JP2011235809A - Device and method for controlling vehicles - Google Patents

Abstract

An object of the present invention is to rapidly reduce the rotational speed of an internal combustion engine when both an accelerator pedal and a brake pedal are depressed and the vehicle speed is rapidly reduced.
When an accelerator pedal and a brake pedal are both depressed (YES in S100), the engine ECU calculates a change amount ΔNm of the second MG rotational speed (S102), and the change amount ΔNm is calculated. If greater than a predetermined value K (YES in S104), the step of selecting the second fuel cut line (S106) and if the selected fuel cut line is exceeded (YES in S108), A program including a step (S110) of executing fuel cut control is executed.
[Selection] Figure 7

Description

  The present invention relates to control of a vehicle on which an internal combustion engine and a driving rotary electric machine are mounted, and more particularly to a technique for executing fuel cut control of an internal combustion engine in accordance with the amount of change in the rotational speed of the driving rotary electric machine.

  In recent years, as one of countermeasures for environmental problems, a hybrid vehicle that travels by driving force from an internal combustion engine and a rotating electric machine for driving attracts attention. In such a vehicle, when the vehicle speed suddenly decelerates, fuel cut control is performed to stop the fuel supply of the internal combustion engine and quickly reduce the rotational speed of the internal combustion engine. The fuel cut control is executed when execution conditions are established for the vehicle speed and the engine speed, but may be prohibited in order to suppress catalyst deterioration and the like.

  For example, Japanese Patent Application Laid-Open No. 2007-084034 (Patent Document 1) discloses an internal combustion engine while maintaining the operation of the internal combustion engine when a braking force is required while the fuel supply cut to the internal combustion engine is prohibited. Disclosed is a power output device that rapidly reduces the number of revolutions and improves the energy efficiency at that time. This power output device sets the target operating state of the internal combustion engine including intermittent operation of the internal combustion engine based on the set required driving force when the explosion combustion continuation condition for continuing the explosive combustion of the internal combustion engine is not satisfied. When the explosion combustion continuation condition is satisfied, the target operation state setting means for setting the target operation state of the internal combustion engine by continuing the operation of the internal combustion engine based on the set required driving force, and the explosion combustion continuation condition is satisfied When the driving shaft is not in a predetermined driving state in which a braking force or a light load is output to the driving shaft, the internal combustion engine is operated in the set target driving state and the driving force based on the set required driving force is applied to the driving shaft. Medium-to-high load combustion continuation control is executed to control the internal combustion engine, power power input / output means and electric motor so that the output is output. Low-load combustion for controlling the internal combustion engine, the power drive input / output means, and the motor so that the internal combustion engine is operated in the set target operation state and the driving force based on the set required driving force is output to the drive shaft Control means for executing continuous control.

  According to the power output device disclosed in the above-mentioned publication, the internal combustion engine can be operated in the target operation state by reducing the rotational speed of the internal combustion engine while continuing the explosion combustion of the internal combustion engine, and wasteful fuel consumption is reduced. Can be suppressed. As a result, the energy efficiency of the apparatus can be improved.

JP 2007-084034 A

  By the way, as a hybrid vehicle, the structure which connects an internal combustion engine, the rotary electric machine for electric power generation, and the rotary electric machine for a drive using a planetary gear is known. In such a high-rid vehicle, each of the rotational speeds of the internal combustion engine, the power generating rotating electrical machine, and the driving rotating electrical machine is correlated with the other rotational speeds.

  In a hybrid vehicle having such a configuration, for example, when the brake pedal is depressed in parallel with the accelerator pedal depressed after the accelerator pedal is largely depressed and the wheel slips, the wheel returns to the grip state. Thus, the vehicle speed (that is, the rotational speed of the drive rotating electrical machine) is rapidly reduced. In such a case, when the rotational speed of the internal combustion engine is maintained or increased, the power generating rotating electrical machine may be in an overspeed state.

  Although it is conceivable to set the execution condition so that the fuel cut control is executed at an early point in time with respect to the decrease in the vehicle speed in order to prevent the rotating electric machine for power generation from being over-rotated, the execution condition is Is set, there is a problem that the frequency of execution of fuel cut control increases.

  In the power output apparatus disclosed in the above-mentioned publication, such problems are not taken into consideration and cannot be solved.

  The present invention has been made in order to solve the above-described problem, and its purpose is when both the accelerator pedal and the brake pedal are depressed and when the vehicle speed is rapidly reduced. An object of the present invention is to provide a vehicular control device and a vehicular control method that quickly reduce the rotational speed of an internal combustion engine.

  A vehicle control device according to an aspect of the present invention is a vehicle control device for a vehicle including an internal combustion engine, an accelerator pedal, and a brake pedal. The vehicle control device includes a determination unit for determining whether or not a selection condition including a condition that both an accelerator pedal and a brake pedal are depressed, and an internal combustion engine when the selection condition is not satisfied. On the other hand, when the first execution condition for executing the fuel cut control is selected and the selection condition is satisfied, the fuel cut control is executed at a point earlier than the first execution condition when the vehicle speed decreases. A selection unit for selecting the second execution condition, and a control unit for executing fuel cut control when one of the first execution condition and the second execution condition selected by the selection unit is satisfied Including.

  Preferably, the vehicle further includes a drive rotating electrical machine for generating a drive force on the wheels. The selection condition further includes a condition that the absolute value of the change amount of the rotational speed of the drive rotating electrical machine is larger than a predetermined value.

  More preferably, on the coordinate plane in which the rotational speed of the internal combustion engine and the vehicle speed are shown, the second fuel cut line and the second position offset in the direction in which the vehicle speed increases with respect to the first fuel cut line. A fuel cut line is set. The first execution condition is a condition that the operating point of the vehicle crosses the first fuel cut line in the direction in which the vehicle speed decreases on the coordinate plane. The second execution condition is a condition that the operating point crosses the second fuel cut line in the direction in which the vehicle speed decreases on the coordinate plane.

  More preferably, the vehicle further includes a power generation rotating electrical machine for generating power using the power of the internal combustion engine, and a planetary gear mechanism that couples the internal combustion engine, the drive rotating electrical machine, and the power generation rotating electrical machine. The planetary gear mechanism meshes with a planetary carrier connected to an internal combustion engine, a ring gear connected to a driving rotating electrical machine, a sun gear connected to a rotating electrical machine for power generation, a ring gear and a sun gear, and is rotated and rotated by the planetary carrier. And a pinion gear supported so as to be capable of revolving.

  A vehicle control method according to another aspect of the present invention is a vehicle control method for a vehicle including an internal combustion engine, an accelerator pedal, and a brake pedal. This vehicle control method includes a step of determining whether or not a selection condition including a condition that both an accelerator pedal and a brake pedal are depressed, and a fuel for an internal combustion engine when the selection condition is not satisfied. When the first execution condition for executing the cut control is selected and the selection condition is satisfied, the fuel cut control is executed at a point earlier than the first execution condition when the vehicle speed decreases. A step of selecting a condition, and a step of executing fuel cut control when either one of the first execution condition and the second execution condition is satisfied.

It is a figure showing the whole hybrid vehicle composition in this embodiment. It is a perspective view which shows the structure of a power split device. It is a collinear diagram which shows the relationship between a motor generator rotation speed and an engine rotation speed. It is a figure which shows the fuel cut line which is the execution conditions of fuel cut control. It is a functional block diagram of engine ECU which is a vehicle control device according to the present embodiment. It is a figure which shows the fuel cut line in this Embodiment. It is a flowchart which shows the control structure of the program performed by engine ECU which is a vehicle control apparatus which concerns on this Embodiment. It is a timing chart which shows operation of engine ECU which is a control device for vehicles concerning this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  With reference to FIG. 1, the configuration of a vehicle 40 equipped with a vehicle control device according to an embodiment of the present invention will be described.

  The vehicle 40 includes an engine 120, a first motor generator 140 (hereinafter referred to as a first MG 140), a second motor generator 142 (hereinafter referred to as a second MG 142), drive wheels 160, a reduction gear 180, Power split mechanism 200, traveling battery 220, inverter 240, converter 242, battery monitoring unit 260, engine ECU (Electronic Control Unit) 280, MG-ECU 300, HV-ECU 320, and vehicle speed sensor 330 , Accelerator pedal 400, accelerator pedal position sensor 402, brake pedal 404, and brake switch 406.

  The engine 120 is an internal combustion engine that outputs power by burning fuel such as a gasoline engine or a diesel engine, and can electrically control the operation state such as a throttle opening (intake amount), a fuel supply amount, and an ignition timing. It is configured as follows. The control is performed, for example, by an engine ECU 280 mainly composed of a microcomputer.

  Engine 120 includes an intake passage 122, an exhaust passage 124, a fuel injection device 130, and an engine speed sensor 380.

  In the intake passage 122, an air cleaner 122A for capturing dust of intake air, an air flow meter 122B for detecting the amount of air taken into the engine 120 through the air cleaner 122A, and the amount of air taken into the engine 120 An electronic throttle valve 122C that is a valve for adjusting the pressure is provided. The electronic throttle valve 122C is provided with a throttle position sensor 122D.

  First MG 140 is a three-phase AC rotating electric machine, and has a function as a generator that generates electric power using engine 120 and a function as a motor that starts engine 120. Second MG 142 is a three-phase AC rotating electric machine, and has a function as a motor for driving vehicle 40 and a function as a generator for generating electric power by regenerative braking.

  Engine 120, first MG 140, and second MG 142 are connected via power split device 200. Power split device 200 is, for example, a planetary gear, and distributes the power generated by engine 120 into two routes, a route to drive wheels 160 and a route to first MG 140. Power split device 200 functions as a continuously variable transmission by controlling the rotation speed of first MG 140.

  Reduction gear 180 is provided between power split device 200 and second MG 140. Reduction gear 180 transmits the power of engine 120 transmitted via power split mechanism 200 or the power generated by second MG 142 to drive wheels 160. Reduction gear 180 transmits the reaction force from the road surface transmitted via drive wheel 160 to engine 120 via power split mechanism 200 or to second MG 142.

  Inverter 240 mutually converts DC power and AC power according to a control signal received from MG-ECU 300. For example, inverter 240 converts DC power of traveling battery 220 supplied via converter 242 to AC power and supplies it to first MG 140 or second MG 142, or is generated by power generation using first MG 140 or second MG 142. The converted AC power is converted into DC power and supplied to the converter 242. MG-ECU 300 controls first MG 140, second MG 142, and inverter 240 according to the state of vehicle 40.

  A motor rotation speed sensor 408 is connected to MG-ECU 300. Motor rotation speed sensor 408 detects rotation speed Nm of second MG 142. Motor rotation speed sensor 408 transmits a signal indicating rotation speed Nm of second MG 142 to MG-ECU 300. Motor rotation speed sensor 408 may directly transmit a signal indicating rotation speed Nm of second MG 142 to HV-ECU 320.

  Converter 242 is provided between battery for traveling 220 and inverter 240. Converter 242 boosts the voltage supplied from battery for traveling 220 to a target voltage corresponding to the state of vehicle 40 and supplies it to inverter 240. Converter 242 charges traveling battery 220 by reducing the voltage of the electric power generated using first MG 140 or second MG 142 and supplying it to traveling battery 220. Converter 242 includes a smoothing capacitor, and charges are stored in the smoothing capacitor when the boosting operation is performed. Converter 242 operates in accordance with a control signal received from MG-ECU 300.

  Traveling battery 220 is a power storage device that stores electric power for driving first MG 140 or second MG 142, and is, for example, a secondary battery or a capacitor. The battery monitoring unit detects the voltage, current, and temperature of the traveling battery 220 and transmits the detected voltage to the HV-ECU 320.

  To engine ECU 280, an air flow meter 122B, a throttle position sensor 122D, and an engine speed sensor 380 are connected.

  The air flow meter 122B detects the amount of intake air to the intake passage 122. Air flow meter 122B transmits a signal indicating the detected intake air amount to engine ECU 280.

  The throttle position sensor 122D detects the opening of the electronic throttle valve 122C (hereinafter referred to as the throttle opening). Throttle position sensor 122D transmits a signal indicating the detected throttle opening to engine ECU 280.

  Engine speed sensor 380 detects the speed of engine 120. Engine speed sensor 380 transmits a signal indicating the detected speed of engine 120 to engine ECU 280.

  Engine ECU 280 controls the operation state of engine 120 based on information input from air flow meter 122B, throttle position sensor 122D, engine speed sensor 380, and HV-ECU 320.

  A vehicle speed sensor 330, an accelerator pedal position sensor 402, and a brake switch 406 are connected to the HV-ECU 320.

  The vehicle speed sensor 330 detects the speed of the vehicle 40. The vehicle speed sensor 330 transmits a signal indicating the detected speed of the vehicle 40 to the HV-ECU 320. Instead of the vehicle speed sensor 330, a wheel speed sensor that detects the rotation speed of the drive wheel 160 may be used.

  The accelerator pedal position sensor 402 detects the depression amount of the accelerator pedal 400. The accelerator pedal position sensor 402 transmits a signal indicating the detected depression amount of the accelerator pedal 400 to the HV-ECU 320.

  The brake switch 406 is a switch that is turned on when the depression amount of the brake pedal 404 is greater than or equal to a predetermined amount, and is turned off when the amount is smaller than the predetermined amount. The brake switch 406 transmits a signal indicating on or off to the HV-ECU 320. Instead of the brake switch, a stroke sensor that detects the amount of depression of the brake pedal 404 may be used, or a sensor that can detect whether or not the brake pedal 404 is depressed, such as a master cylinder pressure sensor, may be used. .

  The HV-ECU 320 manages and controls the engine ECU 280 and the MG-ECU 300 to control the entire hybrid system so that the vehicle 40 can operate most efficiently.

  In FIG. 1, each ECU is configured separately, but may be configured as an ECU in which two or more ECUs are integrated (for example, MG_ECU 300 and HV_ECU 320, as shown by a dotted line in FIG. 1). An example is an integrated ECU).

  The HV_ECU 320 controls the output and power generation amount of the first MG 140 and the second MG 142 according to the required power based on the depression amount of the accelerator pedal 400 and the like, and causes the engine ECU 280 to control the output of the engine 120.

  In the vehicle 40 equipped with the hybrid system as shown in FIG. 1, the HV-ECU 320 is in a state where the engine 120 is stopped and the second MG 142 is stopped when the engine 120 is inefficient at the time of starting or running at a low speed. Second MG 142 is controlled so as to travel using the power of.

  During normal travel, the HV-ECU 320 is controlled by the first MG 140 to, for example, two paths, a path for directly transmitting the power of the engine 120 to the drive wheels 160 by the power split mechanism 200 and a path for transmitting the power to the first MG 140 for power generation. Distribute. At this time, the HV-ECU 320 drives the second MG 142 using the electric power generated in the first MG 140 to assist in driving the driving wheels 160.

  Further, during high-speed traveling, HV-ECU 320 further supplies power from traveling battery 220 to second MG 142 to increase the output of second MG 142 and add driving force to drive wheels 160.

  On the other hand, at the time of deceleration, HV-ECU 320 causes second MG 142 driven by drive wheel 160 to function as a generator to perform regenerative power generation, and stores the collected power in traveling battery 220.

  Note that the HV-ECU 320 increases the power generation amount using the first MG 140 by increasing the output of the engine 120 when the charging amount of the traveling battery 220 decreases and charging is particularly necessary. Increase charge.

  Further, the HV-ECU 320 may perform control to increase the driving force of the engine 120 as necessary even during low speed traveling. For example, it is necessary to charge the traveling battery 220 as described above, to drive an auxiliary machine such as an air conditioner, or to raise the temperature of the cooling water of the engine 120 to a predetermined temperature.

  Furthermore, HV-ECU 320 stops engine 120 in order to improve fuel efficiency depending on the driving state of the vehicle and the state of battery for traveling 220. Thereafter, the HV-ECU 320 restarts the engine 120 according to the driving state of the vehicle and the state of the traveling battery 220.

  As shown in FIG. 2, the power split mechanism 200 includes a sun gear 202, a ring gear 206, a plurality of pinion gears 208 that mesh with the sun gear 202 and the ring gear 206, and a planetary carrier 204 that holds the pinion gear 208 so that it can rotate and revolve. Is a planetary gear mechanism including Sun gear 202 is connected to the rotation shaft of first MG 140. Ring gear 206 is connected to the rotation shaft of second MG 142. Planetary carrier 204 is connected to the output shaft of engine 120. Therefore, each of the rotational speeds of engine 120, first MG 140, and second MG 142 is correlated with the other rotational speeds.

  A chain drive sprocket (1) 216 is further connected to a rotating shaft on which the second MG 142 and the ring gear 206 rotate integrally. The power in the chain drive sprocket (1) 216 is transmitted to the chain drive sprocket (2) 212 via the chain 210, and the chain drive sprocket (2) 212 transmits power from the counter drive gear 214 to the reduction gear 180.

  The rotational force of the engine 120 is input to the planetary carrier 204. The rotational force of engine 120 input to planetary carrier 204 is transmitted to first MG 140 via sun gear 202. The rotational force of engine 120 input to planetary carrier 204 is further transmitted to second MG 142 and the output shaft (drive wheel 160 side) via ring gear 206. In this way, the rotational force of engine 120 is distributed by power split mechanism 200 into two routes, the route to drive wheel 160 and the route to first MG 140.

  It is assumed that the vehicle 40 as described above accelerates with the engine 120 operated. When the driver depresses the accelerator pedal greatly, the output of the second MG 142 may increase and a slip state may occur. At this time, since the rotational speed Nm of the second MG 142 increases, in the alignment chart of FIG. 3, the straight line connecting the rotational speeds of the engine 120, the first MG 140, and the second MG 142 is in the state shown by the solid line in FIG.

  When the driver depresses the accelerator pedal in parallel with the accelerator pedal depressed, the rotation of the drive wheel 160 is limited by the operation of the brake. In addition, the rotation speed Nm of the second MG 142 decreases due to the decrease in the rotation speed of the drive wheel 160, and the drive wheel 160 returns from the slip state to the grip state.

  At this time, the straight line connecting the rotation speeds of engine 120, first MG 140, and second MG 142 changes from the state shown by the solid line in FIG. 3 to the state shown by the broken line in FIG.

  When the state of the solid line in FIG. 3 changes to the state of the broken line, the rotational speed Nm of the second MG 142 rapidly decreases, so that the rotational speed of the first MG 140 greatly increases with the rotational speed of the engine 120 as a fulcrum. The first MG 140 may be in an overspeed state.

  Therefore, by performing fuel cut control on the engine 120, the first MG 140 changes the state shown by the broken line in FIG. 3 from the state shown by the dashed line in FIG. It can suppress that it will be in an over-rotation state.

  Therefore, engine ECU 280 executes fuel cut control when a predetermined execution condition is satisfied. The predetermined execution condition is a condition for the engine speed and the vehicle speed at which fuel cut control is started. Specifically, as shown in FIG. 4, a fuel cut line indicated by a thick solid line in FIG. 4 is set on a coordinate plane in which the vertical axis represents the vehicle speed V and the horizontal axis represents the engine speed Ne. Engine ECU 280 is configured such that position A on the coordinate plane in FIG. 4 (also referred to as an operating point in the following description) based on actual vehicle speed and actual engine speed Ne of vehicle 40 decreases the vehicle speed with respect to the fuel cut line. It is determined that a predetermined execution condition is satisfied when crossing in the left direction (the left direction in FIG. 4).

  The fuel cut line is set in a region surrounded by an upper limit line for engine speed Ne, an upper limit line for vehicle speed V, and a lower limit line for engine speed Ne.

  However, when the fuel cut line is set so as to suppress over-rotation of the first MG 140 caused by depressing the brake pedal in parallel with the accelerator pedal depressed, the rotational speed of the second MG 142 is set. Since fuel cut control is executed regardless of the amount of change in Nm, the execution frequency of fuel cut control may increase.

  Therefore, in the present embodiment, first execution condition for engine ECU 280 to perform fuel cut control on engine 120 when the selection condition that both the accelerator pedal and the brake pedal are depressed is not satisfied. When the selection condition is satisfied, the second execution condition for executing the fuel cut control at a time point faster than the first execution condition when the vehicle speed is reduced is selected and selected. The fuel cut control is performed when one of the conditions is satisfied.

  In the present embodiment, the selection condition further includes a condition that the absolute value of change amount ΔNm of rotation speed Nm of second MG 142 is larger than a predetermined value.

  Furthermore, in the present embodiment, the first execution condition is that the operating point of the vehicle 40 crosses the first fuel cut line in the direction in which the vehicle speed decreases on the coordinate plane between the engine speed Ne and the vehicle speed V. This is the condition.

  The second execution condition is a condition that the operating point of the vehicle 40 crosses the second fuel cut line in the direction in which the speed of the vehicle 40 decreases on the coordinate plane.

  The first fuel cut line is set on a coordinate plane on which the rotational speed Ne of the engine 120 and the vehicle speed V are indicated. The second fuel cut line is set at a position offset in the direction in which the speed of the vehicle 40 increases with respect to the first fuel cut line.

  The operating point of the vehicle 40 refers to a position specified on the coordinate plane based on the actual rotational speed detected by the engine speed sensor 380 and the actual vehicle speed detected by the vehicle speed sensor 330.

  FIG. 5 shows a functional block diagram of engine ECU 280 which is a vehicle control apparatus according to the present embodiment. Engine ECU 280 includes a both-step determination unit 500, a change amount calculation unit 502, a line selection unit 504, an excess determination unit 506, a fuel cut control unit 508, and an engine control unit 510.

  The both step determination unit 500 determines whether or not both the accelerator pedal 400 and the brake pedal 404 are depressed. For example, the both-step determination unit 500 determines that the accelerator pedal 400 is depressed when the amount of depression of the accelerator pedal 400 received from the accelerator pedal position sensor 402 is equal to or greater than a predetermined value. Further, when the both-step determination unit 500 receives an ON signal from the brake switch 406, it determines that the brake pedal 404 is depressed. Note that the both-step determination unit 500 may turn on the both-step determination flag when it is determined that both the accelerator pedal 400 and the brake pedal 404 are depressed, for example.

  The change amount calculation unit 502 calculates the change amount ΔNm of the rotational speed of the second MG 142 when the both step determination unit 500 determines that both the accelerator pedal 400 and the brake pedal 404 are depressed. The change amount calculation unit 502 may calculate the change amount per unit time of the rotational speed Nm of the second MG 142 as the change amount ΔNm, or may change the predetermined amount per predetermined time corresponding to the calculation cycle of the engine ECU 280. The amount of change in the rotational speed Nm of the 2MG 142 may be calculated as the amount of change ΔNm.

  The line selection unit 504 is a rotation of the second MG 142 calculated by the change amount calculation unit 502 when it is determined that both the accelerator pedal 400 and the brake pedal 404 are depressed by the both step determination unit 500. When the number change amount ΔNm is equal to or less than a predetermined value, the first fuel cut line is selected.

  The line selection unit 504 is the second MG 142 calculated by the change amount calculation unit 502 when it is determined by the both step determination unit 500 that both the accelerator pedal 400 and the brake pedal 404 are depressed. The second fuel cut line is determined when the amount of change ΔNm in the rotational speed is greater than a predetermined value K.

  In addition, the line selection part 504 selects a 1st fuel cut line, when it is determined by the both step determination part 500 that both the accelerator pedal 400 and the brake pedal 404 are not depressed.

  The second fuel cut line is set so that the fuel cut control is executed at a point earlier than when the first fuel cut line is used when the speed of the vehicle 40 decreases.

  The first fuel cut line in the present embodiment is indicated by a solid line in FIG. 6, and the second fuel cut line is indicated by a broken line in FIG. The first fuel cut line and the second fuel cut line are not particularly limited to those indicated by the solid line and the broken line in FIG.

  In the present embodiment, the first fuel cut line is set similarly to the conventional fuel cut line. That is, the first fuel cut line is considered when both the accelerator pedal 400 and the brake pedal 404 are depressed, and when the amount of change ΔNm in the rotation speed of the second MG 142 is greater than a predetermined value K. Set without.

  On the other hand, the second fuel cut line is set at a position offset from the first fuel cut line by a predetermined value in the direction in which the speed of the vehicle 40 increases. The second fuel cut line is when both the accelerator pedal 400 and the brake pedal 404 are depressed, and when the change amount ΔNm of the rotation speed of the second MG 142 is larger than a predetermined value K. When the fuel cut control is executed, the first MG 140 is set so as to be prevented from over-rotating.

  In the present embodiment, the first fuel cut line and the second fuel cut line are described as being linear, but are not particularly limited to being straight.

  Further, in the present embodiment, it has been described that the first fuel cut line is selected when it is determined that both the accelerator pedal 400 and the brake pedal 404 are not depressed, but the present invention is particularly limited to this. Instead, the line selection unit 504 may select a third fuel cut line different from each of the first fuel cut line and the second fuel cut line.

  The excess determination unit 506 selects the line of the operating point A of the vehicle 40 (that is, the position on the coordinate plane between the vehicle speed and the engine speed shown in FIG. 6 specified based on the actual vehicle speed and the actual engine speed). It is determined whether or not the fuel cut line selected by the unit 504 is crossed in the direction in which the vehicle speed decreases. For example, the excess determination unit 506 determines whether the previous operation point of the vehicle 40 is on the right side of the fuel cut line and the current operation point of the vehicle 40 is on the left side of the fuel cut line. It is determined that 40 operating points have crossed the fuel cut line.

  Note that the excess determination unit 506 turns on the excess determination flag when, for example, it is determined that the operating point of the vehicle 40 has crossed the fuel cut line selected by the line selection unit 504 in the direction in which the vehicle speed decreases. May be.

  The fuel cut control unit 508 executes fuel cut control when it is determined by the excess determination unit 506 that the operating point of the vehicle 40 has crossed the fuel cut line selected by the line selection unit 504 in the direction in which the vehicle speed decreases. . That is, the fuel cut control unit 508 stops fuel injection by the fuel injection device 130. Note that the fuel cut control unit 508 may restart the fuel injection by the fuel injection device 130 when the engine speed is equal to or lower than the lower limit value.

  The engine control unit 510 performs normal engine control when the excess determination unit 506 determines that the operating point of the vehicle 40 does not cross the fuel cut line determined by the line selection unit 504 in the direction in which the vehicle speed decreases. Execute. That is, engine control unit 510 determines the target rotational speed and target torque based on the required power received from HV-ECU 320, and controls engine 2 so that the determined target rotational speed and target torque are realized.

  In the present embodiment, both the tread determination unit 500, the change amount calculation unit 502, the line selection unit 504, the excess determination unit 506, the fuel cut control unit 508, and the engine control unit 510 are all engine ECUs 280. The CPU is described as functioning as software realized by executing a program stored in the memory, but may be realized by hardware. Such a program is recorded on a storage medium and mounted on the vehicle.

  With reference to FIG. 7, a control structure of a program executed by engine ECU 280 which is the vehicle control apparatus according to the present embodiment will be described.

  In step (hereinafter, step is referred to as S) 100, engine ECU 280 determines whether or not both accelerator pedal 400 and brake pedal 404 are depressed. If both accelerator pedal 400 and brake pedal 404 are depressed (YES in S100), the process proceeds to S102. If not (NO in S100), the process proceeds to S108.

  In S102, engine ECU 280 calculates amount of change ΔNm in the rotational speed of second MG 142. In S104, it is determined whether or not the calculated change amount ΔNm is larger than a predetermined value K. If calculated change amount ΔNm is larger than predetermined value K (YES in S104), the process proceeds to S106. If not (NO in S104), the process proceeds to S108.

  In S106, engine ECU 280 selects the second fuel cut line. In S108, engine ECU 280 determines the first fuel cut line.

  In S110, engine ECU 280 determines whether or not the fuel cut line where the operating point of vehicle 40 has been determined has been crossed in a direction in which the vehicle speed decreases. If the fuel cut line for which the operating point has been determined is crossed in the direction in which the vehicle speed decreases (YES in S110), the process proceeds to S112. If not (NO in S110), the process proceeds to S114.

  In S112, engine ECU 280 performs fuel cut control. In S114, engine ECU 280 performs normal engine control. Since normal engine control is as described above, detailed description thereof will not be repeated.

  The operation of engine ECU 280, which is the vehicle control apparatus according to the present embodiment based on the above-described structure and flowchart, will be described with reference to FIG.

  For example, it is assumed that the engine 120 is in operation, the depression amount of the accelerator pedal 400 is 100%, the operation of the brake pedal 404 is released, and the brake switch 406 outputs an off signal. .

  The vehicle 40 is controlled by the HV-ECU 320 so that the required power corresponding to the depression amount of the accelerator pedal 400 is 100%. Therefore, the rotational speed Nm of the second MG 142 increases, and the rotational speed Ng of the first MG 140 increases as the engine rotational speed Ne increases, so that the drive wheel 160 enters a slip state.

  When the driver depresses the brake pedal 404 at time T (0) while maintaining the depression amount of the accelerator pedal 400 (YES in S100), the rotation of the drive wheel 160 is limited by the operation of the brake. Therefore, the rotation speed Nm of the second MG 142 decreases rapidly. As the rotation speed Nm of the second MG 142 decreases, the drive wheel 160 shifts from the slip state to the grip state. At this time, the change amount ΔNm of the rotation speed of the second MG 142 is calculated (S102), and when the calculated change amount ΔNm is larger than a predetermined value K (YES in S104), the second fuel cut line is selected. (S106).

  If it is determined at time T (1) that the operating point of vehicle 40 has crossed the second fuel cut line in the direction in which the vehicle speed decreases (YES in S110), fuel cut control is executed (S112). Therefore, the engine speed Ne decreases, and the engine speed Ne of the first MG 140 decreases as the engine speed Ne decreases.

  As described above, when the second fuel cut line is selected when the change amount ΔNm of the rotation speed of the second MG 142 is larger than the predetermined value K, the fuel cut control is executed using the first fuel cut line. The fuel cut control is executed at a time T (1) that is earlier than the execution timing time T (2) in the case of performing (a thin solid line in FIG. 8).

  By executing the fuel cut control earlier than when performing fuel cut control using the first fuel cut line, the engine speed Ne is higher than when performing fuel cut control using the first fuel cut line. Can be quickly reduced. As a result, when the fuel cut control is executed using the first fuel cut line, the rotation speed of the first MG 140 exceeds the upper limit as shown by the thin line in FIG. 8, whereas the second fuel cut line is used. By executing the fuel cut control, it is possible to suppress the rotation speed Ng of the first MG 140 from exceeding the upper limit value.

  As described above, according to the vehicle control device of the present embodiment, both the accelerator pedal and the brake pedal are depressed, and the amount of change ΔNm in the second MG rotational speed is larger than the predetermined value K. When the selection condition of large is satisfied, fuel cut control can be executed at an earlier timing than when the first fuel cut line is used when the vehicle speed decreases, so the engine speed can be quickly increased. Can be reduced. By rapidly decreasing the engine speed, it is possible to suppress the first engine MG speed Ng from being over-rotated. Therefore, when the accelerator pedal and the brake pedal are depressed in parallel and when the vehicle speed is rapidly reduced, the vehicle control device and the vehicle control method for rapidly reducing the rotational speed of the internal combustion engine Can be provided.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  40 Vehicle, 120 Engine, 122 Intake passage, 122A Air cleaner, 122B Air flow meter, 122C Electronic throttle valve, 124 Exhaust passage, 124B Three-way catalytic converter, 124D Silencer, 130 Fuel injection device, 140, 142 MG, 160 Drive wheel, 180 reduction gear, 200 power split mechanism, 202 sun gear, 204 planetary carrier, 206 ring gear, 208 pinion gear, 210 chain, 214 counter drive gear, 220 battery for running, 240 inverter, 242 converter, 260 battery monitoring unit, 280 engine ECU, 300 MG-ECU, 320 HV-ECU, 330 vehicle speed sensor, 380 engine speed sensor, 400 accelerator pedal, 402 accelerator Le pedal position sensor, 402 brake pedal 404 the brake pedal, 406 brake switch, 500 both depression determination section, 502 change amount calculation unit, 504 a line selection unit, 506 excess determination unit, 508 fuel cut control unit, 510 the engine control unit.

Claims (5)

A vehicle control device for a vehicle including an internal combustion engine, an accelerator pedal, and a brake pedal,
The vehicle control device includes:
A determination unit for determining whether a selection condition including a condition that both the accelerator pedal and the brake pedal are depressed is satisfied;
When the selection condition is not satisfied, a first execution condition for performing fuel cut control on the internal combustion engine is selected, and when the selection condition is satisfied, the vehicle speed is decreased. A selection unit for selecting a second execution condition in which the fuel cut control is executed at a time earlier than the first execution condition;
And a control unit configured to execute the fuel cut control when one of the first execution condition and the second execution condition selected by the selection unit is satisfied. The vehicle further includes a rotating electric machine for driving for generating driving force on the wheels,
The vehicle control device according to claim 1, wherein the selection condition further includes a condition that an absolute value of a change amount of a rotation speed of the driving rotating electrical machine is larger than a predetermined value. On the coordinate plane on which the rotational speed and vehicle speed of the internal combustion engine are indicated, the first fuel cut line and the second fuel at a position offset in the direction in which the vehicle speed increases with respect to the first fuel cut line. Cut line is set,
The first execution condition is a condition that an operating point of the vehicle crosses the first fuel cut line on the coordinate plane in a direction in which the speed of the vehicle decreases.
The vehicle control device according to claim 2, wherein the second execution condition is a condition that the operating point crosses the second fuel cut line in a direction in which the speed of the vehicle decreases on the coordinate plane. The vehicle further includes a generator rotating electric machine for generating electric power using the power of the internal combustion engine, and a planetary gear mechanism that connects the internal combustion engine, the driving rotary electric machine, and the power generating rotary electric machine,
The planetary gear mechanism meshes with a planetary carrier connected to the internal combustion engine, a ring gear connected to the driving rotating electrical machine, a sun gear connected to the rotating electrical machine for power generation, and the ring gear and the sun gear. And a pinion gear supported by the planetary carrier so as to be capable of rotating and revolving. A vehicle control method for a vehicle including an internal combustion engine, an accelerator pedal, and a brake pedal,
The vehicle control method includes:
Determining whether a selection condition including a condition that both the accelerator pedal and the brake pedal are depressed is satisfied;
When the selection condition is not satisfied, a first execution condition for performing fuel cut control on the internal combustion engine is selected, and when the selection condition is satisfied, the vehicle speed is decreased. Selecting a second execution condition in which the fuel cut control is executed at a time earlier than the first execution condition;
And a step of executing the fuel cut control when either one of the first execution condition and the second execution condition is satisfied.

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