JP4082171B2 - Slip control device for torque converter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for controlling slip rotation between input / output elements of a torque converter used in an automatic transmission including a continuously variable transmission.
[0002]
[Prior art]
Torque converter lock-up control device inserted in the power transmission system of an automatic transmission including a continuously variable transmission requires torque increasing action and shift shock to reduce the deterioration of fuel consumption caused by torque converter slip In the operation region where no torque is input, the input / output elements of the torque converter are directly connected. This state is referred to as a lock-up mode. In addition to this, a converter mode in which the input / output elements are completely opened and torque is transmitted via the fluid, and the lock-up clutch is in a semi-engaged state to maintain a predetermined slip state. Three modes, including slip modes, are provided and are switched as appropriate according to the driving state. The control in the converter mode is referred to as converter control, the control in the slip mode is referred to as slip control, and the control in the lockup mode is referred to as lockup control.
[0003]
In general, in slip control, the differential pressure is increased by open control immediately after the start of control, and then switched to feedback control. The target slip rotation speed is determined from the vehicle operating state determined based on the throttle opening, vehicle speed, etc. The fastening force of the lockup clutch is controlled so that the actual slip rotation speed of the converter becomes the target slip rotation speed.
[0004]
However, with regard to the above-described slip control, the followability of the actual slip with respect to the target slip rotation speed, that is, the feedback control response is uniquely determined by the transfer characteristics of the slip rotation feedback control system, the slip control response is poor, and the fuel consumption There has been a problem that an operating state that deteriorates the operation occurs.
[0005]
In order to solve this problem, there is a method using a target slip rotation speed correction value obtained by passing the target slip rotation speed through a compensation filter corresponding to the vehicle operating state of the pre-compensator (Patent Document 1).
[0006]
[Patent Document 1]
Japanese Patent No. 3240979
[0007]
[Problems to be solved by the present invention]
However, Patent Document 1 does not mention the timing of switching from open control to feedback control and the control of the slip rotation speed immediately after switching to feedback control.
[0008]
If the timing for switching from open control to feedback control is poor and the lockup differential pressure is too high or insufficient, the actual slip speed immediately after the switch will deviate significantly from the target slip speed, and the engine speed will Hunting may occur.
[0009]
In particular, if the differential pressure is increased too much at a low throttle opening, the engine rotation will drop sharply, causing a lock-up clutch engagement shock, or if the engine speed falls below the engine stall determination speed, the engine rotation will be avoided to avoid engine stall. A lock-up release shock may occur due to sudden return to converter mode.
[0010]
In addition, since the target slip rotation speed is determined based on the throttle opening, etc., it is possible that the generated slip rotation speed will be different even at the same throttle opening due to individual differences in torque converters and changes in characteristics due to deterioration over time. In this case, the target slip rotation speed is not set to an appropriate value, and the deviation from the actual slip rotation speed becomes large.
[0011]
Therefore, the present invention provides a control device in which the actual slip rotation speed immediately after switching from the open control to the feedback control does not deviate from the target slip rotation speed even when there is a change in characteristics due to individual differences in the torque converter or deterioration over time. The purpose is to do.
[0012]
[Means for Solving the Problems]
In a slip control device that is used in a torque converter that transmits rotation from a prime mover and controls actual slip rotation between input and output elements of the torque converter by engagement of a lock-up clutch provided in the torque converter, an initial slip control is started. Increases the lock-up differential pressure by open control, and switches to feedback control when the difference in actual rotation speed between the input element and output element (actual slip rotation) falls below the set value. The fixed time immediately after the start of feedback control is set as the evaluation time, and the deviation between the target slip rotation and the actual slip rotation is integrated during this evaluation time. Based on the magnitude of this integrated value The set value set as a condition for switching to feedback control is corrected.
[0013]
[Action / Effect]
According to the present invention, since the deviation generated between the initially set slip rotation and the actual machine slip rotation is corrected based on the actually measured value, the switching from the open control to the feedback control becomes smooth, and the merchantability is improved. improves.
[0014]
In addition, since a change in characteristics due to deterioration with time or the like is corrected based on the actually measured value, it can be handled with high accuracy and the original quality of the product can be maintained over a long period of time.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
FIG. 1 shows a drive system of a vehicle including a torque converter equipped with a slip control device according to a first embodiment of the present invention. Reference numeral 1 denotes an engine as a prime mover, and 2 denotes power output from the engine 1 to an automatic transmission 3. The torque converter 4 for transmitting is a differential gear device for transmitting the power output from the automatic transmission 3 to the tire 5.
[0017]
In the torque converter 2, there are provided a pump impeller 2 a as an input element driven by the engine 1 and a turbine runner 2 b as an output element coupled to the input shaft of the transmission 3. Power transmission between input and output elements. Furthermore, a lockup clutch 2c that rotates together with the turbine runner 2b is provided. When the lockup clutch 2c is fastened to the pump impeller 2a, the torque converter 2 is in a lockup state in which the input / output elements are directly connected.
[0018]
11 is a lock-up control valve for controlling the differential pressure for operating the lock-up clutch 2c, and 13 is a signal pressure P applied to the lock-up control valve 11. _S Is a lockup solenoid 12 for inputting the lockup duty D to the lockup solenoid 13 based on the signal from each sensor.
[0019]
Here, the operation of the lock-up clutch 2c will be described with reference to FIG.
[0020]
The lock-up clutch 2c has a torque converter apply pressure (hereinafter referred to as apply pressure) P on both sides thereof. _A And torque converter release pressure (release pressure) P _R Differential pressure P _A -P _R In response to the release pressure P _R Apply pressure P _A Higher than that, the lockup clutch 2c is released and the torque converter input / output elements are not directly connected, and the release pressure P _R Apply pressure P _A If lower than that, the lock-up clutch 2c is fastened to directly connect the torque converter input / output elements.
[0021]
In the directly connected state, the fastening force of the lock-up clutch 2c, that is, the lock-up capacity is the above-described differential pressure P. _A -P _R The lockup capacity of the lockup clutch 2c increases as the differential pressure increases.
[0022]
Differential pressure P _A -P _R Is controlled by a lockup control valve 11, and the lockup control valve 11 has an apply pressure P _A And release pressure P _R And the spring force of the spring 11a in the same direction as the apply pressure PA, and at the same time the release pressure P _R Signal pressure P to be described later in the same direction as _S Act.
[0023]
The lock-up control valve 11 has a differential pressure P so that these forces are balanced. _A -P _R To decide. Where signal pressure P _S Is the pump pressure P _P Is generated according to the lock-up duty D output from the controller 12.
[0024]
The controller 12 is input with signals indicating the driving state of the vehicle and the driving situation of the driver, for example, signals from the output shaft rotation sensor, the turbine rotation sensor 23, the impeller rotation sensor 22, the ATF oil temperature sensor 24, and the like. Based on this, the lockup clutch is engaged and released.
[0025]
The controller 12 calculates the drive duty S of the lock-up solenoid 13 by calculation according to the control system configuration diagram shown in FIG. _DUTY And a correction according to a signal from the power supply voltage sensor 28 to determine the lockup duty D.
[0026]
FIG. 3 shows a control system configuration diagram (block diagram) of the controller 12, and the operation inside the controller 12 will be described.
[0027]
In the target slip rotation calculation unit (S100), the vehicle speed signal v from the vehicle speed sensor 25, the throttle opening signal TVO from the throttle opening sensor 21, the transmission ratio signal ip obtained by the transmission ratio calculation unit 26, and the ATF oil temperature sensor 24. Based on the oil temperature signal TATF, etc., the target slip rotation ω _SLPT To decide.
[0028]
In the actual slip rotation calculation unit (S103), the rotational speed ω of the pump impeller 2a _IR To the rotational speed ω of the turbine runner 2b _TR The actual slip rotation ω of the torque converter 2 by subtracting _SLPR Is calculated. Here, the rotational speed of the pump impeller 2a is the rotational speed of the engine 1, and the rotational speed of the turbine runner 2b is a speed equivalent to the primary rotational speed.
[0029]
In the pre-compensator (S101), the target slip rotation ω _SLPT Is passed through a compensation filter set so as to have a response intended by the designer, thereby obtaining a target slip rotation correction value ω. _SLPTC Is calculated.
[0030]
In the slip rotation speed deviation calculation unit (S102), the target slip rotation correction value ω _SLPTC And actual slip rotation speed ω _SLPR Slip rotation deviation ω between _SLPER The
ω _SLPER = Ω _SLPTC −ω _SLPR ... (1)
Calculate from
[0031]
In the slip rotation command calculation unit (S104), the slip rotation deviation ω _SLPER In order to eliminate the slip rotation command value ω by a feedback compensator configured by proportional integral control (hereinafter referred to as PI control). _SLPC The
ω _SLPC = K _p ・ Ω _SLPER + (K _I / S) ・ ω _SLPER ... (2)
However, K _p : Proportional control constant
K _I : Integral control constant
S: Differential operator
Calculate from
[0032]
In the slip rotation gain calculation unit (S106), the current turbine rotation speed ω is calculated from the map shown in FIG. _TR Slip rotation gain corresponding to _SLPC Search for and ask.
[0033]
In the target converter torque calculator (S105), the turbine rotational speed ω _TR Slip rotation command value ω _SLPC Target converter torque t to achieve _CNVC The
t _CNVC = Ω _SLPC / g _SLPC ... (3)
Calculate from
[0034]
The engine torque estimation unit (S108) uses the engine total performance map shown in FIG. 10 to calculate the engine torque map value t from the engine speed Ne and the throttle opening TVO. _ES And the dynamic characteristics of the engine 1 as a time constant T _ED Engine torque estimated value t _EH The
t _EH = [1 / (1 + T _ED ・ S)] ・ t _ES ... (4)
Calculate from
[0035]
In the target lock-up clutch engagement capacity calculation unit (S107), the estimated engine torque t _EH To target converter torque t _CNVC Is subtracted from the target lockup clutch engagement capacity t. _LU Is calculated.
[0036]
t _L = T _EH -T _CNVC ... (5)
In the lockup clutch engagement pressure command value calculation unit (S109), the current target lockup clutch engagement capacity t is determined from the lockup clutch capacity map shown in FIG. _LU Lockup clutch engagement pressure command value P for achieving _LUC Search for.
[0037]
In the solenoid drive signal calculation unit (S110), the actual lockup clutch engagement pressure is changed to the lockup clutch engagement pressure command value P. _LUC Lock-up duty S _DUTY To decide.
[0038]
Next, of the control contents in the control unit 12, the evaluation of the slip rotation for determination in the switching from the open control to the feedback control and the correction method thereof, which are the points of the present invention, will be described with reference to the flowchart of FIG.
[0039]
In step S1, it is determined whether or not the current control is slip control based on the throttle opening TVO, the vehicle speed v, and the like. If it is determined that the control is slip control, the process proceeds to step S4. Proceed to S2.
[0040]
In step S2, it is determined in the same manner as above whether or not the control to be performed is the lock-up control. If it is determined that the control is the lock-up control, the process proceeds to step S3, and if not, the process proceeds to step S22.
[0041]
In step S3, it is determined whether or not the lock-up control has shifted to the complete lock-up state (the state where the differential pressure command value is maximum). If the shift-up has been completed, the lock-up is completed, and the process proceeds to step S21. . If not, the process proceeds to step S4 in order to perform control for shifting to the lock-up state using slip control together.
In step S4, it is determined whether or not the previous control state is converter control. If it is converter control, the process proceeds to step S5. Otherwise, the process proceeds to step S7.
[0042]
In step S5, an initial differential pressure is set according to the current throttle opening TVO from a previously set map of FIG. 12 based on the flowchart of FIG.
[0043]
In step S6, a flag (F = 1) indicating that the boosting operation by the open control is being executed is set.
[0044]
As described above, only in the first time when the operation region shifts to the converter mode or the lock-up mode in steps S5 and S6, preparation for starting the pressure increasing process by the open control is performed, and the second and subsequent times are not performed.
[0045]
In step S7, it is determined by the flag set in step S6 whether or not the boost operation by the open control is currently being executed. If the boost operation is being executed (F = 1), the process proceeds to step S8, and the open control is completed. Determination slip rotation is calculated, and if the step-up operation is not being executed (F = 0), the process proceeds to step S15.
[0046]
In step S8, determination slip rotation ω for determining whether or not the boosting operation by the open control may be terminated. _SLPEND Follow the procedure below.
[0047]
First, the map value ω corresponding to the current throttle opening is obtained from the map of FIG. _SLPMAP To obtain this map value ω _SLPMAP In contrast, the correction amount ω calculated in step S20 to be described later _SLPADJ Is added, and slip rotation ω for judgment _SLPEND And (Equation (6) below)
ω _SLPEND = Ω _SLPMAP + Ω _SLPADJ ... (6)
Slip rotation ω for judgment _SLPEND The lower limit value is set for, and the calculated slip rotation for determination ω _SLPEND Is clearly inappropriate, for example, when it becomes a negative value, the lower limit value is set to the slip rotation ω for determination. _SLPEND And
[0048]
Also, the correction amount ω _SLPADJ The initial value is zero, but once calculated, this value is stored in a non-volatile memory, etc. _SLPADJ Can be held inside the controller.
[0049]
In step S9, the current slip rotation ω _SLPR And slip rotation for judgment ω _SLPEND Comparison of
ω _SLPR ≦ ω _SLPEND ... (7)
In this case, it is determined that the slip rotation starts to react to the differential pressure command due to the boosting operation and the differential pressure control is possible, the boosting operation by the open control is terminated, and the process proceeds to step S12 and the feedback control is performed. Switch.
[0050]
If the expression (7) is not satisfied, it is determined that the slip rotation is not responding to the differential pressure command, and the process proceeds to step S10.
[0051]
In step S10, the pressure increase amount per unit time during the open control is set according to the current throttle opening TVO from the previously set map of FIG.
[0052]
Note that the unit time is equivalent to a control cycle. For example, when the open control is performed every 20 ms, the boosting amount per 20 ms is set.
[0053]
Next, in step S11, the differential pressure command value during the open control is calculated by adding the pressure increase amount per unit time calculated in step S10 to the current differential pressure command value.
[0054]
On the other hand, in step S12, the control system is initialized in order to end the step-up operation by the open control and switch to the feedback control.
[0055]
This initialization process is performed by initializing the output of the predistorter (S101) with the actual slip rotation at the time of switching to the feedback control in the control system configuration diagram of FIG. 3, and the feedback compensator in the rotation command calculation unit (S104). Is initialized by slip rotation corresponding to the actual differential pressure.
[0056]
In the subsequent step S13, the flag (F = 1) indicating that the boost operation is being performed by the open control is cleared (F = 0). In step S14, the response of the actual slip rotation to the target slip rotation immediately after the feedback control is started is evaluated. Then, an operation start process (initialization) of a timer that measures the evaluation period is performed, an integral value INTG_ERR of a slip rotation deviation described later is cleared to zero, and the process proceeds to step S15.
[0057]
In step S15, a feedback control calculation based on the control system configuration diagram of FIG. 3 is performed to calculate a differential pressure command value during slip control, and the process proceeds to step S16.
[0058]
For example, when performing a drive slip (when the accelerator is ON and the engine speed is greater than the primary speed), the target slip calculation unit (S100) sets the target slip rotation ω. _SLPT Is set to 40 rpm, and 0 rpm is set for the lock-up state. And this set target slip rotation ω _SLPT The feedback control system acts so as to match.
[0059]
As described above, in steps S8 to S11, the differential pressure command value at the time of open control is set, and in steps S8, 9, 12, 13, and 14, the switching process from the open control to the normal feedback control is performed. In S15, a differential pressure command value for normal feedback control is calculated.
[0060]
Subsequent steps S16 to S20 are points of the present invention in which the slip rotation for determination used as a condition for switching from the open control to the feedback control is corrected by evaluating the response of the actual slip rotation to the target rotation immediately after the feedback control is started. is there.
[0061]
First, in step S16, it is determined whether or not the evaluation period timer that has started measurement at the time of starting feedback control in step S14 has passed a preset evaluation period. If it has already elapsed, no evaluation is performed. If it has not elapsed, the evaluation process after step S17 is performed.
[0062]
In step S17, the current target slip rotation ωSLPTC and the actual slip rotation ω _SLPR Is calculated from the above equation (1), and the integrated value of this slip rotation deviation is calculated.
INTG_ERR = INTG_ERR + ω of previous cycle _SLPER ... (8)
Calculate with.
[0063]
In step S18, the evaluation period timer is counted, and when it is determined that the evaluation period set in advance in step S19 has elapsed, the process proceeds to step S20 and is based on the flowchart of FIG. The amount of slip rotation correction is calculated.
[0064]
Step S21 is a state in which the fastening operation (complete lockup) in the lockup control is completed and the differential pressure is maintained at the maximum pressure.
[0065]
Step S22 is a state in which the release operation (unlock up) of the lock-up clutch in the converter control is completed and the differential pressure is kept at the minimum pressure.
[0066]
Next, an example of the initial differential pressure setting method in step S5 of FIG. 7 will be described based on the flowchart of FIG.
[0067]
First, in step S50, a preset initial differential pressure value (hereinafter referred to as map value) is read from the map of FIG. 12 in accordance with the current throttle opening.
[0068]
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.
[0069]
If the current differential pressure is less than or equal to the map value, the process proceeds to step S53, and the map value is selected as the initial differential pressure.
[0070]
As a result, even when the preset map value is lower than the current differential pressure, a value equal to or greater than the current differential pressure can always be set as the initial differential pressure.
[0071]
Next, the slip rotation ω for determination in step S20 in FIG. _SLPEND Correction amount ω _SLPADJ The calculation method of will be described based on the flowchart of FIG.
[0072]
First, in step S60, it is determined whether or not the integral value INTG_ERR of the slip rotation deviation calculated in step S17 of FIG. 7 is within a preset range.
[0073]
If it is within the predetermined range, it is determined that “no correction is necessary” and the process proceeds to step S68, where the correction amount ω _SLPADJ The
ω _SLPAD = 0 (9)
And
[0074]
If it is not within the predetermined range, it is determined that “correction is necessary” and the process proceeds to step S61.
[0075]
Here, the predetermined range is the correction value ω _SLPADJ Is a range that does not exceed the upper limit.
[0076]
For example, when the slip rotation is allowed up to 10 rotations per unit time, the evaluation period is 500 ms, and the execution of the program is 20 ms per time,
INTG_ERR = 10 rotations × (500 ms / 20 ms) = 250 rotations
If it is 250 revolutions or less, it is within the range.
[0077]
In step S61, the sign of the integral value INTG_ERR of the deviation of slip rotation is determined. If it is positive, the process proceeds to step S62, and if negative, the process proceeds to step S65.
[0078]
In steps S62 and S63, the upper limit of the integral value is set before calculating the correction amount. In step S64, the correction amount ω is calculated from the following equation. _SLPADJ Is calculated.
[0079]
ω _SLPADJ = INTG_ERR × α (10)
α is a correction coefficient set in accordance with the current throttle opening from the previously set map of FIG. 17, and is a dedicated coefficient assuming that the sign of the integral value INTG_ERR of the slip rotation deviation is positive. is there.
[0080]
If the sign of the slip rotation deviation integral value INTG_ERR is negative in step S61, the process proceeds to step S65. In steps S65 and S66, the integral value is limited to a lower limit before calculating the correction amount. In S67, the correction amount ω _SLPADJ Is calculated.
[0081]
ω _SLPADJ = INTG_ERR × β (11)
β is a correction coefficient that is set according to the current throttle opening from the previously set map of FIG. 17, and is a dedicated coefficient that assumes a case where the sign of the integral value INTG_ERR is negative.
[0082]
As an example, a case where the sign of the integral value INTG_ERR of the slip rotation deviation is positive at the end of the evaluation period will be described.
[0083]
The sign of the integral value of the deviation of slip rotation is positive, indicating that the tendency of slip rotation during the evaluation period is “target slip rotation ω _SLPT > Actual slip rotation ω _SLPR As the situation, the target slip rotation ω was detected during the evaluation period immediately after the start of feedback control because the differential pressure was excessively increased during the boost during open control. _SLPT Against actual slip rotation ω _SLPR It is inferred that was below.
[0084]
In this case, if the correction coefficient α is set as a positive value, the correction amount ω calculated from the equation (10) _SLPADJ Always has a positive value.
[0085]
In this situation, the slip rotation ω for determining the end of the open control _SLPEND Is calculated from the equation (6), the slip rotation ω for determination is compared with that before the correction. _SLPEND Becomes larger.
[0086]
This indicates that the open control ends at an earlier timing than before correction and switches to feedback control. _SLPEND By performing this correction, it is possible to prevent an excessive increase in the differential pressure in the open control.
[0087]
On the contrary, when the integral value INTG_ERR of the slip rotation deviation is negative, the slip rotation tendency during the evaluation period is expressed as “target slip rotation ω _SLPT <Actual slip rotation ω _SLPR ".
[0088]
This means that the boost during open control was insufficient, and the correction amount ω to be calculated _SLPADJ Is the correction amount ω calculated from equation (11) if the correction coefficient β is a positive value. _SLPADJ Always has a negative value, and the slip rotation ω for judgment _SLPEND Becomes smaller than before correction.
[0089]
As a result, the boosting time in the open control becomes long and the insufficient boosting can be solved.
[0090]
Further, when the integral value INTG_ERR is zero, the tendency of slip rotation during the evaluation period is “target slip rotation ω _SLPT = Actual slip rotation ω _SLPR The correction amount ω calculated based on the present invention is not necessary. _SLPADJ Will be zero, so there will be no problem.
[0091]
As for the correction coefficient, α and β can be set separately according to the sign of the integral value INTG_ERR of the deviation of the slip rotation, that is, according to the response of the actual slip rotation ωSLPR with respect to the target. Is possible.
[0092]
The effect of the above embodiment is demonstrated using the timing chart of FIG.
[0093]
FIG. 4 shows a case where the correction using the actual measurement value is not performed, and FIG. 5 shows a case where the correction using the actual measurement value according to the present invention is performed.
[0094]
4 and 5, initially, the differential pressure is increased by the open control, and as the differential pressure increases, the fastening force of the lockup clutch 2c becomes stronger and the actual slip rotation ω. _SLPR Decreases and slip rotation ω for judgment _SLPEND Switching to feedback control is performed when it falls to.
[0095]
In FIG. 4, the actual slip rotation ω immediately after switching to the feedback control (T3) _SLPR Is the target slip rotation ω _SLPT Is far below.
[0096]
This is because the engagement force of the lock-up clutch 2c has become too high because the differential pressure increase due to the open control is excessive. As a result, the engine speed has also dropped sharply.
[0097]
On the other hand, FIG. 5 shows a case where the integral value INTG_ERR of the slip rotation deviation is positive. _SLPEND Therefore, the switching to the feedback control performed at T3 in FIG. 4 is accelerated to T2 in FIG.
[0098]
As a result, since the control is switched to the feedback control before the differential pressure increases excessively, it can be understood that the drop in the engine rotation immediately after the switching that occurs due to the excessive increase of the differential pressure can be prevented.
[0099]
As described above, the slip rotation ω for determination that was initially set _SLPEND Even if there is a discrepancy between the actual value and the appropriate value on the actual machine, a correction such as a drop in engine speed occurs immediately after switching from the open control to the feedback control because correction is performed based on the measured value. It can be done smoothly.
[0100]
Next, a second embodiment will be described.
[0101]
FIG. 8 is a flowchart of the control performed in the second embodiment, which is basically the same as that in the first embodiment shown in FIG. 7, but is preset in step S119 corresponding to step S19 in FIG. In the determination of whether or not the evaluation period that has been passed has passed, if it is determined that the evaluation period is still within the evaluation period, the part that proceeds to step S121, and the correction amount ω of the determination slip rotation in step S120 _SLPADJ How to find is different.
[0102]
In step S121, the sign of the slip rotation deviation is determined. When the sign is switched from positive to negative or from negative to positive during the evaluation period, the evaluation is completed even during the evaluation period and the process proceeds to step S120. The evaluation is performed using the integration value at that time.
[0103]
FIG. 6 shows a time chart when the evaluation is completed by switching the sign of the slip rotation deviation during the evaluation period.
[0104]
The upper time chart in FIG. 6 shows before correction, and the lower side shows after correction is performed.
[0105]
Target slip rotation ω at 5B _SLPT And actual slip rotation ω _SLPR Is reversed, that is, the sign of the deviation is switched. Nevertheless, if the integration operation is continued, the integration value INTG_ERR starts to decrease as shown by the dotted line 5A, and accurate evaluation cannot be performed.
[0106]
Therefore, the occurrence of the above problem can be prevented by terminating the integration at the time (TC) when the sign of the slip rotation deviation is switched.
[0107]
Next, the correction amount ω of the slip rotation for determination in step S120 _SLPADJ The calculation method of will be described.
[0108]
The map shown in FIG. 17 for obtaining the correction coefficients α and β used in the above-described equations (10) and (11) is determined for the initially set evaluation period, and therefore when the evaluation period is shortened. Slip rotation correction amount ω using the above-mentioned equations (10) and (11) as they are _SLPADJ If it asks for, evaluation accuracy will fall.
[0109]
Therefore, in the present embodiment, the following formulas (12) and (13) obtained by correcting the formulas (10) and (11) according to the reduction ratio of the evaluation period are used.
[0110]
ω _SLPADJ = INTG_ERR × α × γ ₁ / 100 (12)
ω _SLPADJ = INTG_ERR × β × γ ₂ / 100 (13)
Correction coefficient γ ₁ , Γ ₂ : (Actual evaluation period) / (Set evaluation period)
As described above, by correcting the correction coefficients α and β according to the reduction rate of the evaluation period, high evaluation accuracy can be maintained even when the evaluation period is shortened.
[0111]
Correction coefficient γ ₁ , Γ ₂ Is the evaluation period shortening rate itself, as shown in FIG. ₁ , Γ ₂ A method is also conceivable in which a map is prepared so that fine adjustment is possible.
[0112]
As described above, in the present embodiment, even within the preset evaluation period, when the feedback control comes into effect, the evaluation is completed, and the correction amount is calculated according to the reduced ratio of the evaluation period. Therefore, accurate correction can be performed.
[0113]
In this embodiment, the actual slip rotation ωSLPR is set in advance in step S9 in FIG. _SLPEND Is determined as the switching point from the open control to the feedback control, but other means can determine the degree of the influence of the differential pressure control of the present invention, such as the rate of change of the engine rotation. Can be applied as a criterion. That is, the correction according to the present invention can be applied not only to the slip rotation but also to the change amount of the engine rotation.
[0114]
Based on the same concept, even if the differential pressure command value, pressure increase time, etc. are set as switching conditions from open control to feedback control, means for correcting the switching criterion value by the integrated value of slip rotation deviation during the evaluation period It is applicable if applied to.
[0115]
Further, when referring to the map in steps S5, S8, and S10 in FIG. 7, the throttle opening TVO is used as a parameter representing the load state. For example, slip rotation having the same property can be used as a parameter.
[0116]
Further, although the evaluation period described in the embodiment is set to a fixed value set in advance, it can be arbitrarily switched according to the operation state at the time of evaluation, for example, the throttle opening degree.
[0117]
The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made within the scope of the technical idea described in the claims.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a control system according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a slip control system of a torque converter according to the present invention.
FIG. 3 is a block diagram of slip control performed by a controller in the present invention.
FIG. 4 is a time chart of control switching according to the prior art without performing correction according to the present invention.
FIG. 5 is a time chart of control switching when correction according to the first embodiment is performed.
FIG. 6 is a time chart of control switching when correction according to the second embodiment is performed.
FIG. 7 is a flowchart showing a control routine of the first embodiment.
FIG. 8 is a flowchart showing a control routine of the second embodiment.
FIG. 9 is a slip rotation gain map.
FIG. 10 is an overall engine performance map.
FIG. 11 is a lock-up clutch map.
FIG. 12 is an initial differential pressure map.
FIG. 13 is an open control end slip rotation map;
FIG. 14 is an open control boost amount map;
FIG. 15 is an initial differential pressure setting flowchart.
FIG. 16 is a flow chart for setting a correction amount for an open control end slip rotation.
FIG. 17 is a correction coefficient (α, β) map.
FIG. 18: Correction coefficient (γ ₁ , Γ ₂ ) Map.
[Explanation of symbols]
1 engine
2 Torque converter
2a pump impeller (input element)
2b turbine runner (output element)
2c lock-up clutch
3 Automatic transmission
4 Differential gear unit
5 wheels
11 Slip control valve
12 Controller
13 Lock-up solenoid
21 Throttle opening sensor
22 Impeller rotation sensor
23 Turbine rotation sensor
24 Oil temperature sensor
25 Vehicle speed sensor
26 Gear ratio calculation unit
27 Engine rotation sensor

Claims (5)

A lock-up clutch disposed between input and output elements of a torque converter that transmits power from the prime mover;
Hydraulic control means for adjusting the hydraulic pressure supplied to the lock-up clutch and controlling the engaged state;
In the slip control device configured to control the slip rotation between the input and output elements according to the engagement state of the lockup clutch,
Means for open control to increase the lockup hydraulic pressure toward the target pressure with the start of the engagement control of the lockup clutch;
Means for feedback-controlling the lock-up hydraulic pressure in accordance with the deviation between the target slip rotation and the actual slip rotation when the slip rotation corresponding to the rotational speed difference between the input element and the output element falls below a set value;
Means for correcting the set value based on response evaluation of actual slip rotation with respect to target slip rotation immediately after shifting to the feedback control ,
The means for correcting the set value uses a fixed time immediately after the start of the feedback control as an evaluation time, integrates the deviation between the target slip rotation and the actual slip rotation for the evaluation time, and sets the setting based on the magnitude of the integrated value. A slip control device for a torque converter, wherein the value is corrected . When the integral value is positive, it is evaluated that the boost by open control is excessive, and when it is negative, the boost is insufficient, and the set value is increased or decreased according to the magnitude of the integral value. The slip control device for a torque converter according to claim 1 . Even within the evaluation time, if the sign of the deviation between the target slip rotation and the actual slip rotation changes, the integration of the deviation is terminated at that time, and the set value is based on the integral value until the deviation ends. The torque converter control device according to claim 1, wherein the torque converter is corrected . The correction performed based on the magnitude of the integral value is changed according to the magnitude of the shortened time when the evaluation time is shortened because the sign of the deviation between the target slip rotation and the actual slip rotation has changed. 4. The torque converter control device according to 3 . A lock-up clutch disposed between input and output elements of a torque converter that transmits power from the prime mover;
Hydraulic control means for adjusting the hydraulic pressure supplied to the lock-up clutch and controlling the engaged state;
In the slip control method for controlling the slip rotation between the input and output elements according to the engagement state of the lockup clutch,
Open control to increase the lock-up hydraulic pressure toward the target pressure with the start of lock-up clutch engagement control,
When the slip rotation corresponding to the rotational speed difference between the input element and the output element becomes less than the set value, feedback control of the lockup hydraulic pressure is performed according to the deviation between the target slip rotation and the actual slip rotation,
A fixed time immediately after the start of the feedback control is set as an evaluation time, the deviation between the target slip rotation and the actual slip rotation is integrated for the evaluation time, and the set value is corrected based on the magnitude of the integration value. Torque converter slip control method.

Images