JP2003202075A - Control device of torque converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve control characteristics in a converter state (torque converter area). <P>SOLUTION: The control device of a torque converter has a front compensator for calculating a target slip rotation compensation value, a feedback compensation means for calculating an instruction value to let the target slip rotation compensation value follow an actual slip rotation and a linearization compensation means for converging a fastening pressure of a lock up clutch with the fastening pressure instruction value in accordance with the slip rotation instruction value. The feedback compensation means has: a deviation calculation means 102a for calculating an actual slip rotation deviation from the target slip rotation compensation value and an actual slip rotation; a pseudo deviation calculation means 102b for calculating a pseudo slip rotation deviation; and a switch means 102c for temporarily selecting an output of the pseudo deviation calculation means 102b when the converter state transfers into a fastening state or a slip state as well as for selecting an output of the deviation calculation means 102a when normal control is executed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a control device for a torque converter having a lockup clutch.

[0002]

2. Description of the Related Art A lockup control device for a torque converter inserted in a power transmission system of an automatic transmission including a continuously variable transmission has a torque increasing action in order to reduce deterioration of fuel consumption due to slip of the torque converter. A lockup clutch that directly connects the input and output elements of the torque converter is provided in an operating region that does not require the shift shock absorption function. This is called a lock-up mode, and in addition to this, a converter mode (torque converter state) in which the input and output elements are completely released and torque is transmitted via fluid,
The lock-up clutch is in a semi-engaged state and has three slip modes in which a predetermined slip state is maintained, and is appropriately switched depending on the operating state.

By the way, when switching the above-mentioned operation mode, for example, when switching from the torque converter state to the lockup state through the slip state, when the lockup clutch is engaged, the rotational speed between the torque converter and the lockup clutch varies. If the differences do not match, a shock may occur and drivability may be impaired.

The same problem may occur when switching from the torque converter state to the slip state.

Further, the slip rotation speed (engine rotation speed-input shaft rotation speed) is F / B (feedback control).
Or by performing pre-compensation on the target slip rotation (for example, Japanese Patent Laid-Open No. 11-141677), the response characteristic of the actual slip rotation with respect to the target slip rotation is improved, and the shock at the time of engagement is reduced. The method of doing is proposed.

[0006]

However, in the above conventional example, when the operating condition is low, the difference between the engine rotation speed and the input shaft rotation speed is small even in the torque converter state, that is, the slip rotation speed is small. However, considering the case where the target slip rotation is set to 0 rpm or the like to shift to the lockup state in this state,
Since the difference between the target slip rotation and the actual slip rotation, which is the input of the feedback compensator, becomes smaller than that at high load, the input deviation of the feedback compensator becomes small and it is necessary to operate the lockup clutch. There is a problem in that the desired boosting speed cannot be obtained, and the torque converter state cannot be smoothly shifted to the lockup state or the slip state.

For example, the above-mentioned conventional example JP-A-11-1416
In Japanese Patent Publication No. 77, the target slip rotation speed of the torque converter calculated according to the operating condition is pre-compensated so that the actual slip rotation speed difference follows with a predetermined response characteristic.

In this predistorter, the denominator is composed of a filter having a time constant corresponding to the current operating state (vehicle speed or input shaft rotation speed), and the numerator is the control system (for example, slip rotation speed) of interest. It is composed of the reverse system.

That is, in the configuration in which the above-described conventional predistorter is divided into the reference model G _R (s) and the F / F (feed forward) compensator G _M (s), the slip rotation model P (s) is obtained. ) Transfer function of

[0010]

[Equation 1]

Therefore, the reference model G _R (s)
To

[0012]

[Equation 2]

In this case, the F / F compensator G _M (s) is

[0014]

[Equation 3]

[0015] In this configuration, if the model is consistent in all areas controlled (that is, can be modeled by the denominator of the above expression (3)), the denominator of the above expression (3) and the controlled object cancel each other as a result. , The numerator portion (that is, the output of the reference model) acts as a command value, and the effect of the F / F compensator can be exhibited.

However, what is actually modeled is the state in the slip region where the differential pressure across the torque converter has risen to some extent, so in control from the complete torque converter state, the model does not match and the denominator can be canceled. The output of the F / F compensator may deviate from the reference model output, and eventually problems such as excess and deficiency of the differential pressure command occur.

For example, as shown in FIG. 18, when the slip rotation speed difference control region is entered in a low load state in which the slip rotation speed (difference between the engine rotation speed and the input shaft rotation speed) is not so large, the slip rotation which is an input deviation. Since the speed is low, followability is poor, and the desired boost speed cannot be obtained.Therefore, the response delay until shifting to the lockup or slip state becomes large. There are cases where it is not possible to make a smooth transition to the state.

If the slip rotation model can be modeled in all regions from the complete torque converter region to the slip region to the lockup region, it can be assumed that the delay in response can be improved with only the F / F compensator. , In order to completely match the models, the transfer function formula of the model becomes complicated (the order becomes high), and as a result, the formula of the F / F compensator becomes complicated, which makes programming extremely difficult. There is a problem that becomes.

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to improve the control performance in the non-modeled portion (torque converter region = converter state) while making the most of the advantage of the conventional example in the slip region. And

[0020]

A first aspect of the present invention is to obtain a target slip rotation of a torque converter from a driving condition of a torque converter, which is provided with a lockup clutch and is interposed between a prime mover and an automatic transmission. A target slip rotation calculation unit, a constant of a compensating filter is set based on the operating state of the vehicle, and a precompensator for obtaining a target slip rotation correction value by passing the target slip rotation through the compensating filter, Feedback compensation means for calculating a slip rotation command value for matching the actual slip rotation with the target slip rotation from the target slip rotation correction value and the actual slip rotation, and a lockup clutch corresponding to the slip rotation command value. Linearization compensation that calculates the engagement pressure command value and matches the engagement pressure of the lockup clutch with the command value. And a stage, the slip control system of a torque converter controlled by engagement of the lockup clutch actual slip rotation between input and output elements of the torque converter, the feedback compensation means,
A slip rotation deviation calculation means for calculating an actual slip rotation deviation from the target slip rotation correction value and an actual slip rotation; a pseudo deviation calculation means for calculating a pseudo slip rotation deviation based on the operating state of the vehicle; Switching means for temporarily selecting the output of the pseudo deviation calculating means when the up clutch shifts from the disengaged state to the engaged state or the slip state, while selecting the output of the slip rotation deviation calculating means during normal control. And a slip rotation command value calculation means for calculating the slip rotation command value so as to eliminate the deviation output by the switching means.

The switching means may select the output of the pseudo deviation calculating means for a predetermined time from the start of the control for shifting the lockup clutch from the released state to the engaged state or the slip state.

In a second aspect based on the first aspect, the switching means switches from the pseudo deviation calculating means to the slip rotation deviation calculating means when the engine speed drops to a predetermined value.

In a third aspect based on the first aspect, the slip rotation command value computing means includes at least a proportional term and an integral term, and the switching means selects a pseudo deviation computing means. Calculates by switching the proportional term from a predetermined value to 0. Alternatively, the calculation is performed by including the integral term excluding the proportional term.

Further, in a fourth aspect based on the third aspect, the slip rotation command value computing means restores the proportional term to a predetermined value when the engine speed drops to a predetermined value.

Further, in a fifth aspect based on the first aspect, the switching means, when the slip rotation deviation of the slip rotation deviation calculating means exceeds a predetermined value, the lock-up clutch is in a disengaged state or in a disengaged state. Even when shifting to the slip state, the selection of the pseudo deviation calculating means is prohibited.

[0026]

Therefore, according to the first aspect of the invention, when the control for shifting from the released state (converter state) of the lockup clutch to the lockup side is started, the deviation is caused by the pseudo slip rotation deviation from the pseudo deviation calculation means. Since it is forcibly set to a large value, it is possible to quickly increase the lockup clutch engagement pressure even in the low load operation region where the slip rotation speed difference is small, and it is possible to improve the control performance in the converter state. .

In the second aspect of the invention, the slip rotation deviation is actually calculated by the pseudo deviation calculating means when the engine speed decreases to a predetermined value after the shift control of the lockup clutch to the engagement side is started. By switching to the slip rotation deviation calculation means, it is possible to return to normal feedback control, terminate the open loop control due to the pseudo deviation, and continue smooth control.

In the third aspect of the invention, the proportional term (proportional gain) is set to 0 during the period during which the switching means selects the pseudo deviation calculating means, in other words, during the shift control of the lockup clutch to the engagement side. By so doing, when returning to the normal feedback control, it is possible to prevent a step from being generated in the command value and the like and obtain a smooth control characteristic.

The fourth aspect of the invention is to return the proportional term from 0 to a predetermined value when the engine speed drops to a predetermined value after the control of shifting the lockup clutch to the engagement side is started. The open loop control due to the pseudo deviation can be terminated, the normal feedback control can be restored, and the smooth control can be continued.

In the fifth aspect of the invention, when the actual slip rotation deviation exceeds a predetermined value, it is possible to sufficiently follow the feedback control, so that smooth control is continued without using the output of the pseudo deviation calculating means.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing the system configuration of the present invention.

In FIG. 1, reference numeral 1 denotes a torque converter installed in a power transmission system such as an automatic transmission including a continuously variable transmission, for transmitting power between input / output elements via an internal working fluid. It is a thing.

The torque converter 1 further has a built-in lockup clutch 2 that rotates together with a torque converter output element (turbine).
When the torque converter 1 is fastened to the input element (impeller), the torque converter 1 is brought into a lockup state in which the input / output elements are directly connected.

The lockup clutch 2 responds to the pressure difference PA-PR between the torque converter apply pressure PA and the torque converter release pressure PR on both sides (front and rear) of the lockup clutch 2, and lockup occurs when the release pressure PR is higher than the apply pressure PA. The clutch 2 is released and the torque converter input / output elements are not directly connected, and the release pressure PR is the apply pressure PA.
When it becomes lower than the above, the lockup clutch 2 is engaged to directly connect the input and output elements of the torque converter.

In the latter engagement, the engagement force of the lockup clutch 2, that is, the lockup capacity is determined by the above differential pressure PA-PR. The greater the pressure difference, the greater the engagement force of the lockup clutch 2. To increase the lockup capacity.

The differential pressure PA-PR is controlled by a well-known lockup control valve 3, and this lockup control valve 3 has:
The apply pressure PA and the release pressure PR are made to act so as to oppose each other, and the spring 3 is moved in the same direction as the apply pressure PA.
The urging force of a and the spring force act in the same direction as the release pressure PR, and at the same time, the signal pressure PS in the same direction as the release pressure PR.
Act on each.

The lockup control valve 3 determines the differential pressure PA-PR so that the hydraulic pressure and the biasing force of the spring are balanced.

The signal pressure Ps applied to the lock-up control valve 3 is generated by the lock-up solenoid 4 according to the lock-up duty D using the pump pressure PP as a source pressure. , Differential pressure P via lock-up solenoid 4
Control A-PR.

A signal indicating the running condition of the vehicle or the driving condition of the driver, such as a signal from the output shaft rotation sensor 9 provided in the automatic transmission, a signal from the turbine rotation sensor 8 of the torque converter 1, is sent to the controller 5. A signal from the impeller rotation sensor 7 that detects the input rotation speed to the torque converter 1 and a signal from the oil temperature sensor 11 are input, and the detection signals control the engagement and release of the lockup clutch 2 or slip. To do.

The controller 5 determines the lock-up duty D for driving the lock-up solenoid 4 by calculation in accordance with the control system configuration diagram shown in FIG.
The lockup duty D is corrected according to the power supply voltage signal 6.

Next, the calculation inside the controller will be described based on the control system configuration diagram of FIG.

The target slip rotation calculation unit S100 determines the target slip rotation ω _SLPT based on the vehicle speed, the throttle opening (or the accelerator operation amount), the oil temperature, etc., at the place where the torque fluctuation or the muffled noise is least generated.

The actual slip rotation calculating section S103 subtracts the turbine runner rotation speed ω _TR from the pump impeller rotation speed ω _iR to calculate the actual slip rotation ω _{SL PR} of the torque converter 1.

Here, the rotational speed of the impeller is equivalent to the engine rotational speed, and the turbine rotational speed is equivalent to the input shaft rotational speed.

[0046] In predistorter S101, a target slip rotational omega _SLPT, by passing the compensating filter was set to be a response to a designer's intention, and calculates the target slip rotational correction value ω _SLPTC.

In the slip rotation speed deviation calculation unit S102, the slip rotation deviation ω _SLPER between the target slip rotation correction value ω _SLPTC and the actual slip rotation speed ω _SLPR is _calculated as ω _SLPER = ω _SLPTC − ω _SLPR. ).

However, at the start of the control for increasing the lockup clutch engagement hydraulic pressure, as shown in FIG. 3, the slip rotation speed deviation calculation unit S102 temporarily outputs the slip rotation deviation ω _SLPER, which is the output, as shown in FIG. By _increasing the slip rotation deviation ω _SLPER for a predetermined time by switching to the map value shown below), the boosting speed is increased.

Therefore, the slip rotation speed deviation calculation unit S
_{Reference numeral} 102 denotes a deviation calculation means 102a for calculating the slip rotation speed deviation ω _SLPER during normal feedback control, a pseudo deviation calculation means 102b for forcibly increasing the deviation, and a lockup state or a slip state from the converter state. At the start of the control for shifting to, the slip rotation speed deviation ω _SLPER to be output is calculated by the deviation calculating means 102.
Temporary (predetermined time) from a to pseudo deviation calculation means 102b
The switching means 102c for switching to.

In the slip rotation command value calculation unit S104 (feedback compensator), in order to eliminate the slip rotation deviation ω _SLPER , the slip rotation command value is _adjusted by a feedback compensator configured by proportional / integral control (hereinafter, PI control). _Let ω _SLPC be ω _SLPC = Kp x ω _SLPER + (Ki / S) x ω _SLPER (5) where Kp: proportional control constant (proportional gain) Ki: integral control constant (integral gain) S: from a differential operator calculate. As the gains Kp and Ki, values obtained in advance by experiments or the like are used. However, when the switching means 102c is switched to the pseudo deviation calculating means 102b, the proportional gain Kp = 0.

In the slip rotation speed gain calculation section S106, the current turbine rotation speed ω is calculated from the map shown in FIG.
_The slip rotation gain g _SLPC corresponding to _TR is searched for.

In the target converter torque calculation unit S105, the target converter torque t _CNVC for achieving the slip rotation command value ω _SLPC at the turbine rotation speed ω _TR.
Is calculated from t _CNVC = ω _SLPC / g _SLPC (6).

In the engine torque estimating section S108, FIG.
Using the engine performance map shown in, the engine rotational speed Ne and the throttle opening TVO, and search engine torque map value t _ES, when this dynamic characteristics of the engine and the first-order lag of time constant T _ED After passing through the filter, the estimated engine torque value t _EH is

[0054]

[Equation 4]

It is calculated from

The target lockup clutch engagement capacity calculation unit S107 calculates the target lockup clutch engagement capacity t _LU by subtracting the target converter torque t _CNVC from the estimated engine torque value t _EH .

T _LU = t _EH −t _CNVC (8) In the lock-up clutch engagement pressure command value calculation unit S109, the current target lock-up clutch engagement capacity t _{LU is} calculated from the lock-up clutch capacity map shown in FIG. The lockup clutch engagement pressure command value P _LUC for achieving the above condition is searched.

In the solenoid drive signal calculation unit S110,
A lockup duty S _DUTY for setting the actual lockup clutch engagement pressure to the lockup clutch engagement pressure command value P _LUC is determined.

Next, of the controls performed by the control unit 5, the control for increasing the lockup clutch engagement hydraulic pressure using the feedback compensator, which is the main part of the present invention, will be described with reference to the flowchart of FIG.

In step S1, it is determined whether or not the control to be performed at present is the slip control based on the throttle opening, the vehicle speed and the like. If it is determined that the slip control is performed, the process proceeds to step S4, and the slip control is not performed. If determined, the process proceeds to step S2.

In step S2, it is determined in the same manner as described above whether or not the control to be performed at present is lockup control. If it is determined to be lockup control, the process proceeds to step S3 and it is determined that it is not lockup control. In this case, the process proceeds to step S19.

In step S3, in lockup control, a complete lockup state (state in which the differential pressure command is maximum)
It is determined whether or not the process has been completed, and if it is possible, the lockup is completed, and the process proceeds to step S18.

On the other hand, if the complete lockup state has not been achieved, slip control is also used to perform control to enter the lockup state, so that the operation proceeds to step S4.

In step S4 in which it is determined that the current control state is slip control or lockup control, if the previous control state is converter control, the process proceeds to step S5, and if it is not converter control, the process proceeds to step S8.

In step S5, the initial differential pressure is searched and set according to the current throttle opening from the preset map of FIG. 10 based on the flowchart of FIG. 5 (described later).

In step S6, the time limit for executing the boosting operation using the feedback control system of this time is set according to the current throttle opening degree from the preset map of FIG. Note that in FIG. 11, the larger the throttle opening TVO, the longer the time limit is set. This is because the larger the throttle opening, the larger the slip amount at the start of control, which corresponds to this slip amount. Is.

Then, in step S7, a flag (FLAG1) indicating that the boosting operation is being executed is set.

In steps S5 to S7, the preparatory process for starting the boosting process is performed only for the first time when the operating region is changed from the converter state (torque converter state) to the slip state or the lockup state, and the second and subsequent times are not performed. .

At step S8, whether or not the boosting operation by the open loop is currently being executed is judged by the flag (FLAG1) set at step S7.
When the boost operation is being executed (FLAG1 = 1). In step S9, it is determined whether or not the boosting operation is continued. If the boosting operation is not being performed (FLAG1 = 0), the processing proceeds to step S15.

In step S9, the determination slip rotation ω _SLPEND for ending the boosting operation is calculated from the map of FIG. 12 according to the flowchart of FIG. 6 (described later).

Then, the current slip rotation ω _SLPR and the judgment slip rotation ω _SLPEND are compared. If ω _SLPR ≤ ω _SLPEND (9), the slip rotation responds to the differential pressure command due to the boosting operation. For the first time, it was judged that the differential pressure control was possible,
Step S1 after ending the boosting operation by the open loop
Then, the process proceeds to step 3 to perform the switching process to the normal feedback control.

If the above equation (9) is not satisfied, it is determined that the slip rotation has not responded to the increase of the differential pressure command, and the routine proceeds to step S10.

In step S10, the time limit set in step S6 is compared with the elapsed time from the start of boosting, and if the time limit has elapsed, the conditions for slip rotation in step S9 are satisfied. Even if it is not, the process proceeds to step S13, and the switching process to the normal feedback control is performed.

On the other hand, when the time limit has not passed,
It is determined that the boosting operation is to be continued, and the process proceeds to step S11.

In step S11, the P (proportional) gain Kp of the feedback compensator constituted by PI control is set to Kp = 0 ... In order to perform the boosting operation equivalent to the open control while using the feedback control system. (10) In step S12, the slip rotation deviation ω _SLPER , which is also the input of the feedback compensator, is not ω _SLPER = ω _SLPERMAP , which is the equation (4) used during normal feedback control. ) Is calculated as.

This ω _SLPERMAP is a value for forcibly setting the slip rotation deviation which is the input of the feedback compensator, and is set by searching from the map in FIG. 13 according to the current throttle opening. Here, the map of FIG. 13 is
Since it is set to a negative value over the entire throttle opening, the deviation input to the feedback compensator is fixed to a negative value.

Since the P gain is set to 0, as a result, the operation of the feedback compensator operates as a mere integrator of the input, and the output of the feedback compensator has a negative slope. This represents that the slip rotation command value ω _SLPC decreases, which is equivalent to the converter torque t _CNVC decreasing.

When the converter torque t _CNVC decreases, the lockup capacity t _LU is calculated by the above equation (8), but in the state where the engine torque t _EH does not fluctuate significantly as compared with the converter torque t _CNVC , The lockup capacity t _LU will increase. An increase in the lockup capacity indicates that the differential pressure command value increases,
By the above control, the open boosting operation using the feedback control system proposed in the present invention is realized.

On the other hand, in step S13, the control system is initialized in order to end the boosting operation by the open loop and switch to the conventional feedback control.

In this initialization processing, in the control system configuration diagram of FIG. 2, the output of the predistorter S101 is initialized by the actual slip rotation at the time of switching to the feedback control, and the feedback compensation in the rotation command value calculation unit S104 is performed. The device is also initialized by slip rotation corresponding to the actual differential pressure.

In the following step S14, a flag (FLAG
1) is cleared and the process proceeds to step S15.

In step S15, in order to perform the conventional feedback control, the P gain Kp of the feedback compensator is returned to a normal value other than 0, and in step S16, the slip rotation deviation ω _SLPER which is the input of the feedback compensator is _changed to The difference between the normal target slip rotation ω _SLPTC and the actual slip rotation ω _SLPR is calculated and set by the above equation (4).

In the above steps S8 to S12, the control system parameters (P gain and input deviation of the feedback compensator) at the time of boosting by the open loop are set, and step S9, S13 to S16 or step S9,
In steps S10 and S13 to S16, switching processing from boosting by open loop to normal feedback control is performed, and in steps S8, S15 and S16, control system parameters for normal feedback control are set.

Then, in step S17, as shown in FIG.
Slip control calculation is performed based on the control system configuration diagram of FIG.
For example, when a drive slip is performed, the target slip computing unit S100 sets the target slip rotation ω _SLPT to, for example, 40 rpm, and when the lock-up state is set, 0 rpm is set.

Then, the feedback control system operates so as to match the set target slip rotation.

In step S18, the engagement operation (complete lockup) in the lockup control is completed and the differential pressure is kept at the maximum pressure.

In step S19, the lockup clutch releasing operation (unlocking up) in the converter control is completed and the differential pressure is kept at the minimum pressure.

Next, an example of setting the initial differential pressure in step S5 of FIG. 4 will be described with reference to the flowchart of FIG.

First, in step S50, a preset initial differential pressure value (hereinafter abbreviated as a map value) is read from the map of FIG. 10 according to the current throttle opening.

In step S51, the current differential pressure is compared with the map value. If the current differential pressure is larger than the map value, the process proceeds to step S52, and the current differential pressure is selected as the initial differential pressure. The current differential pressure PA-PR may be estimated from the value of the lock-up duty D, or may be detected by providing hydraulic pressure sensors for the release pressure PR and the apply pressure PA (not shown).

On the other hand, if the current differential pressure is less than or equal to the map value, the flow advances to step S53 to select the map value as the initial differential pressure.

As a result, even when the preset map value is lower than the current differential pressure, the initial differential pressure can always be set to a value equal to or higher than the current differential pressure.

Next, an example of calculation of the determination slip rotation ω _SLPEND in step S9 of FIG. 4 will be described with reference to the flowchart of FIG.

First, in step S60, the current actual slip rotation and the target slip rotation are compared. As a result, when the actual slip rotation is larger than the target slip rotation, in step S61, the determination slip rotation according to the current throttle opening is set from the map of FIG. Since the larger the throttle opening is, the larger the slip amount at the time of starting the slip control, the slip for determination is set to be large in the region where the throttle opening is large.

On the other hand, if the actual slip rotation at the present time is less than or equal to the target slip rotation, the determination slip rotation is set to the current target slip rotation in step S62.

From the above, the target slip rotation is calculated as shown in FIG.
When it is set to change depending on the turbine rotation and throttle opening as shown in, even if the target slip rotation may be larger than the actual slip depending on the operating condition, the slip rotation as a termination judgment condition is normally detected. Can be set.

An example of shifting from the converter state to the lockup state by the above control is shown in the timing chart of FIG.

In this timing chart, the throttle opening TVO is kept constant and the input shaft rotation of the automatic transmission (primary rotation in the figure) is kept constant, and the converter state is changed from the time T0 to the lockup state (or slip state). This is the case when the control shifts toward.

At the start of the shift control (T0), the initial differential pressure and the boosting limit time are set in accordance with the operating state and the proportional constant Kp is forcibly set to 0 in steps S5, S6, S11 and S12. Set and switch the feedback compensator input (slip rotation speed deviation ω _SLPER ) to the map value.

As a result, the slip rotation speed deviation ω _SLPER is set to a negative value from the time T0 in FIG. 15 according to the map in FIG. 13, the deviation temporarily increases, and the output of the feedback compensator (slip rotation command The value ω _SLPC ) acts in a direction to eliminate this pseudo deviation, and the differential pressure _{across the} lockup clutch can be quickly increased.

From time T0, the slip rotation speed deviation ω
_{Since SLPER} is fixed to the map value, the control becomes an open loop, and since the proportional gain Kp is set to 0 and the feedback compensation is performed only with the integral gain Ki, even if the slip rotation deviation changes suddenly. It is possible to smoothly change the slip rotation command value ω _SLPC , converter torque, and lockup capacity without generating a step in the output of the feedback compensator.

When the lockup capacity increases as the differential pressure increases, the engine speed decreases, and at time T1 in the figure, the engine speed becomes equal to or lower than the determination slip rotation ω _SLPEND obtained in step S9. As a result, the boosting control when going from the converter state to the lockup state is completed, and thereafter, normal feedback control is performed.

As described above, even in a low load condition where the slip rotation speed deviation is not so large, the lock-up clutch engagement hydraulic pressure can be rapidly increased by forcibly increasing the deviation, and the proportional gain Kp By temporarily setting 0 to 0, it is possible to prevent a step difference from occurring in the slip rotation command value and the differential pressure command value at the time of switching from the open loop control to the feedback control, so that the driver does not feel uncomfortable. It is possible to smoothly shift from the converter state to the lockup state or the slip state.

The forced deviation (map value) input to the feedback compensator is set in consideration of the operating state (load) such as throttle opening TVO and slip rotation speed. Since appropriate parameter settings can be set without significantly changing the conventional control system, it is possible to avoid complication of the control content and reduce the manufacturing cost.

Even if the operating state changes, such as the throttle opening changing during boost control, the linearization compensation in the latter stage (similar to Japanese Patent Laid-Open No. 11-82726) works, so that the torque change is appropriate. It can be replaced by the change in differential pressure and can quickly follow changes in operating conditions. In addition, since a dedicated logic for boosting at the start of control is not required, storage means such as ROM capacity can be reduced, and simplification of the logic can improve reliability and maintainability.

That is, FIG. 16 shows the case where the throttle opening is changed approximately at the middle of the time T0 and T1 during the execution of the pressure increase by the open loop. Even in this case, as shown in the map of FIG. Since the linear compensation in which the estimated engine torque t _EH changes according to the change in the throttle opening is performed, the boost amount (speed) can be changed even during the open loop control. This is similar to the conventional example (Japanese Patent Laid-Open No. 11-141677, etc.), and linearization compensation by engine torque estimation (S107 in FIG. 2).
Since it is equipped with, it is possible to more flexibly cope with such a change in the operating state. The linearization compensator includes a target converter torque calculation unit S105, an engine output torque calculation unit S108, a target lockup clutch engagement capacity calculation unit S107, a lockup clutch engagement hydraulic pressure command value calculation unit S109, and a solenoid drive signal calculation shown in FIG. Department S1
It consists of 10.

Further, while the slip rotation deviation input to the feedback compensator is forcibly set, the gain setting in the feedback compensator configured by PI control is set to P gain = 0, so the feedback compensator is set. When the forced setting of the deviation input to is completed (that is, returns to the conventional feedback control) and the input deviation of the feedback compensator changes suddenly, the P component control works excessively and the slip rotation command value (≈ differential pressure command Although there is a step in the value), setting the P gain to 0 can prevent the step from occurring in the command value.

Further, by fixing the input deviation of the feedback compensator, the boosting progresses sufficiently and when the decrease of the actual slip rotation is detected, the input deviation is fixed and the P gain = 0.
Since the setting of is canceled and the conventional feedback control is started, it is possible to switch to the feedback control after the actual slip rotation speed shows a movement, and it is possible to prevent excessive boosting, etc., and from the torque converter state to the lockup state or slippage. You can smoothly transition to the state.

During the steam boost control period, the proportional gain K
When p is not set to 0, the timing chart shown in FIG. 17 is obtained.

In this case, the time T at which the deviation of the feedback compensator is switched from the map value to the actual slip rotation deviation.
1 (at the end of boosting control), a step difference occurs in the slip rotation command value, and as a result, a step difference also occurs in the differential pressure command value.
It can be seen that the lockup capacity and the converter torque suddenly change and the drivability is deteriorated.

In this embodiment, step S in FIG.
In 9, the time when the actual slip rotation becomes smaller than the preset map value is determined as the time when the open-loop control is switched to the feedback control. Any means that can determine the degree of influence of pressure control can be applied.

Further, in steps S5, S6, and S9 of FIG. 4, the throttle opening is used as a parameter indicating the load state at the time of referring to the map, but slip rotation having the same property can also be used as a parameter. is there.

Further, the map of FIG. 13 for setting the slip rotation speed deviation ω _SLPER temporarily used during the boost control is
It is set in advance by an experiment or the like. When the deviation is large, the boosting speed increases, and when the deviation is small, the boosting speed decreases. Therefore, it may be set according to the proportional gain Kp, the integral gain Ki, or the like.

Further, the map of FIG. 11 is for setting the time limit of the boost control, that is, for making the deviation to prompt the start of the voltage boost. Therefore, if the time limit becomes too large, the period of the open loop control is increased. May become excessively large and lock up suddenly, so an appropriate value may be set through experiments.

Further, when the actual slip rotation speed ω _SLPR is larger than a preset value, the map value of the pseudo deviation calculating means is set even when the shift from the released state of the lockup clutch to the engaged state or the slip state is started. It may be prohibited to switch to the actual slip rotation speed ω
_{If SLPR} is sufficiently large, it can be followed by normal feedback control.

Incidentally, Japanese Patent Laid-Open No. 11-1 shown in the above-mentioned conventional example.
As shown in the control block diagram shown in FIG. 6 of Japanese Patent No. 41677, the predistorter may be divided into a reference model and an F / F compensator. In this case, in the block shown by the feedback compensator 34, the present embodiment is performed. The invention described with reference to FIGS. 3 to 6 is applied.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a torque converter showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a controller.

FIG. 3 is a conceptual diagram showing a main part of the feedback compensator.

FIG. 4 is a flowchart showing an example of boost control performed by a controller.

FIG. 5 is a flowchart of a subroutine for setting an initial differential pressure.

FIG. 6 is a flowchart of a subroutine for setting slip rotation for determination.

FIG. 7 is a map showing the relationship between turbine rotation speed and slip rotation gain.

FIG. 8 is a map showing the relationship between engine speed and engine torque according to throttle opening.

FIG. 9 is a map showing the relationship between lockup clutch engagement pressure and lockup clutch capacity.

FIG. 10 is a map showing the relationship between throttle opening and initial differential pressure.

FIG. 11 is a map showing the relationship between throttle opening and control time limit.

FIG. 12 is a map showing the relationship between throttle opening and end slip rotation.

FIG. 13 is a map showing a relationship between throttle opening and pseudo slip rotation deviation.

FIG. 14 is a map showing the relationship between turbine rotational speed and target slip rotation according to throttle opening.

FIG. 15 is a graph showing the relationship between each value and time when shifting from the converter state to the lockup state, showing engine rotation, input shaft (primary) rotation, actual slip, throttle opening, slip rotation deviation, compensator proportional The relationship between the gain, the slip rotation command value, the converter torque, the engine torque, the lockup capacity, the differential pressure command value, and time is shown.

FIG. 16 is a graph showing the relationship between each value and time when the throttle opening changes when shifting from the converter state to the lockup state, showing engine rotation, input shaft (primary) rotation, actual slip, and throttle opening. , Slip rotation deviation, compensator proportional gain, slip rotation command value, converter torque, engine torque, lockup capacity, differential pressure command value, and time relationship are shown.

FIG. 17 is a graph showing the relationship between each value and time when the converter state shifts to the lockup state without setting the proportional gain Kp to 0, and shows engine rotation, input shaft (primary) rotation, actual slip, and throttle opening. , Slip rotation deviation, compensator proportional gain, slip rotation command value, converter torque, engine torque, lockup capacity, differential pressure command value, and time relationship are shown.

FIG. 18 is a graph showing a relationship between each value and time when shifting from a converter state with a small slip rotation deviation to a lockup state in a conventional example, and shows engine rotation, input shaft (primary) rotation, actual slip, and throttle. The relationship between the opening, the slip rotation deviation, the compensator proportional gain, the slip rotation command value, the converter torque, the engine torque, the lockup capacity, the differential pressure command value, and time is shown.

[Explanation of symbols]

1 Torque converter 2 lock-up clutch 3 Lock-up control valve 4 Lock-up solenoid 5 controller

Claims (5)

[Claims] 1. A torque converter provided with a lock-up clutch between a prime mover and an automatic transmission, a target slip rotation calculation unit for obtaining a target slip rotation of the torque converter from an operating state of the vehicle, and a vehicle operation. A pre-compensator that sets a constant of the compensating filter based on the state and passes the target slip rotation through the compensating filter to obtain a target slip rotation correction value, and the target slip rotation correction value and the actual slip rotation. From this, feedback compensation means for calculating a slip rotation command value for matching the actual slip rotation with the target slip rotation, and a lockup clutch engagement pressure command value corresponding to this slip rotation command value are calculated, And a linearization compensating means for matching the engagement pressure of the up clutch with the command value. In the slip control device of the torque converter for controlling the actual slip rotation between the input and output elements of the inverter by engaging the lockup clutch, the feedback compensating means may calculate the actual slip rotation deviation from the target slip rotation correction value and the actual slip rotation. A slip rotation deviation calculation means for calculating the slip rotation deviation, a pseudo deviation calculation means for calculating a pseudo slip rotation deviation based on the operating state of the vehicle, and when the lockup clutch shifts from the released state to the engaged state or the slip state. , A switching means for temporarily selecting the output of the pseudo deviation calculating means, while selecting the output of the slip rotation deviation calculating means during normal control, and a slip rotation command for canceling the deviation output by the switching means. It is equipped with a slip rotation command value calculation means for calculating the value. Torque converter slip control device according to. 2. The torque converter according to claim 1, wherein the switching means switches from the pseudo deviation calculating means to the slip rotation deviation calculating means when the engine speed decreases to a predetermined value. Control device. 3. The slip rotation command value computing means includes at least a proportional term and an integral term, and the proportional term is switched from a predetermined value to 0 while the pseudo deviation computing means is selected by the switching means. The control device for a torque converter according to claim 1, wherein the control device calculates. 4. The control device for a torque converter according to claim 3, wherein the slip rotation command value calculation means restores the proportional term to a predetermined value when the engine speed drops to a predetermined value. 5. The pseudo-deviation means, when the slip rotation deviation of the slip rotation deviation calculating means exceeds a predetermined value, even when the lockup clutch shifts from a disengaged state to an engaged state or a slip state. The control device for a torque converter according to claim 1, wherein selection of the calculation means is prohibited.