JPH1078121A - Control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable proper L/U controlling suitable for an L/U automatic trans mission adopting slipping controlling by suppressing direct transmitting of engine torque variation even when a throttle is closed, and avoiding disadvantages such as deterioration of drivability. SOLUTION: A control device for optionally setting a fastening capacity of an L/U clutch and a means for measuring a differential rotational speed are arranged for performing L/U controlling so that keeping of the present differential rotational speed is stopped and the L/U clutch is smoothly fastened in the case that reduction of an engine torque is predicted or sensed. A transmission controller gradually reduces the slipping rotation to indicate L/U fastening (t1 -t2 ) for the preparation of restarting of slipping to the extent that reduction of the slippint rotation speed is not influenced, for instance, when a throttle (TVO) is closed (time t1 ) during slipping L/U controlling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission in a vehicle, and more particularly to an improvement in lock-up control of the automatic transmission.

[0002]

2. Description of the Related Art In an automatic transmission for a vehicle, a torque converter inserted in a transmission system thereof is used in a vehicle in a lock-up region where a torque increasing function and a torque fluctuation absorbing function are not required. There is a tendency to switch to a lock-up type in which a lock-up state in which input / output elements are directly connected can be established. Further, in the lock-up (L / U) type, slip control (slip L / U) is performed in which the torque converter (T / C) is brought into a control state in which slip occurs to allow relative rotation between input and output elements. Is also adopted.

[0003]

In the control of this type of lock-up type automatic transmission, conventionally, when the engine throttle is closed during the slip control, the engine torque is reduced, so that the control is independent of the slip control. , L / U
Since the state changes in the fastening direction, methods for avoiding this have been discussed.

For example, assuming an ideal slip rotation control device and a change in engine torque that decreases stepwise, if the slip rotation before and after the change in engine torque is completely the same (FIG. 10 (b) (engine rotation and turbine rotation). (C), the inertia energy of the engine-T / C system changes only by the acceleration / deceleration of the vehicle.
The torque transmitted to the transmission by the C and the L / U changes stepwise, just like the engine torque ((a) to (d)). That is, FIG. 10 is a diagram to be referred to also in the following description, in which the throttle opening is closed during the slip control (for example, the closing operation is performed by releasing the accelerator pedal when the driver releases his / her foot from the accelerator pedal). ), A change in various amounts such as a throttle opening TVO, an engine rotation, an L / U control command value, and an engine torque as a comparative example in the scene ((a)). In the method, the change in the engine torque is transmitted as it is, and when the change is abrupt, it is understood that the drivability may be impaired.

[0005] The present invention is improved based on the above considerations, and is preferably applied to control of a lock-up type automatic transmission in the case where slip control is also employed. It is intended to avoid disadvantages and perform appropriate lock-up control. Further, in this case, there is provided a more improved automatic transmission control device capable of appropriately releasing the inertia energy of the engine and the torque converter and controlling the change in the engine torque to be transmitted smoothly. It is to try.

[0006]

According to the present invention, there is provided the following control device for an automatic transmission. That is, the present invention is an automatic transmission control device for a vehicle having a control device capable of arbitrarily setting the engagement capacity of a lock-up clutch, and a unit for measuring a differential rotation speed of lock-up. Means for performing lock-up control so as to stop maintaining the current differential rotation speed and to smoothly engage the lock-up clutch when a decrease in torque is predicted or detected. It is a control device for an automatic transmission.

Further, in the above, when the decrease in the engine torque is predicted or detected, the lock-up fastening force at that time is maintained until the slip rotation reaches a value at which the lock-up engagement can be confirmed. It is assumed that.

[0008] Further, the decrease in the engine torque is predicted,
Or, if it is detected, from the lock-up fastening force at that time, at a speed that does not affect the decrease in slip rotation,
The lock-up fastening force is reduced until the slip rotation reaches a value at which lock-up engagement can be confirmed.

Further, the decrease in the engine torque is predicted,
Or, if it is detected, control is performed with a low follow-up property for a predetermined period of time, the control is switched to a control with a high follow-up property before the lock-up is engaged, and control is performed so as to change the reduction speed of the slip rotation. is there.

Further, when the control characteristic is switched, the control followability is changed by switching the control gain or by switching the control target value.

Further, the control switching point is set so that the inertia energy of the engine and the torque converter obtained from the slip rotation speed before the control is started is divided at a predetermined ratio.

In addition, the division ratio of the inertia energy between the engine and the torque converter, which is obtained from the slip rotation speed before the start of the control, is calculated as follows:
1-e ^-1 , and the period after the switching is selected so as to be divided by the ratio of e ^-1 or substantially by the ratio.

Further, the switching of the control is performed by one of time, slip rotation, engine rotation, or a product of a time integral value of a change speed thereof and an inertia value, which is calculated to have the above-mentioned division ratio. It is characterized by the following.

Further, after the lock-up engagement is confirmed, the slip control is restarted after a predetermined time has elapsed.

A prediction of the decrease in the engine torque;
Alternatively, the detection method is characterized in that it includes a method of comparing the engine torque or an amount representing the engine torque with a predetermined threshold value or a change amount with a threshold value. The engine further includes means for detecting a throttle opening degree of the engine. In the method for predicting a decrease in the engine torque, a current detected throttle opening degree and a delay time corresponding to a delay time from a throttle opening operation to a change in engine torque are provided. It is characterized in that a decrease in the engine is predicted by comparing the throttle opening with the throttle opening.

[0016]

The present invention is based on the idea that the torque converter releases the inertia energy to mitigate the change in engine torque when the engine throttle is closed. And a control method for better utilizing this can be provided. In the first aspect, a control device capable of arbitrarily setting the engagement capacity of the lock-up clutch, and a means for measuring a differential rotation speed thereof are provided to predict a decrease in engine torque,
Or, if it is detected, stop maintaining the current differential speed, and smoothly engage the lock-up clutch,
Lockup control can be performed using the control device and the measurement unit. Therefore, even during slip control,
Even when the engine throttle is closed, a step-like change in the engine torque is not transmitted as it is as shown in FIG. 10, so that disadvantages such as impaired driving performance can be avoided and appropriate lock-up control can be performed. Thus, it is possible to realize an improved control method suitable for control of a lock-up type automatic transmission in a case where slip control is also employed.

According to a second or third aspect of the present invention, when the decrease in the engine torque is predicted or detected, the lock-up engagement force at that time is determined, and the slip rotation is a value that enables the lock-up engagement to be confirmed by slip rotation. Or from the lock-up fastening force at that time, at a speed that does not affect the reduction of slip rotation, until the slip-up rotation reaches a value at which lock-up engagement can be confirmed. According to any one of the embodiments in which the force is reduced, a smooth lock-up clutch can be similarly engaged. In addition, in this case, until the slip rotation reaches a value indicating lock-up engagement, the current lock-up engagement force is maintained, or is gradually decreased at a speed that does not affect the slip rotation decrease. Due to the inertia and viscous resistance of the engine and the torque converter, the inertia energy stored in the engine and the torque converter changes smoothly at least until the slip rotation becomes zero. Even when the vehicle is engaged, the engagement shock is unlikely to occur as in the case of FIG. 10, and therefore, it is possible to control such that the inertia energy is successfully released and the change in the engine torque can be transmitted smoothly. An improved useful control scheme is realized.

Further, when the decrease in the engine torque is predicted or detected as described in claim 4, control with low tracking is performed for a predetermined period, and control with high tracking is performed before engagement of lockup. The present invention can be suitably implemented as a configuration for performing control to change the speed at which the slip and the slip rotation are reduced, and the above can be similarly realized. In this case, control that also takes into account the followability can be realized. If a decrease in engine torque is predicted or detected, the first half is controlled with low followability, and in the subsequent period before lock-up is engaged, the followability is reduced. With high control, control can be performed while changing the reduction speed of the slip rotation, taking into account such followability, which is more effective, and a control mode in which the above-described action can be used even better. And the like.

In this case, it is preferable that claim 5 is adopted.
As described above, when switching the control characteristics, the present invention can be implemented by changing the control gain by switching the control gain or by switching the control target value to change the control followability. Can be realized. By switching the control gain in this manner, the first half performs control with low tracking, and may change the tracking of control so as to switch to control with high tracking before the lock-up is engaged. When changing the rotation decreasing speed, the slip rotation can be made to follow a predetermined locus by switching the control target value instead of switching the control gain to switch the control characteristics.

Preferably, the control is switched so that the inertia energy of the engine and the torque converter obtained from the slip rotation speed before the start of the control is divided by a predetermined ratio. In this case, it is preferable to set a control switching point. The present invention can be suitably implemented in such a configuration, and similarly, the above can be realized. In this case,
Further, it is possible to set a control switching point adapted to the inertia energy of the engine-torque converter system before the start of control, and therefore, the advantages of the control method targeted by the present invention can be more effectively obtained. It will be.

In this case, when the division ratio is selected, the inertia energy stored in the engine-torque converter system before the start of the control is always adjusted and the torque is reduced. Change 1
The next delay (FIG. 9) can be approximated, the effect of optimizing the release of the inertia energy, and the effect of smoothly transmitting the change in engine torque can be further obtained.

Further, as in claim 8, the switching of the control is performed by calculating a time ratio, a slip rotation, an engine rotation, or a time integral value of a change speed thereof, which is calculated so as to obtain the division ratio according to claim 7. The present invention can be implemented as a configuration that is performed by any of the products of the inertia values, and the above can be similarly realized. Again,
As in the case of the seventh aspect, the effect of optimizing the release of the inertia energy and transmitting the change in the engine torque gently can be obtained.

Preferably, the present invention can be embodied as a configuration in which the slip control is restarted after a predetermined time has elapsed after confirming the lock-up engagement, as described in claim 9.
Similarly, the above can be realized. By doing so, it is possible to appropriately resume the slip control, and smoothly resume the slip control. For example, it is possible to excellently resume the slip control, and further obtain an effect that the driver does not feel uncomfortable. .

In the case where the decrease in the engine torque is predicted or detected, it is preferable that the engine torque be reduced.
As described above, the present invention is implemented as a method of predicting or detecting a decrease in engine torque by comparing the engine torque or an amount representing the engine torque with a predetermined threshold value, or comparing the change amount with a threshold value. Yes, and the same can be achieved in a similar manner. Here, as the representative amount, for example, an engine throttle opening, an engine intake air amount or an intake air negative pressure, a fuel injection amount, or other engine torque equivalent amounts can be applied. In this case, preferably, the apparatus further comprises a means for detecting the throttle opening of the engine, wherein the present detected throttle opening and the throttle opening are included in the method for predicting a decrease in the engine torque. The present invention can be implemented as a configuration for predicting a decrease in the engine by comparing the throttle opening before the delay time from the degree operation to the engine torque change, and the above can be realized in the same manner. . By doing so, it is possible to make more detailed control contents taking into account the delay time from the actual throttle opening operation to the actual engine torque change,
Better switching control can be realized.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an automatic transmission control device (lockup control device) for lockup control according to one embodiment of the present invention. In the figure, reference numeral 1 denotes an engine as a prime mover, and 2 denotes an automatic transmission (A / T). The automatic transmission 2 receives the power of the engine 1 through a torque converter (T / C) 3, changes the input rotation at a gear ratio according to the selected shift speed, and transmits the input rotation to the output shaft 4.

Here, the automatic transmission 2 is turned on and off of the shift solenoids 6 and 7 in the control valve 5.
The selected gear stage is determined by the combination of F. The torque converter 3 also controls the lock-up clutch (L / U clutch) between the input and output elements by the duty (Duty) control of the lock-up solenoid 8 in the control valve 5. ), Or a converter state in which input / output elements are not directly connected.

Further, for example, the lock-up solenoid 8
Means that when the drive duty (D) is 0%, T / C3 is set to L /
When the U-clutch is released, the converter state is established. For example, if the drive duty is 100%, the lock-up state is established by engaging the L / U clutch under the maximum lock-up engaging force. The lock-up control valve in the control valve 5 used to control this is
A hydraulic control valve (control valve) that switches to the open side at a drive duty of 0% and to the engagement side at a drive duty of 100%.
The engagement capacity of the L / U clutch can be arbitrarily set according to the duty. Here, a part of the lock-up control system can be configured to include the lock-up solenoid 8, the lock-up control valve, and the hydraulic control system of the L / U clutch.

ON / OFF of shift solenoids 6, 7;
The transmission duty of the lock-up solenoid 8 is controlled by a transmission controller 9. The controller 9 receives a signal from a throttle opening sensor 10 for detecting the throttle opening TVO of the engine 1, A signal from a transmission output rotation sensor 13 for detecting the rotation speed No of the machine output shaft 4 is input. Here, the controller 9 sends a signal from an engine rotation sensor 11 for detecting the rotation speed Ne of the engine 1 and an input rotation speed of the automatic transmission 2 (output rotation speed of T / C3 (turbine rotation speed)) Nt. And the like from the turbine rotation sensor 12 that detects

Here, the input information from the throttle opening degree sensor 10 can be used not only for shifting control but also for predicting or detecting a decrease in the torque of the engine 1. The input information from the engine rotation sensor 11 and the turbine rotation sensor 12 is also used for detecting the differential of L / U, and the measuring means for measuring the differential rotation speed is provided by these sensors and the controller 9. It is configured to include a part.

The controller 9 includes an input detection circuit, an arithmetic processing circuit, a storage program for storing a control program executed by the arithmetic processing circuit, such as a shift control and an L / U control, and a calculation result. 6, 7 and an output circuit for sending a drive control signal to the lock-up solenoid 8, and based on the input information, the shift control and L
/ U control is executed.

The shift control can be performed by a well-known calculation based on the input information of the throttle opening and the rotation of the transmission output shaft. That is, in the shift control, the controller 9 sets the throttle opening TVO
And the vehicle speed V calculated from the transmission output rotational speed No, the optimum gear position for the current driving state is obtained by, for example, a look-up method from table data, and the optimum gear position is selected. Shift solenoids 6, 7 are O
N, OFF to perform a predetermined shift.

In L / U control, basically, T / U
Judgment of the control area such as whether the motor is operating in the L / U area where the torque increasing function or the torque fluctuation absorbing function by C3 is unnecessary, or the operation in the converter area where these functions are necessary, is performed according to the control request. The drive control of the lock-up solenoid 8 is performed by the / U control command value. In the L / U range, the power of the engine 1 is transmitted by setting the input / output element to the L / U state in which the input / output elements are directly connected by engaging the L / U clutch.

Further, in the present embodiment, the controller 9
Slip L / U control is also executed, and slip L / U
In U, when applicable, control for switching the L / U control state targeted by the present invention is also executed based on a control program as shown in FIG. If detected, the current differential rotation speed is stopped from being maintained, and L / U control can be performed so that the L / U clutch is smoothly engaged.

In this case, preferably, when a decrease in the torque of the engine 1 is predicted or detected, the L / U fastening force at that time is maintained until the slip rotation reaches a value at which the L / U engagement can be confirmed. . Preferably, when a decrease in the engine torque is predicted or detected, the controller 9 determines, based on the L / U fastening force at that time, that the slip rotation is at a speed that does not affect the decrease in the slip rotation.
The L / U fastening force is reduced until the / U engagement is confirmed. Preferably, the controller 9 restarts the slip control after a lapse of a predetermined time after confirming L / U engagement.

Further description will be made with reference to FIG. Here, FIG. 2 shows the same engine rotation Ne as in FIG.
Of the various amounts when the throttle closing operation is performed during the slip L / U control with the slip rotation caused by the difference between the engine speed and the turbine rotation Nt, that is, the throttle opening TVO (FIG. 2A), the engine rotation Ne. And the respective values of turbine rotation Nt (same (b)), L / U control command value (same (c)), engine 1 torque, T / C3 turbine torque, etc. (same (d)) It is an example of a change transition under example control. The hatched portion in FIG. 2D represents an inertia torque due to a change in slip rotation (a change in the difference between Ne and Nt).

In this embodiment, when such a driving operation is performed, the controller 9 basically maintains the current L / U control command value until the slip rotation reaches a value indicating L / U engagement. Or at a speed that does not affect the decrease in slip rotation.

This is based on the following viewpoint. In other words, it was found that the T / C 3 has an effect of releasing the inertia energy and reducing the change in the torque of the engine 1 when the engine throttle is closed. A control method for better use was developed and realized. Specifically, in the case of FIG. 10 described above, even when a driving operation that causes a similar decrease in the engine torque is performed, the change in the engine torque is transmitted as it is, as described above. In such a case, the driving performance is impaired, for example, such that a suddenly large engagement shock is generated.
On the other hand, even in the same driving operation scene as shown in FIG. 2A, before and after the change in the torque of the engine 1, the change in the slip rotation is ignored and the L / U control command value is changed. If not changed, due to inertia and viscous resistance of the engine 1 and the T / C3, the torque is stored in the rotating body of the engine 1 and the T / C3 at least until the slip rotation (Ne-Nt) becomes zero. It changes smoothly while releasing inertia energy (Fig. 2 (b)
(D)) Even if L / U is fastened as it is, a fastening shock hardly occurs. Therefore, when the engine throttle is closed during the slip control, this control method that effectively releases the inertia energy and smoothly transmits the change in the engine torque becomes useful.

In the case of the embodiment control based on the control contents of FIG.
While monitoring the input information from the sensors 11 and 12, the controller 9 checks at every predetermined program control period whether or not the torque of the engine 1 has decreased during the slip L / U control. One preferred embodiment of a method for predicting or detecting a decrease in engine torque for this monitoring is:
This is shown in a control program example described below with reference to FIGS. For example, when the slip L / U control is being executed as shown in the state before time t1 in FIG. 2, when the engine throttle is closed (time t1), the slip rotation is correspondingly performed. Until the value indicates the L / U engagement (time t1 to t2).
The control command value is maintained or gradually reduced at a speed that does not affect the slip rotation reduction in preparation for slip resumption. Here, the controller 9 performs control to gradually decrease the slip speed at a speed that does not affect the slip rotation decrease in preparation for slip resumption (time t3).

In this manner, until the slip rotation becomes zero, the inertia energy is smoothly changed while releasing the inertia energy. Even if the L / U is engaged as it is, the engagement shock is not generated as shown in FIG. Does not occur.
Therefore, even when the throttle is closed by releasing the driver's accelerator pedal during the slip L / U control, FIG.
Unlike the case where the inertia energy simply changes by the amount of acceleration / deceleration as in 0 (d), the inertia energy is successfully released as shown in FIG. 2 and the change in engine torque can be transmitted gently, resulting in impaired drivability. Such disadvantages can be avoided beforehand. Also, L
After confirming the / U engagement, slip control can be resumed.

In this case, the slip L
/ U, the engine speed Ne decreases and then increases again in response to the closing operation of the throttle opening TVO.
It is further preferable that the control command at that time is maintained for a predetermined time after the U-connection. As a result, in this case, after the elapse of the predetermined period, the shift to the slip L / U is smoothly performed (FIG. 2A).
(D)). However, if the waiting time is too long, a muffled sound may be generated. Therefore, the time from the confirmation of the L / U engagement to the resumption of the slip control after the elapse of a predetermined time is not affected by the above-described uncomfortable feeling. It is better to choose a time when there is no sound. In addition, although the occurrence of slip is delayed due to the excess capacity, it is more preferable to set the slip restart time including this.

In the case of the control of the above-described embodiment, as shown in FIG. 2C, the controllability of the control is not emphasized (not expected), and the control is performed so as to reduce it in preparation for the slip resumption. According to the control program of the embodiment shown in FIG.
Furthermore, when a decrease in the torque of the engine 1 is predicted or detected, control with low tracking is performed in the first half (predetermined period), and control is switched to control with high tracking before L / U is engaged. The process for changing the slip rotation reduction speed (see FIG. 8) is also shown as being incorporated.

FIG. 3 is an example of a main flowchart according to this embodiment. First, in FIG.
Checks in step S101 whether slip L / U control is currently being performed. Step S102 shown below
The actual control of the contents in steps S113 to S113
Since this is executed only during / U control, as will be described later, if the answer to step S101 is NO, step S114 (other L / U control) is executed, and this program ends.

If the answer to step S101 is YES,
Further, next, in step S102, the current high response slip L
Check whether / U control is being performed. Here, the high response slip L / U control is not being performed (the answer in step S102 is N
If O), it is determined whether or not to switch to the high response slip L / U control in the following processing. First, step S
At 103, the responsiveness switching flag is confirmed.
The responsiveness switching flag is a flag that is switched from the OFF state to the ON state in step S106 described later. When the flag is ON, it means that steps S107 and S108 (response switching timer initialization processing and responsive switching time setting processing) have already been executed.

Here, as a result of the flag check in step S103, if the responsiveness switching flag is now OFF, the process proceeds to step S104 and thereafter, and the responsiveness switching needs to be performed in the following process. Is determined. That is, first, in step S104, based on the input information from the sensor 10, the current throttle opening TVO and the throttle opening TVO corresponding to the delay time from the throttle opening operation to the engine torque change.
The throttle opening T before the sampling cycle n times corresponding to
By taking the difference from the VO value, the throttle opening change amount ΔTV
Ask for O.

Next, at step S105, this ΔTV
The O value is compared with a predetermined threshold value as a comparative value for gain switching, and if the ΔTVO value is larger than the gain switching threshold value (the answer of step S105 is YE
In the case of S), it is determined that a driving operation requiring switching of the slip L / U control gain (here, a throttle closing operation by releasing the accelerator pedal) has been performed.

As described above, in the present program example, the means for predicting or detecting the decrease in the engine torque can be implemented by using the throttle opening TVO, and in that case, the method for predicting the decrease in the engine torque At
By comparing the current throttle opening TVO with the throttle opening TVO corresponding to the delay time from the throttle opening operation to the engine torque change, a decrease in the torque of the engine 1 can be predicted. In this way, even when setting the responsiveness switching time, more detailed control can be performed in consideration of the delay time from the actual operation of the throttle opening to the actual change in the engine torque. realizable.

When it is determined that a driving operation requiring switching of the slip L / U control gain has been performed, the responsiveness switching flag is set to 0 in step S106.
N, the responsiveness switching timer is initialized in step S107, a predetermined responsiveness switching time is obtained in step S108, and the process proceeds to step S111 and thereafter to prepare for responsiveness switching control (FIG. 8; After time t1).

When it is determined that the driving operation that requires switching of the slip L / U control gain has not been performed as a result of the comparison determination in step S105 (step S1).
If the answer to step S05 is NO), the above steps S106 to S106 are repeated.
S108 is skipped, and the process directly proceeds to step S109. In this step S109, slip L / U control with a focus on normal stability (low response) is performed.

By the way, in the flag check of the above-mentioned step S103, in the processing before the previous loop, the above-mentioned step S103 is executed.
If the responsiveness switching flag has been switched from OFF to ON as a result of execution of steps 106, S107, and S108, step S110 will be selected thereafter from step S103. That is, when the responsiveness switching flag is ON in step S103, it is determined that the responsiveness switching is waiting, and first, in step S110, the initialization is completed every time this step (S110) is executed. Of the responsiveness switching timer is sequentially incremented for each control cycle, and the elapsed time since the driving operation requiring the switching of the slip L / U control gain is performed is counted.

After the operation in step S108 or step S109, in step S111, the value of the responsiveness switching timer is compared with the responsiveness switching time set in step S108 to determine the slip L / U control gain. (Step S11)
When the answer to 1 is NO), the low response slip F / B control in step S109 is continued (FIG. 8; time t1 to time t1).
t12) If it is confirmed that the responsiveness switching time has elapsed since the driving operation that required the switching of the slip L / U control gain is performed (when the answer to step S111 is YES), the step is performed. In step S111, step S112 is selected, and the control state of the L / U is switched to the high response slip L / U control in step S112 (FIG. 8; time t12).

Thus, after the control state of the L / U is switched to the high response slip L / U control in step S112, it is determined that the high response slip L / U control is being performed in step S102 thereafter. If confirmed (when the answer to step S102 is YES), step S11
At 3, the high response slip L / U control is executed (FIG. 8; after time t12). If it is determined in step S101 that slip L / U control is not being performed, other L / U control is performed in step S104 as described. The specific content of the control is not directly related to the purpose of the control of the present embodiment, but may be the above-described general one.

In this control, FIGS. 8 (a) to 8 (d)
When the engine throttle is closed (time t1), a predetermined time (first predetermined period) elapses, as illustrated in a timing chart showing a change transition of the same quantities as shown in the example of FIG. After that, that is, until the responsiveness switching time set in step S108, which is the responsiveness switching waiting period, (before the control switching), the control with low responsiveness is performed (time t1 to t12), and after the lapse of the predetermined time. After the subsequent predetermined period (second predetermined period), that is, after the control is switched, control with high tracking performance is performed (time t12 to t2).
3) The change speed (reduction speed) of the slip rotation can be changed. In the above description, the switching of the control characteristics is based on the switching based on time using a responsiveness switching timer process or the like. Alternatively, the switching may be performed based on slip rotation, for example. Therefore, when the throttle is closed, after a predetermined time elapses, or until the slip rotation reaches a certain rotation (predetermined rotation), the control with low followability is performed (time t1 to t12), and after the predetermined time elapses Alternatively, if the slip rotation becomes a certain rotation, control with high tracking performance may be performed (time t12 to t23) to change the slip rotation change speed.

According to the present control, in addition to the above-described effects, the control can be favorably realized in consideration of the following ability. That is, when the decrease in the torque of the engine 1 is predicted or detected, the slip rotation is performed until the slip rotation reaches the value indicating the L / U engagement (time t1 to t23 in FIG. 8).
The first half (similarly from time t1 to t12) is controlled by the control with low followability, and the subsequent second half period (similarly at time t1).
2 to t23), after the switching point of the control characteristic (also at time t12), with the control having high followability switched before the engagement of the L / U, while changing the reduction speed of the slip rotation, FIG. The same control as in the case is possible, and it is more effective because it also takes into account such followability,
A control mode in which the above-described operation described with reference to FIG.

Then, after the L / U is engaged, the F / B control is interrupted, the control command value at that time is maintained, and a predetermined period elapses (time t23 to t23 in FIG. 8) as described in the above embodiment.
After t3), it is also possible to smoothly shift to the slip L / U (FIGS. 8A to 8D). Therefore, maintaining the full L / U for the predetermined period may be the same as that in the above-described embodiment, and in such a case, the same operational effects as in the above-described case, such as smooth resumption of slip and the like in which discomfort is prevented, are obtained.

In the above example, when the control characteristics are changed, the slip L / U control gain is switched. However, instead of switching the control gain, the slip control is performed by switching the control target value. The same is true for causing the rotation to follow a predetermined trajectory. Therefore, in the mode according to the present example, there is included a mode in which the control followability is changed by switching the control target value instead of switching the control gain.

Further, the threshold value for the control performance change is determined from the slip rotation at the time of detecting the throttle operation, the inertia energy which the engine 1-T / C3 currently has, and the change in the engine torque is smoothly corrected. In order to be able to do this, divide it with appropriate distribution before and after control switching,
A period corresponding to the minute before control switching (t1 to t1 in FIG. 8).
It is preferable that the control is switched after (t12) has elapsed.

As described above, the switching point of the control is determined by determining whether the engine 1 and the T / T, which are obtained from the slip rotation speed before the start of the control, are controlled.
If the inertia energy of C3 is set so as to be divided at a predetermined ratio, it is possible to set a control switching point (timing) adapted to the inertia energy of the engine-T / C system before the start of control (see FIG. At time t12), the change in engine torque can be smoothly corrected. Therefore, as described above, the inertia energy stored in the rotating body of the engine 1 and the T / C 3 is released to make a smooth change, and the inertia energy is optimally released to make the change in the engine torque gentle. The advantage of the control method aimed at by the present invention, which can be transmitted in a controlled manner, can be more effectively derived and exerted.

In the control example of FIG. 8, from this viewpoint, the energy released during the first half (t1 to t12) is set so as to be a predetermined ratio of the inertia energy before the throttle operation of the engine 1-T / C3 system. The case where the gain is switched at the control switching timing at time t12 is shown. In this case, the engine 1 and T
When the inertia energy of / C3 is divided at a predetermined ratio, the ratio of the first half 1-exp (-1)... The second half exp (-1). In this case, the method of dividing the engine torque is always adjusted to the inertia energy stored in the engine 1-T / C3 before the start of the control, and the change in the engine torque is approximated to a gentle decrease characteristic. This method is effective in avoiding the engagement shock and avoiding the deterioration of driving performance. Where ex
p (-1) is the exponential function of the base of the natural logarithm, and is e- ¹ .

For example, if the threshold value of the control performance change is obtained as follows, the change in torque can be approximated to a first-order lag. 63.2 [%] of the inertia energy of the engine 1-T / C3 system obtained from the slip rotation when the throttle operation is detected (strictly speaking, (1-ex
p (-1) × 100 [%]) is defined as the inertia energy before control switching (FIG. 9).

FIG. 9 is a diagram for explaining the division ratio.
The state of the next lag energy distribution is shown. Where f (t)
= Kexp (−t / τ), the total area obtained in the range of time t = 0 to ∞ is S (t = 0 to ∞), and the area S (t = 0 to ∞) is expressed by the following equation 1. If the area of the hatched portion in the drawing is S (t = 0 to τ), the area S (t =
0 to τ) is expressed by the following equation 2, and therefore, S (t = 0 to
τ) / S (t = 0 to ∞) is represented by the following equation 3 (where K is a constant, τ is a time constant).

[0061]

(Equation 1)

(Equation 2)

S (t = 0 to τ) / S (t = 0 to ∞) = Kτ
(1-exp (-1)) / Kτ ≒ 63.2 [%] When the inertia energy is divided by this ratio, the slip rotation is 38.6 [%] of the original value (strictly speaking, e ^-1 ×
100 [%]).

Next, the quotient of the inertia torque due to the change in the engine speed predicted from this and the current engine speed Ne change speed is set as the control switching basic time. from now on,
The time obtained by subtracting the control command value update cycle and the delay time of the control oil pressure, or the slip rotation when this time has elapsed is obtained from the current engine rotation change speed and the current slip rotation, and is set as a threshold value (or control switching). A method of switching the control by comparing the pre-inertia energy with the integral of the rotation change is also conceivable, and this may be done).

Hereinafter, a supplementary explanation will be added, including the contents of the modified examples of the above-described embodiment. First, FIG.
3 is an example of a sub-flowchart showing a specific example of step S108 of the main flowchart in FIG. 3, that is, a calculation process for setting the responsiveness switching time. In the present program example, in step S201, an estimated slip rotation change width obtained from the product of the throttle opening change amount ΔTVO and TVO─slip rotation characteristic gain is obtained. Subsequently, in step S202, an estimated necessary control command value change width is obtained from a quotient obtained by dividing the estimated slip rotation change width by the control command value / the slip rotation characteristic gain.

Further, in step S203, a slip rotation control target value and a slip rotation control value, which are substitutes for the slip rotation control error in the L / U engagement state, which are substitutes for the control command value change width per control cycle. The estimated required control command value change width (step S
The estimated slip return delay time is obtained from the quotient obtained by dividing the value obtained in step 202). That is, the slip return delay time is basically estimated as a quotient obtained by dividing the estimated value of the required control command value change width by the above-mentioned slip control target value × slip control integral gain.

Then, in step S204, the estimated slip return delay time is subtracted from the target slip return time obtained from the muffled sound growth time determined by the sound vibration characteristics of the vehicle body, etc. I do.
In this case, it is also a countermeasure when there is a concern about occurrence of the muffled sound, and also a countermeasure for excellent and optimal slip resumption. Step S108 in the main flowchart of FIG. 3 may be performed as having such processing contents.

Similarly, FIG. 5 is a sub-flowchart showing another specific example of step S108. In this case, in step S211, 36.8 [%] of the slip rotation control target value is divided by the current engine rotation change rate, and the responsiveness switching time is used. Step S108 in FIG. 3 may be performed with such processing contents.

Next, FIG. 6 is applicable as a control program executed by the controller 9 in the embodiment device.
It is another example of a main flowchart. According to the present invention, in the control mode in which the control speed is switched from low control to high control to change the slip rotation decreasing speed, in addition to the method of switching depending on whether a predetermined time has elapsed, the slip rotation is controlled as described above. In this case, the control switching point is set to the engine 1-T / C3 by the ratio of
This can be done either by time, slip rotation, engine rotation, or the product of the time integral of their rate of change and the inertia value, calculated to divide the system's inertia energy.

FIG. 6 shows an example in which the responsiveness is switched by comparing the responsiveness switching timing with the time in the case of FIG. 3 by comparing the slip rotation with a threshold value. Specifically, as shown in FIG. 6, the steps S107 (response switching timer initialization processing) and S108 (response switching time calculation processing) in the main flowchart of FIG. Is replaced by
Step S111 (responsiveness switching timer ≧
The control switching determination process based on the responsiveness switching time is replaced by the comparison between the responsiveness switching slip rotation threshold value and the current slip rotation in step S152 as shown in FIG. The content processing of the other steps is the same as in the case of FIG. Also by this, the control speed can be switched from low control to high control to change the slip rotation reduction speed, and the same operation and effect as the above embodiment can be obtained.

FIG. 7 is a sub-flowchart showing a specific example of step S151 in the main flow chart of FIG. In this case, in step S221, 36.8 [%] of the slip rotation control target value is set as the responsiveness switching slip rotation threshold value. Step S151 in FIG. 6 may be performed as having such processing contents.

It should be noted that the present invention is not limited to the above-described embodiments, modifications, and the like. For example, a method of predicting or detecting a decrease in engine torque is based on engine torque,
Alternatively, a representative value (for example, the throttle opening TVO, an engine intake air amount, an intake air negative pressure, an amount equivalent to engine torque such as a fuel injection amount, and the like) is compared with a predetermined threshold value, or the amount of change is calculated. And a comparison with a threshold value.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an example of an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a timing chart for explaining the contents of a switching control process for switching a lock-up control state executed by a transmission controller.

FIG. 3 is a diagram illustrating an example (main flowchart 1) of a main flowchart of a control program including switching control.

FIG. 4 is a diagram specifically showing a part of a main flowchart in the same example and showing an example of a sub-flowchart (sub-flowchart 1) applicable to a responsiveness switching time calculation routine.

FIG. 5 is a view showing another example (sub-flowchart 2) of the sub-flowchart.

FIG. 6 is a diagram showing another example (main flowchart 2) of the main flowchart of the control program including the switching control.

FIG. 7 is a diagram showing an example of a sub-flowchart that can be applied to the responsiveness switching slip rotation threshold value calculation of the main flowchart in the same example.

FIG. 8 is a diagram showing another example of a timing chart for explaining the contents of the switching control process.

FIG. 9 is a diagram provided for explaining the contents of control according to the present invention, and is a diagram illustrating a first-order lag energy distribution.

FIG. 10 is a timing chart of a comparative example in the case of using the conventional method, as compared with the control method according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 engine 2 automatic transmission (A / T) 3 torque converter 5 control valve 6 shift solenoid 7 shift solenoid 8 lock-up (L / U) solenoid 9 controller 10 throttle opening sensor 11 engine rotation sensor 12 turbine rotation sensor 13 transmission Output rotation sensor

Claims (11)

[Claims] An automatic transmission control device for a vehicle, comprising: a control device capable of arbitrarily setting an engagement capacity of a lock-up clutch; and means for measuring a lock-up differential rotational speed. If a decrease in torque is predicted or detected, the current differential rotation speed is stopped from being maintained, and the lock-up clutch is smoothly engaged so that lock-up control is provided. Transmission control device. 2. When the decrease in engine torque is predicted or detected, the lock-up fastening force at that time is maintained until the slip rotation reaches a value at which lock-up engagement can be confirmed. Item 2. A control device for an automatic transmission according to Item 1. 3. When the decrease in engine torque is predicted or detected, a value at which the slip rotation can confirm lock-up engagement at a speed that does not affect the decrease in slip rotation is determined from the lock-up engagement force at that time. 2. The control device for an automatic transmission according to claim 1, wherein the lock-up fastening force is reduced until: 4. When the decrease in the engine torque is predicted or detected, control is performed with low responsiveness for a predetermined period of time, and the control is switched to control with high responsiveness before the lock-up is engaged. Control to change
The control device for an automatic transmission according to claim 1, wherein: 5. The control of an automatic transmission according to claim 4, wherein when switching the control characteristics, the control followability is changed by switching a control gain or a control target value. apparatus. 6. The control switching point according to claim 4, wherein the control switching point is set such that the inertia energy of the engine and the torque converter obtained from the slip rotation speed before the start of the control is divided by a predetermined ratio. A control device for an automatic transmission, comprising: 7. The method according to claim 6, wherein a division ratio of the inertia energy between the engine and the torque converter obtained from the slip rotation speed before the start of the control is 1-e ^-1 during a period before the control is switched, and The control device for an automatic transmission, wherein the period is selected so as to be divided by a ratio of e ^-1 or substantially by the ratio. 8. The method according to claim 7, wherein the switching of the control is performed such that time, slip rotation,
The control device for an automatic transmission according to any one of claims 4 to 6, wherein the control is performed by any one of engine rotation or a product of a time integral value of a change speed of the engine and an inertia value. 9. The control device for an automatic transmission according to claim 1, wherein the slip control is restarted after a predetermined time has elapsed after the confirmation of the lock-up engagement. 10. The method for predicting or detecting a decrease in engine torque includes comparing the engine torque or an amount representing the engine torque with a predetermined threshold value or comparing a change amount with a threshold value. The control device for an automatic transmission according to any one of claims 1 to 9, wherein: 11. A method for predicting a decrease in engine torque, further comprising: means for detecting a throttle opening of the engine, wherein a current detected throttle opening and a delay time from a throttle opening operation to a change in engine torque. 11. The control device for an automatic transmission according to claim 10, wherein a decrease in the engine is predicted by comparing the throttle opening with a considerably earlier throttle opening.