JP3488993B2 - Lockup control device for automatic transmission - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lockup control device for an automatic transmission in a vehicle.

[0002]

2. Description of the Related Art An automatic transmission has a torque converter inserted in its transmission system under a vehicle operating condition in a lockup 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 elements are directly connected can be established. In addition, during the coasting of the vehicle, in such a lockup type, the torque converter locks this up (L
/ U) control is also adopted.

[0003]

When such a so-called coast L / U is slowed down for the purpose of improving fuel economy,
On the other hand, there is a problem that an engine stall (stalling) is likely to occur during sudden braking on a low μ road. As a measure for L / U release response to avoid this, it is effective to make the L / U intermediate capacity during coasting, but the control range of the capacity is the open response that is required from the stalling resistance as the upper limit, The lower limit is limited by the required capacity required for L / U slip prevention. However, in terms of the precision of the capacity control, it is difficult to keep it within this control range only by improving the hardware technology. Therefore, control that suppresses variations in L / U capacity is desired.

If the above L / U capacity setting value during coasting is fixed, the L value during coasting may vary due to individual variations.
/ U capacity may be set in an area where engine stall cannot be avoided. Further, on the other hand, in the learning in the direction of decreasing the capacity, if this frequency is too high, the slip rotation frequency will be high and the fuel efficiency effect will be impaired. From this point, it is difficult to increase the frequency too much. Therefore, from this point of view, in order to ensure the engine stall avoidance as the initial quality, it is conceivable to set the initial value so as to surely fall within the region where engine stall can be avoided.

However, on the other hand, in this case, due to the similar individual variation, it is impossible to set the L / U to the complete L / U during the coast until the learning control is finished in many individuals, and the fuel consumption effect of the coast L / U is not achieved. You will not be able to demonstrate it. Further, these problems are inconvenient because they occur every time the controller memory is cleared, such as when the power supply is removed due to maintenance or the like.

The present invention has been improved based on the above consideration, and also adopts coast lockup (lockup during coasting) to provide an automatic transmission in which the engagement capacity of the lockup clutch can be arbitrarily set. Suitable for control applications,
The above-mentioned disadvantages and inconveniences can be avoided and appropriate lockup control can be performed. Also,
Locking the automatic transmission that realizes coast lock-up capacity control that can be kept within an appropriate range where learning in the direction of decreasing capacity rarely occurs after a certain amount of initial learning while also aiming to avoid engine stall, fuel efficiency effect, etc. The purpose is to provide an up control device.

[0007]

According to the present invention, the following lockup control device for an automatic transmission is provided. That is, the first is an automatic transmission control device in a vehicle that has a control device that can arbitrarily set the engagement capacity of the lockup clutch and a means that detects the differential of the lockup clutch. When the initial value is set to a control command value that makes it clear that slip rotation does not occur, and the predetermined flag in the controller memory is cleared, the lockup state was set during the first coasting. Sometimes the control command value is rapidly decreased to cause slip rotation, or the control command value is preset.
Therefore, when it becomes clear that both engine stall avoidance and slip rotation occurrence prevention, which are set as learning lower limit values , become apparent, the value at that time is corrected in consideration of individual variations, and lockup control during coasting is performed. A lock-up control device for an automatic transmission, characterized in that it is configured to be used as a reference value of a command value .

Further, the present invention includes a control device that can be arbitrarily set torque capacity of the lock-up clutch, lockup
A means for measuring the differential rotation speed of the clutch, a first storage means capable of holding the value regardless of the power connection, and a second storage means capable of changing the value but holding the value by the power connection. And means for detecting power-on, and the second
When the power source is first connected and the power source is first turned on after the content of the storage means is cleared, the differential of the lock-up clutch preset in the first storage means A lock-up control command value at the time of coasting that is sure not to occur is read into the second storage means, and the lock-up clutch is engaged and the lock-up state of the vehicle at coasting is first set after the power supply is connected. When the lockup control command value during coasting is used as an initial value, control is performed to reduce the lockup engagement capacity, and as a result of the lockup capacity reduction control thus performed, the lockup is performed. If the differential of the clutch is confirmed, the lockup engagement capacity at that time is stored and the value is used to set the lockup capacity in the coasting state from the next time. 1 a control for correcting, after the power connecting
A lockup control device for an automatic transmission, characterized in that the lockup control device is provided with a control means for performing only once.

Further, in the above, the lock-up capacity set value in the coasting state is set according to the motion state of the vehicle and the operating condition of the automatic transmission control system, and the correction condition is set accordingly. The feature is that the correction is performed according to them.

Further, as the movement states of the vehicle, vehicle speed, engine throttle opening, engine rotation, engine intake air amount, engine intake negative pressure, auxiliary machine drive state,
It is characterized in that any one of the braking device operating state or the change speed, the vehicle traveling load, and the engine torque obtained from them is used.

Further, as the operating condition of the automatic transmission control system, any one of transmission operating oil temperature, line pressure, pilot pressure and control power supply voltage is used.

Further, when the slip of the lockup clutch is detected and the learning control is started, while the learning control is continued, the normal lockup control during coasting is interrupted to maintain the current engagement capacity. It is characterized by:

Before the differential of the lockup clutch is confirmed, the lockup control command value is the control command value-
When it becomes smaller than the predetermined value determined from the engagement capacity characteristic, the lockup capacity reduction control is terminated, and the control command value for the coasting lockup control is determined by the lockup control command value at that time. , Is characterized.

[0014]

In the lock-up control device for an automatic transmission according to the present invention, learning in the lock-up capacity lowering control in the direction of decreasing the lock-up capacity works advantageously in terms of engine stall avoidance. , Lockup club
As the frequency of slip rotation of the switch increases, the effect of improving the fuel efficiency decreases, so that it is clear that, as described in claim 1, first, absolutely no slip rotation occurs with respect to the initial value. With a control command value that can secure a sufficient required capacity such as, for example, immediately when the first coast lockup state occurs when a specific flag of the controller memory is cleared, and None to reduce the control command value during a very short time, or slip rotation occurs or before
When the control command value becomes a value that is compatible with both engine stall prevention and slip rotation prevention, which is set as the learning lower limit value in advance , the value at that time is corrected in consideration of individual variations, and the value is adjusted when coasting. Base of lock-up control command value
If it is used as a quasi-value , even if there are individual variations, basically, it is possible to keep most of the individuals within the range where learning hardly occurs thereafter, and the disadvantages, inconveniences, inconveniences, etc. described above It is possible to realize an improved coast lockup control which can be solved.

According to the second aspect of the present invention, the contents of the second storage means which has each of these means and whose value can be changed but whose value is held by the power connection is cleared. After that, when the power source is first connected and then the power source is first turned on, the difference of the lock-up clutch preset in the first storage means capable of holding the value regardless of the power source connection. A lock-up control command value during coasting that ensures that no movement will occur is read into a second storage means whose value can be changed but whose value is held by a power connection, and, for example,
Then, when the lockup clutch is engaged and the coast lockup state is first established after the power supply is connected, the lockup control command value at the time of coasting is used as an initial value to perform control to reduce the lockup engagement capacity, and also
If the lockup clutch differential is confirmed as a result of the lockup capacity reduction control, the lockup engagement capacity at that time is stored and the value is used to set the lockup capacity in the coast state from the next time. If the control for correcting the value is configured to be performed only once after the power supply is connected, the present invention can be suitably implemented, and the above can be similarly realized.

Therefore, in this case, the lockup control device for an automatic transmission according to the present invention also makes the coast lockup control slower in order to increase the fuel consumption improving effect, and further, the lockup control during coasting. In order to prevent the engine from stalling due to sudden braking on a low μ road, the lockup capacity control during coasting, which sets the engagement capacity of the lockup clutch to an intermediate capacity, is also aimed at improving the responsiveness of the lockup release to avoid stalling. Even if it is done, it can be applied to a wide range of many individuals, and regardless of the individual to which it is applied, the control range of the lockup capacity is controlled to prevent the engine stall and improve fuel efficiency while suppressing the variation in the lockup capacity. Is optimized, and even if the power supply is removed for maintenance, etc. Even if the memory contents of the tracker are cleared, the process by the optimal initial learning of the lock-up control command value during coast is executed once after the power supply connection so that the situation can be dealt with regardless of such a case. What is obtained in the initial learning can be used as a reference for the lockup control at the corresponding coast thereafter. Therefore, it is possible to set the lock-up capacity setting during coasting within a range in which learning hardly occurs thereafter, and thus within an appropriate control range, which is not the capacity control range in which slip rotation frequently occurs, which impairs the fuel efficiency effect. If the value is fixed, the lock-up capacity at coast may be set to an area where engine stall cannot be avoided due to individual variations, and if the learning to reduce the capacity is too frequent, the slip rotation frequency will increase. It is difficult to increase the frequency too much because it impairs the fuel consumption effect.On the other hand, when setting the initial value so that the engine stall avoidance is surely set as the initial quality, the same individual variation may occur. , Complete lock on the coast until the learning control is completed in many individuals However, if the power supply is removed due to maintenance, etc., it is possible to avoid coast lockup fuel consumption effect. There is no inconvenience that occurs each time the controller memory is cleared.

Preferably, in the lock-up control device, the lock-up capacity set value in the coasting state is set in accordance with the motion state of the vehicle and the operating condition of the automatic transmission control system. Moreover, the present invention can be implemented as a configuration in which correction conditions are set according to them and the correction is performed according to them, and the above can be similarly realized. In this case, further correction can be performed according to the motion state of the vehicle and the operating condition of the automatic transmission control system, and more detailed control can be performed.

Here, as described in claims 4 and 5, vehicle speed, engine throttle opening, engine rotation, engine intake air amount, and
Engine suction negative pressure, auxiliary equipment drive state, braking device operating state or change speed required from them, vehicle running load,
And engine torque, and any one of transmission operating oil temperature, line pressure, pilot pressure, and control power supply voltage can be used as an operating condition of the automatic transmission control system. .

Further, in the lock-up control device, when the slip-up of the lock-up clutch is detected and the learning control is started, the normal coasting is continued while the learning control is continued. The present invention can be suitably implemented by configuring the lockup control to be interrupted and maintaining the current engagement capacity, and the above can be achieved in the same manner.

When the lock-up control command value becomes smaller than a predetermined value determined from the control command value-engagement capacity characteristic before the differential of the lock-up clutch is confirmed as described in claim 7. In the configuration, the lock-up capacity lowering control is terminated, and the lock-up control command value at that time determines the control command value at the coast lock-up. Can be realized. in this case,
Furthermore, in this way, it is possible to determine an appropriate control command value that is compatible with both engine stall avoidance and slip rotation occurrence prevention, without actually seeing slip rotation occurrence.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a lockup control device for an automatic transmission according to an embodiment of the present invention. In the figure,
1 is an engine as a prime mover, 2 is an automatic transmission (A /
T) is shown. The automatic transmission 2 receives the power of the engine 1 through a torque converter (T / C) 3, shifts the input rotation at a gear ratio according to the selected shift stage, and outputs the output shaft 4
Shall be communicated to.

Here, the automatic transmission 2 is provided with various valves and the like to regulate a line pressure which is an operating hydraulic pressure, or a constant pressure (pilot) which is used for shift control and lockup control based on the line pressure. It has a control valve 5 capable of producing pressure, etc. Automatic transmission 2
Is determined by the combination of ON and OFF of the shift solenoids 6 and 7 in the control valve 5, and the torque converter 3 is also input / output element by the duty control of the lockup solenoid 8 in the control valve 5. A lock-up clutch (see reference numeral 3a in the model of FIG. 3) can be used to establish a lock-up (L / U) state or a converter state (T / C state) where input / output elements are not directly connected. To do.

Incidentally, for example, the lockup solenoid 8
When the drive duty (D) is 0%, the torque converter 3 is brought into the converter state by releasing the lockup clutch, and when the drive duty is 100%, the torque converter 3 is brought into the lockup state by engaging the lockup clutch. I shall. The lockup control valve in the control valve 5 used for this control 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%, and has a range between them. In the intermediate capacity control based on the duty value, the engagement capacity of the lockup clutch can be arbitrarily set according to the duty. The lockup control system in the automatic transmission control system can be configured to include the lockup solenoid 8, the hydraulic control system for the lockup control valve and the lockup clutch, and a part of the following controller.

ON / OFF of the shift solenoids 6 and 7,
Further, the drive duty (L / U control command value) of the L / U solenoid 8 is controlled by the transmission (A / T) controller 9, and the controller 9 detects the throttle opening TVO of the engine 1. Throttle opening sensor 1
The signal from 0 is input, and the signal from the transmission output rotation sensor 13 that detects the rotation speed No of the transmission output shaft 4 is input. In addition, in the controller 9, here,
A signal from an engine rotation sensor 11 that detects a rotation speed Ne of the engine 1, a signal from a turbine rotation sensor 12 that detects an input rotation speed (output rotation speed of the torque converter 3) Nt of the automatic transmission 2, a transmission hydraulic oil. Temperature (A / T oil temperature)
A signal or the like from the oil temperature sensor 14 for detecting is input. In addition, the controller 9 has an ignition key ON /
It is assumed that the ON / OFF signal by the OFF operation is input.

The input information from the throttle opening sensor 10 input to the A / T controller 9 is applied to the shift control and the vehicle coasts.
It can also be used to determine whether or not a condition exists. The input information from the transmission output rotation sensor 13 can be used to calculate the vehicle output speed V from the transmission output rotation speed No. Further, when a mode in which the operating state of the vehicle is reflected in the setting of the engagement capacity of the L / U clutch in detail is adopted, for example, the vehicle speed V, the throttle opening sensor 10, the engine rotation sensor 11 or the like. The input information from can be used as an indication of the driving state of the vehicle. On the other hand, the input information from the engine rotation sensor 11 and the turbine rotation sensor 12 can also be used to detect the differential of the L / U clutch, and in this case, measuring means for measuring the differential rotation speed. Is configured to include these sensors and a part of the controller 9. In addition, the oil temperature sensor 1 is applied when a mode is adopted in which the operating conditions of the A / T control system are reflected in the setting of the engagement capacity of the L / U clutch.
The input information from 4 can be used to indicate the operating conditions of the A / T control system. Also, the controller 9
Can detect power-on by turning on the ignition key.

The A / T controller 9 is connected to an on-vehicle battery as a power source, and has an input detection circuit and
An arithmetic processing circuit, a shift control program executed by the arithmetic processing circuit, an L / U control program, and a control program such as a coast initial learning control program described later according to the present invention, and an arithmetic result and other information are stored and stored. Memory circuit, and an output circuit for sending a drive control signal to the shift solenoids 6, 7 and the L / U solenoid 8. The program processing by the controller 9 is started and started based on the power supply being turned on by turning on the ignition key, and the controller 9 executes shift control and L / U control based on the input information.

Regarding the gear shift control, the following gear shift control can be performed by well-known calculation, which is not shown here, based on the input information of the throttle opening and the transmission output shaft rotation. That is, in the shift control, the A / T controller 9 determines the optimum shift speed for the current driving state from the throttle opening TVO and the vehicle speed V calculated by the transmission output speed No. Then, the shift solenoids 6 and 7 are turned on and off to perform a predetermined shift so that the optimum shift speed is selected.

In the L / U control, the torque increasing function and the torque fluctuation absorbing function of the torque converter 3 are unnecessary in the L / U control.
The control area is determined such as whether the operation is performed in the area or the converter area that requires these functions, and the drive control of the L / U solenoid 8 is performed in accordance with the control request. In the converter region, the torque converter 3 is controlled so that the torque converter 3 is brought into the L / U state and the torque converter 3 is brought into the converter state.

For such control, the A / T controller 9 preliminarily sets the throttle opening TVO and the vehicle speed V, for example.
Lock-up ON line and lock-up OFF set in and
The lockup vehicle speed line (L / U line) data (table data) by a line is used to determine the L / S specified based on the current throttle opening TVO and the vehicle speed V of the vehicle in operation.
It is determined whether the vehicle is operating in the U region or the converter region, and the torque converter 3 is determined according to the determination result.
In the L / U region, the L / U clutch is engaged to bring the input / output elements into a directly connected L / U state, and in the converter region, the L / U clutch is released to bring the converter into a released state. It can be done by

Further, in this example, when the driver corresponds to the coast running condition in which the accelerator pedal is released, the coast L / U control is performed so that the fuel consumption improving effect can be expanded.
Furthermore, in the L / U state during coasting, the engagement capacity of the L / U clutch is intermediate for the purpose of improving L / U release responsiveness in order to avoid engine stall due to sudden braking on a low μ road, for example. In addition to performing L / U capacity control during coast setting to capacity, and L / U capacity control during the coast,
The A / T controller 9 also performs the following initial learning under constant conditions. That is, regardless of the individual to which the L / U capacity is applied, the L / U capacity control range is optimized to suppress the engine stall and improve fuel efficiency while suppressing the variation in the L / U capacity. Even if the memory contents of the controller 9 that have been accumulated and stored until then are cleared by the removal of the power supply (battery) at the time, etc., it is possible to cope with the situation regardless of such a case. The optimum initial learning process for the control command value is executed once after connecting the power source, and the result obtained by the initial learning is L / L at the corresponding coast after that.
This is the standard for U control.

Basically, the execution of learning in the L / U capacity lowering control in the direction of decreasing the L / U capacity works advantageously in terms of engine stall avoidance, but on the other hand, the occurrence of L / U slip rotation occurs. As the frequency increases, the effect of improving the fuel consumption decreases, so first set the initial value to a control command value that makes it clear that slip rotation will never occur. When the specific flag is cleared, the control command value is decreased immediately when the first coast L / U state is entered, and within a very short time, and slip rotation occurs or the engine stall occurs. When the control command value is such that avoidance and prevention of slip rotation are both achieved, the value at that time is corrected in consideration of individual variations, and the L /
It can be used as a reference value of the U control command value . After doing this, except for some,
For most individuals, it can be put in a range where learning hardly occurs thereafter.

In this case, preferably, the A / T controller 9 is provided with a value (data) regardless of the power connection.
A first memory as a first storage means capable of holding
Although the value (data) can be changed, a second memory as a second storage means for holding the value (data) by power connection is provided, and the first memory is provided with the L / U at coast time. As the control command value, a predetermined L / U control command value that ensures that the differential of the L / U clutch of the torque converter 3 does not occur is stored in advance. Regarding the L / U control, when the power is first connected after the contents of the second memory are cleared and then the power is first turned on, the value can be held regardless of the power connection. The L / U control command value during the predetermined coast, which is set in advance in the first memory,
When the L / U is read into the second memory and then the L / U is concluded and the coast L / U state is first established after the power supply is connected, the above L / U control command value during coast is applied as an initial value to / U control is performed to reduce the engagement capacity, and as a result of the L / U capacity reduction control, L / U
When the differential of the clutch is confirmed, the L / U engagement capacity at that time is stored, and the L / U capacity setting value in the coasting state (coast running state) from the next time is corrected with the stored value. The control is controlled so that it is performed only once after the power supply is connected. Further, preferably, the controller 9 sets the L / U capacity set value in the inertia running state according to the motion state of the vehicle and the operating condition of the A / T control system, and sets the correction condition accordingly. And, the control is performed so that the correction is performed according to them.

Among the above-mentioned storage means, the second storage means whose value can be changed but whose value is held by power connection is used as a battery backup memory, and the value is independent of power connection. Can be made to function as a memory (for example, EEPROM) that does not need to be backed up, and these can be configured as a part of the memory circuit of the controller 9.

As for the monitoring and detection of the differential of the L / U clutch (occurrence of slip rotation), as described above, for example, the difference (N between the engine rotation Ne and the automatic transmission input rotation Nt).
The measurement can be performed by e-Nt), or can be performed by using the ratio or the amount corresponding to them. Here, it is assumed that the controller 9 monitors the difference between the engine rotation and the input rotation of the automatic transmission, and uses this as a quantity representing the differential of L / U to execute the generation and confirmation of the differential.

FIG. 2 is a control program flow chart of a main routine of one control example including the above-mentioned correction processing executed by the A / T controller 9. The initial learning routine which is the main routine of this control is called only when the L / U control state becomes the coast L / U state in the L / U control routine. Incidentally, whether or not the coast L / U is requested is determined in an L / U control program (not shown). Further, in that case, the controller 9 determines whether or not the vehicle is in the coast state based on a signal from the sensor 10, for example, whether or not the throttle opening TVO is equal to or smaller than a minute set value.
Alternatively, it goes without saying that it is also possible to make a determination based on a signal from an idle switch that is turned on when the accelerator pedal is released.

First, the initial learning routine, when called, confirms the current control state by a flag and initializes it if necessary. First, in step S1, the initialization completion flag is checked. Here, the initialization end flag is a flag that is switched from OFF to ON by the execution of step S10 described later in this program example, and the flag initial value is OFF. Further, the initialization end flag is turned on by program execution, and then the power is removed due to maintenance or the like (when the controller 9 itself is removed without removing the battery itself from the vehicle body, This flag is turned off when the controller memory is cleared (including the case where the connection with the power supply is disconnected). In step S1, the state of such a flag is observed. Therefore, in this flag check, if the initialization end flag is actually ON, it is assumed that the initial learning has already been completed in this state, and the following initial learning is performed. Skip the routine and exit.

On the other hand, when the initialization completion flag is OFF, it can either correspond to the scene first initial learning routine in the present loop to the vehicle is performed, or corresponds to such as the following scene. In other words, if the above-mentioned maintenance is done and the initialization end flag is also cleared, then the situation where this initial learning routine is again executed for the first time in this loop (after the maintenance etc. is completed, This corresponds to the state where the program is started by turning on the power after the state of being connected to the battery terminal for the first time and the state is the coast L / U state for the first time, and this routine is called for the first time).

In any of the cases of this program example,
If the initialization end flag is OFF, then
In step S2, further, it is assumed that checks the initialization start flag. At this time, if the initialization start flag is also OFF, step S2 is performed only once.
A process to proceed to step S5 and subsequent steps through steps S3 and S4 is selected. In step S3, the L / UDuty initial value (data) is fetched from the ROM area (first memory) in which the stored contents (data) are held even if there is no power backup to the controller 9, It is substituted into the L / UDuty learning value of the RAM area (second memory) in which the stored contents (data) are retained by the power backup. After that, in step S4, the initialization start flag is turned on to set the initial learning start mode.

Here, the values applied in the L / U Duty initial value set in step S3 are preliminarily set as L / U control command values at the time of coasting so as to ensure that the differential of the L / U clutch does not occur. Can be set to a value that makes it clear that slip rotation does not occur. Here, the initial value data preset in the first memory that does not require power backup is At the timing of execution of step S3, the data is read into the second memory that requires power backup. In this way, when the initialization start flag is turned on and the process proceeds from step S1 to step S2 in the next loop, step S2
Skips steps S3 and S4 and goes directly to step S
The process can be advanced to 5 or later. As described above, the current control state can be confirmed by the flag.

After confirming the control state, the initial learning routine shifts to the actual control. First, the current slip rotation speed is checked based on the signals from the sensors 11 and 12, and the current L / UDuty
Verify that slip rotation has not occurred. Step S
At 5, the threshold value for detecting the occurrence of slip rotation is read.
This threshold value is mainly changed by the vehicle speed V because the accuracy of the rotation sensor and the magnitude of the rotation unevenness need to be changed.
The value has a parameter such as the engine rotation Ne.

When the slip rotation occurrence detection threshold value is determined, this threshold value is compared with the current absolute value of slip rotation [abs (slip rotation)] in step S6. If the absolute value of the slip rotation number is large, that is, if abs (slip rotation)> slip rotation occurrence detection threshold is satisfied and the occurrence of slip rotation is detected, then step S11 described below is performed.
If the absolute value of the slip rotation number is small, that is, if abs (slip rotation)> slip rotation occurrence detection threshold is not satisfied, the following processing is selected to start learning, and step S7 is selected, and step S7 is selected. At L / UDyty
The learning value is updated at a predetermined decrease rate. The rate of decrease at this time is determined by the responsiveness of the L / U system.

If the L / UDuty initial value is set to a control command value such that it is clear that slip rotation will never occur, when the coast L / U state is first set, the L / UDuty initial value is basically set. The condition of step S6 is not satisfied first, and at this time, the process on the L / UDyty learning value decreasing side of step S7 can be selected so that the control command value can be immediately decreased in an extremely short time. L / U by step S7
After updating the duty learning value, in this program example, the value updated in step S8 is set to the L / UDuty learning lower limit value (L / U
Compared with the value at which the engine can avoid engine stall without the clutch slipping).
If the updated value is smaller than this lower limit value, the processing of steps S9 and S10 is selected, but if not so, steps S9 and S10 are skipped and the processing in the loop at that time is ended. (Step S6 after the next loop
If the step S7 side is selected, the processing of the step S7 is repeated again).

When the process proceeds to step S9, the L / UDuty value during coasting is determined by using the L / UDuty learning value as the lower limit value in this step. Then, in step S10, the initialization end flag is turned on to end the initial learning. This L / UDuty learning value lower limit value is considered to be sufficient to avoid engine stall in consideration of variations.
/ UDuty value.

When the process is executed in a loop that goes through the above steps S5 → S6 → S7, the L / U engagement capacity is reduced with the above-mentioned coast L / UDuty initial value as the initial value. The L / U capacity lowering control is performed. At this time, as a result of the progress of this processing while obtaining a negative answer in the slip rotation check in step S6, even before slip rotation occurs, step S7 → step S8 → step S9 → step S10 is executed. In such a situation, the coasting L / UDuty value = L / UDuty learning value lower limit value, which is obtained in step S9, reduces the control command value from the initial value to avoid engine stall and slip rotation. A value that can be obtained when the control command value has a clear compatibility with prevention of occurrence, and can be used as a value that can be used as a reference value for the L / U Duty value during coasting after correction in consideration of individual variations. Means that. By doing so, even if there is individual variation in the L / U capacity, basically, for most individuals, learning will not occur thereafter, or substantially no learning will occur thereafter, thus impairing the fuel efficiency effect. It is possible to set it within an appropriate control range that is not the displacement control range where slip rotation frequently occurs.

In this case, L / U is preferable.
Before the differential of the clutch is confirmed (before the answer of step S6 changes from negative to positive), L
If the / U control command value becomes smaller than a predetermined value determined from the control command value-engagement capacity characteristic, the L / U capacity reduction control is terminated, and the coast is adjusted by the L / U control command value at that time. The L / U time control command value is determined. By doing so, it is possible to determine an appropriate coast L / U control command value that is compatible with both engine stall avoidance and slip rotation occurrence prevention without actually seeing slip rotation occurrence.
In the L / U control including the control device that can arbitrarily set the engagement capacity of the U clutch, it is possible to more appropriately absorb the variation according to the individual to which it is applied.

Further, as a result of the L / U capacity reduction control, when the differential of the L / U clutch is confirmed in this process, the L / U at that time point (the time point when the slip rotation occurs).
U capacity is stored and L / in the next coast state
The control for correcting the U capacity setting value is executed. That is, as described above, as a result of the comparison in step S6, if the relation of absolute value abs of slip rotation at that time (slip rotation)> slip rotation occurrence detection threshold is satisfied, learning is started, and the step S7 is started. Instead of the following process, the process on the step S11 side is selected. As a result, the correction is performed in step S11 and thereafter, but at this time, preferably, the L / U capacity set value in the coast state is set according to the motion state of the vehicle and the operating condition of the A / T control system. In this case, the correction conditions are set according to them, and the correction is performed according to them.

In this program example, if learning is to be started, the engine torque is changed in step S11.
Acceleration / deceleration inertia component is calculated in step S12.
13, the auxiliary machine load, the vehicle running load in step S14,
Each is calculated, and from these calculation results, step S15
Calculate the required fastening capacity at. Next, in step S16, the control command value-engagement capacity characteristic is corrected based on this engagement capacity, and the coast L / UDuty value is obtained based on this correction result in step S17. When the learning is completed, the initialization completion flag is turned on in step S10. Here, in the present L / U control device, preferably, when the learning control is started when the slip of the L / U clutch is detected as described above, the normal coast L / U is maintained while the learning control is continued. The U control shall be interrupted and the current engagement capacity shall be maintained.

Thus, the above steps S11 to S1
7 → By executing step S10, the control for correcting the L / U capacity set value in the elliptic state from the next time is 1 after the power is connected.
Only once, and as a result, the initialization end flag goes from OFF to O.
When it becomes N, even if this program is called next time, the processing of steps S2 to S17 is skipped even in the coast L / U state.

Thereafter, the steps S2 to S1
The reason that the initial learning routine by 7 is performed again is shown at the beginning when the controller memory is cleared when the power is removed due to maintenance or the like, and the initialization end flag is cleared to OFF by this. At such timing, the traveling control state of the vehicle first becomes the coast L / U state after the power supply is connected.

According to the above control, the initial value of the L / U control command value is set to a control command value that makes it clear that slip rotation does not occur, and a predetermined flag (initial value end flag) in the controller memory is set. If is cleared, the control command value is decreased as soon as possible when the first coast L / U state is reached, and when slip rotation occurs, the value at that time is subject to individual variation. L / U control finger during coast after correction considering
It can be used as a reference value for the regulation value, and in this way, even if there are individual variations in L / U capacity,
After that, learning is not generated or practically hardly occurs. Therefore, it is possible to set it in an appropriate control range that is not the displacement control range in which slip rotation frequently occurs, which impairs the fuel economy effect. Can be applied to a wide range of individuals. Further, in this case, the L / U capacity set value in the coast state is set according to the motion state of the vehicle and the operating condition of the A / T control system, the correction condition is set accordingly, and If the correction is performed in this manner, finer control can be performed.

FIG. 3 (torque converter, torque converter, etc.) for calculating the engine torque in step S11 and subsequent steps for the correction process when the differential of the L / U clutch is confirmed during the L / U capacity reduction control L / U model)
These can be performed as described below, for example, with reference to.

In the following, the following various quantities have the following contents.

[Formula 1] T ₁ ; T / C + L / U system input torque (engine torque) T ₂ ; T / C + L / U system output torque N ₁ ; T / C input rotation (engine rotation) N ₂ ; T / C output rotation I ₁ ; T / C input side inertia (engine inertia +
T / C input part inertia) I ₂ ; T / C output side inertia (T / C output part inertia + automatic transmission inertia) Tinp; T / C input part bearing torque Ttur; T / C output part bearing torque T ₁ clt L / U input side shared torque T ₂ clt; L / U output side shared torque τ; T / C torque capacity coefficient t; T / C input / output torque ratio Also, e indicates speed ratio = N ₁ / N ₂ , (T (e), t (e)), which will be indicated by adding (e) in the following description,
It is a function of. Also, (d / dt) indicates the first derivative, and therefore will be expressed using (d / dt) later.
(d / dt) N ₁ and (d / dt) N ₂ respectively represent their differential values.

First, it is known that the engine torque is generally mapped by the engine rotation Ne and the intake air amount Q or the fuel injection amount. Therefore, the engine torque depends on the vehicle to which it is applied, for example,
If you use this, you can easily find it.

Further, since the acceleration / deceleration inertia component is the inertia change of the engine 1 and the inertia change of the transmission and the vehicle system, it can be obtained by multiplying the inertia of each part obtained in advance by the rotation change amount.

On the other hand, regarding the auxiliary equipment load, the operating state of the main auxiliary equipment is monitored by ON / OFF of the switch,
There is a method of assigning an appropriate value thereby, and a method of estimating the magnitude by comparing engine loads with and without the auxiliary machine in a non-operating state (or forcedly making it). Any of these methods can be applied.

Regarding the vehicle running load, for example,
Each vehicle has a map based on the vehicle speed, which will be used. Further, the required fastening capacity is, for example, as shown in FIG.
Using these values for a simple model such as, the required fastening capacity is obtained from the equations (7) and (8) based on the following equations (1) to (6).

[0057]

## EQU00002 ## T ₁ = Tinp + T ₁ clt (1) Tinp = τ (e) ・ N ₁ ² (2) Ttur = t (e) ・ Tinp ・ ・ ・ (3) T ₁ clt = T ₂ clt (4) T ₂ = Ttur + T ₂ clt (5) ∴T ₁ clt = T ₁ −τ (e) ・ N ₁ ² (6)

Here, the equation (6) is obtained by adding the equation (2) to the equation (1).
Substitute and arrange to obtain. Then, by applying −I ₁ · (d / dt) N ₁ to the right side of Expression (6),

Equation 3] _{T 1 clt = T 1 -τ (} e) · N 1 2 -I 1 · (d / dt) N 1 ··· (7) Equation (4), to organize similarly (5) = T ₂ becomes -t (e) · τ (e ) · N 1 2 -I 2 · (d / dt) N 2 ··· (8).

Note that T ₂ −t (e) · τ on the right side of the equation (8)
(e) · N ₁ ² may give a T ₂ clt = T ₂ -Ttur the equation (5), by applying the equation (3) together with obtaining a T ₂ -t (e) · Tinp thereto, to Further, it can be obtained by applying the equation (2). As described above, the corresponding calculation can be performed after step S11, and the present invention may be implemented in this manner.

The present invention is not limited to the above-mentioned embodiments, modifications and the like. For example, the EEPROM is given as an example of the first memory that does not require a battery backup and can retain the value regardless of the power connection.
Not limited to this, for example, a flash memory may be used, and any non-volatile memory that can hold data without a backup power supply can be applied to the first memory.

Further, for example, in the above program example, in the processing of steps S2 to S4, the L / UDuty initial value from the first memory is set to the L / UDuty of the second memory.
Although it is substituted into the learning value, such a process may be performed once in the L / U control routine or the like after the power source is first connected after the initial learning program of FIG. 2 is not performed. Good. That is, for example, when the power supply is removed for maintenance and, as a result, the contents of the second memory are cleared, the power is first connected when the maintenance is completed, and then the power is first turned on. The L / UDuty initial value preset in the first memory may be read into the second memory at a timing. Even in this case, after the L / U is connected and the power is connected, the coast L / U is first
When the state is reached, the L / U duty initial value can be used as an initial value to perform control to reduce the L / U engagement capacity.

Further, for example, when the correction is performed according to the motion state of the vehicle, the vehicle speed V, the throttle opening TVO, the engine rotation Ne, the intake air amount Q (or fuel) of the engine 1 is used as an indication of the motion state of the vehicle. It is also possible to use any one of the injection amount), the suction negative pressure, the auxiliary machine driving state, the braking device operating state or the change speed obtained from them, the vehicle running load, and the engine torque. Similarly, in the case of performing correction, instead of or including the A / T oil temperature, which indicates the operating condition of the A / T control system,
Any one or more of A / T oil temperature, line pressure, pilot pressure, and control power supply voltage can be used.

In any of the above cases, the L / L in the coast state depends on the motion state of the vehicle and the operating conditions of the A / T control system.
Since the U capacity set value is set, the correction condition is set according to the set value, and the correction can be performed according to the set value, more precise correction can be performed.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of a lockup control device for an automatic transmission according to the present invention.

FIG. 2 is an example of a program flowchart for explaining an initial learning routine executed by a controller in the same example.

FIG. 3 is a diagram showing an example of a model of a torque converter and a lockup system.

[Explanation of symbols]

1 engine 2 Automatic transmission (A / T) 3 Torque converter 5 control valves 6 shift solenoid 7 shift solenoid 8 Lockup (L / U) solenoid 9 Controller 10 Throttle opening sensor 11 Engine rotation sensor 12 Turbine rotation sensor 13 Transmission output rotation sensor 14 Transmission operating oil temperature (A / T oil temperature) sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-118264 (JP, A) JP-A-7-71595 (JP, A) JP-A-8-28691 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) F16H 61/14

Claims (7)

(57) [Claims] 1. An automatic transmission control device for a vehicle, comprising: a control device capable of arbitrarily setting an engagement capacity of a lockup clutch ; and means for detecting a differential of the lockup clutch , wherein a lockup control command value is provided. When the initial value of is set to a control command value that makes it clear that slip rotation does not occur, and the predetermined flag in the controller memory is cleared, when the lockup state occurs during the first coasting Promptly decrease the control command value to cause slip rotation, or the control command value is set as the learning lower limit value in advance.
Where both of the engine stall avoidance slip rotation prevention that defines revealed values, during coasting after performing the correction in consideration of the individual variation of the value of the time
A lockup control device for an automatic transmission, which is configured to be used as a reference value of a lockup control command value . 2. A control device capable of arbitrarily setting the engagement capacity of the lock-up clutch , means for measuring the differential rotation speed of the lock-up clutch , and first storage means capable of holding the value irrespective of power connection. And a second storage means capable of changing the value but holding the value by power connection, a means capable of detecting power-on, and a first power source after the contents of the second storage means are cleared. Is connected, and when the power is first turned on, the lock for coasting is set in the first storage means in advance and it is certain that the differential of the lockup clutch does not occur. up control command value, read in the second storage means, when said lock-up clutch becomes coasting lockup condition of fastened first vehicle after the power connection, locking during coasting of the When the lockup engagement command value is an initial value, control for reducing the lockup engagement capacity is performed, and as a result of the lockup capacity reduction control thus performed, a differential of the lockup clutch is confirmed, The lockup engagement capacity at that time is stored, and means for controlling the lockup capacity setting value in the coasting state from the next time to be corrected only once after the power supply is connected by storing the lockup engagement capacity at that time. A lock-up control device for an automatic transmission, characterized by being provided. 3. The lockup control device sets a lockup capacity set value in a coasting state according to a motion state of a vehicle and an operating condition of an automatic transmission control system, and a correction condition according to the set value. The lock-up control device for an automatic transmission according to claim 1 or claim 2, characterized in that: 4. A vehicle speed, an engine throttle opening, an engine rotation, an engine intake air amount, an engine intake negative pressure, an auxiliary machine driving state, a braking device operating state, or a change obtained from them as a motion state of the vehicle. speed,
The lockup control device for an automatic transmission according to claim 3, wherein one of a vehicle running load and an engine torque is used. 5. The transmission operating fluid temperature, line pressure, pilot pressure, or control power supply voltage is used to indicate the operating condition of the automatic transmission control system. The lockup control device for an automatic transmission according to claim 4. 6. In the lock-up control device, when the slip-up of the lock-up clutch is detected and the learning control is started, the normal coasting lock-up control is suspended while the learning control is continued. The lockup control device for an automatic transmission according to any one of claims 1 to 5, wherein the current engagement capacity is maintained. 7. If the lockup control command value becomes smaller than a predetermined value determined from the control command value-engagement capacity characteristic before the differential of the lockup clutch is confirmed, the lockup capacity lowering control is performed. The automatic transmission according to any one of claims 1 to 6, wherein the control command value of the lockup control during coasting is determined by the lockup control command value at that time. Lockup controller.