pins 55, 58 and the connecting shaft 59, the distance between the centers of the upper pin 55 and the lower pin 58 is the rocker arm shaft. 56 and the distance between the centers of the connecting shafts 59, so that, as shown in FIG. 6A, when the intake cam 6 rotates, the contact point between this and the roller 57 is reduced. The moving amount of the adjusting bolt 52a is larger than the moving amount.

  On the other hand, when the lower link 54 is at the minimum lift position, the distance between the centers of the upper pin 55 and the lower pin 58 is shorter than the distance between the centers of the rocker arm shaft 56 and the connecting shaft 59 in the four-bar link. Accordingly, as shown in FIG. 6B, when the intake cam 6 rotates, the moving amount of the adjusting bolt 52a is smaller than the moving amount of the contact point between the intake cam 6 and the roller 57. Become.

  For the above reasons, the intake valve 4 opens with a larger valve lift Liftin when the lower link 54 is at the maximum lift position than when it is at the minimum lift position. Specifically, during the rotation of the intake cam 6, when the lower link 54 is at the maximum lift position, the intake valve 4 is opened according to the valve lift curve shown by the solid line in FIG. 7, and the valve lift Liftin has its maximum value. Liftin_H is shown. On the other hand, when the lower link 54 is at the minimum lift position, the valve opens according to the valve lift curve shown by the two-dot chain line in FIG. 7, and the valve lift Liftin indicates the minimum value Liftin_L.

  As described above, in this variable valve lift mechanism 50, the valve lift Liftin is set to the maximum value Liftin_H and the minimum by rotating the lower link 54 between the maximum lift position and the minimum lift position via the actuator 60. It can be changed steplessly between the value Liftin_L.

  Note that the variable valve lift mechanism 50 is provided with a lock mechanism (not shown). As will be described later, this lock mechanism causes the ECU 2 when the lift control input Uliftin is set to a value of 0, or due to disconnection or the like. When the lift control input Uliftin from is not input to the lift actuator 60, the operation of the variable valve lift mechanism 50 is locked. That is, the change of the valve lift Liftin by the variable valve lift mechanism 50 is prohibited, and the valve lift Liftin is held at the minimum value Liftin_L. Note that the minimum value Liftin_L is set to a value that ensures a predetermined failure time value as the intake air amount, and this predetermined failure time value is appropriate for idle operation and engine start while the vehicle is stopped. At the same time, the intake air amount is set so as to maintain a low-speed traveling state during traveling.

  Further, the engine 3 is provided with a rotation angle sensor 26 (see FIG. 2), and the rotation angle sensor 26 outputs a detection signal indicating the rotation angle of the short arm 65 to the ECU 2. The ECU 2 calculates the valve lift Liftin based on the rotation angle of the short arm 65.

  Further, as shown in FIG. 2, an atmospheric pressure sensor 27, an accelerator opening sensor 28, a vehicle speed sensor 29, an ignition switch (hereinafter referred to as “IG · SW”) 30 and a brake switch 31 are connected to the ECU 2. ing.

  The atmospheric pressure sensor 27 is composed of a semiconductor pressure sensor, and outputs a detection signal representing the atmospheric pressure PA to the ECU 2. The accelerator opening sensor 28 outputs to the ECU 2 a detection signal indicating the depression amount (hereinafter referred to as “accelerator opening”) AP of an accelerator pedal (not shown) of the vehicle.

  The vehicle speed sensor 29 is attached to an axle (not shown) of the vehicle, and outputs a detection signal representing the vehicle speed VP that is the traveling speed of the vehicle to the ECU 2. Further, the IG / SW 30 is turned ON / OFF by operating an ignition key (not shown), and outputs a signal indicating the ON / OFF state to the ECU 2. The brake switch 31 is provided near the brake pedal 19a, and outputs an ON signal to the ECU 2 when the brake pedal 19a is depressed by a predetermined amount or more, and outputs an OFF signal otherwise.

  The ECU 2 includes a microcomputer including a CPU, a RAM, a ROM, an I / O interface (all not shown), and the like. The detection signals of the various sensors 20 to 29 and the various switches 30 and 31 described above. The operating state of the engine 3 is determined according to the ON / OFF signal and the variable mechanism control process is executed. In this variable mechanism control process, as will be described later, the throttle valve opening TH and the valve lift Liftin are controlled via the throttle valve mechanism 11 and the variable valve lift mechanism 50, respectively, whereby the intake pipe internal pressure PB and the intake air are controlled. Each quantity Gcyl is controlled.

  In the present embodiment, the ECU 2 corresponds to target value setting means, non-interacting input calculation means, and identification means.

  Next, the control apparatus 1 of this embodiment is demonstrated. As shown in FIG. 8, the control device 1 controls the plant 90 and includes a target value calculation unit 100, a response designation type controller 101, and a non-interacting controller 102. Note that both the calculation unit 100 and the controllers 101 and 102 are configured by the ECU 2.

  As shown in FIG. 9, the plant 90 is defined as an interference system having the target throttle valve opening TH_cmd and the target valve lift Liftin_cmd as control inputs, and the intake pipe pressure PB and the intake air amount Gcyl as control amounts. 1 includes a valve opening controller 91, a valve lift controller 92, the engine 3, and the like. Both the controllers 91 and 92 are constituted by the ECU 2.

  The target throttle valve opening TH_cmd and the target valve lift Liftin_cmd are target values of the valve lift Liftin and the throttle valve opening TH, and are calculated as described later.

  Further, in the valve opening controller 91, the opening control input Uth is calculated by a target value filter type two-degree-of-freedom response designating control algorithm [equations (29) to (32) to be described later]. When Uth is input to the throttle valve mechanism 11, the throttle valve opening TH is controlled to follow the target throttle valve opening TH_cmd.

  Further, in the valve lift controller 92, the lift control input Uliftin is calculated by a target value filter type two-degree-of-freedom response designating control algorithm [formulas (33) to (36) described later], and the lift control input Uliftin is variable. By inputting to the valve lift mechanism 50, the valve lift Liftin is controlled to follow the target valve lift Liftin_cmd.

  In the plant 90 as described above, when the throttle valve opening TH is controlled to follow the target throttle valve opening TH_cmd, both the intake pipe internal pressure PB and the intake air amount Gcyl change accordingly. Further, when the valve lift Liftin is controlled to follow the target valve lift Liftin_cmd, both the intake pipe internal pressure PB and the intake air amount Gcyl change accordingly. That is, the plant 90 is an interference system in which mutual interference exists between the target throttle valve opening TH_cmd and the target valve lift Liftin_cmd as control inputs and the intake pipe internal pressure PB and the intake air amount Gcyl as control amounts. ing.

  Therefore, in the control apparatus 1 of the present embodiment, in such an interference system plant 90, control that can control both the intake pipe internal pressure PB and the intake air amount Gcyl independently of each other while avoiding the mutual interference. The target throttle valve opening TH_cmd and the target valve lift Liftin_cmd are calculated as inputs, that is, non-interacting inputs.

  Specifically, first, in the target value calculation unit 100 (target value setting means), the target values of the intake pipe internal pressure PB and the intake air amount Gcyl are set by either table search or map search as will be described later. An intake air amount Gcyl_cmd and a target intake pipe internal pressure PB_cmd are respectively calculated.

  Next, the response specifying controller 101 (non-interacting input calculating means) calculates a follow-up input vector W defined as shown in the following equation (1).

  In this equation (1), TH′_cmd is a follow-up input for causing the intake pipe internal pressure PB to follow the target intake pipe internal pressure PB_cmd, and Liftin′_cmd makes the intake air amount Gcyl follow the target intake air amount Gcyl_cmd. This is a follow-up input. Each discrete data with the symbol (k) indicates that the data is sampled or calculated in synchronization with a predetermined control period ΔT (10 msec in the present embodiment), and the symbol k indicates each discrete data Represents the order of sampling or calculation cycles. For example, the symbol k indicates a value sampled or calculated at the current control timing, and the symbol k-1 indicates a value sampled or calculated at the previous control timing. This also applies to the following discrete data. In the following description, the symbol (k) in each discrete data is omitted as appropriate.

  Specifically, this follow-up input vector W is calculated by a response designation type control algorithm expressed by equations (2) to (8).

  As shown in the above equation (2), the tracking input vector W is calculated as the sum of the equivalent control input vector Weq, the reaching law input vector Wrch, and the adaptive law input vector Wadp. 3) is calculated. In the equation (3), Sp and Sg are switching function setting parameters, respectively, and are set so that -1 <Sp <0 and -1 <Sg <0 are satisfied.

  In addition, the reaching law input vector Wrch in the equation (2) is calculated by the above equation (4), and in the equation (4), Krch_p and Krch_g are predetermined reaching law gains. In addition, σp and σg in the equation (4) are switching functions, and the switching function vector σ having these as elements is calculated by the above equation (6). In the equation (6), S is a matrix defined as in the above equation (7), and E ′ is a deviation vector defined as in the above equation (8).

  Further, the adaptive law input vector Wadp in the equation (2) is calculated by the above equation (5). In the equation (5), Kadp_p and Kadp_g are predetermined adaptive law gains.

  Further, the non-interacting controller 102 (non-interacting input calculating means) uses the following input vector W calculated by the response designating controller 101, that is, two following inputs TH′_cmd and Liftin′_cmd, and the following equation (9 The non-interacting input vector U is calculated by the non-interference control algorithm shown in FIG. This non-interacting input vector U is defined as the following equation (10).

  In the above equation (9), Fth is a non-interacting parameter, and is a non-linear function value calculated according to the intake pipe internal pressure PB and the atmospheric pressure PA, as will be described later. Flf is also a non-interacting parameter and is a non-linear function value calculated according to the intake pipe internal pressure PB and the engine speed NE, as will be described later. Furthermore, Rt is a coefficient defined as described later. In the present embodiment, the atmospheric pressure PA and the engine speed NE correspond to the internal variables of the plant.

  As described above, this control apparatus 1 uses the control algorithm shown in the above-described equations (2) to (9), that is, the control algorithm that combines the response designating control algorithm and the non-interference control algorithm, to provide a non-interacting input vector. U (that is, non-interacting input target throttle valve opening TH_cmd and target valve lift Liftin_cmd) is calculated. The control algorithms shown in these equations (2) to (9) are derived as described below.

  First, the calculation formula of the intake air amount Gcyl in the engine 3 is defined as the following formulas (11) to (13).

  Gth in equation (11) is the TH passing intake air amount estimated to pass through the throttle valve 11a, and is calculated by equation (12). In addition, Rt ′ in Expression (11) is a coefficient calculated by Expression (13). In the equation (13), Vb represents the intake pipe internal volume, and R represents a predetermined gas constant.

  When the above equation (11) is shifted to the future side by the discrete time “1” and transformed, the following equation (14) is obtained. In addition, Rt of Formula (14) is a coefficient defined as the following Formula (15).

  On the other hand, the following relationships (16) and (17) are established between Gth and TH_cmd and between Gcyl and Liftin_cmd, respectively.

  Substituting the right sides of the above equations (16) and (17) into Gth and Gcyl in equation (14), the following equation (18) is obtained.

  When the above formulas (17) and (18) are collectively expressed as one formula, the following formula (19) is obtained.

  This equation (19) can be regarded as a model of the plant 90 with PB and Gcyl as control variables and TH_cmd and Liftin_cmd as control inputs, and the non-interacting parameters Fth and Flf can be regarded as model parameters of this model. . This equation (19) can be expressed as the following equations (20) to (24). In the following description, X represented by Expression (21) is referred to as a control amount vector.

  In order to convert the plant 90 of the interference system expressed as the above equation (20) into a linear system without mutual interference, the non-interacting input calculated by the following equation (25) is used as the control input vector U. Vector U is used. This equation (25) is derived from the non-interference control law (cross controller).

  Substituting the right side of the above formulas (21), (23), and (24) and the right side of the above formula (1) into X, A, B, and W of this formula (25), the following formula (26) is obtained. can get.

  Further, substituting the right side of the above-described equation (17) into Gcyl of this equation (26) yields the following equation (27), that is, the above-described equation (9).

  Furthermore, the following equation (28) is obtained by substituting the right side of the equation (27) into the equation (20) described above and rearranging.

  This equation (28) represents a model of a linear virtual plant having no mutual interference, in which the following input vector W is the control amount vector X, and this virtual plant includes the above-described plant 90, the non-interacting controller 102, and the like. Is equivalent to a combination of Since it is possible to design a linear controller for such a linear virtual plant without mutual interference, the intake pipe internal pressure PB is set to the target intake pipe internal pressure PB_cmd with respect to the virtual plant represented by Expression (28). When the response specifying control law is applied so that the intake air amount Gcyl follows the target intake air amount Gcyl_cmd, the above-described equations (2) to (8) are obtained.

  As described above, since the system combining the non-interacting controller 102 and the plant 90 becomes a linear virtual plant without mutual interference, the equations (2) to (8) can be applied to such a virtual plant. By inputting the follow-up input vector W calculated by the response assignment control algorithm, both the intake pipe internal pressure PB and the intake air amount Gcyl as control amounts are controlled independently of each other without causing mutual interference. Can do. That is, when the tracking input vector W is input to the non-interacting controller 102, the non-interacting input vector U calculated by the above-described non-interference control algorithm of Equation (9) is input to the plant 90, thereby Both the intake pipe internal pressure PB and the intake air amount Gcyl can be controlled independently of each other without causing mutual interference. More specifically, the target throttle valve opening TH_cmd can control the intake pipe internal pressure PB to follow the target intake pipe internal pressure PB_cmd without affecting the intake air amount Gcyl, and the target valve lift Liftin_cmd The intake air amount Gcyl can be controlled to follow the target intake air amount Gcyl_cmd without affecting the intake pipe internal pressure PB.

  Hereinafter, the variable mechanism control process executed by the ECU 2 will be described with reference to FIG. This process calculates two control inputs Uth and Uliftin for controlling the throttle valve mechanism 11 and the variable valve lift mechanism 50, respectively, and is executed at the aforementioned predetermined control cycle ΔT (10 msec).

  In this process, first, in step 1, it is determined whether or not an engine start flag F_ENGSTART is “1”. This engine start flag F_ENGSTART is set in a determination process (not shown) by determining whether engine start control is being performed, that is, whether cranking is being performed, according to the engine speed NE and the ON / OFF signal of IG • SW30. Specifically, it is set to “1” when the engine start control is being performed, and to “0” otherwise.

  If the determination result is YES and the engine start control is being performed, the process proceeds to step 2, and the start time value Gcyl_cmd_crk of the target intake air amount is calculated by searching the table shown in FIG. 11 according to the engine coolant temperature TW. To do.

  In this table, the starting value Gcyl_cmd_crk is set to a larger value as the engine coolant temperature TW is lower in the range where the engine coolant temperature TW is higher than the predetermined value TWREF1, and is set to a predetermined value in the range of TW ≦ TWREF1. It is set to Gcylref. This is for compensating for the friction of the variable valve lift mechanism 50 when the engine coolant temperature TW is low.

  Next, in step 3, the target intake air amount Gcyl_cmd is set to the starting value Gcyl_cmd_crk.

  Next, the process proceeds to step 4 to calculate a target intake pipe internal pressure PB_cmd. Specifically, the target intake pipe internal pressure PB_cmd is calculated as shown in FIG.

  That is, first, in step 20, it is determined whether or not the brake operation flag F_BRON is “1”. The brake operation flag F_BRON is set to “1” when the ON signal is output from the brake switch 31, and is set to “0” when the OFF signal is output.

  When the determination result of step 20 is NO and the brake pedal 19a is not depressed, the process proceeds to step 21, and the map shown in FIG. 13 is searched according to the time count Tast and the intake air temperature TA of the post-start timer. A brake off value PB_cmd_pg of the target intake pipe internal pressure is calculated. This after-start timer measures the elapsed time after the end of engine start control, and is composed of an up-count timer.

  In FIG. 13, PB1 to PB4 are predetermined values of the intake pipe internal pressure PB in which the relationship of PB1 <PB2 <PB3 <PB4 is established, and PB4 = 1 atm is set. This also applies to FIG. 14 described later. Further, Tast1 and Tast2 are predetermined values that satisfy the relationship of Tast1 <Tast2, and TA1 to TA3 are predetermined values of the intake air temperature TA that satisfy the relationship of TA1 <TA2 <TA3. As shown in the figure, in this map, the brake-off value PB_cmd_pg is set to a higher value as the intake air temperature TA is lower. In the range of Tast1 ≦ Tast ≦ Tast2, the time value Tast of the post-start timer is small. The lower value is set, and in the range of Tast <Tast1, a constant value (PB1 or PB2) lower than the set value in the range of Tast2 <Tast is set.

  This is because, immediately after the engine 3 is started, the intake pipe internal pressure PB is controlled to the negative pressure side, so that the evaporated fuel adsorbed by the canister 18a while the engine is stopped is appropriately introduced into the intake pipe 10. . Further, since the amount of evaporated fuel generated in the fuel tank 18c is small at low temperatures, the fuel consumption is improved by controlling the throttle valve opening TH to a large value and the intake pipe internal pressure PB to a higher value. This is to make it happen. Further, at the time of high temperature, in addition to the amount of evaporated fuel adsorbed by the canister 18a being increased, the amount of evaporated fuel generated during traveling also increases, so the intake pipe internal pressure PB is controlled to be on the negative pressure side than at low to medium temperatures. This is because such a large amount of evaporated fuel is appropriately introduced into the intake pipe 10.

  Next, in step 22, the target intake pipe internal pressure PB_cmd is set to the brake-off value PB_cmd_pg, and then this process is terminated.

  On the other hand, when the determination result in step 20 is YES and the brake pedal 19a is depressed, the process proceeds to step 23, and the table shown in FIG. 14 is searched according to the vehicle speed VP, so that the brake on of the target intake pipe internal pressure is A use value PB_cmd_br is calculated. In FIG. 14, VP1 and VP2 are predetermined values of the vehicle speed VP that satisfy the relationship of VP1 <VP2.

  In this table, the brake-on value PB_cmd_br is set to a lower value as the vehicle speed VP is higher in the range of VP1 ≦ VP ≦ VP2, and is set in the range of VP2 <VP in the range of VP <VP1. The value PB2 is set higher than the value PB1. This is because, at high vehicle speeds, a larger braking force, that is, a larger assist force is required than at low vehicle speeds, so the degree of negative pressure consumption in the negative pressure chamber of the master back 19 increases and the pressure in the negative pressure chamber increases. This is because the intake pipe internal pressure PB is controlled to a value on the negative pressure side and a sufficient negative pressure is stored in the negative pressure chamber to ensure a necessary assist force. On the contrary, since the required braking force is small at low vehicle speeds, the pumping loss is reduced and the fuel consumption is improved by controlling the intake pipe internal pressure PB to a higher value.

  Further, as apparent from comparing FIG. 14 with FIG. 13 described above, the brake-on value PB_cmd_br is set to a value PB2 lower than the set value in the range of Tast2 <Tast of the brake-off value PB_cmd_pg. . This is because, when Tast2 <Tast, that is, when the process of introducing the evaporated fuel into the intake pipe 10 immediately after the start of the engine 3 is completed and the normal operation state is reached, when the brake pedal 19a is not depressed, This is because by controlling the intake pipe internal pressure PB to a higher value, the pumping loss is reduced and the fuel consumption is improved, while the necessary assist force is appropriately ensured when the brake pedal 19a is depressed.

  Next, in step 24, the target intake pipe internal pressure PB_cmd is set to the brake-on value PB_cmd_br, and then the present process is terminated.

  Returning to FIG. 10, after calculating the target intake pipe internal pressure PB_cmd in step 4 as described above, the process proceeds to step 5 to calculate the target throttle valve opening TH_cmd and the target valve lift Liftin_cmd. Specifically, these values TH_cmd and Liftin_cmd are calculated as shown in FIG.

  First, in step 30, the non-interacting parameter Fth is calculated by searching the table shown in FIG. 16 according to the ratio PB / PA of the intake pipe internal pressure PB and the atmospheric pressure PA.

  In this table, the non-interacting parameter Fth is set to a larger value as the ratio PB / PA is closer to the value 1. This is because as the ratio PB / PA is closer to the value 1, that is, as the intake pipe pressure PB is closer to the atmospheric pressure PA, the TH passing intake air amount Gth is larger than the target throttle valve opening TH_cmd. By showing.

  Next, the routine proceeds to step 31, where a non-interacting parameter Flf is calculated by searching a map shown in FIG. 17 according to the intake pipe internal pressure PB and the engine speed NE. In the figure, PB5 to PB7 are predetermined values of the intake pipe internal pressure PB that satisfies PB5 <PB6 <PB7.

  In this map, the non-interacting parameter Flf is set to a larger value as the intake pipe internal pressure PB is higher. This is because the intake air amount Gcyl shows a larger value with respect to the target valve lift Liftin_cmd as the intake pipe internal pressure PB is higher. Further, the non-interacting parameter Flf is set to a larger value as the engine speed NE is higher when PB = PB5 and PB6. This is because when the intake pipe internal pressure PB is in such a range, the intake air amount Gcyl shows a larger value as the engine speed NE is higher.

  In addition, as described above, the reason for calculating the non-interacting parameter Flf according to the engine speed NE is as follows. That is, in the case of an interference system such as the engine 3 of the present embodiment, the relationship of mutual interference between the control amounts PB and Gcyl and the control inputs TH_cmd and Liftin_cmd changes according to the engine speed NE, and the engine speed Since the number NE has a large fluctuation range during operation, by calculating the non-interacting parameter Flf in accordance with the engine speed NE that fluctuates in this way, the non-interacting inputs TH_cmd and Liftin_cmd are set to the engine speed. This is because the fluctuation of the relationship of mutual interference accompanying the fluctuation of the number NE is calculated as a value that can be appropriately compensated.

  Next, the routine proceeds to step 32, where the target throttle valve opening TH_cmd and the target valve lift Liftin_cmd are calculated by the control algorithm of the above-described equations (2) to (9), and then this processing is terminated.

  Returning to FIG. 10, as described above, after calculating the target throttle valve opening TH_cmd and the target valve lift Liftin_cmd in step 5, the process proceeds to step 6 to calculate the opening control input Uth and the lift control input Uliftin. Specifically, these control inputs Uth and Uliftin are calculated as shown in FIG.

  First, in step 40, it is determined whether or not the throttle valve mechanism failure flag F_THNG and the lift mechanism failure flag F_LIFTNG are both “0”. This throttle valve mechanism failure flag F_THNG is set to “1” when it is determined that the throttle valve mechanism 11 has failed in a failure determination process (not shown), and is set to “0” when it is determined to be normal. The The lift mechanism failure flag F_LIFTNG is also set to “1” when it is determined that the variable valve lift mechanism 50 has failed in a failure determination process (not shown), and is set to “0” when it is determined that the variable valve lift mechanism 50 is normal. Is done.

  When the determination result in step 40 is YES and both the throttle valve mechanism 11 and the variable valve lift mechanism 50 are normal, the process proceeds to step 41 to calculate the opening control input Uth. The opening control input Uth is a value for causing the throttle valve opening TH to follow the target throttle valve opening TH_cmd by a target value filter type two-degree-of-freedom response designating control algorithm expressed by the following equations (29) to (32). Is calculated as

  In the above equation (29), Krch_th represents a predetermined reaching law gain, Kadp_th represents a predetermined adaptive law gain, and σ_th is a switching function defined as in equation (30). In the equation (30), E_th is a deviation calculated by the equation (31), and pole_th is a switching function setting parameter, and is set to a value in a range of −1 <pole_th <0. In Expression (31), TH_cmd_f is a filter value of the target throttle valve opening, and is calculated by a target value filter algorithm (first-order lag filter algorithm) shown in Expression (32). In the equation (32), pole_f_th is a target value response designation parameter, and is set to a value within a range of −1 <pole_f_th <0.

  Next, the routine proceeds to step 42, where the lift control input Uliftin is calculated. The lift control input Uliftin is calculated as a value for causing the valve lift Liftin to follow the target valve lift Liftin_cmd by a target value filter type two-degree-of-freedom response designating control algorithm expressed by the following equations (33) to (36).

  In the above equation (33), Krch_lf represents a predetermined reaching law gain, Kadp_lf represents a predetermined adaptive law gain, and σ_lf is a switching function defined as in equation (34). In the equation (34), E_lf is a deviation calculated by the equation (35), and pole_lf is a switching function setting parameter, and is set to a value in a range of −1 <pole_lf <0. In Expression (35), Liftin_cmd_f is a filter value of the target valve lift, and is calculated by a target value filter algorithm (first-order lag filter algorithm) shown in Expression (36). In the equation (36), pole_f_lf is a target value response designation parameter, and is set to a value within a range of −1 <pole_f_lf <0.

  As described above, after calculating the lift control input Uliftin in step 42, the present process is terminated.

  On the other hand, if the determination result in step 40 is NO and at least one of the throttle valve mechanism 11 and the variable valve lift mechanism 50 has failed, the process proceeds to step 43, and whether or not the throttle valve mechanism failure flag F_THNG is “1”. Is determined.

  If the determination result is NO, only the variable valve lift mechanism 50 fails and the throttle valve mechanism 11 is normal, the routine proceeds to step 44, where the map shown in FIG. 19 is made according to the engine speed NE and the accelerator pedal opening AP. Is calculated to calculate a value TH_cmd_fs for failure of the target throttle valve opening. In the figure, AP1 to AP3 are predetermined values of the accelerator opening AP at which a relationship of AP1 <AP2 <AP3 is established, and this point is the same in FIG.

  In this map, the failure value TH_cmd_fs is set to a larger value as the accelerator opening AP is larger or the engine speed NE is higher. This is because the larger the accelerator pedal opening AP or the higher the engine speed NE, the greater the required output to the engine 3 and the greater the required intake air amount.

Next, the routine proceeds to step 45, where the opening degree control input Uth is calculated. This opening control input Uth is obtained by using the target value filter type two-degree-of-freedom response designating control algorithm represented by the following equations (37) to (40) to set the throttle valve opening TH to the value for failure of the target throttle valve opening. Calculated as a value to follow TH_cmd_fs .

  In the above equation (39), TH_cmd_fs_f is a filter value for a failure time value, and is calculated by the equation (40).

  Next, the process proceeds to step 46, the lift control input Uliftin is set to a value of 0, and this process is terminated. Thereby, as described above, the valve lift Liftin is held at the minimum value Liftin_L.

  On the other hand, if the determination result in step 43 is YES and at least the throttle valve mechanism 11 is out of order, the opening control input Uth and the lift control input Uliftin are set to 0 in steps 47 and 48, respectively. Exit. As a result, as described above, the valve lift Liftin is held at the minimum value Liftin_L, and the throttle valve opening TH is held at the predetermined initial opening, so that the idling operation and the engine start can be appropriately performed while the vehicle is stopped. At the same time, an intake air amount Gcyl that can maintain a low-speed traveling state is secured during traveling.

  Returning to FIG. 10, in step 6, after calculating the opening control input Uth and the lift control input Uliftin as described above, the present process is terminated.

  On the other hand, when the determination result of step 1 is NO and the engine start control is not being performed, the routine proceeds to step 7 where it is determined whether or not the accelerator opening AP is smaller than a predetermined value APREF. If the result of this determination is YES and the accelerator pedal is not depressed, the routine proceeds to step 8, where it is determined whether or not the time measured value Tast of the post-start timer is smaller than a predetermined value Tastlmt.

  If the determination result is YES and Tast <Tastlmt, it is determined that the catalyst warm-up control should be executed, and the process proceeds to Step 9 where the catalyst warm-up value Gcyl_cmd_ast of the target intake air amount is set to the time count value Tast of the timer after starting. And it calculates by searching the map shown in FIG. 20 according to engine water temperature TW. In the figure, TW1 to TW3 indicate predetermined values of the engine coolant temperature TW that satisfy the relationship of TW1 <TW2 <TW3.

  In this map, the catalyst warm-up value Gcyl_cmd_ast is set to a larger value as the engine coolant temperature TW is lower. This is because the lower the engine water temperature TW, the longer the time required for the activation of the catalyst. Therefore, by increasing the exhaust gas volume, the time required for the activation of the catalyst is shortened. In addition, in this map, the catalyst warm-up value Gcyl_cmd_ast is set to a larger value as the time value Tast is larger while the time value Tast of the post-start timer is smaller, and the time value Tast becomes somewhat larger. After that, the larger the measured value Tast, the smaller the value is set. This is because if the intake air amount is not reduced when the friction decreases due to the warm-up of the engine 3 as the execution time of the catalyst warm-up control elapses, the engine speed NE is set to the target value. This is because the ignition timing is excessively retarded in order to maintain it, and the combustion state becomes unstable, which is avoided.

  Next, the routine proceeds to step 10 where the target intake air amount Gcyl_cmd is set to the catalyst warm-up value Gcyl_cmd_ast. Thereafter, as described above, after executing Steps 4 to 6, the present process is terminated.

  On the other hand, when the determination result of step 7 or 8 is NO, that is, when the accelerator pedal is depressed, or when Tast ≧ Tastlmt, the routine proceeds to step 11 where the normal intake value Gcyl_cmd_drv of the target intake air amount is It is calculated by searching the map shown in FIG. 21 according to the rotational speed NE and the accelerator pedal opening AP.

  In this map, the normal time value Gcyl_cmd_drv is set to a larger value as the engine speed NE is higher or the accelerator pedal opening AP is larger. This is because the higher the engine speed NE or the greater the accelerator pedal opening AP, the greater the required output for the engine 3 and the greater the required intake air amount.

  Next, the routine proceeds to step 12, where the target intake air amount Gcyl_cmd is set to the normal value Gcyl_cmd_drv. Thereafter, as described above, after executing Steps 4 to 6, the present process is terminated.

  As described above, in this variable mechanism control process, the two target values TH_cmd and Liftin_cmd are calculated by the control algorithm [Equations (2) to (9)] combining the response designation control algorithm and the non-interference control algorithm. In addition, the two control inputs Uth and Uliftin are calculated so that the actual values TH and Liftin follow these target values TH_cmd and Liftin_cmd. Accordingly, the intake pipe internal pressure PB is controlled to follow the target intake pipe internal pressure PB_cmd and the intake air amount Gcyl follows the target intake air amount Gcyl_cmd while avoiding mutual interference between the control inputs TH_cmd and Liftin_cmd. .

  Next, simulation results (hereinafter referred to as “control results”) of variable mechanism control by the control device 1 of the present embodiment will be described. 22 and 23 show the control results by the control device 1 of the first embodiment. In particular, FIG. 22 shows the case where there is no modeling error in the above-described equation (19), that is, the non-interacting parameters Fth and Flf. The control result when there is no calculation error is shown, and FIG. 23 shows the control result when there is a modeling error.

  For comparison, FIG. 24 shows that the intake pipe internal pressure PB is controlled to follow the target intake pipe internal pressure PB_cmd only by the response specifying control algorithm without using the non-interference control algorithm in the variable mechanism control process. In addition, a control simulation result when the intake air amount Gcyl is controlled to follow the target intake air amount Gcyl_cmd, that is, a control result of the interference system is shown.

  First, as apparent from FIG. 24, in the control result of this interference system, when the target intake air amount Gcyl_cmd is changed to a larger value in a stepped manner while the target intake pipe internal pressure PB_cmd is kept constant (time) t21), the throttle valve opening TH and the valve lift Liftin are both controlled to increase, and as a result, the intake pipe internal pressure PB greatly deviates to the lower side with respect to the target intake pipe internal pressure PB_cmd. A large deviation will occur.

  Further, when the target intake pipe internal pressure PB_cmd is changed to a lower value in a step shape while keeping the target intake air amount Gcyl_cmd constant (time t22), the throttle valve opening TH is controlled to be temporarily decreased. In addition, the valve lift Liftin is controlled to increase, and as a result, the intake air amount Gcyl greatly deviates to a smaller value side with respect to the target intake air amount Gcyl_cmd, and a large deviation occurs between the two. End up.

  Furthermore, when the target intake pipe internal pressure PB_cmd is changed to a higher value and the target intake air amount Gcyl_cmd is changed to a smaller value in steps (time t23), the intake pipe internal pressure PB overshoots the target intake pipe internal pressure PB_cmd. As a result, a large deviation occurs between them, and a deviation also occurs between the intake air amount Gcyl and the target intake air amount Gcyl_cmd.

  On the other hand, as shown in FIG. 22, when there is no modeling error, when the target intake air amount Gcyl_cmd is changed to a larger value in a stepped manner while the target intake pipe pressure PB_cmd is kept constant. At (time t1), it can be seen that the intake pipe internal pressure PB appropriately follows without departing from the target intake pipe internal pressure PB_cmd.

  In addition, when the target intake pipe internal pressure PB_cmd is changed to a lower value in a step shape (time t2) while the target intake air amount Gcyl_cmd is kept constant, the intake air amount Gcyl is smaller than the target intake air amount Gcyl_cmd. It can be seen that they are following appropriately without any deviation.

  Further, when the target intake pipe internal pressure PB_cmd is changed to a higher value and the target intake air amount Gcyl_cmd is changed to a smaller value in steps (time t3), the intake pipe internal pressure PB is set to the target intake pipe internal pressure PB_cmd. It can be seen that the intake air amount Gcyl appropriately follows the target intake air amount Gcyl_cmd.

  Further, as shown in FIG. 23, when there is a modeling error, when the target intake air amount Gcyl_cmd is changed to a larger value in a step shape with the target intake pipe internal pressure PB_cmd kept constant (time t11) Unlike the case where there is no modeling error in FIG. 22 described above, the intake pipe internal pressure PB slightly deviates from the target intake pipe internal pressure PB_cmd. However, the degree of the deviation is that of the interference system in FIG. It is smaller than the control result, and it can be seen that the followability, that is, the control accuracy is improved.

  Further, when the target intake pipe internal pressure PB_cmd is changed to a lower value in a step shape while keeping the target intake air amount Gcyl_cmd constant (time t12), the intake air amount Gcyl is smaller than the target intake air amount Gcyl_cmd. A deviation equivalent to the case where there is no modeling error in FIG. 22 is generated, and the degree of the deviation is smaller than the control result of the interference system in FIG. 24, and it can be seen that followability, that is, control accuracy is improved.

  In addition to this, when the target intake pipe internal pressure PB_cmd is changed to a higher value and the target intake air amount Gcyl_cmd is changed to a smaller value (step t13), unlike the case where there is no modeling error in FIG. The intake pipe internal pressure PB slightly overshoots the target intake pipe internal pressure PB_cmd, causes a slight deviation therebetween, and the intake air amount Gcyl slightly undershoots the target intake air amount Gcyl_cmd. And there is a slight deviation between them. However, the degree of deviation is smaller than the control result of the interference system of FIG. 24, and it can be seen that the followability, that is, the control accuracy is improved.

  As described above, according to the control device 1 of the first embodiment, the response designation type control algorithm and the non-interference control algorithm based on the plant model [Equation (19)] modeled as a discrete time system model are combined. Since the non-interacting input vector U, that is, the two non-interacting inputs TH_cmd and Liftin_cmd are calculated by the control algorithm [Equations (2) to (9)], the intake pipe pressure PB and the intake air are eliminated while eliminating the mutual interference. The amount Gcyl can be made to accurately follow the target intake pipe internal pressure PB_cmd and the target intake air amount Gcyl_cmd. Further, since the discrete-time system model is used in the calculation of the non-interacting input vector U, the modeling error can be reduced as compared with the conventional case using the continuous-time system model, whereby the controller gain Krch_p, While setting Krch_g, Kadp_p, and Kadp_g to higher values, it is possible to ensure a control stability margin. In addition to this, since the discrete time system model is used, unlike the conventional case using the continuous time system model, it is not necessary to use the differential value of the controlled variable as a variable constituting the switching function, so that the control cycle is short. Even in this case, it is possible to ensure the robustness that is a feature of the response assignment control algorithm. As described above, controllability and control accuracy can be improved.

  In the first embodiment, the non-interacting input vector U is calculated by the equation (9). Instead, the non-interacting input vector U may be calculated by the equation (26). .

  In the first embodiment, as shown in equations (2) to (9), one of the two non-interacting inputs TH_cmd is set according to the two non-interacting parameters Fth and Flf and the control amount PB. In this example, the remaining non-interacting input Liftin_cmd is calculated according to the non-interacting parameter Flf and the control amount Gcyl. However, the method of calculating the non-interacting input is not limited to this, and a plurality of non-interacting inputs are used. What is necessary is just to calculate the non-interacting input according to at least one of the parameter and the plurality of non-interacting inputs.

  Furthermore, although 1st Embodiment is an example which calculated two non-interacting inputs by the control algorithm which combined the response designation | designated control algorithm and the non-interference control algorithm, it uses for calculation of several non-interacting inputs. The control algorithm is not limited to this, and any control algorithm including a combination of a response designating control algorithm and a non-interference control algorithm may be used.

  Next, a control device 1A according to a second embodiment of the present invention will be described with reference to FIG. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. As shown in the figure, this control device 1A controls the same plant 90 as in the first embodiment, and includes a target value calculation unit 100, a two-degree-of-freedom response designation type controller 201, and a non-interacting controller 202. I have. In the present embodiment, the two controllers 201 and 202 correspond to a non-interacting input calculation unit.

  In this two-degree-of-freedom response assignment type controller 201, the following input vector W is calculated by a target value filter type two-degree-of-freedom response assignment type control algorithm expressed by the following equations (41) to (49).

  In the above equation (42), PB_cmd_f and Gcyl_cmd_f are filter values of the target intake pipe internal pressure and the target intake air amount, respectively, and are calculated by equations (48) and (49). Rp and Rg in these expressions (48) and (49) are target value response designation parameters, and are set to values that satisfy -1 <Rp <0 and -1 <Rg <0. E in Expression (45) is a deviation vector defined as in Expression (47).

  The above formulas (41) to (49) cause the virtual plant represented by the above-described formula (28) to cause the intake pipe internal pressure PB to follow the target intake pipe internal pressure PB_cmd and the intake air amount Gcyl to be the target intake. It is derived by applying a target value filter type two-degree-of-freedom response designating control algorithm so as to follow the air amount Gcyl_cmd.

  Further, the non-interacting controller 202 calculates the non-interacting input vector U by the following equation (50), similarly to the above-described non-interacting controller 102.

  In the variable mechanism control process executed by the control device 1A, the target throttle valve opening TH_cmd and the target valve lift Liftin_cmd are calculated by the above-described equations (41) to (50) in step 32 of FIG. The other processes are executed in the same manner as the variable mechanism control process of the first embodiment.

  Next, simulation results (hereinafter referred to as “control results”) of variable mechanism control by the control device 1A of the second embodiment will be described. FIG. 26 shows a control result when there is a modeling error, that is, when there is a calculation error of the non-interacting parameters Fth and Flf.

  As is apparent from FIG. 26, in this control result, when the target intake air amount Gcyl_cmd is changed to a larger value in a step shape with the target intake pipe internal pressure PB_cmd held constant (time t31), the intake air The degree of deviation generated between the pipe pressure PB and the target intake pipe pressure PB_cmd is smaller than the control result in the case where there is a modeling error in FIG. 23 of the first embodiment described above, and the intake air amount It can be seen that Gcyl does not overshoot the target intake air amount Gcyl_cmd, and the control accuracy is improved.

  Further, when the target intake pipe pressure PB_cmd is changed to a lower value in a step shape (time t32) while the target intake air amount Gcyl_cmd is kept constant, the control result of FIG. 23 of the first embodiment is different. The intake pipe internal pressure PB does not cause an undershoot with respect to the target intake pipe internal pressure PB_cmd, and the intake air amount Gcyl does not vary with respect to the target intake air amount Gcyl_cmd, so that the control accuracy is improved. I understand. In addition, the degree of change in the throttle valve opening TH when the target intake pipe internal pressure PB_cmd is changed is considerably smaller than the control result (FIG. 23) of the first embodiment, and the actual throttle valve mechanism 11 It can be seen that the controllability is further improved in consideration of the low responsiveness.

  Furthermore, when the target intake pipe internal pressure PB_cmd is changed to a higher value and the target intake air amount Gcyl_cmd is changed to a smaller value in steps (time t33), the intake pipe internal pressure PB becomes smaller than the target intake pipe internal pressure PB_cmd. Although a slight overshoot occurs, the degree thereof is considerably smaller than the control result of FIG. 23 of the first embodiment, and the intake air amount Gcyl does not cause an undershoot with respect to the target intake air amount Gcyl_cmd. It can be seen that the control accuracy is improved. In addition, the degree of change in the throttle valve opening TH when the target intake pipe internal pressure PB_cmd is changed is extremely small compared to the control result of FIG. 23 of the first embodiment, and the actual throttle valve mechanism 11 It can be seen that the controllability is further improved in consideration of the low responsiveness.

  According to the control device 1A of the second embodiment configured as described above, a control algorithm [formulas (41) to (41) that combines a target value filter type two-degree-of-freedom response designation control algorithm and a non-interference control algorithm. 50)], the non-interacting input vector U (that is, the two non-interacting inputs TH_cmd and Liftin_cmd) is calculated. Thus, as with the control device 1 of the first embodiment described above, The intake pipe internal pressure PB and the intake air amount Gcyl can be made to accurately follow the target intake pipe internal pressure PB_cmd and the target intake air amount Gcyl_cmd, respectively.

  Further, since the tracking input vector W (that is, two tracking inputs TH′_cmd and Liftin′_cmd) is calculated by the target value filter type two-degree-of-freedom response designating control algorithm of the equations (41) to (49), The response designating control algorithm [Equations (41) to (47)] can increase the disturbance suppression capability and suppress the decrease in controllability due to the modeling error, and at the same time, the target value filter algorithm [Equations (48), ( 49)], two follow-up inputs TH′_cmd and Gcyl′_cmd can be calculated as values at which the responsiveness of the actually measured values PB and Gcyl with respect to the two target values PB_cmd and Gcyl_cmd becomes gentle. As a result, the non-interacting input vector U, that is, the target throttle valve opening TH_cmd and the target valve lift Liftin_cmd can be calculated as values with small change amounts and change speeds while ensuring high disturbance suppression capability.

  As a result, a deviation between the intake pipe internal pressure PB and the target intake pipe internal pressure PB_cmd and between the intake air amount Gcyl and the target intake air amount Gcyl_cmd due to modeling errors, that is, calculation errors of the non-interacting parameters Fth and Flf. Even when this occurs, the amount of change and the rate of change can be held at a small value, and an increase in deviation can be appropriately suppressed by a high disturbance suppression capability. As described above, controllability and control accuracy can be further improved.

  The second embodiment is an example using a combination of a target value filter algorithm and a response designating control algorithm as a two-degree-of-freedom control algorithm, but the two-degree-of-freedom control algorithm is not limited to this. Any combination of the value filter algorithm and the feedback control algorithm may be used. For example, a combination of a target value filter algorithm and a PID control algorithm may be used.

  Next, a control device 1B according to a third embodiment of the present invention will be described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 27, the control device 1B controls the same plant 90 as in the first embodiment, and includes a target value calculation unit 100, a two-degree-of-freedom response designation type controller 301, a non-interacting controller 302, and An on-board identifier 303 is provided. In the present embodiment, the two controllers 301 and 302 correspond to non-interacting input calculation means, and the on-board identifier 303 corresponds to identification means.

  In the on-board identifier 303, the identification values Fth_hat and Flf_hat of the non-interacting parameters Fth and Flf are calculated by a sequential identification algorithm using the δ correction method shown in the following equations (51) to (61).

  In the above equation (51), θ is a vector of identification values of decoupling parameters whose transpose matrix is defined as in equation (57), and θbase is a transpose matrix whose equation is as shown in equation (59). Is a vector of reference values defined in Fth_base and Flf_base in the equation (59) are reference values for the non-interacting parameters Fth and Flf, respectively, and are calculated by table search and map search as described later.

  Further, dθ in the equation (51) is a correction term vector defined as in the equation (60), and dFth_hat and dFlf_hat in the equation (60) are correction terms (correction values) of the reference values Fth_base and Flf_base. It is. The correction term vector dθ is calculated by the equation (52), and in this equation (52), δ is a forgetting vector defined as in the equation (61). In the equation (61), δ1 and δ2 are forgetting factors, and are set so that 0 <δ1 ≦ 1, 0 <δ2 ≦ 1.

  Furthermore, e_id in Expression (52) is a deviation calculated by Expression (53). Ω in the equation (53) is a virtual output to be described later, and is calculated by the equation (54). Further, ω_hat in the equation (53) is an estimated value of the virtual output, and is calculated by the equation (55). In the equation (55), ξ is a vector whose transposed matrix is defined as in equation (58).

  Further, P in Expression (52) is a quadratic square matrix defined as shown in Expression (56). In the equation (56), I represents a secondary unit matrix, and λ1 and λ2 represent weight parameters, respectively.

In the identification algorithm as described above, one of the following four identification algorithms is selected depending on the setting of the weight parameters λ1 and λ2 of Expression (56).
That is,
λ1 = 1, λ2 = 0; fixed gain algorithm λ1 = 1, λ2 = 1; least squares algorithm
λ1 = 1, λ2 = λ; gradually decreasing gain algorithm λ1 = λ, λ2 = 1; weighted least squares algorithm where λ is a predetermined value set to 0 <λ <1.
In the on-board identifier 303 of the present embodiment, a weighted least squares algorithm is employed to optimally ensure both the identification accuracy and the tracking speed to the optimum value of the vector θ.

  The above identification algorithm is derived as described below. First, the above equation (18) is shifted to the past by the discrete time “1”, and the non-interacting parameters Fth and Flf are replaced with the identification values Fth_hat and Flf_hat to obtain the following equation (62).

  When PB (k−1) on the right side of the equation (62) is moved to the left side, the following equation (63) is obtained.

  In the equation (63), when the left side is defined as ω and the right side is defined as ω_hat, the above-described equations (54) and (55) are obtained. Here, when ω is considered as a virtual output of a virtual plant and ω_hat is considered as an estimated value of such a virtual output, the equation (63) can be considered as a model of such a virtual plant. . Therefore, when the sequential identification algorithm using the δ correction method is applied to identify the model parameter of the virtual plant model so that the deviation e_id between the virtual output ω and the estimated value ω_hat of the virtual output is minimized. The above-described equations (51) to (61) are derived.

  Further, the two-degree-of-freedom response designation type controller 301 has the same control algorithm as the above-described two-degree-of-freedom response designation type controller 201, that is, the target value filter type two-degree-of-freedom response designation shown in the aforementioned equations (41) to (49). The following input vector W is calculated by the type control algorithm.

  Further, the non-interacting controller 302 calculates the non-interacting input vector U by the following equation (64). This equation (64) corresponds to the above-described equation (50) in which the non-interacting parameters Fth and Flf are replaced with identification values Fth_hat and Flf_hat.

  The variable mechanism control process executed by the control device 1B is different from the variable mechanism control process of the first embodiment only in the process of step 5 in FIG. 10 described above. Since this process is executed in the same manner as the variable mechanism control process of the embodiment, only different points will be described below.

  That is, in the variable mechanism control process of the present embodiment, in step 5 of FIG. 10, the target throttle valve opening TH_cmd and the target valve lift Liftin_cmd are calculated as shown in FIG.

  First, in step 60, the reference value Fth_base of the non-interacting parameter is calculated by searching the table shown in FIG. 29 according to the ratio PB / PA of the intake pipe internal pressure PB and the atmospheric pressure PA. In this table, the reference value Fth_base is set to a larger value as the ratio PB / PA is closer to the value 1. This is due to the same reason as described in FIG.

  Next, the routine proceeds to step 61, where the reference value Flf_base of the non-interacting parameter is calculated by searching the map shown in FIG. 30 according to the intake pipe internal pressure PB and the engine speed NE. In this map, the reference value Flf_base is set to a larger value as the intake pipe internal pressure PB is higher. When PB = PB5 and PB6, the reference value Flf_base is set to a larger value as the engine speed NE is higher. Yes. This is due to the same reason as described in FIG.

  Next, the routine proceeds to step 62, where the target throttle valve opening TH_cmd and the target valve lift Liftin_cmd are calculated by the control algorithms of the aforementioned equations (41) to (49), (51) to (61), (64), This process ends.

  Next, simulation results (hereinafter referred to as “control results”) of variable mechanism control by the control device 1B of the third embodiment will be described. FIG. 31 shows a control result when there is a modeling error, that is, when the identification values Fth_hat and Flf_hat of the non-interacting parameters are shifted from the actual values of the non-interacting parameters Fth and Flf at the start of control. Yes.

  As apparent from FIG. 31, in this control result, the identification values Fth_hat and Flf_hat of the non-interacting parameters are set to values very close to the actual values of the non-interacting parameters Fth and Flf by the on-board identifier 303, respectively. Although calculated, there is a slight error without converging on the actual value. Since this error is a simulation result of the variable mechanism control shown in FIG. 31, the change behavior of the two target values PB_cmd and Gcyl_cmd does not satisfy the self-excitation condition that is a condition in which the error does not occur. This is due to On the other hand, in the actual control, the two target values PB_cmd and Gcyl_cmd exhibit a change behavior including various frequency components. Therefore, when the self-excitation condition is satisfied, The identification values Fth_hat and Flf_hat are calculated as values that converge to the actual values of the non-interacting parameters Fth and Flf, respectively.

  Further, in this control result, when the target intake air amount Gcyl_cmd is changed to a larger value stepwise (time t41) while the target intake pipe internal pressure PB_cmd is kept constant, the intake air amount Gcyl becomes the target intake air amount. There is no overshoot with respect to Gcyl_cmd, and no deviation occurs between the intake pipe internal pressure PB and the target intake pipe internal pressure PB_cmd, which is compared with the control result (FIG. 26) of the second embodiment described above. Then, it can be seen that the control accuracy is improved.

  Further, when the target intake pipe internal pressure PB_cmd is changed to a lower value stepwise (time t42) while the target intake air amount Gcyl_cmd is kept constant, the intake pipe internal pressure PB is smaller than the target intake pipe internal pressure PB_cmd. It can be seen that undershoot does not occur and control accuracy equivalent to the control result of the second embodiment is ensured. On the other hand, there is a very small deviation between the intake air amount Gcyl and the target intake air amount Gcyl_cmd, but this deviation is caused by the calculation error of the identification values Fth_hat and Flf_hat described above. As described above, since the calculation error does not occur in the actual control, there is no deviation between Gcyl and Gcyl_cmd, and the control accuracy equivalent to the control result of the second embodiment can be ensured. In addition, the degree of change in the throttle valve opening TH when the target intake pipe internal pressure PB_cmd is changed is also equivalent to the control result of the second embodiment, and equivalent controllability is ensured. I understand.

  Further, when the target intake pipe pressure PB_cmd is changed to a higher value and the target intake air amount Gcyl_cmd is changed to a smaller value in steps (time t43), the intake air amount Gcyl is larger than the target intake air amount Gcyl_cmd. There is no undershoot, and the intake pipe pressure PB does not overshoot the target intake pipe pressure PB_cmd. Compared to the control result of the second embodiment in which a slight overshoot occurs, the control accuracy is higher. It turns out that it is improving. In addition, the degree of change in the throttle valve opening TH when the target intake pipe internal pressure PB_cmd is changed is also equivalent to the control result of the second embodiment, and equivalent controllability is ensured. I understand.

  According to the control device 1B of the third embodiment configured as described above, a control algorithm in which a sequential identification algorithm, a target value filter type two-degree-of-freedom response designation control algorithm, and a non-interference control algorithm are combined. [Expressions (41) to (49), (51) to (61), (64)] calculates the non-interacting input vector U (that is, two incoherent inputs TH_cmd and Liftin_cmd). As with the control devices 1 and 1A of the first and second embodiments, the intake pipe internal pressure PB and the intake air amount Gcyl follow the target intake pipe internal pressure PB_cmd and the target intake air amount Gcyl_cmd with high accuracy while eliminating mutual interference. Can be made.

  Further, since the tracking input vector W (that is, two tracking inputs TH′_cmd and Gcyl′_cmd) is calculated by a target value filter type two-degree-of-freedom response designating control algorithm, the control device of the second embodiment described above. Similarly to 1A, the response designating control algorithm [Equations (41) to (47)] can increase the disturbance suppression capability and suppress the decrease in controllability due to the modeling error, and at the same time, the target value filter algorithm [Equation (48), (49)], the two following inputs TH′_cmd and Gcyl′_cmd can be calculated as values at which the responsiveness of the actually measured values PB and Gcyl with respect to the two target values PB_cmd and Gcyl_cmd becomes gentle. .

  Further, the identification values Fth_hat and Flf_hat of the non-interacting parameters are calculated by the on-board identifier 303 by a sequential identification algorithm [Expressions (51) to (61)] to which the δ correction method is applied. That is, since the non-interacting parameters Fth and Flf that can be direct modeling errors of the plant model are sequentially identified, the two non-interacting inputs TH_cmd and Liftin_cmd are calculated while compensating for the modeling error quickly and appropriately. can do. As a result, as in this embodiment, in the plant 90 in which the degree of mutual interference between TH_cmd, Liftin_cmd and PB, Gcyl is considerably large, modeling errors have occurred due to secular changes and variations among individuals. Even in this case, the modeling error can be compensated quickly and appropriately, thereby ensuring good controllability and control accuracy.

  In addition, since the sequential identification algorithm using the δ correction method is used, immediately after the start of identification, the identification values Fth_hat and Flf_hat of the non-interacting parameters are calculated as values close to the reference values Fth_base and Flf_base. Thus, erroneous identification can be avoided. Further, by multiplying the correction term vector dθ by the forgetting coefficient vector δ, a predetermined forgetting effect is added to the correction term vector dθ. As a result, the identification values Fth_hat and Flf_hat are close to the reference values Fth_base and Flf_base. Since the identification is performed in a restrained state, the absolute value thereof increases, and a phenomenon of an erroneous parameter identification value, that is, a drift phenomenon of the non-interacting parameters Fth and Flf can be avoided, thereby stabilizing the control system. Performance can be ensured, and the identification accuracy can be improved. As described above, controllability and control accuracy can be further improved as compared with the control device 1A of the second embodiment.

  The third embodiment is an example using an identification algorithm (weighted sequential least square algorithm) to which the δ correction method is applied as the sequential identification algorithm, but the sequential identification algorithm is not limited to this, Any one that can sequentially identify the identification values Fth_hat and Flf_hat of the non-interacting parameter may be used. For example, the above-described fixed gain algorithm and normal least square algorithm may be used.

  Further, according to the third embodiment, the identification values Fth_hat and Flf_hat of the non-interacting parameters Fth and Flf are expressed by the equations (51) to (61), the non-interacting inputs TH_cmd and Liftin_cmd as control inputs, This is an example of calculation according to the intake pipe internal pressure PB, the engine speed NE and the atmospheric pressure PA as internal variables of the plant, but the method for calculating the identification value of the non-interacting parameter is not limited to this, and a plurality of non-interference parameters are calculated. Any method may be used as long as it sequentially identifies according to at least one of the interference input, a plurality of control variables, and an internal variable of the plant.

  Next, a control device 1C according to a fourth embodiment of the present invention will be described with reference to FIGS. In the following description, the same components as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted. The control device 1C performs EGR control and supercharging pressure control of the engine 3A. The engine 3A is composed of a diesel engine having no throttle valve mechanism, and includes a turbocharger device 15 and an EGR control valve 16. ing.

  The turbocharger device 15 includes a compressor blade 15a housed in a compressor housing in the middle of the intake pipe 10, a turbine blade 15b housed in the turbine housing in the middle of the exhaust pipe 14, and two blades 15a and 15b. A shaft 15c connected to the cylinder 15 and a wastegate valve 15d are provided.

  In the turbocharger 15, when the turbine blade 15b is rotationally driven by the exhaust gas in the exhaust pipe 14, the compressor blade 15a integrated therewith is also rotated at the same time, so that the intake air in the intake pipe 10 is pressurized. The That is, the supercharging operation is executed.

  On the other hand, the waste gate valve 15d opens and closes a bypass exhaust passage 14a that bypasses the turbine blade 15b of the exhaust pipe 14, and is constituted by an electromagnetic control valve connected to the ECU 2. When a boost pressure control input Upb, which will be described later, is input from the ECU 2, the degree of opening of the waste gate valve 15d changes, whereby the flow rate of exhaust gas flowing through the bypass exhaust passage 14a, in other words, the turbine blade 15b is controlled. The supercharging pressure is changed by changing the flow rate of the exhaust gas to be driven. Thereby, the supercharging pressure is controlled.

  Further, as shown in FIG. 32, the intake pipe internal pressure sensor 24 of the present embodiment is provided on the downstream side of the compressor blade 15a of the intake pipe 10, so that when the supercharging pressure control is being executed, The intake pipe internal pressure PB detected by the pipe internal pressure sensor 24 is equal to the supercharging pressure. Therefore, in the following description, the intake pipe internal pressure PB is referred to as “supercharging pressure PB”.

  On the other hand, the EGR control valve 16 opens and closes an EGR passage 17 extending between the intake pipe 10 and the exhaust pipe 14, thereby executing an EGR operation for returning exhaust gas from the exhaust pipe 14 to the intake pipe 10 side. . The EGR control valve 16 is composed of a linear electromagnetic valve connected to the ECU 2. When an EGR control input Uegr described later is input from the ECU 2, the lift changes linearly. Thereby, the reflux gas amount, that is, the EGR amount Gegr is controlled.

  In addition, an EGR lift sensor 32 is attached to the EGR control valve 16. The EGR lift sensor 32 outputs a detection signal indicating the lift (hereinafter referred to as “EGR lift”) Legr of the EGR control valve 16 to the ECU 2.

On the other hand, an exhaust pipe internal pressure sensor 33 is provided upstream of the turbine blade 15 b of the exhaust pipe 14, and the exhaust pipe internal pressure sensor 33 is a pressure in the exhaust pipe 14 (hereinafter referred to as “exhaust pipe internal pressure” ). A detection signal representing P ex is output to the ECU 2. In the present embodiment, the exhaust pipe internal pressure Pex corresponds to an internal variable of the plant.

  The engine 3A is provided with a valve timing switching mechanism 80. Although not shown, each of the intake cams of the engine 3A includes a low-speed cam and a high-speed cam having a cam nose higher than the low-speed cam. Yes. The valve timing switching mechanism 80 switches the intake cam for opening and closing the intake valve between the low speed cam and the high speed cam, thereby changing the valve timing of the intake valve to the low speed valve timing LO. VT and fast valve timing HI. Switch between VT. The valve timing switching mechanism 80 is electrically connected to the ECU 2 (see FIG. 33), and the switching operation is controlled by the ECU 2. In the present embodiment, two valve timings LO. VT, HI. VT corresponds to an internal variable of the plant.

  Further, in the ECU 2, based on the detection signal of the air flow sensor 22, the intake air amount (hereinafter referred to as “detected intake air amount”) Gin that has passed through the vicinity of the air flow sensor 22 is replaced with Gin on the left side of the above equation (12). It is calculated by the following formula.

  Further, as will be described later, the ECU 2 controls the supercharging pressure PB and the EGR lift Legr, thereby controlling the intake air amount Gcyl (fresh air amount) and the EGR amount Gegr, respectively.

  Next, the control device 1C of the present embodiment will be described. As shown in FIG. 34, the control device 1C controls the plant 404, and includes a target value calculation unit 400, a two-degree-of-freedom response designation type controller 401, a non-interacting controller 402, and an on-board identifier 403. ing. In this embodiment, the target value calculation unit 400 corresponds to the target value setting unit, the two controllers 401 and 402 correspond to the non-interacting input calculation unit, and the on-board identifier 403 corresponds to the identification unit.

  As shown in FIG. 35, the plant 404 is defined as an interference system having the target boost pressure PB_cmd and the target EGR lift Legr_cmd as control inputs, and the intake air amount Gcyl and the EGR amount Gegr as control amounts. , A supercharging pressure controller 405, an EGR controller 406, an engine 3A, and the like.

  These target supercharging pressure PB_cmd and target EGR lift Legr_cmd are target values of the supercharging pressure PB and EGR lift Legr, respectively, and are calculated as described later.

  In the supercharging pressure controller 405, a specific calculation formula is omitted, but the supercharging pressure control input Upb is a target value filter type two-degree-of-freedom response similar to the above-described formulas (29) to (32). By a specified control algorithm, the boost pressure PB is calculated as a value for following the target boost pressure PB_cmd, and this boost pressure control input Upb is input to the wastegate valve 15d, whereby the intake air amount Gcyl is calculated. Be controlled.

  Further, in the EGR controller 406, a specific calculation formula is omitted, but the EGR control input Uegr is a target value filter type two-degree-of-freedom response designation control algorithm similar to the formulas (33) to (36) described above. Thus, the EGR lift Legr is calculated as a value for following the target EGR lift Legr_cmd, and this EGR control input Uegr is input to the EGR control valve 16, whereby the EGR amount Gegr is controlled.

  In the plant 404 as described above, when the supercharging pressure PB is controlled to follow the target supercharging pressure PB_cmd, both the intake air amount Gcyl and the EGR amount Gegr change accordingly. Further, when the EGR lift Legr is controlled to follow the target EGR lift Legr_cmd, both the intake air amount Gcyl and the EGR amount Gegr change accordingly. In other words, the plant 404 is an interference system in which mutual interference exists between the target boost pressure PB_cmd and the target EGR lift Legr_cmd as control inputs, and the intake air amount Gcyl and EGR amount Gegr as control amounts. .

  Therefore, in the control apparatus 1C of the fourth embodiment, in such an interference plant 404, control is performed such that both the intake air amount Gcyl and the EGR amount Gegr can be controlled independently of each other while avoiding the mutual interference. As inputs, that is, non-interacting inputs, the target boost pressure PB_cmd and the target EGR lift Legr_cmd are calculated as follows. In the following description, the various vectors (W, U, X, A, B, C, S, σ, θ), the matrix, and the like in the mathematical formulas are the first to third elements that constitute them. Although the functions and properties as inputs, coefficients, or functions are the same, the same notations and names are used for convenience, although they are different from the mathematical formulas of the embodiments.

  Specifically, first, the target value calculation unit 400 calculates the target intake air amount Gcyl_cmd and the target EGR amount Gegr_cmd. In this case, the target intake air amount Gcyl_cmd is calculated by searching a map shown in FIG. 36 according to the engine speed NE and the accelerator pedal opening AP. As shown in the figure, in this map, the target intake air amount Gcyl_cmd is set to a larger value as the accelerator opening AP is larger. This is because the intake air amount Gcyl is controlled to a larger value in response to the driver's request to increase the driving force.

  Further, the target EGR amount Gegr_cmd is calculated by searching a map shown in FIG. 37 according to the engine speed NE and the accelerator pedal opening AP. As shown in the figure, in this map, the target EGR amount Gegr_cmd is set to a larger value as the accelerator opening AP is larger. As described above, this is because the intake air amount Gcyl is controlled to be increased more as the accelerator opening AP is larger, so that the EGR amount Gegr is also increased accordingly. Further, the target EGR amount Gegr_cmd is set so as to be the largest value when the engine speed NE is in the middle speed range. This is because the engine 3A is in a good combustion state in the middle rotation range, so that the exhaust gas characteristics are improved by increasing the EGR amount Gegr.

  Next, in the two-degree-of-freedom response designating controller 401, the follow-up input vector W defined as shown in the following equation (65) is converted into the target value filter type adaptive two-degree-of-freedom shown in the following equations (66) to (74). Calculated by a response assignment type algorithm.

  In the above equation (65), PB′_cmd is a follow-up input for causing the intake air amount Gcyl to follow the target intake air amount Gcyl_cmd, and Legr′_cmd is for causing the EGR amount Gegr to follow the target EGR amount Gegr_cmd. Follow-up input. As shown in the above equation (66), the tracking input vector W is calculated as the sum of the equivalent control input vector Weq, the reaching law input vector Wrch, and the adaptive law input vector Wadp.

  This equivalent control input vector Weq is calculated by the above equation (67). In the equation (67), Sg and Se are switching function setting parameters, and are set so that -1 <Sg <0 and -1 <Se <0 are satisfied. Further, Heg_hat in the equation (67) is an identification value of a non-interacting parameter Heg described later, and is calculated by the on-board identifier 403 as described later. Further, Gcyl_cmd_f and Gegr_cmd_f in Expression (67) are filter values of the target intake air amount and the target EGR amount, respectively, and are calculated by Expression (73) and Expression (74). Rg and Re in these expressions (73) and (74) are target value response designation parameters, and are set to values that satisfy -1 <Rg <0 and -1 <Re <0.

  Further, the reaching law input vector Wrch of the equation (66) is calculated by the above equation (68). In the equation (68), Krch_g and Krch_e are predetermined reaching law gains. Also, σg and σe in Expression (68) are switching functions, and the switching function vector σ having these as elements is calculated by Expression (70). In the equation (70), S is a matrix defined as in the above equation (71), and E is a deviation vector defined as in the above equation (72).

  Further, the adaptive law input vector Wadp in the equation (66) is calculated by the above equation (69). In the equation (69), Kadp_g and Kadp_e are predetermined adaptive law gains.

  Further, the non-interacting controller 402 calculates the non-interacting input vector U by an adaptive non-interfering control algorithm expressed by the following equation (75). This non-interacting input vector U is defined as the following equation (76).

  In the above equation (75), Rcp_hat and Scp_hat are identification values of the non-interacting parameters Rcp and Scp described later, and are calculated by the on-board identifier 403 as described later.

  On the other hand, the on-board identifier 403 calculates the non-interacting parameter identification values Rcp_hat, Scp_hat, and Heg_hat by a sequential identification algorithm using the δ correction method shown in the following equations (77) to (86).

  In the above equation (77), θ is an identification value vector of a decoupling parameter whose transpose matrix is defined as in equation (82), and θbase is a transpose matrix as in equation (84). A vector of defined reference values. Rcp_base, Scp_base, and Heg_base in the equation (84) are reference values for the non-interacting parameters, and are calculated as described later.

  In addition, dθ in the above equation (77) is a correction term vector defined as in equation (85), and dRcp_hat, dScp_hat, and dHeg_hat in equation (85) are corrections to the reference values Rcp_base, Scp_base, and Heg_base, respectively. Term (correction value). The correction term vector dθ is calculated by the equation (78), and in this equation (78), δ is a forgetting vector defined as the equation (86). Each of δ1 to δ3 in the equation (86) is a forgetting factor, and is set to a value within a range greater than the value 0 and less than or equal to the value 1.

  Furthermore, e_id in Expression (78) is a deviation calculated by Expression (79). Gcyl_hat in the equation (79) is an estimated value of the intake air amount, and is calculated by the equation (80). Ξ in the equation (80) is a vector whose transpose matrix is defined as in the equation (83).

  Further, P in Expression (78) is a cubic square matrix defined as shown in Expression (81). I in the equation (81) represents a cubic unit matrix, and λ1 and λ2 represent weight parameters, respectively. As described above, in the identification algorithm as described above, the characteristics of the identification algorithm can be changed by setting the weight parameters λ1 and λ2 of the equation (81). In the onboard identifier 403 of this embodiment, the identification is performed. A weighted least squares algorithm is employed in order to ensure the accuracy and the tracking speed to the optimal value of the vector θ both optimally.

  Hereinafter, a method of calculating the reference values Rcp_base, Scp_base, and Heg_base of the above-described non-interacting parameters will be described. First, the non-interacting parameter reference value Rcp_base is calculated by searching the table shown in FIG. 38 according to the engine speed NE. As shown in the figure, the table used for calculating the reference value Rcp_base is HI. For VT and LO. Two types for VT are prepared, and one corresponding to the switching timing of the valve timing by the valve timing switching mechanism 80 is selected. In this table, the reference value Rcp_base is set to a value corresponding to the change in the charging efficiency of the engine 3A accompanying the change in the engine speed NE. For example, in the region where the charging efficiency is high, a larger value is set. Is set to

  Scp_base is calculated by the following equation (87). Note that Ktb in the following equation (87) is a model parameter of a model to be described later, and is set to a value that satisfies 0 <Ktb <1.

  Further, the reference value Heg_base of the non-interacting parameter is calculated by searching the table shown in FIG. 39 according to the differential pressure Pex−PB between the exhaust pipe internal pressure Pex and the supercharging pressure PB. In this table, the reference value Heg_base is set to a larger value as the differential pressure Pex−PB is larger. This is because the EGR amount Gegr increases as the differential pressure Pex-PB increases.

  As described above, in this control apparatus 1C, the identification value vector θ of the non-interacting parameter is calculated by the sequential identification algorithm shown in the above-described equations (77) to (86), and this is used to calculate the above-described equation. A non-interacting input vector U is calculated by the control algorithm shown in (66) to (75), that is, a control algorithm combining a target value filter type adaptive two-degree-of-freedom response designation control algorithm and an adaptive non-interference control algorithm. The The above formulas (66) to (75) and (77) to (86) are derived as described below.

  First, when the engine 3A is in a steady operation state, taking into account the dead time until the intake air reaches the cylinder 3a through the intake pipe 10, the intake air amount Gcyl (the fresh air amount not including the EGR amount Gegr) and The following equation (88) is established between the detected intake amount Gin and the following equation (89) is established between the intake air amount Gcp passing through the turbocharger device 15 and the EGR amount Gegr.

  Here, since the intake air amount Gcp that has passed through the turbocharger device 15 is the amount of gas sucked into the cylinder 3a, if the charging efficiency determined by the supercharging pressure PB, the engine speed NE, and the valve timing is Ki. , And can be defined as in the following formula (90).

  On the other hand, the supercharging pressure PB is controlled through the turbocharger device 15, and when a response specifying control algorithm or a target value filter type two-degree-of-freedom response specifying control algorithm is used as the control algorithm, The supercharging pressure PB can be modeled as the following formula (91) with respect to the target supercharging pressure PB_cmd.

  By substituting the right side of this formula (91) into PB of formula (90), the following formulas (92) to (94) are obtained.

  Further, when the above formula (89) is modified, the following formula (95) is obtained. When the right side of the above formula (92) is substituted into Gcp of this formula (95), the following formula (96) is obtained.

  Furthermore, the following expression (97) is obtained from the expression (96) and the above-described expression (88).

  On the other hand, the EGR amount Gegr can be expressed as the following equation (98) using the exhaust pipe internal pressure Pex and the target EGR lift Legr_cmd, and further, this equation (98) is expressed by the discrete time “1” for the future side. When shifting to, the following equation (99) is obtained.

  When the above formulas (97) and (99) are expressed together, the following formula (100) is obtained.

  This equation (100) can be regarded as a model of an interference plant 404 with Gcyl and Gegr as control variables and PB_cmd and Legr_cmd as control inputs, and can be expressed as the following equations (101) to (107). it can.

  In order to convert the plant 404 of the interference system expressed as the above equation (101) into a linear system without mutual interference, the non-interacting input calculated by the following equation (108) is used as the control input vector U. Vector U is used. This equation (108) is derived from the non-interference control law (cross controller).

  In B, A, X, C, D, and W of the formula (108), the right side of the formulas (106), (105), (102), (107), and (104) and the formula (65) described above are used. Substituting each right side, the following equation (109) is obtained.

  Furthermore, the following equation (110) is obtained by substituting the right side of equation (99) described above into Gegr of equation (109).

  In this equation (110), the left side is replaced with U, and in order to compensate for changes in the non-interacting parameters Rcp, Scp, and Heg due to changes in operating conditions and aging, the non-interacting parameters Rcp, Scp, and Heg are changed. When the identification values Rcp_hat, Scp_hat, and Heg_hat are respectively replaced, the control algorithm of the above-described equation (75), that is, the control algorithm of the non-interacting controller 402 is obtained.

  Further, the following equation (111) is obtained by substituting the right side of the above equation (110) into U of the above equation (101) and rearranging.

  This equation (111) represents a model of a linear virtual plant having no mutual interference, in which the following input vector W is the control amount vector X. The virtual plant includes the plant 4040 and the non-interacting controller 402 described above. Is equivalent to a combination of As described above, since a linear controller can be designed for such a linear virtual plant without mutual interference, the intake air amount Gcyl is set for the virtual plant represented by Expression (111). When the target value filter type two-degree-of-freedom response designating control law is applied so that the target intake air amount Gcyl_cmd follows and the EGR amount Gegr follows the target EGR amount Gegr_cmd, the following equations (112) to (120) are obtained. can get.

  In the above formulas (112) to (120), when the non-interacting parameters Rcp, Scp, and Heg are replaced with the identification values Rcp_hat, Scp_hat, and Heg_hat, respectively, for the above-described reasons, the above formulas (66) to (74). That is, the control algorithm of the two-degree-of-freedom response assignment type controller 401 is obtained.

  On the other hand, the identification algorithms of the aforementioned equations (77) to (86) are derived as described below. First, the following equation (121) is obtained by substituting the right side of equation (98) into Gegr of equation (97) described above.

  This equation (121) is shifted to the past by the discrete time “1”, the intake air amount Gcyl is replaced with the estimated value Gcyl_hat, and the non-interacting parameters Rcp, Scp, Heg are respectively identified values Rcp_hat, Scp_hat, Heg_hat. Is replaced by the following formula (122).

  This equation (122) can be considered as a virtual plant model. As described above, since Gcyl (k + 1) = Gin (k), the detected intake air amount Gin and the estimated intake air amount Gcyl_hat When the sequential identification algorithm using the δ correction method is applied in order to identify the model parameter of the virtual plant model so that the deviation e_id of the above is minimized, the above-described equations (77) to (86) are derived. Is done.

  According to the control device 1C of the fourth embodiment configured as described above, the target value filter type two-degree-of-freedom response designation type control based on the plant model [Expression (100)] modeled as a discrete-time system model. The non-interacting input vector U, that is, the two non-interacting inputs PB_cmd and Legr_cmd are calculated by a predetermined control algorithm [Equations (66) to (75)] combining the algorithm and the non-interfering control algorithm. Thus, the intake air amount Gcyl and the EGR amount Gegr can be accurately followed by the target intake air amount Gcyl_cmd and the target EGR amount Gegr_cmd, respectively.

  Further, since the discrete-time system model is used in the calculation of the non-interacting input vector U, the modeling error can be reduced as compared with the conventional case using the continuous-time system model, whereby the controller gain Krch_g, While setting Krch_e, Kadp_g, and Kadp_e to higher values, it is possible to ensure a stable control margin. In addition to this, since the discrete time system model is used, unlike the conventional case using the continuous time system model, it is not necessary to use the differential value of the controlled variable as a variable constituting the switching function, so that the control cycle is short. Even in this case, it is possible to ensure the robustness that is a feature of the response assignment control algorithm.

  In addition, since the tracking input vector W (that is, two tracking inputs Gcyl′_cmd and Gegr′_cmd) is calculated by the target value filter type two-degree-of-freedom response designating control algorithm, the response designating control algorithm [Expression (66 ) To (72)] can improve disturbance suppression capability and suppress deterioration of controllability due to modeling errors, and at the same time, two target values by the target value filter algorithm [Equations (73), (74)]. The two following inputs Gcyl′_cmd and Gegr′_cmd can be calculated as values at which the responsiveness of the actually measured values Gcyl and Gegr with respect to Gcyl_cmd and Gegr_cmd becomes gentle.

  Further, the identification values Rcp_hat, Scp_hat, and Heg_hat of the non-interacting parameters are calculated by the on-board identifier 403 using a sequential identification algorithm [Expressions (77) to (86)] to which the δ correction method is applied. That is, since the non-interacting parameters Rcp, Scp, and Heg that can be a direct modeling error of the plant model are sequentially identified, the two non-interacting inputs Gcyl_cmd, Gegr_cmd are compensated quickly and appropriately. Can be calculated. Thus, as in the present embodiment, in the plant 404 where the degree of mutual interference between the control inputs PB_cmd and Legr_cmd and the control amounts Gcyl and Gegr is considerably large, modeling is performed due to secular change and variation between individuals. Even if an error occurs, the modeling error can be compensated quickly and appropriately, and thereby good controllability and control accuracy can be ensured.

  In addition, since the sequential identification algorithm using the δ correction method is used, immediately after the start of identification, the identification values Rcp_hat, Scp_hat, Heg_hat of the non-interacting parameters are close to the reference values Rcp_base, Scp_base, Heg_base. By calculating as a value, erroneous identification can be avoided. Further, by multiplying the correction term vector dθ by the forgetting coefficient vector δ, a predetermined forgetting effect is added to the correction term vector dθ. As a result, the identification values Rcp_hat, Scp_hat, Heg_hat are converted into the reference values Rcp_base, Scp_base, Since the identification is performed in a state of being constrained in the vicinity by Heg_base, the identification accuracy can be improved. As described above, controllability and control accuracy can be improved.

  In the fourth embodiment, the non-interacting input vector U is calculated by the equation (75). However, when the engine 3A is provided with a detection unit that directly detects the EGR amount Gegr, the above-described equation is used. In (109), the non-interacting input vector U may be calculated by an expression in which the non-interacting parameters Rcp, Scp, and Heg are replaced with identification values Rcp_hat, Scp_hat, and Heg_hat.

  Further, each of the above embodiments is an example in which the control device of the present invention is applied to an interference system plant in which mutual interference exists between two control inputs and two control amounts. The apparatus is not limited to this, and can also be applied to an interference plant in which mutual interference exists between three or more control inputs and three or more control amounts.

  Further, each of the above embodiments is an example in which the control device of the present invention is applied to control of an intake system drive mechanism of an internal combustion engine as an interference plant, but the control device of the present invention is not limited thereto. Needless to say, the present invention can be applied to control of an interference plant such as other industrial equipment.

It is a mimetic diagram showing a schematic structure of an internal-combustion engine to which a control device concerning a 1st embodiment of the present invention is applied. It is a block diagram which shows schematic structure of a control apparatus. It is sectional drawing which shows schematic structure of the variable type intake valve mechanism and exhaust valve mechanism of an internal combustion engine. It is sectional drawing which shows schematic structure of the variable valve lift mechanism of a variable intake valve mechanism. (A) It is a figure which shows the state which the short arm of the lift actuator is in contact with the maximum lift stopper, and (b) the state in contact with the minimum lift stopper. (A) It is a figure which shows the valve opening state of the intake valve when the lower link of the variable valve lift mechanism is at the maximum lift position, and (b) the valve opening state of the intake valve when it is at the minimum lift position. It is a figure which respectively shows the valve lift curve (solid line) of the intake valve when the lower link of the variable valve lift mechanism is at the maximum lift position, and the valve lift curve (two-dot chain line) when at the minimum lift position. It is a functional block diagram which shows schematic structure of a control apparatus. It is a block diagram for demonstrating a plant. It is a flowchart which shows a variable mechanism control process. It is a figure which shows an example of the table used for calculation for starting value Gcyl_cmd_crk of the target intake air amount during engine starting. It is a flowchart which shows the calculation process of target intake pipe internal pressure PB_cmd. It is a figure which shows an example of the map used for calculation of brake off value PB_cmd_pg of target intake pipe internal pressure. It is a figure which shows an example of the table used for calculation of brake-on value PB_cmd_br of target intake pipe internal pressure. It is a flowchart which shows the calculation process of target throttle valve opening TH_cmd and target valve lift Liftin_cmd. It is a figure which shows an example of the table used for calculation of the non-interacting parameter Fth. It is a figure which shows an example of the map used for calculation of the non-interacting parameter Flf. It is a flowchart which shows the calculation process of the opening degree control input Uth and the lift control input Uliftin. It is a figure which shows an example of the map used for calculation of the value TH_cmd_fs at the time of failure of a target throttle valve opening degree. It is a figure which shows an example of the map used for calculation of the value Gcyl_cmd_ast for catalyst warming-up of target intake air amount during catalyst warm-up control. It is a figure which shows an example of the map used for calculation of the normal time value Gcyl_cmd_drv of the target intake air amount during normal operation. It is a timing chart which shows an example (when there is no modeling error) of a simulation result of variable mechanism control by a control device of a 1st embodiment. It is a timing chart which shows an example (when there is a modeling error) of a simulation result of variable mechanism control by a control device of a 1st embodiment. It is a timing chart which shows an example of a simulation result at the time of controlling intake pipe internal pressure PB and intake air quantity Gcyl, without using a non-interference control algorithm. It is a functional block diagram which shows schematic structure of the control apparatus of 2nd Embodiment. It is a timing chart which shows an example (when there is a modeling error) of a simulation result of variable mechanism control by a control device of a 2nd embodiment. It is a functional block diagram which shows schematic structure of the control apparatus of 3rd Embodiment. It is a flowchart which shows the calculation process of the target throttle valve opening TH_cmd and the target valve lift Liftin_cmd by the control apparatus of 3rd Embodiment. It is a figure which shows an example of the table used for calculation of the reference value Fth_base of a non-interacting parameter. It is a figure which shows an example of the map used for calculation of the reference value Flf_base of a non-interacting parameter. It is a timing chart which shows an example (when there exists a modeling error) of the simulation result of variable mechanism control by the control device of a 3rd embodiment. It is a schematic diagram which shows schematic structure of the internal combustion engine to which the control apparatus which concerns on 4th Embodiment of this invention is applied. It is a block diagram which shows schematic structure of the control apparatus of 4th Embodiment. It is a functional block diagram which shows schematic structure of the control apparatus of 4th Embodiment. It is a block diagram for demonstrating the plant of 4th Embodiment. It is a figure which shows an example of the map used for calculation of target intake air amount Gcyl_cmd. It is a figure which shows an example of the map used for calculation of target EGR amount Gegr_cmd. It is a figure which shows an example of the table used for calculation of reference value Rcp_base of a non-interacting parameter. It is a figure which shows an example of the table used for calculation of the reference value Heg_base of a non-interacting parameter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control apparatus 1A-1C Control apparatus 2 ECU (Target value setting means, Decoupling input calculation means, Identification means)
DESCRIPTION OF SYMBOLS 3 Internal combustion engine 4 Intake valve 90 Plant 100 Target value calculation part (target value setting means)
101 Response designation type controller (non-interacting input calculation means)
102 Decoupling controller (Decoupling input calculation means)
201 2-degree-of-freedom response designation type controller (non-interacting input calculation means)
202 Decoupling controller (Decoupling input calculation means)
301 2-degree-of-freedom response designation type controller (non-interacting input calculation means)
302 Decoupling controller (Decoupling input calculation means)
303 On-board identifier (identification means)
400 Target value calculation unit (target value setting means)
401 2-degree-of-freedom response designation type controller (non-interacting input calculation means)
402 Decoupling controller (Decoupling input calculation means)
403 On-board identifier (identification means)
404 plant
TH Opening of throttle valve TH_cmd Target throttle valve opening (control input, non-interacting input)
Liftin intake valve lift Liftin_cmd Target valve lift (control input, non-interacting input)
PB Pressure in intake pipe (pressure in intake passage, control amount)
PB_cmd Target intake pipe pressure (target value)
Gcyl intake air amount (control amount)
Gcyl_cmd Target intake air amount (target value)
Fth Decoupling parameter Fth_hat Identification value Fth_base Reference value dFth_hat Correction term (correction value)
Flf Decoupling parameter Flf_hat Identification value Flf_base Reference value dFlf_hat Correction term (correction value)
NE engine speed (plant internal variable)
PA atmospheric pressure (plant internal variable)
PB supercharging pressure PB_cmd Target supercharging pressure (control input, non-interacting input)
Gcyl intake air amount (control amount)
Gcyl_cmd Target intake air amount (target value)
Legr_cmd Target EGR lift (control input, non-interacting input)
Gegr EGR amount (control amount)
Gegr_cmd Target EGR amount (target value)
Rcp Decoupling parameter Rcp_hat Identification value Rcp_base Reference value dRcp_hat Correction term (correction value)
Scp Decoupling parameter Scp_hat Identification value Scp_base Reference value dScp_hat Correction term (correction value)
Heg non-interacting parameter Heg_hat identification value Heg_base reference value dHeg_hat correction term (correction value)
HI. VT high speed valve timing (plant internal variable)
LO. VT Low-speed valve timing (plant internal variable)
Pex Exhaust pipe internal pressure (plant internal variable)

Claims (6)

A plant control apparatus in which mutual interference exists between a plurality of control inputs and a plurality of control amounts,
Target value setting means for setting a plurality of target values to be the targets of the plurality of control amounts;
Based on a plant model obtained by modeling the plant as a discrete time system model, the plurality of control inputs are obtained by a predetermined control algorithm including a combination of a predetermined response designating control algorithm and a predetermined non-interference control algorithm. A non-interacting input calculating means for calculating each of the control amounts as a plurality of non-interacting inputs for canceling the mutual interference for following the plurality of target values, respectively.
Equipped with a,
The plant model includes a plurality of decoupling parameters for defining a relationship between the plurality of control inputs and the plurality of control amounts,
The non-interacting input calculating means calculates the plurality of non-interacting inputs by the predetermined control algorithm according to at least one of the plurality of non-interacting parameters and the plurality of control amounts,
An identification means for sequentially identifying each of the plurality of non-interacting parameters according to at least one of the plurality of non-interacting inputs, the plurality of control variables, and an internal variable of the plant;
The identification means calculates a reference value of the plurality of non-interacting parameters according to at least one of the plurality of non-interacting inputs, the plurality of controlled variables, and an internal variable of the plant, and According to at least one of the interference input, the plurality of control variables, and the internal variable of the plant, a plurality of correction values are calculated by a predetermined sequential identification algorithm, and reference values of the plurality of non-interference parameters are set. A plant control apparatus , wherein the plurality of non-interacting parameters are identified by correcting each of the plurality of correction values . A plant control apparatus in which mutual interference exists between a plurality of control inputs and a plurality of control amounts,
Target value setting means for setting a plurality of target values to be the targets of the plurality of control amounts;
Based on a plant model obtained by modeling the plant, the plurality of control inputs are obtained by a predetermined control algorithm including a combination of a predetermined target value filter type two-degree-of-freedom control algorithm and a predetermined non-interference control algorithm. A non-interacting input calculating means for calculating each of the control amounts as a plurality of non-interacting inputs for canceling the mutual interference for following the plurality of target values, respectively.
With
The predetermined target value filter type two degree of freedom control algorithm is a target value filter type two degree of freedom feedback control algorithm in which a predetermined target value filter algorithm and a predetermined feedback control algorithm are combined. Control device.   The plant control apparatus according to claim 2, wherein the predetermined feedback control algorithm is a predetermined response assignment control algorithm. A plant control apparatus in which mutual interference exists between a plurality of control inputs and a plurality of control amounts,
The plurality of control inputs are respectively calculated as a plurality of non-interacting inputs for eliminating the mutual interference by a predetermined control algorithm including a predetermined non-interference control algorithm based on a plant model obtained by modeling the plant. A non-interacting input calculating means,
The plant model includes a plurality of decoupling parameters for defining a relationship between the plurality of control inputs and the plurality of control amounts,
The non-interacting input calculating means calculates the plurality of non-interacting inputs by the predetermined control algorithm according to at least one of the plurality of non-interacting parameters and the plurality of control amounts,
An identification means for sequentially identifying each of the plurality of non-interacting parameters according to at least one of the plurality of non-interacting inputs, the plurality of control variables, and an internal variable of the plant ;
The identification means calculates a reference value of the plurality of non-interacting parameters according to at least one of the plurality of non-interacting inputs, the plurality of controlled variables, and an internal variable of the plant, and According to at least one of the interference input, the plurality of control variables, and the internal variable of the plant, a plurality of correction values are calculated by a predetermined sequential identification algorithm, and reference values of the plurality of non-interference parameters are set. A plant control apparatus , wherein the plurality of non-interacting parameters are identified by correcting each of the plurality of correction values . The plurality of control amounts are a pressure and an intake air amount in an intake passage of the internal combustion engine,
The plurality of control inputs are values for controlling the throttle valve opening of the internal combustion engine and values for controlling the lift of the intake valve of the internal combustion engine. The control apparatus of the plant in any one. The plurality of control amounts are an intake air amount and an EGR amount of the internal combustion engine,
5. The control input according to claim 1, wherein the plurality of control inputs are a value for controlling a supercharging pressure of the internal combustion engine and a value for controlling an EGR amount of the internal combustion engine. The plant control device described.

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