JPH0569735B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a shift control method for an automatic transmission for a vehicle, and more particularly, the present invention relates to a shift control method for an automatic transmission for a vehicle, and in particular, a shift control method for an automatic transmission for a vehicle that maintains good shifting characteristics by changing engine torque by a predetermined amount during shifting. Concerning improvements in control methods.

[Conventional technology]

A gear transmission mechanism and a plurality of friction coupling devices are provided, and the coupling of the friction coupling devices is selectively switched by operating a hydraulic control device, and any one of the plurality of gears is set. Automatic transmissions for vehicles configured to achieve this are already widely known. Such automatic transmissions for vehicles generally include a shift lever operated by the driver, a vehicle speed sensor that detects the vehicle speed, and a throttle that detects the throttle opening, which is considered to reflect the engine load. The friction coupling device is equipped with a sensor so that the coupling state of the friction coupling device can be automatically switched in accordance with the range of the shift lever and at least in relation to the vehicle speed and the throttle opening. By the way, in the above automatic transmission for vehicles, the engine torque is changed during gear shifting to obtain good shifting characteristics, and the durability of the friction coupling device is ensured and improved. Various integrated control methods have been proposed (for example, Japanese Patent Laid-Open No. 77138/1983). In other words, this integrated control changes the amount of torque transmitted from the engine during gear shifting, and controls the amount of energy absorbed by each member of the automatic transmission or the friction joint device that brakes them, allowing for short and small gear shifting. The aim was to complete the shift with a shock, give the driver a good shift feeling, and improve the durability of each friction coupling device. As described above, the shift control method for controlling the engine torque during gear shifting is attracting attention as a way of controlling the automatic transmission and the engine in an integrated manner, and is achieving considerable results.

[Problems to be solved by the invention]

However, in general, it goes without saying that the shift characteristics of an automatic transmission are greatly influenced by the type of shift, the vehicle speed at that point, the throttle opening, etc.; It is also greatly affected by various miscellaneous variations such as variations between lots of individual parts, variations over time, and variations in running conditions. Variations that occur during these manufacturing processes,
Alternatively, for variations that occur over time due to use, the amount of engine torque control can be adjusted based on various conditions such as the type of shift, vehicle speed, throttle opening, accelerator depression speed, or longitudinal acceleration of the vehicle. As long as these conditions are determined uniquely, even if more of these conditions are taken into consideration, this is a problem that cannot be solved. In other words, as long as engines or automatic transmissions have various variations, if the control amount of engine torque is determined uniquely, in some cases the shift time will become longer and the friction coupling device will be affected. There are unavoidable problems in that the durability may be deteriorated or, conversely, the shift shock may become large, impeding the driver's good driving sensation.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and improves the accuracy of integrated control of automatic transmission and engine, so that it can be constantly adjusted for each vehicle in the hands of users, regardless of various variations. The purpose of the present invention is to provide a speed change control method for an automatic transmission for a vehicle that can ensure optimal speed change characteristics, and that has simple control logic and fast response and processing speed. do.

[Means to solve the problem]

The present invention provides a method for controlling a shift of an automatic transmission for a vehicle in which the shift characteristics are maintained in good condition by changing the engine torque by a predetermined amount during the shift, and a procedure for detecting a representative characteristic value of the shift. and,
The method includes a step of determining the amount by which the representative characteristic value deviates from a preset reference width (including zero), and a step of correcting the amount of change in engine torque during the next gear shift according to the amount of deviation. This achieved the above objectives. Further, in an embodiment of the present invention, as the representative characteristic values of the shift, the shift time, the output shaft torque of the automatic transmission,
Alternatively, the above-mentioned control can be performed with high accuracy by employing the longitudinal acceleration of the vehicle. Further, in another embodiment of the present invention, a warning is generated when the amount of deviation is excessive, so that the driver can be promptly warned of system abnormality, and various engine- or automatic transmission-related problems can be detected. This system is designed to prompt the necessity of inspection and maintenance of parts. Furthermore, in another embodiment of the present invention, a warning is generated when the amount of change in engine torque corrected according to the amount of deviation exceeds an amount that can actually be changed, This makes it possible to quickly warn the driver that the control is not being fully executed.

[Effect]

In the present invention, when a gear shift is completed, it is determined whether or not the gear shift that was just performed had good characteristics, such as the gear shift time, the output shaft torque of the automatic transmission, or the acceleration in the longitudinal direction of the vehicle. Detect sufficient representative characteristic values, find the amount by which the representative characteristic values deviate from a preset reference width (including zero; in other words, if it is zero, it becomes the reference value), and adjust the engine torque according to this deviation amount. Since the amount of change in engine torque is corrected at the next gear shift, the amount of change in engine torque is corrected so that the representative characteristic value converges in a favorable direction each time a gear is shifted. Optimal shift characteristics can be ensured for each vehicle, taking into consideration various variations such as changes over time of the vehicle at that time.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 6 is an overall schematic diagram of an automatic transmission combined with an intake air amount sensing type automobile electronic fuel injection engine to which the present invention is applied. Air taken in from the air cleaner 10 is sent to an air flow meter 12, a throttle valve 14, a surge tank 16, and an intake manifold 18 in sequence. This air is mixed with fuel injected from the injector 22 near the intake port 20, and
Further, the combustion chamber 26A of the engine body 26 via 4
sent to. Exhaust gas generated as a result of combustion of the air-fuel mixture in the combustion chamber 26A passes through the exhaust valve 2.
8, exhaust port 30, exhaust manifold 32 and exhaust pipe 34 to the atmosphere. The air flow meter 12 is provided with an intake temperature sensor 100 for detecting intake temperature. The throttle valve 14 rotates in conjunction with an accelerator pedal (not shown) provided at the driver's seat.
This throttle valve 14 is provided with a throttle sensor 102 for detecting its opening degree. Further, a water temperature sensor 104 for detecting the engine cooling water temperature is disposed in the cylinder block 26B of the engine main body 26, and a water temperature sensor 104 for detecting the oxygen concentration in the collecting part of the exhaust manifold 32 is disposed in the collecting part of the exhaust manifold 32. An O ₂ sensor 106 is provided. Further, the distributor 38 having a shaft rotated by the crankshaft of the engine body 26 is provided with a crank angle sensor 108 for detecting a crank angle from the rotation of the shaft. The automatic transmission A/T is also provided with a vehicle speed sensor 100 for detecting vehicle speed from the rotational speed of its output shaft, and a shift position sensor 112 for detecting a shift position. Each of these sensors 100, 102, 104, 1
The outputs of 06, 108, 110, and 112 are input to an engine computer (hereinafter referred to as ECU) 40. The ECU 40 calculates the fuel injection amount using input signals from each sensor as parameters, and controls the injector 22 to inject fuel for a predetermined time corresponding to the fuel injection amount. Note that an idle rotation control valve (ISCV) 42 is provided in the circuit that communicates the upstream side of the throttle valve 14 and the surge tank 16, and the ECU 40
The idle speed is controlled by a signal from the engine. As shown in detail in FIG. 7, the ECU 40
A central processing unit (CPU) 40A consisting of a microprocessor, a memory 40B for storing control programs and various data, and converting analog signals from the intake temperature sensor 100, water temperature sensor 104, etc. into digital signals. In order to incorporate
An analog-to-digital converter (A/D converter) 40C having a multiplexer function and outputs from the throttle sensor 102, O ₂ sensor 106, crank angle sensor 108, vehicle speed sensor 110, shift position sensor 112, etc. are directly transmitted. An input interface circuit 40D for inputting the ignition signal to the ignition coil 44 and an ignition signal to the injector 2 according to the arithmetic processing results of the CPU 40A.
Fuel injection signal to ISCV 2, idle rotation control signal to ISCV 42, and ECT for automatic transmission A/T.
and an output interface circuit 40E for outputting signals to the computer 50. On the other hand, the ECT computer 50 includes a central processing unit (CPU) 5 consisting of a microprocessor.
0A, a memory 50B for storing control programs and various data, etc., and a throttle sensor 10.
2. An input interface circuit 50D for inputting outputs from the vehicle speed sensor 110, shift position sensor 112, pattern select switch 120, brake lamp switch 122, cruise control switch 124, and overdrive switch 126; It is comprised of an output interface circuit 50E for outputting control signals to solenoids S ₁ , S ₂ , and S ₃ of the automatic transmission A/T according to the results of arithmetic processing. The automatic transmission A/T includes a 2-3 shift valve 61 driven by the solenoid _S1 , a 1-2 shift valve 62 and a 3-4 shift valve 63 driven by the solenoid _S2 , and a 3-4 shift valve 63 driven by the solenoid S2. A lock-up clutch control valve 64 is actuated by a solenoid _S3 , and a shift valve 6
1 and 62 control a third speed section unit for obtaining a gear ratio configuration of first to third speeds, and a shift valve 63 controls an overdrive unit for obtaining an overdrive gear ratio. ,
A lock-up clutch control valve 64 controls a lock-up clutch that mechanically directly connects the input and output sides of the torque converter. Also, in this ECU40, crank angle sensor 1
Using the fact that the reciprocal of the time interval of the signal for each 30° crank angle output from the crank angle sensor 108 is proportional to the engine rotation speed, the engine rotation speed is calculated based on the output signal from the crank angle sensor 108. I'm looking for. Furthermore, this ECU 40 is an ECT computer 5
0 shift information (shift judgment, shift command, lock-up clutch engagement permission, etc.), executes engine torque down control and uses this control information.
Output to the ECT computer 50. Based on this information, the ECT computer 50 issues a lock-up clutch release command and checks whether the above control is being performed reliably. In this embodiment, the ECU 40 and the ECT computer 50 are separate units, and the ECU 40 determines and executes the amount and timing of engine torque reduction. However, in the present invention, the number of control devices or their control areas It is not limited to. Next, the operation of this embodiment will be explained using FIG. For convenience of explanation, definitions of various symbols will be explained first. t ₁ ... Engine torque down command time t ₂ ... Engine torque recovery command time Δt ... Shift time (=t ₂ − t ₁ ) Δt _A ... Shift time upper limit value Shift type (to 2nd gear, 3rd gear) to 4th gear) and the engine load (throttle opening). Δt _B ...lower limit value of shift time Similarly, the lower limit time is constant. ΔT……Shift time reference width (=Δt _A −Δt _B ) Δt _C ……Shift time deviation amount Δt＞Δt _A Δt _C = Δt−Δt _A Δt＜Δt _B Δt _C = Δt−Δt _B Δt When _B < Δt < Δt _A , Δt _C = 0 (See Figure 2 for the relationship between Δt, Δt _A , Δt _B , and ΔT) Δt _LIM ... Excessive shift time determined according to the type of shift and throttle opening. maximum allowable shifting time. BTDC... Engine set ignition timing ΔBTDC... Initial set retardation amount Retard amount from engine set ignition timing BTDC during gear shifting determined according to the type of shift and throttle opening degree ΔBTDC _F ... Initial retardation correction amount Ignition timing correction amount from the set retard amount ΔBTDC. The advance side correction width is a negative value, and the retardation side correction width is a positive value. ΔBTDC′……Retard amount after correction (=ΔBTDC+
ΔBTDC _F ) The smaller the corrected retardation amount BTDC', the greater the engine torque down amount. BTDC′……Ignition timing after correction (=BTDC−
ΔBTDC−ΔBTDC _F ) (Refer to Figure 3 for the relationship between BTDC, ΔBTDC, ΔBTDC _F , etc.) α _A °……Maximum movable value of engine ignition timing BTDC α _B °……Minimum movable value of engine ignition timing BTDC or more In accordance with the definition, the following steps will be explained in the order shown in FIG. In FIG. 1, steps 200 to 208 show a shift process accompanied by normal engine torque down control. That is, first, in step 200, a shift decision is made in accordance with the vehicle speed and engine load (throttle opening degree), and in step 202, a shift command is issued based on this shift decision. Next, in step 204, when each member of the automatic transmission starts changing the rotation speed for gear shifting, an engine torque down command and a lock-up clutch release command are issued, and in step 206, the rotation speed of each member for gear shifting is changed. An engine torque return command is issued near the end of the number change section. Thereafter, in step 208, a command to engage the lock-up clutch is issued after waiting for the completion of the gear shift. After this series of shift operations have been performed, it is first determined in step 210 whether or not a single shift is being performed.
Here, the term "single shift" refers to a case where the second and third shift decisions are not made between the shift decision and the lock-up clutch permission command. Next, in step 212, it is determined whether or not it is a power-on upshift. Here, the power-on upshift refers to an upshift when the throttle opening is equal to or greater than a predetermined opening. In step 212, steps 200 to 208
If it is determined that the gear shift was a power-on upshift, the process proceeds to step 214, where it is determined whether or not there has been a change in the throttle opening between the engine torque down command and the torque return command. In this way, in steps 210, 212, and 214, it is determined whether or not there is a single gear shift, whether or not there is a power-on upshift, and whether there is no change in the throttle opening. Check whether or not the gear shift that was performed followed the basic shift process that is sufficient to change the amount of torque reduction at the next gear shift, and unnecessarily change the next shift based on the characteristics of the shift that has undergone a special process. This is to prevent the torque down amount from being changed or corrected. When the determination in steps 210, 212, and 214 is YES, the shift time Δt is determined by subtracting the engine torque down command time t ₁ from the engine torque return command time t ₂ in step 216. Calculated. At the same time, the shift time Δt, the initial set retardation amount ΔBTDC, etc. are stored in the backup program. This memory is used for diagnosis, and stores the latest five times, and the previous ones are cleared sequentially. After the shift time Δt is calculated in step 216, it is determined in step 218 whether or not the shift time Δt is within the shift time reference width ΔT, that is, Δt _B
It is determined whether ≦Δt≦Δt _A or not. If the shifting time Δt is within the shifting time reference width ΔT (deviation amount Δt _C = 0), it is determined that the shifting from steps 200 to 208 had good shifting characteristics, and therefore the amount of torque reduction is reduced. It is determined that no correction is necessary, and the routine ends. On the other hand, if it is determined that the shift time Δt is not within the shift time reference width ΔT, the step
Proceeding to 220, it is determined whether the shift time Δt was less than or equal to the excessive shift time Δt _LIM . If the shift time Δt is less than or equal to the excessive shift time Δt _LIM , the ignition timing is corrected in step 222.
Ignition timing correction calculation is based on the shift amount Δt _C of shift time Δt
is calculated according to the above definition, and from the positive/negative and absolute values of this deviation amount Δt _C , the retard angle correction amount ΔBTDC _F is selected from a predetermined diagram, map, etc., such as the one shown by the solid line in Fig. 4, for example. However, this is done by determining the corrected retard amount ΔBTDC' and the corrected ignition timing BTDC' from this. On the other hand, if the shift time Δt is larger than the excessive shift time _ΔtLIM , a warning lamp, for example a red light, is turned on in step 224, and a correction calculation of the ignition timing is performed in step 222. Ignition timing after correction by ignition timing correction calculation
After BTDC' is determined, in step 226, the corrected ignition timing BTDC' is set within the movable range α _A ° ~ _{α B} °
It is determined whether or not it fits within the range. If so, the map of the variable speed ignition timing is changed in step 228. The shift ignition timing map is changed by changing the initial set retard amount ΔBTDC of the portion of the control constant map corresponding to the shift and throttle opening to the corrected retard amount ΔBTDC'. In addition, if this part has already been changed to the corrected retard amount ΔBTDC', the corrected retard amount ΔBTDC' can be further changed to the newly calculated corrected retard amount ΔBTDC''. Note that this corrected retard amount ΔBTDC' can be returned to the initial set retard amount ΔBTDC by a signal from an external switch, etc. On the other hand, within the movable range α _A ° to α _B ° If not, a warning is issued in step 230 using, for example, a yellow lamp, and then the map of the variable speed ignition timing is changed in step 228. In steps 224 and 232, the red and
At the same time as turning on the yellow warning lamp, it is determined whether or not the information corresponds to a warning, and the type of warning (warning red
or yellow) to ensure that useful information is provided when inspecting or maintaining the engine or automatic transmission in accordance with these warnings. Note that if the corrected ignition timing ΔBTDC' deviates from the movable range _αA ° to _αB ° in step 226, the engine set ignition timing BTDC is corrected within the movable range. In this way, the ignition timing
The movable range of BTDC is set based on the set ignition timing when, for example, ignition timing control is used as a means of controlling engine torque as in this example.
The width of BTDC is limited to 5° to 47°, and if the ignition timing is retarded beyond this, the ignition timing will be too far off, resulting in a misfire or a sudden deterioration of the emission condition. This is because it occurs. According to the above embodiment, first steps 210, 212,
214 etc., it has been determined whether or not the current gear shift, which is the basis for changing the amount of torque reduction, went through a standard gear shift process. Unnecessary changes and corrections to the amount of torque down can be prevented, and control can be performed stably and with good convergence. Further, in the above embodiment, the concept of a shift time reference width ΔT is provided, and the shift time Δt is equal to the reference width ΔT.
Since the engine torque is not changed when it is within the range, it is possible to prevent the engine torque change amount from being unnecessarily corrected for each gear shift, and to further stabilize the control system. can. In addition, in the above embodiment, a red lamp is used to issue a warning when the shift time Δt exceeds the excessive shift time Δt _LIM , so it is possible that the automatic transmission may reach an abnormal range due to variations in changes over time, etc. You can quickly tell if it is deteriorating. In addition, a yellow lamp will issue a warning when the corrected ignition timing BTDC' exceeds the movable range, so you can quickly find out that the amount of correction that should have been made is not being made. . Furthermore, in the above embodiment, the process by which these warnings were issued is memorized for diagnostic purposes or labeled, so that the history of the shift characteristics can be accurately checked during maintenance. can be grasped. Next, FIG. 5 shows a time chart when this control is used. In the figure, the solid line shows the characteristic before correction, and the broken line shows the characteristic after correction. In FIG. 5, since the shift time Δt before correction exceeds the shift time upper limit value Δt _A , the retardation correction amount ΔBTDC _F is calculated from the solid line in FIG. 4 according to the shift amount Δt _C , and after the correction A state in which the retard amount ΔBTDC' is determined is shown. As a result, the retard value of the part of the ignition timing map during a shift that corresponds to the type of shift and throttle opening is corrected to make the retard larger. When the type and throttle opening are determined, the ignition timing is further retarded.
Since the engine torque is further reduced, the shift time is reduced to Δt' as shown in the figure, and the shift characteristics are corrected to be favorable. In the above embodiment, as is clear from the definition and the solid line in FIG. 4, when the deviation amount Δt _C increases, the retard angle correction amount ΔBTDC _F is increased. Since _F is changed according to the deviation amount Δt _C ,
The processing speed is fast and the convergence of the control system is high. In the above embodiment, the shift time was adopted as the representative characteristic value, but the representative characteristic value in the present invention is not limited to this, for example, the output shaft torque of an automatic transmission, or the front and rear of the vehicle. Characteristic values whose values increase or decrease depending on the quality of the transmission characteristics, such as the directional acceleration or the rate of change over time of the rotational speed of the engine or automatic transmission rotating member, can be appropriately employed.
It is also possible to control the amount of change by combining these representative characteristic values. Further, in the above embodiment, the ignition timing retardation amount is controlled as a means for changing the engine torque, but the means for changing the engine torque in the present invention is not limited to this. The point is that the engine torque can be quickly changed according to the amount of deviation.For example, it is possible to increase or decrease the amount of fuel injection, adjust the opening/closing timing of the intake and exhaust valves, or increase or decrease the amount of intake air. good. Furthermore, in the above embodiment, the concept of shift time reference width is adopted, and when the shift time falls within the reference range, it is determined that no change or correction is necessary. is not limited to this, but the shift time reference width may be considered as 0, and as a result, correction is always performed. In this case, it is preferable to make the correspondence between the amount of deviation and the amount of retardation correction non-linear, for example, as shown by the broken line in FIG. 4. Note that if the correspondence relationship is as shown by the dashed-dotted line in Fig. 4, the section A in Fig. 4 will essentially become the shift time reference width, and in particular, using the concept of the reference width, the deviation amount Δt _C It is possible to obtain the same effect as in the above embodiment by simply calculating the amount of deviation from a specific reference value without calculating .

【Effect of the invention】

As explained above, according to the present invention, variations in the lot numbers of individual parts of the engine and automatic transmission,
Regardless of various miscellaneous variations such as variations in driving conditions over time, it is possible to perform torque reduction control to the optimum amount at any given time for each vehicle in the hands of the user. This provides an excellent effect of ensuring good speed change characteristics.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing an embodiment of the shift control method for a vehicle automatic transmission according to the present invention, and FIG. 2 shows shift time, upper and lower limits of shift time, shift time reference width, excessive shift time, and deviation. A diagram showing the relationship between quantities, etc.
Fig. 3 is a diagram showing the relationship among the set ignition timing, the initial set retard amount, the retard correction amount, etc.
5th diagram showing the relationship between the amount of deviation and the amount of retardation correction
The figure is a shift transient characteristic diagram showing a comparison between the case where the above embodiment is implemented and the case where it is not implemented.
The figure is an overall schematic diagram of an automatic transmission combined with an intake air amount sensing type automotive electronic fuel injection engine to which the above embodiment is applied, and Fig. 7 shows the input/output relationship of the engine and automatic transmission. It is a block diagram extracted and shown. t ₁ ... Engine torque down command time, t ₂ ...
Engine torque return command time, Δt...shift time,
Δt _A ...Upper limit value of shift time, Δt _B ...Lower limit value of shift time, ΔT...Reference width of shift time, Δt _C ...Amount of shift time deviation, Δt _LIM ...Excessive shift time, BTDC...Engine setting ignition Timing, ΔBTDC……Initial set retardation amount, ΔBTDC _F ……Retardation correction amount, ΔBTDC′…
...Retard amount after correction, BTDC'...Ignition timing after correction,
α _A °……Maximum movable value of ignition timing BTDC during shifting,
α _B °……The minimum movable value of the ignition timing BTDC during shifting.

Claims (1)

[Claims] 1. A shift control method for an automatic transmission for a vehicle that maintains good shift characteristics by changing engine torque by a predetermined amount during a shift, comprising the steps of: A procedure for detecting, a procedure for determining the amount by which the representative characteristic value deviates from a preset reference width (including zero), and a change in engine torque is corrected at the next gear shift according to the amount of deviation. A method for controlling a shift of an automatic transmission for a vehicle, the method comprising: 2. A shift control method for an automatic transmission for a vehicle according to claim 1, wherein the representative characteristic value of the shift is a shift time. 3. The speed change control method for an automatic transmission for a vehicle according to claim 1, wherein the representative characteristic value of the speed change is an output shaft torque of the automatic transmission. 4. The speed change control method for an automatic transmission for a vehicle according to claim 1, wherein the representative characteristic value of the speed change is acceleration in the longitudinal direction of the vehicle. 5. The speed change control method for an automatic transmission for a vehicle according to claim 1, wherein the representative characteristic value of the speed change is a temporal change rate of the rotational speed of the engine or the automatic transmission rotating member. 6. The shift control method for an automatic transmission for a vehicle according to claim 1, wherein a warning is issued when the amount of deviation is excessive. 7. The vehicle automatic according to claim 1, wherein a warning is issued when the amount of change in the engine torque corrected according to the amount of deviation exceeds an amount that can actually be changed. Shift control method for a transmission.