JPH04140567A - Control device for vehicular automatic transmission - Google Patents

Abstract

PURPOSE:To perform automatic speed change control with high-grade timing along the predictive value by measuring the value corresponding to the engine speed and engine output torque at the time of speed change, and changing the speed change line onto the low vehicle speed side in the case of the measured value being higher than the predictive value and onto the high vehicle speed side in the case of the measured value being lower than the predictive value. CONSTITUTION:The read-in of a shift map preset in a ROM and written in a RAM during control is performed according to the throttle opening detected by a throttle opening sensor 9 and the vehicle speed detected by a vehicle speed sensor 8. On the basis of the read shift map, the generation of a speed change signal in a control unit 7 at the time of performing speed change is monitored, and in the case of the speed change signal being generated, the measured value of engine speed at the time of speed change is read by an engine speed measuring sensor 10. The predictive engine speed prestored in the ROM corresponding to the shift map at the time of design is then compared with the measured engine speed by a CPU provided with a comparing circuit, and the shift map on the RAM is rewritten in the direction of the measured value coinciding with the predictive value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Industrial Field of Application)] The present invention relates to a control device for a vehicular automatic transmission for controlling the speed change of an automatic transmission suitable for use in, for example, an automobile.

<Prior Art> Conventionally, automatic transmissions have been used in automobiles, etc., which automatically change gears according to vehicle speed and engine load. In general, gear shifting is performed according to the throttle opening and vehicle speed, which are engine load parameters, but in order to optimize the engine output, engine sound, and acceleration feeling when accelerating, the gear shifting line that performs gear shifting is controlled by the throttle. Shift control is performed by predetermined map control depending on the opening degree and vehicle speed.

By the way, due to the influence of individual variations, aging, changes in the external environment, etc., the engine speed when upshifting while accelerating at a roughly constant throttle opening may differ from the predicted value set at the time of map creation. It may change due to the above influences. For example, in the automatic transmission with the structure disclosed in Japanese Patent Application Laid-open No. 63-30640, the engine speed during gear shifting is always kept below the maximum allowable speed, regardless of changes in the external environment such as intake temperature and intake pressure. It is controlled as follows. However, with the above structure, although it is possible to prevent the harmful effects of overspeed, it is not possible to control the gear shift operation so that the engine speed always matches the predicted value, and the engine speed at the time of gear shifting is not the same as when the map was created. deviates from the predicted value, a problem arises in that the high quality achieved by the originally set shift timing is impaired. Further, the same thing can be considered when, for example, measured values of engine torque, intake pipe negative pressure intake air amount, and fuel injection amount are used as values corresponding to engine output torque.

<Problems to be Solved by the Invention> In view of the problems of the prior art, the main object of the present invention is to reduce the engine speed or To provide a control device for an automatic transmission for a vehicle that can prevent a value corresponding to engine output torque from being deviated from a set value due to changes in the external environment and the like, thereby preventing loss of high quality shift timing. There is a particular thing.

[Structure of the Invention] <Means for Solving the Problems> According to the present invention, the object is to shift the gear shifting operation of the transmission to the high vehicle speed side on the high engine load side and to the low vehicle speed side on the low engine load side. an automatic shift control means that controls the gear shift using a shift line that is set to automatically shift; a means that measures a value corresponding to the engine rotation speed or engine output torque at the time of gear shifting; and a means for measuring a value corresponding to the engine rotation speed or engine output torque when shifting. Comparing a predicted value storage means that stores engine output torque in advance in correspondence with the shift line, and a measured value by the measurement means when a shift operation is performed and a corresponding predicted value by the predicted value storage means. means for shifting the corresponding shift line by a predetermined amount toward a lower vehicle speed when the measured value is larger than the predicted value; and when the measured value is smaller than the predicted value, the corresponding shift line This is achieved by providing a control device for an automatic transmission for a vehicle, which is characterized in that the shift line is shifted by a predetermined amount to a higher vehicle speed side, and subsequent shift operations are controlled using the shifted shift line.

<Operation> By doing this, the shift line preset according to the vehicle speed and engine load can be set so that when the engine speed at the time of shifting is higher than the predicted value stored in advance, the measured value will be low. If the speed is low, the measured value will be high, and the vehicle speed will be shifted to the low or high speed side, so the engine speed at the time of gear shifting may deviate from the set value due to driving conditions, aging, etc. can be prevented. Also, instead of the engine speed, a value corresponding to the engine output torque can be used, and in this case, measured values such as engine torque, intake pipe negative pressure, intake air amount, fuel injection amount, etc. can be used, respectively. The deviation of the measured value from the predicted value may be corrected in the same manner as above.

<Embodiments> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing an outline of an automatic transmission for an automobile to which the present invention is applied. In FIG. 1, an automatic transmission 2 is connected to an engine 1, and the automatic transmission 2 includes a torque converter 3 with a lock-up clutch 3a and a gear transmission 4 with, for example, four forward speeds and one reverse speed. Built-in. A differential device 6 of the drive wheels 5 is engaged with the final drive gear 4a of the gear transmission 4, and the output torque of the engine l is transferred to the torque converter 3 and the gear transmission 4.
The signal is transmitted to the drive wheels 5 via the .

Each gear stage of the automatic transmission 2 is controlled to be automatically shifted by a control unit 7 serving as an automatic shift control means in accordance with a vehicle speed signal and a throttle opening signal as an engine load.

The control unit 7 consists of a combination of general circuits, including a CPU, ROM, RAM, input/output circuit 7a,
7b. For example, a pulse signal is input as a vehicle speed signal to the input circuit 7a from a vehicle speed sensor 8 provided near the final drive gear 4a, and a pulse signal is also input as a vehicle speed signal from a throttle opening sensor 9 attached to a throttle body (not shown) of the engine 1. For example, a voltage signal is input as a throttle opening signal. Further, a signal from an engine rotation speed measurement sensor 10 serving as a means for measuring the engine rotation speed is input to the input circuit 7a.

In the control unit 7, the CPU and ROMSRA
M is used to perform map control of speed change according to each signal input to the input circuit 7a. control unit 7
A shift control signal and a lock-up control signal are output from the output circuit 7b to each solenoid valve such as a shift control and a lock-up control of the hydraulic control circuit 11.

This hydraulic control circuit 11 allows the automatic transmission 2 to automatically change gears at each gear stage.

FIG. 2 is a diagram showing a flow of control based on the present invention, and the operation procedure for shifting will be described below with reference to FIG. 3 showing an example of shifting characteristics.

In FIG. 2, in step STI, according to the throttle opening TH detected by the throttle opening sensor 9 and the vehicle speed V detected by the vehicle speed sensor 8, the upshift shift line a-C and the downshift shift line a-C are determined in FIG. The shift map is preset in the ROM with the shift characteristics shown by the shift line df and is written in the RAM during control.

For each shift operation, shift line a is used for upshifting from 1st gear to 2nd gear, shift line A is used from 2nd gear to 3rd gear, and shift line C is used from 3rd gear to 4th gear. , and each downshift is performed when a point determined by the throttle opening TH and the vehicle speed V crosses each shift line df. In the next step ST2, the measured values of the throttle opening TH and the imperial speed V are read.

In step ST3, generation of a shift signal in the control unit 7 is monitored when shifting is performed based on the shift map read in step ST1 in accordance with each measurement value read in step ST2, and the occurrence of a shift signal in the control unit 7 is monitored. If no shift signal is generated, the process returns to step STI, and if a shift signal is generated, the process proceeds to step ST4. In step ST4, the engine rotation speed measurement sensor 10 reads the measured value Ne of the engine rotation speed at the time of shifting.

In the next step ST5, a prediction stored in advance in a ROM, for example, is used as a means for storing the engine rotation speed predicted for the throttle opening TH and vehicle speed V during gear shifting in accordance with the designed shift map. Engine speed Nes
and the measured engine rotation speed Ne read in step ST4.
For example, a CPU having a comparison circuit as a comparison means
If the measured engine speed Ne is lower than the predicted engine speed Nes, the process proceeds to step ST6. In step ST6, for example, in the case of an upshift from 2nd speed to 3rd speed, a corrected shift is performed by shifting the shift line by a predetermined amount α toward the higher vehicle speed side, as shown by the imaginary line in FIG. The line b1 is rewritten in the shift map on the RAM, for example, and the process returns to step STI.

In step ST5, if the measured engine speed Ne is greater than or equal to the predicted engine speed Nes, the process proceeds from step ST5 to step ST7, and in step ST7, it is determined whether the measured value and the predicted value match. Step S
At T7, if both values match, step ST
Returning to step I, if the two values do not match, that is, if the measured engine speed Ne is larger than the predicted engine speed Nes, the process proceeds to step ST8, and in step ST8, the shift line is set to a lower value, contrary to the above. A corrected shift line shifted by a predetermined amount β toward the vehicle speed is rewritten in the shift map on the RAM in the same manner as described above, and the process returns to step ST1.

In this way, if the engine speed Ne at the time of gear shifting deviates from the predicted engine speed at the time of design, the deviation is corrected and the RAM is moved in the direction where the measured value and the predicted value match.
Since the above shift map is rewritten, subsequent gear changes can be performed at a suitable engine speed that matches the predicted value. Therefore, even if the engine speed at the time of gear shifting deviates from the predicted value at the time of design due to the influence of individual variations, aging, changes in the external environment, etc., this deviation can be corrected. , the gear shifting operation can always be performed at the designed engine speed, and high quality gear shifting timing can be maintained.

In addition, the above correction is performed when the shift line a is corrected according to the shift during the shift from 1 to 2, and the correction value α is used to change the shift from 2 to 3.
The corrections of the shift lines 3-4 and 3-4 may also be performed at the same time. By doing this, each shift line a -
Since there is no need to reserve a memory area for each c, it is sufficient to reserve one memory area, the memory capacity can be minimized. Furthermore, by predetermining the one-time correction value to a predetermined value, there is no need to complicately calculate the correction value according to the magnitude of the deviation, and correction control can be performed easily. In addition, the correctable range of each shift line a to C is such that, for example, in the shift characteristics shown in FIG. 3, adjacent shift lines overlap after correction, or both shift lines for upshift and corresponding downshift overlap. In order to avoid shifting too close and causing hunting in the gear shifting operation, it is a good idea to set an upper limit for the amount of correction, and also take into consideration the hysteresis between upshift and downshift when setting the upper limit for correction. good.

Incidentally, in the above embodiment, the correction target is shown as the engine rotational speed at the time of shifting, but the correction target may be a value corresponding to the engine output torque at the time of shifting.

As the value corresponding to this engine output torque, it is possible to use various measured values such as engine torque, intake pipe negative pressure, intake air amount, fuel injection amount, etc., and each measurement sensor can be used instead of the engine rotation speed measurement sensor 100. In step ST4 of FIG. 2, each of the above measured values is read in place of the engine speed.

Then, the deviation between each measured value and each corresponding predicted value stored in advance according to the shift line on the shift map is compared in the same manner as steps ST5 to ST8 in FIG. 2, and the shift line is adjusted to a high vehicle speed. It is possible to make corrections to the side or to the low vehicle speed side.

[Effects of the Invention] As described above, according to the present invention, when the value corresponding to the engine rotation speed or engine output torque during gear shifting is measured, and the measured value is higher than the predicted value stored in advance, Since the shift line is changed to the low vehicle speed side when the vehicle speed is low, and to the high vehicle speed side when the vehicle speed is low, the measured value at the time of shifting may differ from the predicted value at the design time due to individual variations, aging, changes in the external environment, etc. Even if there is a deviation, the deviation can be immediately corrected, and automatic shift control can always be performed with high-quality shift timing in accordance with the predicted value.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an outline of an automatic transmission for an automobile to which the present invention is applied. FIG. 2 is a flow diagram of control according to the present invention. FIG. 3 is a diagram showing an example of shift characteristics of an automatic transmission.

Claims (1)

[Scope of Claims] Automatic shift control means for controlling the shift operation of a transmission with a shift line set so that the shift operation is automatically performed on the high vehicle speed side when the engine load is high, and on the low vehicle speed side when the engine load is low. , a means for measuring a value corresponding to the engine rotation speed or engine output torque at the time of gear shifting, and a predicted value storage means for storing in advance the engine rotation speed or engine output torque predicted at the time of gear shifting in correspondence with the shift line. and means for comparing a measured value by the measuring means when performing a gear shifting operation with a corresponding predicted value by the predicted value storage means, and if the measured value is larger than the predicted value, a corresponding action is taken. Shifting the corresponding shift line by a predetermined amount toward a lower vehicle speed side, and when the measured value is smaller than the predicted value, shifting the corresponding shift line by a predetermined amount toward a higher vehicle speed side, and using the shifted shift line. A control device for an automatic transmission for a vehicle, characterized in that it controls subsequent gear shifting operations.