JP3589970B2 - Vehicle driving torque control device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control method for a vehicle with an automatic transmission, and more particularly to a control method and a control device for reducing a torque fluctuation occurring at the time of a shift, that is, a so-called shift shock.
[0002]
[Prior art]
In a conventional control method of this kind, the start and end points of the engine output reduction control for reducing the shift shock are determined based on the engine speed at the start of the shift, as in Japanese Patent Publication No. 2-20817. As described in Japanese Patent Publication No. Hei 5-5688, the start and end points of the engine output reduction control for reducing the shift shock are determined by the input rotation speed (turbine rotation speed) and the output rotation speed (called a vehicle speed signal) of the transmission. The starting point of the engine output reduction control for reducing the shift shock is determined by the former method as described in Japanese Patent Publication No. 4-81658. May be determined by the latter method.
[0003]
As described in Japanese Patent Publication No. 5-7213, a conventional method of controlling the engine output in this type of control method is to switch from the normal characteristic data memory of the engine control device to the shift characteristic data memory during the above period. In general, 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 map stored in advance.
[0004]
[Problems to be solved by the invention]
FIG. 3 is an example of a time chart illustrating a shift shock reduction method using the above-described conventional technology. The ignition timing is used as a control amount for decreasing the engine output. The control timings t1 and t2 are determined when the input / output rotation ratio obtained above exceeds the set values S1 and S2 stored in advance. During the control period from t1 to t2, the control amount stored in advance, that is, the ignition timing retard amount Δθ is read, and the control is executed by adding this to the basic ignition timing.
[0005]
Therefore, the correction control amount during this correction control period is a constant value, and when the output shaft torque during the control period from t1 to t2 is substantially flat as shown in FIG. The shock reduction effect can be improved. However, the actual torque waveform fluctuates considerably during the above period, and a sufficient correction control effect cannot often be achieved with a fixed correction control amount.
[0006]
Further, the set values S1, S2 and the ignition timing retard amount .DELTA..theta. Have to be adjusted to the optimum values by actual machine tuning at the development stage, and a long time is required for this. Further, even if the optimum value is adapted, the set value determined above may be insufficient due to aging or environmental change, and it has been difficult to completely reduce the shift shock.
SUMMARY OF THE INVENTION It is an object of the present invention to reduce the number of development steps by minimizing a part to be tuned, and to automatically follow a secular change or an environmental change so as to appropriately reduce a shift shock. And a control method.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a drive torque control device for a vehicle according to the present invention includes: a target torque pattern generating means for generating an ideal waveform that should have a drive shaft torque at the time of shifting; Torque calculating means for calculating the control torque for controlling the output torque of the engine such that the estimated driving torque follows the target torque pattern, and engine torque control means for controlling the output torque of the engine Is provided.
[0008]
The target torque generating means recognizes the time when the estimated turbine torque obtained by the turbine torque calculating means in the drive 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 driving torque or the average driving torque immediately before the driving torque is temporarily stored as the pre-shift driving torque, the post-shift driving torque is calculated from the pre-shift driving torque and the gear ratio before and after the shifting, and the driving torque before the shifting and the driving torque after the shifting are calculated. It may have a function of calculating an inclination angle with respect to the elapsed time of the target torque from the difference and a predetermined shift time set in advance, and calculating the target torque in accordance with the inclination angle for each predetermined calculation cycle. .
[0009]
The engine torque control amount calculating means is a deviation calculating means for calculating a deviation 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 a deviation calculated by the deviation calculating means. And an engine torque control amount conversion means for calculating the engine torque control amount by multiplying the engine torque 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 driving torque value is larger than the target torque value, it is preferable to set the predetermined eigenvalue to a value obtained by dividing the predetermined eigenvalue by a coefficient of an elapsed time after the second predetermined period.
[0010]
The driving torque calculating means includes a first driving torque calculating means for estimating the driving torque using a previously stored engine torque characteristic, and a driving torque using a previously stored characteristic of the torque converter. And a second drive torque calculating means for estimating the slippage of the torque converter, wherein the second drive torque calculating means is used in an area where the slip of the torque converter is large, and the first drive torque calculating means is used in an area where the slip of the torque converter is small. It is preferable to provide switching means for switching so as to estimate the torque of the output shaft of the automatic transmission by using the above. In addition, 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 calculation means, and the load torque of the accessory is corrected when the first drive torque calculation means is used. preferable.
[0011]
The first drive torque calculating means for estimating using the engine torque characteristic includes 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 calculating means. Means for calculating the torque ratio of the torque converter by inputting the slip ratio information of the torque converter, and multiplying the torque ratio output from the torque ratio calculating means by the engine torque read from the engine torque characteristic storage means, and Turbine torque calculating means for outputting shaft torque, and automatic transmission for multiplying the output shaft torque of the torque converter from the turbine torque calculating means by the gear ratio of the currently engaged gear stage to output torque on the output shaft of the automatic transmission. Machine output shaft torque calculating means.
[0012]
The engine torque characteristic storage means stores the accelerator pedal opening or throttle opening and the engine speed, the engine intake air mass flow rate and the engine speed, the intake pressure and the intake temperature and the engine speed, or the injector drive pulse width and the engine speed. Can be used as a parameter to store the engine torque.
The second drive torque calculating means for estimating the drive torque using the characteristics of the torque converter includes a pump capacity coefficient characteristic storage means for the torque converter, a means for calculating a slip ratio of the torque converter, and a slip ratio calculation 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. A torque converter input torque calculating means for calculating the input torque of the torque converter, and multiplying the torque ratio output from the torque ratio calculating means by the torque converter input torque from the torque converter input torque calculating means to output an output shaft torque of the torque converter. 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, since the output shaft torque of the engine is feedback-controlled so that the actual drive shaft torque becomes equal to the target torque, ideal torque control at the time of shifting can be performed, and the development man-hour required for tuning and the like is greatly reduced. Can be reduced. Further, the shift shock can be suitably reduced by automatically following aging and environmental changes.
[0014]
When calculating the engine torque control amount by multiplying the deviation between the target torque value and the estimated drive torque value by a conversion coefficient set and stored in advance, by changing the conversion coefficient according to the period from the actual shift timing. Thus, it is possible to avoid the possibility of excessive correction, and to smoothly connect the drive torque during the shift with the drive torque during the normal running after the shift. As the driving torque calculating means, the first driving torque calculating means using the engine torque characteristics and the second driving torque calculating means using the characteristics of the torque converter are used in combination. By using the first driving torque calculating means in the region where the slippage of the torque converter is small, the accuracy of the estimation of the driving torque can be improved.
[0015]
In addition, it is driven by a map search based on measurement parameters such as accelerator pedal opening, throttle opening, engine speed, engine intake air mass flow, intake pressure, intake temperature, injector drive pulse width, and torque converter slip ratio. By adopting the method of estimating torque, it is possible to perform drive torque control using only existing sensors built in for engine control without using expensive torque sensors, resulting in increased costs. Function can be enhanced without any problem.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will 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 a drive wheel, and 6 is an AT hydraulic circuit. Reference numeral 7 denotes an AT control unit (electronic control device) with a built-in microcomputer, which is referred to herein as ATCU. Reference numeral 8 denotes a control unit (electronic control device) for an engine with a built-in microcomputer, which is herein referred to as an ECU. 9 is an air cleaner, 10 is an air flow sensor, 11 is a throttle chamber, 12 is a suction manifold, and 13 is an injector for injecting fuel. The interior of the AT 2 is further divided into a torque converter 14 and a gear train 15, and a turbine sensor 16 for detecting an output shaft rotation speed of the torque converter 14, that is, a transmission input shaft rotation speed, and a mission output for detecting a transmission output shaft rotation speed. A shaft rotation sensor 17 is provided.
[0017]
The ECU 8 receives information from the crank angle sensor, the air flow sensor 10, the throttle sensor 18 and the like, executes an engine speed signal and other various calculations, and outputs a valve opening drive signal to the injector 13 to control the fuel amount. Various control methods such as outputting a valve opening drive signal to the idle speed control valve ISC19 to control the correction air amount, and outputting an ignition signal to a spark plug (not shown) to control the ignition timing. Execute On the other hand, the ATCU 7 receives signals from the transmission output shaft rotation sensor 17, the AT oil temperature sensor, etc., the engine speed, the throttle opening signal from the ECU 8, executes various calculations, and is mounted on the hydraulic circuit 6. Further, a hydraulic control switching electromagnetic valve 20 valve opening drive signal, an ISC 19 drive signal, an ignition timing correction signal, and the like are output.
[0018]
FIG. 2 shows a configuration example of a control device such as the above-described ATCU and ECU. The control device includes at least a CPU 33, a ROM 35, a RAM 36, an input / output interface circuit 38, and a bus 34 for connecting these components. As shown in FIG. 1, when the ATCU 7 and the ECU 8 are connected via a LAN, a LAN control circuit 37 is required.
The present invention can exert the same effect even in a type in which the above-described ATCU and ECU are integrated and one CPU controls both functions.
[0019]
FIG. 4 is a time chart for explaining the method of reducing the upshift shock according to the present invention. The shift control is started by a shift command. The estimated turbine torque is obtained by executing a calculation at predetermined time intervals irrespective of the shift command. The method of calculating the estimated turbine torque will be described later. Although not shown, when a shift command is issued, the hydraulic switching solenoid valve 20 for the shift stage is actuated, and engagement of engagement frictional elements such as clutches and brakes for the shift stage is started. The engagement of the gear for the step is started. When the engagement of the gear is started, the estimated turbine torque increases almost stepwise as shown in the figure. This is because the engine speed and the turbine speed rapidly decrease due to the upshift, and the inertia of the engine and the like are superimposed.
[0020]
In the present invention, the rising point of the estimated turbine torque is detected and identified by the slice level St, and the time t0 is used as a step-by-step switching point of the gear ratio used for calculating the estimated output shaft torque and a generation point of the target torque pattern. Similar to the estimated turbine torque, the estimated output shaft torque is also calculated at predetermined time intervals irrespective of the shift command.
[0021]
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 at time t0 is entered, the gear ratio used for the above calculation is switched stepwise from the gear ratio before the gearshift command to the gear ratio after the gearshift command (gear ratio after engagement). This is because the rising point of the estimated turbine torque is the switching start point from the gear before the shift command to the gear after the shift command, and is the switching point of the torque transmission path.
[0022]
Due to the stepwise switching of the gear ratio, the estimated output shaft torque temporarily decreases stepwise at time t0, and then exhibits a waveform proportional to the rising waveform of the estimated turbine torque (refer to the illustrated torque waveform before control). .
When the engagement of the gear is completed, the estimated turbine torque returns to a predetermined low value again as shown in the figure. The period during which the estimated turbine torque increases in a trapezoidal wave is the actual gear engagement period, and is the period during which the engine speed and the turbine speed rapidly decrease. During this period, the estimated turbine torque is increased in a trapezoidal wave due to the release of the inertia torque. Therefore, the estimated output shaft torque also exhibits a waveform proportional to the estimated turbine torque waveform, so that the torque during shifting can be accurately estimated. The occupant senses the 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 reduce the temporal change of the estimated output shaft torque.
[0023]
In the present invention, this is achieved as follows. At time t0, the average value Tob of the estimated output shaft torque immediately before the shift is determined. The estimated output shaft torque is calculated every predetermined time (for example, every 10 ms) and is sequentially stored in the RAM. In this case, an arbitrary plurality (for example, 14) of storage numbers is prepared, and when the latest estimated calculation value is stored, the previously stored estimated calculation value is sequentially moved to the next storage location, and The old estimated calculation value is made to disappear. Therefore, at time t0, all or some of the stored estimated calculation values are read out, and the average value Tob of the estimated output shaft torque immediately before shifting is obtained.
[0024]
Next, the output shaft torque Toa immediately after the shift is
Toa = (Tob / gear ratio before shifting) × (gear ratio after shifting)
It is estimated and calculated as follows. Then, the output shaft torque difference ΔTo before and after the shift is determined from the difference between the two. From the previously set target shift time Δtus and ΔTo, the temporal inclination angle θt of the target torque pattern during the shift is obtained, and as shown in FIG. Then, the target torque is calculated. Finally, as shown in the figure, the target torque pattern has an oblique characteristic during the shift. During the target torque pattern generation period, a deviation δ between the estimated output shaft torque To calculated at predetermined time intervals and the target torque is obtained, and the ignition timing of the engine is corrected and controlled to make the deviation δ zero. The output torque is controlled. here,
(Estimated output shaft torque To) − (target torque) = deviation δ
When δ is positive, the ignition timing is retarded (retarded), and when δ is negative, the ignition timing is advanced (advanced).
[0025]
In the example of FIG. 4, when δ is negative during a predetermined elapsed time (for example, 50 ms) from time t0, the ignition timing is not advanced (advanced), and the ignition timing is changed from the time when δ becomes positive. The retard is set. This is because, if an attempt is made to correct the drop in torque at the beginning of the shift, the ignition timing advance amount (advance angle amount) may be increased to a region where knocking occurs. If this effect can be ignored, such a method need not be used.
[0026]
The ignition timing correction amount Δθig is obtained by multiplying the deviation δ obtained above by a predetermined conversion coefficient kc,
Δθig = kc × δ
Is calculated as This calculation method is performed between times t0 and t2. From time t2 to t3, in order to smoothly end the torque feedback control performed as described above,
Δθig = (kc / N) × δ
To calculate the ignition timing correction amount Δθig. Here, N is a monotonically increasing function of the number of calculations or the time of the ignition timing correction amount Δθig in a predetermined calculation cycle after time t2, and takes a value of 1 or more. The conversion coefficient kc or kc / N is a kind of feedback control gain. The control gain is a constant value between time t0 and t2, and is decreased with time from time t2 to t3. . Time t2 represents the timing for changing the control gain, and time t3 represents the timing for terminating the ignition control and returning to the line pressure.
[0027]
Next, a method of controlling the line pressure will be described. The first shift line pressure PL1 is determined from the estimated turbine torque immediately after the shift command with respect to the normal line pressure PL0 before the shift command, and the second line pressure PL1 is reduced by a predetermined ratio from the line pressure PL1 at time t1. The shift-time line pressure PL2 is determined, and at time t3, the normal-time line pressure PL0 'after the shift is returned. If the first shift line pressure PL1 is set immediately after the shift command, there is a possibility that the gear engagement start timing (t0 in the figure) may be delayed. If the normal line pressure is not reached until time t0 or a time slightly earlier than this. A method of using PL0 and then setting the first shift-time line pressure PL1 may be used.
[0028]
By performing the above-described control, the estimated output shaft torque To substantially follows the target torque pattern as shown by the dotted line in FIG. 4, and the shift shock can be greatly reduced.
The timer values Δtus, t1, t2, t3 used in FIG. 4 are stored in a table as control constants for the type of shift as shown in FIG. 5, and are read out and used each time. Here, it is not necessary to use all the timer values described above. For example, t1 and t2 are not used, and the ratio between the input rotation speed (turbine rotation speed) and the output rotation speed (called a vehicle speed signal) of the transmission, that is, the input / output rotation speed Using the ratio or the ratio of the engine speed to (vehicle speed × gear ratio after shifting), that is, the magnitude of the pseudo torque converter slip ratio, and the like, when this reaches a predetermined value, the contents executed at t1 and t2 are performed. It may be so. In many cases, the use of the above-described rotation information can accurately capture the control timing.
[0029]
Next, the method of torque estimation will be described in detail. When roughly classified, there are a method of estimating from an engine characteristic and a method of estimating from a torque converter. There are several methods for estimating from the 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 Qa
(3) Method of estimating engine torque from engine speed Ne, intake pressure and intake temperature
(4) Method of estimating engine torque from engine speed Ne and injector pulse width
[0030]
FIG. 6 is a control block diagram of the method (1) for estimating the engine torque from the engine speed Ne and the throttle opening TVO. The engine torque Te is read from a map stored in the ROM in advance and used. In this map, Ne corresponding to Ne and TVO is stored for each predetermined size, and TVO is obtained from information from the throttle opening sensor, and Ne is obtained from information from the crank angle sensor (or via the ECU). Is input, a map is searched in block 40, and interpolation calculation is executed to calculate the engine torque Te at that time. In block 41, the operation of e = Nt / Ne is executed to calculate the slip ratio e of the torque converter. Here, Nt is an output rotation speed of the torque converter, and is generally called a turbine rotation speed. The turbine speed may be obtained either by a method of directly detecting and using the turbine speed sensor 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 (= output torque Tt of the torque converter / input torque Te of the torque converter) is retrieved from the characteristic map of the torque ratio t to e stored in the ROM in advance, and interpolation calculation is performed. Ask. In block 43, the output torque Tt of the torque converter, that is, the turbine torque Tt is calculated as Tt = Te × t. In block 44, the output shaft torque To of the transmission is determined by multiplying the gear ratio at that time.
[0031]
FIG. 7 is a control block diagram of the method (2) for estimating the engine torque from the engine speed Ne and the air mass flow Qa. The difference from the method of FIG. 6 is that the air mass flow rate Qa is used instead of TVO. In the method of FIG. 6, it is difficult to estimate the engine torque with high accuracy under conditions where the surrounding air density changes extremely, such as at high altitudes, high temperatures, and low temperatures. Method 7 is preferred.
[0032]
FIG. 8 is a control block diagram of the method (3) for estimating the engine torque from the engine speed Ne, the intake pressure and the intake temperature. The difference from the method of FIG. 7 lies in 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 these two is input to the block 45, and the air mass flow rate Qa is obtained by calculation. Taking the case of a four-cycle four-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. Find the mass flow rate Qa. This method can expect the same effect as FIG.
Qa = [(Ne / 60) Vc · η · Pa] / (2 · R · Ta)
[0033]
Alternatively, an intake pressure Pa may be used in place of the air mass flow rate Qa, and a map search for the engine torque may be performed based on the intake pressure Pa and the engine speed Ne. In this case, the block 45 is omitted, a map in which Te corresponding to Ne and Pa is stored for each predetermined size is prepared, and a map search and interpolation are performed based on the intake pressure Pa detected by the sensor and the engine speed Ne. The calculation is performed to calculate the engine torque Te, and thereafter, the output shaft torque To of the transmission is determined by the same procedure.
[0034]
FIG. 9 is a control block diagram of the method of (4) for estimating the engine torque from the engine speed Ne and the injector pulse width Ti. 6 in that the injector pulse width Ti is used instead of TVO. In block 46, the injector pulse width Ti is obtained from information indicating the state of the engine such as Ne and Qa (part of the engine control routine), and Te is calculated from Ti and Ne. In block 46, Ti is calculated based on, for example, the following equation.
Ti = Qa · K / Ne + Ts
Here, K is a constant, and Ts is an injector response delay time. The first term of the above equation calculated from Qa and Te corresponds to the effective pulse width.
[0035]
The advantage of this method is that the engine torque can be accurately and accurately estimated even when the air-fuel ratio A / F of the air-fuel mixture supplied to the engine varies depending on parameters such as the engine water temperature and the throttle opening other than Qa and Ne. Where you can. This benefit is obtained during cold start warm-up, rapid acceleration output air-fuel mixture, lean burn, rich burn switching operation, and the like. Note that Ti can use a value in the ECU.
[0036]
Next, a method of estimating the torque from the characteristics of the torque converter will be described with reference to FIG. Ne is input based on information from the crank angle sensor (or via the ECU), and a block 41 executes a calculation of e = Nt / Ne to calculate a slip ratio e of the torque converter. Here, Nt is an output rotation speed of the torque converter, and is generally called a turbine rotation speed. The turbine speed may be obtained by a method of directly detecting and using the turbine speed sensor or by a method of indirectly obtaining the vehicle speed Vsp by multiplying the gear ratio at that time. This e is input, and in block 47, the Cp value at that time is retrieved from the characteristic map of the slip ratio e and the pump capacity coefficient Cp of the torque converter, which is stored in advance in the ROM, and is obtained by interpolation calculation. Ne at block 48 ² Is calculated, and at block 49, Tp = Cp × Ne ² To calculate the input torque Tp (= Te) of the torque converter. Subsequent routines are the same as those in FIGS.
[0037]
As described above, the method of estimating the output shaft torque of the transmission, that is, the method of estimating the drive torque, is roughly classified into a method using an engine characteristic and a method using a torque converter characteristic. Is desirable. FIG. 11 shows an example of this characteristic. In the torque converter characteristic utilization method, when the slip ratio e increases, the pump displacement coefficient Cp rapidly approaches 0, that is, the slope of Cp with respect to e becomes steep, and the estimation error also increases sharply. 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, an estimation error is caused by the load torque of the accessory. The estimation error increases in a region where the magnitude of the load torque of the accessory is relatively large with respect to the magnitude of the output torque of the engine, that is, in a low-speed, low-load operation range. From the above, if both are used properly according to the magnitude of the slip ratio e, that is, if the boundary value is set to A, the torque converter characteristic utilization method is used when e ≦ A, and the engine characteristic utilization method is used when e> A. To do.
[0038]
FIG. 12 is a block diagram showing a learning method for the load torque of the auxiliary machine. In block 50, the engine output torque Te is calculated using the engine characteristic utilization method, and in block 51, the input torque Tp of the torque converter is calculated using the torque converter characteristic utilization method. A block 53 is a switch for selectively using the two depending on the magnitude of the slip ratio e. In a block 52, when e ≦ A, the calculation of Tacc = Tp−Te is always performed to calculate the load torque Tacc of the accessory. Then, an average value of the calculated value for a predetermined number of times is stored in the RAM, and is updated every predetermined number of times. Here, if e> A, and the system is switched to calculate the engine output torque Te using the engine characteristic utilization method, the latest auxiliary machine load torque Tacc learned and stored in the block 52 is subtracted from this Te. Thus, the input torque Tp of the torque converter is calculated and used for the drive torque estimation.
[0039]
FIG. 13 is a detailed time chart of the torque feedback control according to the present invention. In other words, details are shown between times t0 and t3 in FIG. It is assumed that the estimated torque is as shown in FIG. 13 for the target torque pattern generated obliquely from time t0. Actually, the target torque value tTon and the estimated torque value Ton are calculated and obtained for each calculation cycle Δts and used for the torque feedback control.
[0040]
During the target torque pattern generation period, a deviation δ between the estimated output shaft torque Ton calculated for each predetermined time interval Δts and the target torque tTon is obtained, and the ignition timing of the engine is corrected and controlled to make the deviation δ zero. The output torque is controlled. here,
(Estimated output shaft torque Ton) − (Target torque tTon) = Deviation δ
When δ is positive, the ignition timing is retarded (retarded), and when δ is negative, the ignition timing is advanced (advanced).
[0041]
In the example of FIG. 13, when δ is negative during a predetermined elapsed time ΔTx (for example, 50 ms) from time t0, the ignition timing is not advanced (advanced), and the ignition timing is changed from the time when δ becomes positive. The retard is set. This is because, if an attempt is made to correct the drop in torque at the beginning of the shift, the ignition timing advance amount (advance angle amount) may be increased to a region where knocking occurs. If this effect can be ignored, such a method need not be used.
[0042]
The ignition timing correction amount Δθig is obtained by multiplying the deviation δ obtained above by a predetermined conversion coefficient kc,
Δθig = kc × δ
Is calculated as This calculation method is performed between times t0 and t2. At time t2 to t3
Is to smoothly end the torque feedback control performed above,
Δθig = (kc / N) × δ
To calculate the ignition timing correction amount Δθig. Here, N is a monotonically increasing function of the number of times or the time of calculating the ignition timing correction amount Δθig in the calculation cycle Δts after time t2, and takes a value of 1 or more. The conversion coefficient kc or kc / N is a kind of feedback control gain. The control gain is a constant value between time t0 and t2, and is decreased with time from time t2 to t3. .
[0043]
At time t0 + Δts, δ1 = To1−tTo1 <0, but ΔTx, so that the conversion coefficient kc = 0 is substituted into Δθig1 = kc × δ1, and Δθig1 = 0 and the ignition timing correction amount is set to 0 and output. . Next, the same calculation is performed at time t0 + 2Δts, and the ignition timing correction amount is set to 0 and output. Next, at time t0 + 3Δts, δ3 = To3−tTo3> 0, the conversion coefficient kc = B and a predetermined value, and Δθig3 = kc × δ3 is output as the ignition timing correction amount (retard). Next, the same calculation is performed at time t0 + 4Δts. This routine is repeated until the time t2 is reached to output the ignition timing correction amount (retard).
[0044]
When the time t2 is reached, the ignition timing correction amount calculation formula is calculated as Δθig = (kc / N) × δ. First, at time t2 + Δts, for example, Δθig = (kc / 1) × δ and N are set to 1 to calculate Δθig. At time t2 + 2Δts, N is set to 2 to calculate Δθig, and at time t2 + 3Δts, N is calculated to N. 3 is added and Δθig is calculated and output by repeating the calculation in order. At time t2, δ = To−tTo <0, but not within the above-mentioned ΔTx. Therefore, the arithmetic expression of Δθig = (kc / N) × δ is used as it is to output the ignition timing correction amount Δθig. From here, the ignition timing correction amount is advanced (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]
【The invention's effect】
By using the present invention, the torque during shifting is controlled by feedback so as to follow the target torque set so as to smoothly connect the shift speeds. Therefore, the engine torque conventionally tuned for each throttle opening and each shift speed is conventionally controlled. There is no need to map the control start and end timings and the engine torque control amount (for example, the ignition timing correction amount) and store them in the storage element ROM. Further, since the tuning man-hour can be greatly reduced, the effect that the development period can be shortened is also obtained. is there. Further, since the control is performed so as to follow the target torque set so as to smoothly connect the shift speeds, the shift shock can be significantly reduced. Furthermore, even if the engine changes over time or the engine torque characteristics are extremely different from those of the standard ones in high altitudes, extremely cold regions, and extremely hot regions, the target torque is created based on the engine torque at that time, and the feedback is made. Since the control is performed, there is also an effect that a stable and smooth shift feeling can always be ensured.
[Brief description of the 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 driving torque from engine characteristics.
FIG. 7 is a block diagram of a second method for estimating 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 for estimating drive torque from engine characteristics.
FIG. 10 is a block diagram of a method for estimating a driving torque from torque converter characteristics.
FIG. 11 is an error characteristic diagram of a method for estimating driving torque from torque converter characteristics and engine characteristics.
FIG. 12 is a switching block diagram of a method for estimating a driving torque from torque converter characteristics and engine characteristics.
FIG. 13 is a diagram showing a detailed time chart of an upshift shock reduction method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 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

Claims (4)

Estimating the output shaft torque during shifting of the automatic transmission for the vehicle,
Based on the estimated output shaft torque value, calculate a target torque value during shifting,
Calculating the ignition timing correction amount of the engine based on the value of the output shaft torque and the value of the target torque,
A driving torque control method for a vehicle, comprising: controlling an ignition timing based on the ignition timing correction amount to control an engine output torque. Estimating the output shaft torque during shifting of the automatic transmission for the vehicle,
Based on the estimated output shaft torque value, calculate a target torque value during shifting,
Calculate a deviation δ between the value of the output shaft torque and the value of the target torque,
An ignition timing correction amount Δθig (= kc × δ) of the engine is calculated based on a predetermined conversion coefficient kc and the deviation δ,
A driving torque control method for a vehicle, comprising: controlling an ignition timing based on the ignition timing correction amount Δθig to control an engine output torque. Using the value N of the number of operations or the value N represented by a monotonically increasing function of time,
3. The vehicle driving torque control method according to claim 2, wherein the ignition timing correction amount Δθig is calculated as Δθig = (kc / N) × δ. 2. The vehicle drive according to claim 1, wherein the target torque calculates a value from the start of the shift to the end of the shift based on the estimated difference between the output shaft torque before the shift and after the shift. Torque control method .

Images