JPH08121202A - Vehicle drive torque control device - Google Patents

Abstract

(57) [Summary] [Purpose] The drive torque during shifting is controlled so as to have a smooth ideal waveform to reduce shift shock. The drive torque calculation means estimates the torque of the output shaft of the automatic transmission from the engine torque characteristic or the characteristic of the torque converter, and generates a target torque pattern during shifting based on the estimated drive torque. The engine torque control calculating means calculates a control amount for controlling the output torque of the engine to eliminate the deviation between the target torque and the driving torque estimated by the driving torque calculating means, that is, an ignition timing correction amount Δθig. By this ignition timing correction, the drive torque is approximated to a smooth target torque.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for a vehicle equipped with an automatic transmission, and more particularly to a control method and a control apparatus for reducing torque fluctuations that occur during gear shifting, so-called shift shock.

[0002]

2. Description of the Related Art In the conventional control method of this type, for example, as in Japanese Patent Publication No. 20817/1990, the start and end points of engine output reduction control for gear shift shock reduction are determined by the engine speed at the start of gear shift. 5-5
As in No. 688, the start and end points of the engine output reduction control for gear shift shock reduction are defined by the ratio of the transmission input rotation speed (turbine rotation speed) to the output rotation speed (referred to as a vehicle speed signal), that is, the input speed. What is determined by the size of the output rotation ratio, and as in Japanese Patent Publication No. 4-81658, the starting point of the engine output reduction control for gear shift shock reduction is the former method described above, and the ending point is the latter method described above. There are things that are decided by the method.

As described in Japanese Patent Publication No. 5-7213, a conventional engine output reduction control method in this type of control method is described in Japanese Patent Publication No. 5-7213. It is common to switch to a memory, and it is necessary to search and control the control timing and control amount for each shift speed and for each engine load amount from a previously stored map.

[0004]

FIG. 3 is an example of a time chart for explaining a shift shock reducing method using the above-mentioned conventional technique. Ignition timing is used as a control amount for reducing the engine output. Control timing t ₁ , t
₂ is determined when the input / output rotation ratio obtained above exceeds the preset values S ₁ and S ₂ stored in advance. This t ₁ →
In the control period of t ₂ , the control amount stored in advance, that is, the ignition timing retard amount Δθ is read out, and this is added to the basic ignition timing to execute the control.

Therefore, the correction control amount in this correction control period is a constant value, and when the output shaft torque in the control period of t ₁ → t ₂ is substantially flat as shown in the figure, a remarkable torque fluctuation is caused by the retard control described above. It is possible to improve the effect of reducing gear shift shock. However, the actual torque waveform fluctuates considerably during the above period,
In many cases, a sufficient correction control effect cannot be obtained with a constant correction control amount.

Further, the set values S ₁ and S ₂ and the ignition timing retard amount Δθ need to be adjusted to the optimum values by tuning the actual machine at the development stage, which requires a great amount of time. In addition, even if it is adapted to the optimum value, the set value determined above may be insufficient due to aging and environmental changes, and it has been difficult to completely reduce the shift shock. The object of the present invention is to reduce the development man-hours by eliminating the tuning portion as much as possible, and to preferably control the shift shock by automatically following the changes over time and the environment. And a control method.

[0007]

In order to achieve the above object, a vehicle drive torque control apparatus according to the present invention is a target torque pattern generating means for generating an ideal waveform which should have a drive shaft torque at the time of gear shifting. Drive torque calculating means for highly accurately estimating the drive shaft torque of the engine, engine torque control amount calculating means for calculating a control amount for controlling the output torque of the engine so that the estimated drive torque follows the target torque pattern, and the engine Engine torque control means for controlling the output torque is provided.

The target torque generating means recognizes the time point when the estimated turbine torque obtained by the turbine torque calculating means in the driving torque calculating means becomes equal to or more than a predetermined value within a predetermined time after the gearshift command, as an actual gearshift timing. The drive torque at the shift timing or the average drive torque up to immediately before that is temporarily stored as the pre-shift drive torque, and the post-shift drive torque is calculated from the pre-shift drive torque and the gear ratio before and after the shift. It has a function of calculating the inclination angle with respect to the elapsed time of the target torque from the difference between the driving torque and a preset predetermined shift time, and calculating the target torque according to the inclination angle for each predetermined calculation cycle. be able to.

The engine torque control amount calculation means is a deviation calculation means between the target torque value generated by the target torque generation means and the drive torque value calculated by the drive torque calculation means in each predetermined calculation cycle, and the deviation calculation means. It is possible to include an engine torque control amount conversion means for calculating the engine torque control amount by multiplying the calculated deviation by a conversion coefficient set and stored in advance. The conversion coefficient is 0 when the drive torque value is smaller than the target torque value within the first predetermined period from the actual shift timing, and within the second predetermined period longer than the first predetermined period from the actual shift timing. When the drive torque value is larger than the target torque value, a predetermined eigenvalue is preferably set, and when the drive torque value is larger than the target torque value, the predetermined eigenvalue is preferably divided by a coefficient of the elapsed time.

As the driving torque calculating means, the first driving torque calculating means for estimating the driving torque by utilizing the engine torque characteristic stored in advance and the characteristic of the torque converter stored in advance are used. A second drive torque calculating means for estimating a drive torque by using the second drive torque calculating means in a region where the torque converter slips large, and a first drive torque in a region where the torque converter slips small. It is preferable to include switching means for switching to estimate the torque of the output shaft of the automatic transmission using the torque calculation means. Further, the load torque of the accessory of the engine is learned from the deviation of the drive torque by the first and second drive torque calculating means, and the load torque of the accessory is corrected when the first drive torque calculating means is used. preferable.

The first drive torque calculating means for estimating using the engine torque characteristic is an engine torque characteristic storing means for storing the engine torque characteristic in advance, a means for calculating a slip ratio of the torque converter, and a slip ratio. A means for calculating the torque ratio of the torque converter by inputting the slip ratio information from the calculating means, and a torque by multiplying the engine torque read from the engine torque characteristic storage means by the torque ratio output from the torque ratio calculating means. Turbine torque calculation means for outputting the output shaft torque of the converter, and the output shaft torque of the automatic transmission by multiplying the torque converter output shaft torque from the turbine torque calculation means by the gear ratio of the currently engaged gear stage. And an automatic transmission output shaft torque calculating means.

The engine torque characteristic storage means stores the accelerator pedal opening or the throttle opening and the engine speed,
The engine torque can be stored using the engine intake air mass flow rate and engine speed, the intake pressure and intake temperature and engine speed, or the injector drive pulse width and engine speed as parameters. The second drive torque calculating means for estimating the drive torque by utilizing the characteristics of the torque converter includes pump capacity coefficient characteristic storing means of the torque converter, means for calculating the slip ratio of the torque converter, and slip ratio calculating means. Means for calculating the torque ratio of the torque converter by inputting the slip ratio information, and multiplying the pump capacity coefficient read from the pump capacity coefficient characteristic storage means by the engine speed square signal from the engine speed square means. Torque converter input torque calculating means for calculating the torque converter input torque, and the torque ratio output from the torque ratio calculating means is multiplied by the torque converter input torque from the torque converter input torque calculating means to output the output torque of the torque converter. Turbine torque calculating means and a torque converter from the turbine torque calculating means. It can be an output shaft torque and an automatic transmission output shaft torque calculating means for multiplying the gear ratio of the gear output torque of the output shaft of the automatic transmission currently fastening the motor.

[0013]

According to the present invention, the output shaft torque of the engine is feedback-controlled so that the actual drive shaft torque becomes equal to the target torque. Therefore, ideal torque control during gear shifting becomes possible, and the development required for tuning, etc. Man-hours can be reduced significantly. In addition, it is possible to appropriately follow the changes over time and the environment to reduce shift shock appropriately.

When the engine torque control amount is calculated by multiplying the deviation between the target torque value and the estimated drive torque value by the conversion coefficient which is set and stored in advance, the conversion coefficient is changed according to the period from the actual shift timing. By doing so, it is possible to avoid the possibility of overcorrection, and to smoothly connect the driving torque during shifting and the driving torque during normal running after shifting. As the drive torque calculating means, the first drive torque calculating means utilizing the engine torque characteristic and the second drive torque calculating means utilizing the characteristic of the torque converter are used together, and the second drive torque calculating means is used in the region where the slip of the torque converter is large. By using the drive torque calculating means of No. 1 and the first drive torque calculating means in the region where the torque converter slips small, the accuracy of estimating the drive torque can be improved.

A map based on measured parameters such as accelerator pedal opening, throttle opening, engine speed, engine intake air mass flow rate, intake pressure, intake temperature, injector drive pulse width, and torque converter slip ratio. By adopting the method of estimating the driving torque by searching, it is possible to perform the driving torque control using only the existing sensor that is built in for engine control without using an expensive torque sensor, which increases the cost. It is possible to enhance the function without involving.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a system configuration diagram of the present invention. 1 is an engine, 2 is an automatic transmission (AT), 3 is a propeller shaft, 4 is a differential device also serving as a final reduction gear, 5 is drive wheels, 6
Is an AT hydraulic circuit. Reference numeral 7 denotes an AT control unit (electronic control unit) built in a microcomputer, which is referred to as an ATCU here. Reference numeral 8 denotes a control unit (electronic control device) for an engine with a built-in microcomputer, which is referred to as an ECU here. 9 is an air cleaner, 1
0 is an air flow sensor, 11 is a throttle chamber,
Reference numeral 12 is an intake manifold, and 13 is an injector for injecting fuel. The inside of the AT 2 is further divided into a torque converter 14 and a gear train 15. A turbine sensor 16 for detecting the output shaft speed of the torque converter 14, that is, the mission input shaft speed, and a mission output for detecting the mission output shaft speed. A shaft rotation sensor 17 is attached.

Information such as a crank angle sensor, an air flow sensor 10, and a throttle sensor 18 is input to the ECU 8, and various calculations such as an engine speed signal are executed and a valve opening drive signal is output to the injector 13 to output fuel. Control the amount, output a valve opening drive signal to the idle speed control valve ISC19 to control the correction air amount, and, although not shown, output an ignition signal to the spark plug to control the ignition timing. Performs various controls. On the other hand, AT
Signals from the mission output shaft rotation sensor 17, the AT oil temperature sensor, etc., the engine speed, the throttle opening signal, etc., from the ECU 8 are input to the CU 7, and various calculations are executed, so that the hydraulic pressure attached to the hydraulic circuit 6 is increased. Control switching solenoid valve 2
A 0-valve drive signal, an ISC 19 drive signal, an ignition timing correction signal, etc. are output.

FIG. 2 shows a structural example of a control device such as the ATCU and ECU described above. The control device is at least a CPU
33, a ROM 35, a RAM 36, an input / output interface circuit 38, and a bus 34 that connects them, and a LAN control circuit 37 is required when the ATCU 7 and the ECU 8 are connected by a LAN as shown in FIG. ATC mentioned above
The present invention can exhibit the same effect even in a type in which U and ECU are integrated and one CPU controls both functions.

FIG. 4 is a time chart for explaining an upshift shock reducing method according to the present invention. The shift control is started by a shift command. The estimated turbine torque is obtained by executing the calculation at a predetermined time interval regardless of the shift command. The method of calculating the estimated turbine torque will be described later. Although not shown, when a gear shift command is issued, the hydraulic pressure switching solenoid valve 20 for that gear shift stage is actuated, and the fastening friction elements such as the clutch and brake for that gear shift stage are started.
As a result, the engagement of the gear for that shift speed is started. When the engagement of the gears is started, the estimated turbine torque increases almost stepwise as shown. This is because the engine speed and the turbine speed rapidly decrease due to the upshift, and inertia components of the engine and the like are superimposed.

In the present invention, the rising point of this estimated turbine torque is detected and identified by the slice level St, and at this time t.
₀ is used as the stepwise switching point of the gear ratio used for the calculation of the estimated output shaft torque and the generation point of the target torque pattern. Similar to the estimated turbine torque, the estimated output shaft torque is also calculated at a predetermined time interval regardless of the shift command.

The estimated output shaft torque is the output shaft torque of the mission obtained by multiplying the estimated turbine torque by the gear ratio at that time. When the information of the time t ₀ is entered, the gear ratio used for the above calculation is stepwise switched from the gear ratio before the gear shift command to the gear ratio after the gear shift command (the gear ratio after the engagement).
This is the starting point of the estimated turbine torque switching starting from the gear before the gear change command to the gear after the gear change command,
This is due to the switching point of the torque transmission path.

By stepwise switching of the gear ratio,
At time t ₀ , the estimated output shaft torque once decreases in a stepwise manner, and then exhibits a waveform proportional to the rising waveform of the estimated turbine torque (see the pre-control torque waveform shown in the figure). When the gear engagement is completed, the estimated turbine torque returns to a predetermined low value again as shown in the figure. The period during which this estimated turbine torque is trapezoidally large is
This is the actual gear engagement period, and is the period during which the engine speed and turbine speed are rapidly decreasing. During this period, the estimated turbine torque is trapezoidally increased due to the release of the inertial torque. Therefore,
The estimated output shaft torque also exhibits a waveform proportional to the estimated turbine torque waveform, and the torque during shifting can be faithfully estimated. A person in the vehicle perceives a temporal change in the estimated output shaft torque and feels a shift shock.
Therefore, in order to reduce the shift shock, it is necessary to suppress the temporal change of the estimated output shaft torque.

The present invention achieves this as follows. At time t ₀ , the average value Tob of the estimated output shaft torque immediately before the shift is calculated. The estimated output shaft torque is estimated and calculated every predetermined time (for example, every 10 ms), and sequentially stored in the RAM. In this case, an arbitrary number (for example, 14) of stored numbers is prepared, and when the latest estimated calculation value is stored, the estimated calculation values stored before that are sequentially moved to the next storage location, The old estimated calculation value is made to disappear. Therefore, time t
_{At 0} , all or part of the stored estimated calculation values are read out, and the average value Tob of the estimated output shaft torque immediately before the shift is calculated.

Next, the output shaft torque Toa immediately after shifting is estimated and calculated as Toa = (Tob / gear ratio before shifting) × (gear ratio after shifting). Then, the output shaft torque drop ΔTo before and after the shift is calculated from the difference between the two.
The target shift time Δt _us set in advance and the above Δ
From To, the temporal inclination angle θt of the target torque pattern during shifting is obtained, and the target torque is calculated at predetermined time intervals at the temporal inclination angle θt from time t ₀ as shown in the figure. Finally, as shown in the figure, the target torque pattern has an oblique characteristic during shifting. Then, during this target torque pattern generation period, a deviation δ between the estimated output shaft torque To calculated at each predetermined time interval and the target torque is obtained, and the ignition timing of the engine is corrected and controlled so that the deviation δ becomes zero. It is designed to control the output torque. Here, the deviation δ is calculated by (estimated output shaft torque To) − (target torque) = deviation δ. When δ is positive, the ignition timing is retarded (retarded), and when δ is negative, Advance the ignition timing.

In the example of FIG. 4, when δ is negative during a predetermined elapsed time from time t ₀ (for example, 50 ms), the ignition timing is not advanced (advanced) and the time when δ becomes positive. Therefore, the ignition timing is retarded. This is because there is a possibility that the ignition timing advance amount (advance amount) may be increased up to the region where knocking occurs if an attempt is made to correct the amount of torque drop at the beginning of gear shift. If this effect can be ignored, such a method may not be used.

The ignition timing correction amount Δθig is calculated as Δθig = kc × δ by multiplying the deviation δ obtained above by a predetermined conversion coefficient kc. This calculation method is performed between times t _{0 and} t ₂ . At times t _{2 to} t ₃ , the ignition timing correction amount Δθig is calculated as Δθig = (kc / N) × δ in order to smoothly end the torque feedback control performed as described above. Where N
Is a monotonically increasing function of the number of calculations of the ignition timing correction amount Δθig in a predetermined calculation cycle after time t ₂ or a time, and takes a value of 1 or more. The conversion factor kc or kc / N is a kind of feedback control gain, between times t ₀ ~t ₂ control gain constant value, between the time t ₂ ~t ₃ by reducing the control gain with the passage of time I will go. Time t ₂ represents the timing for changing the control gain, and
₃ represents ignition control termination and line pressure recovery timing.

Next, a method of controlling the line pressure will be described. With respect to the normal line pressure P _L0 before the gear change command, from the estimated turbine torque immediately after the gear change command to the first line pressure P during the gear change
_L1 is determined, and at the time t ₁ , the second shift line pressure P _L2 is determined so as to be smaller than the line pressure P _L1 by a predetermined ratio. At time t ₃ , the normal line pressure P _L0 'after shifting is set. Restore. If there is a possibility that the gear engagement start timing (t _{0 in the} figure) may be delayed by setting the first line pressure P _L1 during shifting immediately after the gear shift command, it is normal until time t ₀ or some time before this. The time line pressure P _L0 may be used, and then the first line speed P _L1 during shifting may be used.

By executing the above control, the estimated output
The force axis torque To is almost equal to the target torque as shown by the dotted line in FIG.
The shape follows the Luc pattern, which greatly reduces gear shift shock.
Can be reduced to. The parameters used in Figure 4
Immersion value Δt_us, T₁, T₂, T₃Is the one shown in FIG.
Store a table as a control constant for each type of gearshift
I read it every time and use it. The above
It is not necessary to use all the Immer values, for example t₁, T ₂
Input speed of the mission (turbine speed)
And the output speed (which is called the vehicle speed signal), that is,
Input / output speed ratio, or engine speed and (vehicle speed x gear change
Rear gear ratio), that is, the pseudo torque converter slip ratio
Using the size, etc., when this reaches a predetermined value, t₁, T
₂It may be configured to perform the content that was executed in.
Using the above-mentioned rotation information makes the control timing correct.
Often caught accurately.

Next, the method of torque estimation will be described in detail. When roughly classified, there are a method of estimating from the engine characteristic and a method of estimating from the torque converter. There are several methods for estimating from engine characteristics as shown below, and one of them may be used. (1) Method of estimating engine torque from engine speed Ne and throttle opening TVO (2) Method of estimating engine torque from engine speed Ne and air mass flow rate Qa (3) Engine speed Ne, intake pressure, intake air Method of estimating engine torque from temperature (4) Method of estimating engine torque from engine speed Ne and injector pulse width

FIG. 6 shows the engine speed N in (1) above.
It is a control block system diagram of the method of estimating an engine torque from e and throttle opening TVO. Engine torque T
e is read from the map stored in the ROM in advance and used. In this map, Te corresponding to Ne and TVO is stored for each predetermined size, and TVO is determined by the information from the throttle opening sensor, and Ne is determined by the information from the crank angle sensor (also via the ECU). Is input, a map search is performed in block 40, interpolation calculation is executed, and the engine torque Te at that time is calculated. In block 41, the calculation of e = Nt / Ne is executed to calculate the slip ratio e of the torque converter. Here, Nt is the output speed of the torque converter and is commonly called the turbine speed. This turbine rotation speed may be obtained either by directly detecting it from a turbine rotation speed sensor and by using it, or indirectly by multiplying the vehicle speed Vsp by the gear ratio at that time. In block 42, the torque ratio t of the torque converter (= torque converter output torque Tt / torque converter input torque Te) is searched for and interpolated from the characteristic map of the torque ratio t with respect to e stored in the ROM in advance. Ask for. In block 43, Tt =
The output torque Tt of the torque converter, that is, the turbine torque Tt is calculated as Te × t. Block 44
Then, the output shaft torque To of the transmission is obtained by multiplying the gear ratio at that time.

FIG. 7 shows the engine speed N in (2) above.
It is a control block system diagram of the method of estimating an engine torque from e and air mass flow rate Qa. The difference from the method of FIG. 6 is that the air mass flow rate Qa is used instead of TVO. The method of FIG. 6 makes it difficult to estimate the engine torque with high accuracy under conditions where the surrounding air density changes drastically, such as in highlands, high temperatures, and low temperatures. Method 7 is preferred.

FIG. 8 shows the engine speed N in (3) above.
It is a control block system diagram of the method of estimating engine torque from e, intake pressure, and intake temperature. The difference from the method of FIG. 7 is that the intake pressure and the intake temperature are used as sensor information instead of the air mass flow rate Qa. The sensor information of both of these is input to the block 45, and the air mass flow rate Qa is calculated. Taking the case of a 4-cycle 4-cylinder engine as an example, the gas constant is R,
The intake air temperature is Ta, the intake pressure is Pa, the engine displacement is Vc, and the charging efficiency is η, and the block 45 obtains the air mass flow rate Qa based on the following equation. This method can be expected to have the same effect as in FIG. Qa = [(Ne / 60) Vc · η · Pa] / (2 · R ·
Ta)

Alternatively, instead of the air mass flow rate Qa, the intake pressure Pa is used, and the intake pressure Pa and the engine speed Ne are
The engine torque may be searched from the map. In that case, block 45 is omitted and Ne and Pa are omitted.
A map in which Te corresponding to is stored for each predetermined size is prepared, a map is searched from the intake pressure Pa detected by the sensor and the engine speed Ne, an interpolation calculation is performed to calculate the engine torque Te, and the same applies. Determine the output shaft torque To of the transmission by following the procedure.

FIG. 9 shows the engine speed N in (4) above.
It is a control block system diagram of the method of estimating engine torque from e and injector pulse width Ti. The difference from the method of FIG. 6 is that instead of TVO, the injector pulse width T
i is used. N at block 46
The injector pulse width Ti is obtained from information indicating the state of the engine such as e and Qa (part of the engine control routine), and Te is calculated from this Ti and Ne. In block 46, Ti is calculated based on the following equation, for example. Ti = QaK / Ne + Ts Here, K is a constant and Ts is an injector response delay time. The first term in the above equation calculated from Qa and Te corresponds to the effective pulse width.

The advantage of this method is that even if the air-fuel ratio A / F of the air-fuel mixture supplied to the engine changes depending on parameters such as engine water temperature and throttle opening in addition to Qa and Ne, the engine can be faithfully and accurately engineered. This is where the torque can be estimated. This benefit comes from low temperature start-up and warm-up, sudden acceleration output mixture, lean burn and rich burn switching operation. The value in the ECU can be used as Ti.

Next, a method of estimating the torque from the characteristics of the torque converter will be described with reference to FIG. Ne is input by the information from the crank angle sensor (may also be passed through the ECU), and a block 41 calculates e = Nt / Ne to calculate the slip ratio e of the torque converter. Here, Nt is the output speed of the torque converter and is commonly called the turbine speed. This turbine rotation speed may be obtained either by directly detecting it from a turbine rotation speed sensor and by using it, or indirectly by multiplying the vehicle speed Vsp by the gear ratio at that time. This e is input, and in block 47, the Cp value at that time is retrieved and interpolated from the characteristic map of the slip ratio e and the pump capacity coefficient Cp of the torque converter stored in the ROM in advance. Ne ² is calculated in block 48, and block 49
Then, the calculation of Tp = Cp × Ne ² is performed, and the input torque Tp (= Te) of the torque converter is obtained. Since the subsequent routines are the same as those in FIGS. 6 to 9, the description thereof will be omitted.

As described above, the method of estimating the output shaft torque of the transmission, that is, the drive torque is roughly classified into an engine characteristic utilization method and a torque converter characteristic utilization method. It is desirable to use them properly. FIG. 11 shows an example of this characteristic. In the torque converter characteristic utilizing method, when the slip ratio e becomes large, the above-mentioned pump capacity coefficient Cp rapidly approaches 0, that is, the slope of Cp with respect to e becomes steep, and the estimation error also sharply increases. On the other hand, the engine characteristic utilization method is a method of estimating the output torque of the engine, and cannot estimate the load torque of auxiliary equipment such as an air conditioner, a hydraulic pump for power steering, and a headlamp.
Therefore, the estimation error is generated by the load torque of the auxiliary machine. For the magnitude of the output torque of the engine,
The estimation error is large in a region where the load torque of the auxiliary machine is relatively large, that is, in a low speed and low load operation region. From the above, if the two are selectively used depending on the magnitude of the slip ratio e, that is, if the boundary value is set as A, the torque converter characteristic utilization method is set as e> A when e ≦ A.
In A, the engine characteristic utilization method is used.

FIG. 12 is a block system diagram showing a learning method for the load torque of the above-mentioned auxiliary machine. In block 50, the engine output torque Te is calculated by the engine characteristic utilization method, and in block 51, the torque converter input torque Tp is calculated by the torque converter characteristic utilization method. A block 53 is a switching device for selectively using the two depending on the magnitude of the slip ratio e. In the block 52, when e ≦ A, the calculation of Tacc = Tp−Te is always executed to calculate the load torque Tacc of the auxiliary machine. Then, an average value of the calculated values for a predetermined number of times is stored in the RAM and is updated every predetermined number of times. Here, e> A, and when the output torque Te of the engine is calculated by the engine characteristic utilization method, the latest auxiliary load torque Tacc learned and stored in block 52 is subtracted from this Te. The input torque Tp of the torque converter is calculated and used for driving torque estimation.

FIG. 13 is a detailed time chart of the torque feedback control according to the present invention. That is, the details are shown between the times t _{0 and} t ₃ in FIG. Time t ₀
It is assumed that the estimated torque is as shown in FIG. 13 with respect to the target torque pattern generated obliquely from. Actually, the target torque value tTon and the estimated torque value Ton are calculated and calculated for each calculation cycle Δts and used for the torque feedback control.

During the target torque pattern generation period, a deviation δ between the estimated output shaft torque Ton and the target torque tTon calculated at predetermined time intervals Δts is obtained, and the ignition timing of the engine is corrected and controlled so that the deviation δ becomes zero. , The output torque of the engine is controlled. Here, the deviation δ is calculated by (estimated output shaft torque Ton) − (target torque tTon) = deviation δ. When δ is positive, the ignition timing is retarded, and when δ is negative. Advances the ignition timing.

In the example of FIG. 13, when δ is negative during a predetermined elapsed time ΔTx (for example, 50 ms) from time t ₀ , the ignition timing is not advanced (advanced), and δ starts to become positive. Therefore, the ignition timing is retarded. This is because there is a possibility that the ignition timing advance amount (advance amount) may be increased up to the region where knocking occurs if an attempt is made to correct the amount of torque drop at the beginning of gear shift. If this effect can be ignored, such a method may not be used.

The ignition timing correction amount Δθig is calculated as Δθig = kc × δ by multiplying the deviation δ obtained above by a predetermined conversion coefficient kc. This calculation method is performed between times t _{0 and} t ₂ . At times t _{2 to} t ₃ , the ignition timing correction amount Δθig is calculated as Δθig = (kc / N) × δ in order to smoothly end the torque feedback control performed as described above. Where N
Is a monotonically increasing function of the number of times the ignition timing correction amount Δθig is calculated in the calculation cycle Δts after time t ₂ or a monotonically increasing function, and takes a value of 1 or more. The conversion factor kc or kc / N is a kind of feedback control gain, between times t ₀ ~t ₂ control gain constant value, between the time t ₂ ~t ₃ by reducing the control gain with the passage of time I will go.

Time t₀At + Δts, δ₁= To₁-TT
o₁Since <0, but between ΔTx, the conversion coefficient kc = 0
As Δθig₁= Kc x δ₁Substituting into Δθig₁
= 0, the ignition timing correction amount is output as 0. Next
Time t₀Ignition timing is corrected by performing the same calculation with + 2Δts
The quantity is output as 0. Next, time t₀+ 3Δts
Is δ₃= To₃-TTo₃> 0 and the conversion coefficient kc = B
And a predetermined value, Δθig₃= Kc x δ₃The ignition timing
Output as a positive amount (retard). Next, time t ₀+4
The same calculation is performed for Δts. Time t₂Until you reach
Ignition timing correction amount (retard) by repeating this routine
Is output.

When the time t ₂ is reached, the ignition timing correction amount calculation formula is calculated as Δθig = (kc / N) × δ. First,
At time t ₂ + Δts, for example, Δθig = (kc / 1)
Calculate Δθig by putting 1 in × δ and N, time t ₂ + 2Δ
At ts, 2 is put into N to calculate Δθig, and time t ₂ +
At 3Δts, N is set to 3 and Δθig is repeatedly calculated and output sequentially. At time t ₂ , δ =
To-tTo <0, but since it is not within the above-mentioned ΔTx, the ignition timing correction amount Δθig is output using the arithmetic expression of Δθig = (kc / N) × δ as it is. From this point, the ignition timing correction amount becomes advanced. When the end point tf of the target torque pattern is reached, the above torque feedback control (ignition timing correction amount control) ends.

[0045]

By using the present invention, the torque during shifting is feedback-controlled to follow the target torque set so as to smoothly connect the shift stages.
It is not necessary to map the engine torque control start and end timings and engine torque control amount (for example, ignition timing correction amount), which were tuned for each throttle opening and each shift stage, and store them in the storage element ROM. It also has the effect of shortening the development period because the man-hours can be greatly reduced. Further, since the target torque set to smoothly connect the shift speeds is controlled to be controlled, the shift shock can be significantly reduced. Furthermore, even if the engine ages or the engine torque characteristics are extremely different from the standard one in highlands, extremely cold regions, and extremely hot regions, the target torque is created based on the engine torque at that time and feedback is provided. Since it is controlled, there is also an effect that a stable and smooth shift feeling can always be ensured.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of the present invention.

FIG. 2 is a diagram showing a configuration example of a control device such as an ATCU and an ECU.

FIG. 3 is a diagram showing a time chart of a conventional upshift shock and its reduction method.

FIG. 4 is a diagram showing a time chart of the upshift shock reduction method of the present invention.

FIG. 5 is a diagram showing an example of a timer table.

FIG. 6 is a block diagram of a first method for estimating drive torque from engine characteristics.

FIG. 7 is a block diagram of a second method for estimating a drive torque from engine characteristics.

FIG. 8 is a block diagram of a third method for estimating drive torque from engine characteristics.

FIG. 9 is a block diagram of a fourth method of estimating a drive torque from engine characteristics.

FIG. 10 is a block diagram of a method for estimating a driving torque from a torque converter characteristic.

FIG. 11 is an error characteristic diagram of a drive torque estimation method based on torque converter characteristics and engine characteristics.

FIG. 12 is a switching block diagram of a drive torque estimation method based on torque converter characteristics and engine characteristics.

FIG. 13 is a diagram showing a detailed time chart of an upshift shock reduction method.

[Explanation of Codes] 1 ... Engine, 2 ... AT, 3 ... Drive shaft, 4 ... Differential device,
5 ... drive wheel, 6 ... AT hydraulic circuit, 7 ... ATCU, 8 ...
ECU, 9 ... Air cleaner, 10 ... Air flow sensor,
11 ... Throttle chamber, 12 ... Intake manifold,
13 ... Injector, 14 ... Torque converter, 15 ...
Gear train, 16 ... Turbine sensor, 17 ... Mission output shaft rotation detection sensor (vehicle speed sensor), 18 ... Throttle sensor, 19 ... Idle speed control valve (ISC), 20 ... Hydraulic control, switching solenoid valve, 33
... CPU, 34 ... Bus, 35 ... ROM, 36 ... RAM,
37 ... LAN control circuit, 38 ... Input / output interface circuit

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technology display location F02P 5/15 (72) Inventor Masahiko Masamoto Hama 2520 Takaba, Katsuda, Ibaraki Hitachi, Ltd. Automotive Equipment Division (72) Inventor Kazuhiko Sato 2477 Kashima Yatsu, Katsuta City, Ibaraki Pref. 3 Hitachi Automotive Engineering Co., Ltd. (72) Inventor Mitsuyoshi Okada 2520 Takata, Katsuta City, Ibaraki Hitachi Ltd. Automotive Equipment Division

Claims (13)

[Claims] 1. A drive torque control device for a vehicle, comprising: an engine, an automatic transmission having a torque converter, and a control device which contains at least one microcomputer and controls the engine and the automatic transmission. The drive torque calculating means for estimating the torque of the output shaft of the automatic transmission, the target torque generating means for generating the target torque during the shift based on the drive torque estimated by the drive torque calculating means, and the target torque generating means. Engine torque control amount calculation means for calculating a control amount for controlling the output torque of the engine to eliminate the deviation between the generated target torque and the drive torque estimated by the drive torque calculation means, and a signal of the engine torque control amount calculation means And a engine torque control means for controlling the output torque of the engine. Torque control device. 2. The drive torque calculating means includes turbine torque calculating means for estimating a turbine torque, and the target torque generating means uses the estimated turbine torque obtained by the turbine torque calculating means in the drive torque calculating means as a shift command. The time when a predetermined value or more is reached within a later predetermined time is recognized as the actual shift timing, and the drive torque at the actual shift timing or the average drive torque up to immediately before that is temporarily stored as the pre-shift drive torque. The post-shift drive torque is calculated from the torque and the gear ratio before and after the shift, and the inclination angle with respect to the elapsed time of the target torque is calculated from the difference between the pre-shift drive torque and the post-shift drive torque and the preset predetermined shift time. 2. The vehicle according to claim 1, which has a function of calculating and calculating a target torque according to the inclination angle for each predetermined calculation cycle. Drive torque control device. 3. The engine torque control amount calculation means,
Deviation calculating means between the target torque value generated by the target torque generating means and the driving torque value calculated by the driving torque calculating means for each predetermined calculation cycle, and the deviation calculated by the deviation calculating means is preset and stored. 3. The vehicle drive torque control device according to claim 1, further comprising engine torque control amount conversion means for calculating the engine torque control amount by multiplying by the conversion coefficient. 4. The conversion coefficient is 0 when the drive torque value is smaller than the target torque value within a first predetermined period from the actual gear shift timing, and the conversion coefficient is 0 from the actual gear shift timing. If the drive torque value is larger than the target torque value within a second predetermined period that is longer than the predetermined period of time, the drive torque value is a predetermined eigenvalue. The drive torque control device for a vehicle according to claim 3, wherein the drive torque control device has a value divided by a coefficient. 5. A first drive torque calculating means for estimating a drive torque by utilizing a previously stored engine torque characteristic as the drive torque calculating means, and a characteristic of a torque converter stored in advance. A second drive torque calculating means for estimating a drive torque by utilizing the second drive torque calculating means in a region where the torque converter slips large, and a first drive torque in a region where the torque converter slips small. The drive torque control device for a vehicle according to any one of claims 1 to 4, further comprising: switching means for switching to estimate the torque of the output shaft of the automatic transmission by using the drive torque calculation means. 6. The torque deviation of both drive torque calculation means immediately before the switching from the second drive torque calculation means to the first drive torque calculation means by the switching means is taken as the load torque of the auxiliary machine of the engine. An auxiliary machine torque learning means for learning and storing is further provided, and after switching from the second drive torque calculating means to the first drive torque calculating means, the estimated torque from the first drive torque calculating means is changed to The drive torque control device for a vehicle according to claim 5, wherein the load torque of the accessory is corrected by subtracting the accessory torque stored in the accessory torque learning means. 7. A first drive torque calculating means for estimating using an engine torque characteristic, an engine torque characteristic storing means for storing the engine torque characteristic in advance, and a means for calculating a slip ratio of the torque converter. Means for calculating the torque ratio of the torque converter by inputting the slip ratio information from the slip ratio calculating means, engine torque read from the engine torque characteristic storage means, and torque output from the torque ratio calculating means Turbine torque calculation means for multiplying the ratio to output the output shaft torque of the torque converter, and the automatic transmission by multiplying the output shaft torque of the torque converter from the turbine torque calculation means by the gear ratio of the currently engaged gear stage. 7. The automatic transmission output shaft torque calculating means for outputting the torque of the output shaft of the above-mentioned item, is provided. Vehicle drive torque control device. 8. The drive torque control device for a vehicle according to claim 7, wherein the engine torque characteristic storage means stores the engine torque using the accelerator pedal opening or the throttle opening and the engine speed as parameters. . 9. The drive torque control device for a vehicle according to claim 7, wherein the engine torque characteristic storage means stores the engine torque using the engine intake air mass flow rate and the engine speed as parameters. 10. The engine torque characteristic storage means includes:
10. The drive torque control device for a vehicle according to claim 9, further comprising means for calculating an engine intake air mass flow rate from an intake pressure and an intake temperature. 11. The engine torque characteristic storage means includes:
8. The drive torque control device for a vehicle according to claim 7, wherein the engine torque is stored using the intake pressure, the intake temperature, and the engine speed as parameters. 12. The engine torque characteristic storage means,
8. The vehicle drive torque control device according to claim 7, wherein the engine torque is stored using the injector drive pulse width and the engine speed as parameters. 13. A second drive torque calculating means for estimating a drive torque by utilizing the characteristic of the torque converter,
A pump capacity coefficient characteristic storage means for storing pump capacity coefficient characteristics of the torque converter in advance, means for calculating the slip ratio of the torque converter, and slip ratio information from the slip ratio calculation means are input to input torque of the torque converter. A torque converter for calculating a torque converter input torque by multiplying the pump capacity coefficient read from the pump capacity coefficient characteristic storage means by the engine speed square signal from the engine speed squaring means. Input torque calculation means, turbine torque calculation means for multiplying the torque ratio output from the torque ratio calculation means by the torque converter input torque from the torque converter input torque calculation means, and outputting the output shaft torque of the torque converter; Torque converter output shaft torque from turbine torque calculation means and current engagement Claim multiplied by the gear ratio of the gear, characterized in that it comprises an automatic transmission output shaft torque calculating means for outputting the torque of the output shaft of the automatic transmission 5 to 11
The drive torque control device for a vehicle according to any one of 1.