JPH02264131A - Control method for vehicle having automatic speed change gear - Google Patents

Abstract

PURPOSE:To reduce the generation of a gear shifting shock by a method wherein the decision number of revolutions during completion of control of variation of an engine output for relaxation of a gear shifting shock is set in a way that from a change in the number of revolutions during preceding gear shifting, the number of gear shifting completion revolutions responding to an actual gear shifting completion period is determined and learning control is effected. CONSTITUTION:Based on various sensor signals and a gear shifting delay angle pulse signal from a speed change gear control unit 12, an engine control unit 11 outputs an ignition signal to an igniter 9 at a given timing and controls variation of an output for reducing the generation of a shock during gear shifting. Meanwhile, a gear shift control unit 12 inputs a throttle opening, a car speed, and a range signal from sensors 18-20 to control gear shifting of an automatic speed change gear 3. The gear shifting control unit sets the decision number of revolutions during completion of variation of an output in a way that from a change in the number of revolutions at a preceding gear shifting period, the number of gear shifting completion revolutions responding to an actual gear shifting completion period is determined and learning control is effected, and decides completion of gear shifting by means of a signal from a crank angle sensor 15. This method enables proper reduction of the generation of a gear shifting shock.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic transmission that reduces the shift shock that occurs during a shift operation in an automatic transmission installed in a vehicle by changing the engine output. The present invention relates to a method of controlling a vehicle equipped with a vehicle.

(Prior Art) Conventionally, in vehicles equipped with automatic transmissions, determining when to start or end a gear shifting operation has been important in performing various controls such as automatic transmission control and engine output control. There is a technique in which the start and end of this shift state are set based on the engine speed, etc., which change according to a predetermined characteristic with the speed change operation, as disclosed in, for example, Japanese Patent Application Laid-Open No. 1983-1999. This is known as seen in Japanese Patent No. 69738.

By the way, when a gear change operation is performed in an automatic transmission, although the vehicle speed hardly changes due to the inertia of the vehicle, the engine speed changes depending on the change in the gear ratio in the automatic transmission, and accordingly, the automatic gear change occurs. Torque fluctuations occur on the output shaft of the machine, and the acceleration of the vehicle body changes due to the torque fluctuations on the output shaft, causing a so-called shift shock. As a possible measure to reduce such shift shock, it may be possible to control the hydraulic pressure supplied to the frictional engagement elements so that the frictional engagement elements in the transmission mechanism are smoothly released and engaged. If this is done, the period during which the frictional engagement elements are kept in a sliding state becomes longer, and there is a risk that the frictional engagement elements may seize or become severely worn.

Therefore, when a gear shift operation is performed in an automatic transmission, the engine output is temporarily changed by engine ignition timing control, etc., thereby reducing the gear shift shock and improving the durability of the frictional engagement element. is also known.

(Problem to be Solved by the Invention) However, when the engine output is changed in accordance with the shift operation of an automatic transmission as described above to reduce shift shock, there is a problem in the start and end timing of the shift operation. It is important to perform output change control in an accurate manner. Rotational fluctuations during a gear shifting operation change depending on various conditions, and it is difficult to accurately determine the output change in response to these changes.

In other words, if the timing of the output change control is out of sync with the gear shift operation, for example, in a gear shift operation during acceleration, if the control that reduces the engine output continues even after the gear shift has finished, acceleration performance may be affected. On the other hand, if the change control is terminated before the shift is completed and the engine output is increased, the load on the engagement of the frictional engagement elements of the automatic transmission will increase, leading to problems such as impairing durability. occurs.

In addition, when the engine speed or turbine speed changes due to a gear shift operation, an inflection point occurs at the start and end of the gear shift operation, so the change in the engine speed is detected and the inflection point is determined. When output control is performed, there are times when a clear inflection point does not occur in the change in rotational speed depending on various operating conditions during gear shifting, and in such cases, it is difficult to determine. In this regard, a rotation speed that fluctuates by a predetermined amount from the rotation speed when the shift command is issued is set at the start of the shift, and this starting rotation speed is multiplied by the gear ratio to determine the rotation speed after the shift ends. It has been considered to provide a predetermined range for the rotation speed and set the speed change end determination rotation speed.

However, if there are individual differences in the frictional engagement elements of automatic transmissions, changes over time, or changes in the viscosity of the oil in the transmission,
The actual timing at which the frictional engagement elements complete engagement deviates from the rotational speed. For example, the engagement point changes depending on the state of the torque transmitted from the engine, and engagement may be completed early in low torque states. At high torques, the completion of engagement tends to be delayed, and the shift completion rotation speed changes accordingly. As a result, the desired characteristics in terms of driving performance, durability, etc., may not be obtained, and there is a possibility that the gear shift shock may not be appropriately alleviated.

Therefore, in view of the above circumstances, the present invention provides an automatic transmission system that appropriately reduces the shift shock by setting an appropriate shift end time even in response to individual differences in automatic transmissions, changes over time, etc. The object of the present invention is to provide a method for controlling a vehicle equipped with a machine.

(Means for Solving the Problems) In order to achieve the above object, the control method of the present invention changes the engine output at the time of gear shifting for an automatic transmission that shifts to a predetermined gear in response to a gear shift signal. This is to reduce the shift shock associated with shift operation, and the output change control for reducing shift shock is based on the fact that the rotation speed such as the engine rotation speed or turbine rotation speed changes according to a predetermined characteristic in response to the shift. The end time is set by the judgment rotation speed,
To end the output change control when the detected rotation speed reaches the above-mentioned judgment rotation speed, calculate the shift end rotation speed corresponding to the actual shift end time from the rotation speed change due to the previous shift,
The determination rotation speed is set by learning control based on the speed change end rotation speed.

(Function) In the method of controlling a vehicle equipped with an automatic transmission as described above,
To set the end time of output change control using the determination rotation speed, the shift end rotation speed corresponding to the actual shift end time is determined from the change in the rotation speed due to the previous shift, and the learning control based on this shift end rotation speed is performed. This method sets a judgment rotation speed and changes this judgment rotation speed so that it approaches the actual speed at which the gear shift ends, and even when variations such as individual differences in transmissions or changes over time occur, the speed at which the gear shift operation ends can be adjusted. Correspondingly, the engine output change control is accurately terminated to ensure good driving performance, durability of the frictional engagement elements, etc., and to appropriately reduce shift shock.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a schematic configuration of a power train portion of a vehicle equipped with an automatic transmission.

The output of the engine 1 is input to the automatic transmission 3 via the torque converter 2, and the solenoid valve 4 of the automatic transmission 3
, 5, and is output to drive wheels 7 via a propeller shaft 6. The solenoid valves 4 and 5 of the automatic transmission 3 are installed, for example, three for shifting and one for locking up, and the combination of their respective operations operates the frictional engagement element of the clutch or brake inside the transmission, thereby changing the gear. It switches the power transmission path of the gear mechanism, performs a gear shift operation such as 1st to 4th speed, and engages/disengages a lock-up clutch. It should be noted that the details of the internal structure of the automatic transmission 3 are well known, and their explanation will be omitted.

On the other hand, the engine 1 is equipped with an ignition system 10 that includes a distributor 8, an igniter 9, etc., and is configured to adjust the ignition timing for each cylinder using the ignition system 0 to change the engine output. has been done.

An engine control unit 1 and a shift control unit 12 are provided to control the output of the engine and control the speed change of the automatic transmission 3 as described above.

The engine control unit 11 includes a crank angle sensor 15.
A crank angle signal (engine speed signal) from the engine, a water temperature signal from the water temperature sensor 16, a knock signal from the knocking sensor 17, a throttle signal obtained from the throttle opening sensor 18, and the like are input. Based on these various detection signals and the shift retard pulse signal supplied from the transmission control unit 12, the engine control unit 11
The igniter 9 is activated at a predetermined time when the ignition signal is calculated.
In addition to controlling the ignition timing under normal operating conditions, the output is also controlled to change the output to reduce shift shock during gear shifting.

The transmission control unit 12 includes a throttle opening sensor 1.
A throttle signal obtained from 8, a vehicle speed signal obtained from vehicle speed sensor 19, a water temperature signal from water temperature sensor 16, a shift lever range signal obtained from shift position sensor 20, and the like are input, respectively. The transmission control unit 12 performs speed change control and lock-up control by selectively supplying speed change signals based on these various detection signals to the solenoid valves 4 and 5 of the automatic transmission 3, respectively.

The ignition timing process by the engine control unit 1 and the speed change process by the transmission control unit 12 will be explained with reference to flowcharts shown in FIGS. 2 to 4.

Before explaining these flowcharts, basic processing of engine rotational speed fluctuations, shift determination, and ignition timing control during gear shifting associated with the processing will be explained using upshifting based on FIG. 5. (A) shows changes in engine speed Ne, and (B) shows changes in ignition advance angle θ, which is set in relation to vehicle speed and throttle opening as engine speed Ne increases. A shift command is output at eight points where the gear position determined by the map crosses the shift line and changes to the high speed side. From this point on, the engine speed Ne decreases from the inflection point Neo in response to the power transmission path being switched by the operation of various friction engagement elements accompanying the operation of the solenoid valve 4, and reaches the above-mentioned inflection point Ne.

A start command for output change control is output at point b, at which the rotational speed Nel is lower by a predetermined value α (fixed value). In response to this, the ignition timing is retarded to control output reduction. continue,
The engine speed Ne decreases with the gear shifting operation, and the gear shift ends at point d when the engine speed Ne3 drops to the speed Ne3 corresponding to the gear ratio, and then the engine speed Ne increases. The target rotation speed Ne4 for determining the end of the shift is set higher by a predetermined value β (fixed value) than the lower limit rotation speed Nc3. However, the determination rotation speed Nc2 for determining the actual shift completion, which is set based on the value stored in the learning map, is set to a value higher than the target rotation speed Ne4, for example, and the engine rotation speed Nc2 is set to a value higher than the target rotation speed Ne4.
At point C, where e reaches this determination rotational speed Nr32, it is determined that the gear shift is completed, and an output change control termination command is output. Correspondingly, the ignition timing retard is gradually advanced to return to the normal advance.

Then, in the rotation speed change and shift end determination as described above, the actual lower limit rotation speed Ne3 in the previous shift at the same gear stage is detected, the target rotation speed Ne4 is determined from this lower limit rotation speed Ne3, and the previously determined rotation speed is determined. Deviation ΔNe from the number Ne2
The next judgment rotation speed Ne2 is set by correcting the judgment rotation speed Ne2 with a value of 1/2. In addition, the difference value ΔN e corresponding to the judgment rotation speed Ne2 and the target rotation speed Ne4 is
2. Learning control is performed to update ΔNe4 to a value at a predetermined address corresponding to the throttle opening degree and gear position in the learning map.

First, Fig. 2 shows the main routine for shift determination in shift control. After the control starts, in step S1, the engine speed Ne, throttle opening, TVO, vehicle speed V, etc. are read, and in step S2, Determine whether the output change control condition is met. This condition is, for example, when the engine is cold or not in a low throttle opening state, so that it is determined that the combustion state of the engine is unstable and the engine output is not inappropriately changed.

If the determination in Step S2 of 1. is YES, the process proceeds to Step S3 to determine whether or not to shift. It is determined whether or not it is the time of gear change. When changing gears, the gear position and throttle opening TVO at the time of step S4 are stored, and the corresponding address of the learning gear is accessed.

Next, in step S5, it is determined whether or not the 1-2 gear shift is to be performed.
In step 6, it is determined whether or not it is a 2-3 gear shift.
In the case of a -4 shift, the subroutine of step S9 performs the start and end determination of output change control in response to a change in engine speed, the command output thereof, and the learning control of the speed change determination speed.

The subroutine of steps 87 to S9 is shown in FIG. 3, and after the start of the shift, step S1. The current engine rotation speed Nci and the start determination rotation speed NeL are obtained by subtracting a predetermined value α from the upper limit rotation speed Nco at the inflection point, and the two are compared and the output is changed when the start determination rotation speed Nc1 is reached in step SI2. It is determined whether the control is in the start state. Then, if the determination in step SI2 is YES, step S
After the start determination rotation speed Ncl is memorized in step S13, a shift retard pulse for starting output change control is outputted in step S14.

Next, in steps SL5 to S2], the speed change end determination rotation speed Ne
Perform the calculation settings in step 2. First, in step S1.5, a predetermined value β is added to the previous actual lower limit rotation speed Ne3i-1 to obtain the previous 1'' reference rotation speed Ne4i-1, and this value is used to determine the previous start determination rotation speed Nel. The difference ΔNe4i-1 is calculated 1. (SIB), and further, the start determination rotation speed Ne11-1
and the previous determined rotation speed Ne2+-] ΔNe2j-
1 (S17), and calculate the deviation ΔN ei-1 of Ne4i-1 and ΔNc2i-1 from each difference (S1
g), and in step Si9 the previous deviation ΔN ei
−1]/2 is the current deviation ΔNet, and this value ΔNe
i is added to the previous target difference ΔNc2+-1 to obtain the current target difference Δ
Na2i is calculated (520), and in step S21, a final 1'11 constant rotational speed Ne2i is set based on the current start determination rotational speed Nel and the current target difference ΔNc2i, and is compared with the current engine rotational speed Nci.

Before it is determined in step S23 whether the engine rotational speed Ne has reached the determination rotational speed Nc2i at which a shift end determination is made and the output change control has ended, it is determined whether the throttle opening TVO has changed in step S22. Determine. When the determination in step S22 is NO and there is no change in the throttle opening degree TVO, when the determination in step S23 reaches the shift end rotation speed Nc2i, step S24
Outputs a pulse to end output change control.

On the other hand, when the determination in step S22 is YES and the throttle opening TVO has changed, the process proceeds to step S25, where the output change control is terminated before the rotational speed reaches the determined rotational speed Ne2i, and the learning map is changed to step S826. ΔN to register
The values of e2 and ΔNe4 are not rewritten and the previous values are stored as they are.

FIG. 4 shows the ignition timing control routine, step S31
Various sensor signals are inputted in step 532), and the basic ignition timing θb is set based on these signals.In steps S33 and S34, it is determined whether the retardation permission condition is met. Then, in step S35, it is determined whether or not the shift retard pulse was output in step S14 of FIG. set. When executing this shift retardation, in step 54fli, the shift retardation amount θat+
・It is determined which of the knocking retardation amount θnr is larger, and in steps S48 and S49, the retardation angle acquisition amount θr is set to the larger retardation amount, and in step S49, the final ignition advance angle θ is set. and output.

After the retard pulse is output, step S35 is N.
The determination is O, but if the determination is YES in step 338 in accordance with the setting of the flag Fr, the process proceeds to step S39, where it is determined whether or not the end pulse has been outputted in the step S24, and if it has not been outputted, the process proceeds to step 846. to continue the retard control. Further, when the end pulse is input and the determination in step S3'l becomes YES, step S40
~S43, the ignition timing controlled by the shift retardation is gradually advanced, and the shift retard amount θair is subtracted by a predetermined value Δθ (S40), and when it is determined that it has become 0 or less (S41), The cell IL is set to 0 (S42), and the flag Fr is also reset (S43). In addition, step S
33-S35. Based on the determination in S38, step S4
When proceeding to step 4, the shift retard control is not performed, and the shift retard amount θatr and the flag F r are set to O.

According to the embodiment described above, the period during which ignition timing retard control is performed to reduce shift shock is corrected by learning the target rotation speed for termination determination based on the detection of the previous rotation speed change. , Even if there are changes in various conditions such as individual differences in transmissions or changes over time, the end target rotation speed is set accordingly, and the gearshift I-L is always in the optimum state, based on accurate shift end judgment. It is possible to reduce shift shock by executing engine output change control, and to ensure driving performance such as acceleration by controlling the output reduction to the minimum necessary level.

In the above embodiments, the engine output is changed by ignition timing control, or may be changed by other means such as air-fuel ratio control.

(Effects of the Invention) According to the present invention as described in item 1, engine output change control is performed to alleviate shift shock when changing gears in an automatic transmission, and the end time is set based on the determined rotation speed. By determining the shift end rotation speed corresponding to the actual shift end time from the change in rotation speed accompanying the shift and setting the judgment rotation speed using learning control, individual differences in transmissions, changes over time, oil temperature, Even in response to fluctuations in oil pressure, etc., the engine speed to be determined can be changed to approach the actual speed at which the shift ends, and the engine output change control can be accurately completed in response to the end of the shift operation, resulting in a good engine output change control. It is possible to appropriately reduce shift shock while ensuring driving performance and durability of frictional engagement elements.

[Brief explanation of drawings]

Figure 1 is a schematic configuration diagram showing the power train part of a vehicle equipped with an automatic transmission. Figures 2 to 4 are flowcharts for explaining the processing of the control unit. Figure 5 is the rotation speed during gear shifting. FIG. 3 is an explanatory diagram showing changes, gear shift determination, and ignition timing control. 1... Engine, 2... Torque converter,... Automatic transmission, 4... Solenoid valve, 1 Ignition device, 11... Engine control unit ,...Transmission control unit. 3... 0...

Claims (1)

[Claims] (1) An automatic transmission that shifts gears to a predetermined gear position in response to a gear shift signal is equipped with an automatic transmission that changes engine output during the gear shift to reduce shift shock caused by the gear shift operation. In a vehicle, based on the fact that the rotational speed such as engine rotational speed or turbine rotational speed changes according to a predetermined characteristic with gear shifting, the end timing of output change control for reducing gearshift shock is set based on the determined rotational speed, To end the output change control when the detected rotation speed reaches the above-mentioned judgment rotation speed, calculate the shift end rotation speed corresponding to the actual shift end time from the rotation speed change due to the previous shift, and calculate this shift end rotation speed. A method for controlling a vehicle equipped with an automatic transmission, characterized in that the determined rotation speed is set by learning control based on the following.