JP4321415B2 - Slip control device for torque converter - Google Patents

Description

  The present invention relates to an improvement in a slip control device for a torque converter having a lock-up clutch.

  Conventionally, a torque converter lock-up control device interposed in a power transmission system of an automatic transmission including a continuously variable transmission has been designed to reduce the deterioration of fuel consumption caused by slipping of the torque converter (torque). In the operation area where the function of increasing shock and shock absorption is not required, it has a lock-up mode that directly connects the input and output elements of the torque converter. It is known that there are three modes including a converter mode for transmitting torque and a slip mode in which a lock-up clutch is in a semi-engaged state and maintaining a predetermined slip state. It is switched appropriately. This operation mode is switched by changing the lock-up differential pressure. In the case of the minimum pressure, the converter state is set, and in the case of the maximum pressure, the lock-up state is set.

  Switching from the converter mode to the lock-up mode is known as slip lock-up in which the lock-up differential pressure is increased by open-loop control, and then the slip mode is switched to the lock-up mode through the slip mode by feedback control. Then, the engagement capacity of the lockup clutch necessary for maintaining a predetermined slip rotation is calculated (for example, Patent Document 1).

  In the prior art disclosed in Patent Document 1, slip rotation speed gain setting means for setting the slip rotation speed gain gSLPC according to the operating state, and the target converter torque tCNVC by dividing the slip rotation speed command value ωSLPC by the slip rotation speed gain gSLPC. Target converter torque calculating means for calculating the target lockup clutch engagement capacity by subtracting the target converter torque from the engine output torque.

The target converter torque calculation means is applied to a two-degree-of-freedom slip control system, and F / F slip rotation speed command value calculation means for calculating an F / F (feed forward) slip rotation speed command value ωSLPTC2; The F / B slip rotation speed command value ωSLPC1 is calculated, and the F / F slip rotation speed command value ωSLPTC2 and ωSLPC1 are added to obtain the slip rotation speed command value ωSLPC1. And a target converter torque calculator is provided at a subsequent stage of the adding means.
Japanese Patent No. 3240979

  However, in the above prior art, linearization compensation is performed by changing the slip rotation speed gain in the target converter torque calculation means for the control object that changes according to the operating state, and the calculated lockup is performed. If there is a so-called differential pressure variation between the command pressure of the lock-up control valve corresponding to the clutch engagement capacity and the actual pressure, the deviation is compensated by the operation of the F / B compensator. ing.

  For this reason, when the differential pressure variation differs due to individual differences of the lock-up control valves or oil temperature differences during operation, the operating point of the F / B compensator will be different. This means that the amount of operation of the F / B compensator when the slip rotation speed gain changes due to a change in the operating state varies depending on the differential pressure variation. As a result, the control performance is deteriorated due to the excess or shortage of the differential pressure. There was a problem of inviting.

  In other words, the slip rotation speed gain varies depending on the oil temperature, the operating conditions, and the like, and varies depending on production variations, deterioration with time, etc. even under the same operating conditions. Since the slip rotation speed gain that changes according to such conditions exists in the F / B loop, every time the slip rotation speed gain fluctuates, F / B compensation is performed to suppress the output fluctuation of the control system due to the gain fluctuation. The output of the detector fluctuates, and the F / B compensator operates for a purpose other than eliminating the original slip rotation deviation, and the optimum gain setting cannot be performed in the F / B compensator. There is.

  Furthermore, since there are fluctuating elements in the F / B loop, there is a problem that the degree of freedom in designing the F / B gain is limited and the performance of the entire control system is degraded.

  Therefore, an object of the present invention is to improve the degree of freedom in design and control accuracy of feedback control at the time of slip lock-up by a control system with two degrees of freedom.

The present invention relates to a slip control device for a torque converter comprising: an engagement control unit that switches from the open control unit to the slip control unit when a predetermined condition is satisfied when the lockup clutch is engaged.
In the F / F control system, the slip control means calculates an F / F slip rotation speed command value by feedforward based on the target slip rotation speed, and calculates an F / F slip rotation speed gain based on the turbine rotation speed. The F / F slip rotation speed command value is divided by the F / F slip rotation speed gain to calculate a feed forward F / F target converter torque. On the other hand, in the F / B control system, an F / B slip rotation speed command value is calculated based on the target slip rotation speed and the actual slip rotation speed, an F / B slip rotation speed gain is obtained based on the turbine rotation speed, An F / B target converter torque is calculated by dividing the F / B slip rotation speed command value by the F / B slip rotation speed gain. When the lockup clutch is engaged with the sum of the F / F target converter torque and the F / B target converter torque as the target converter torque, the fluctuation range of the F / B slip rotation speed gain is set to the F / F slip rotation. Set smaller than the fluctuation range of the speed gain.

  Therefore, according to the present invention, even when the degree of freedom in the gain design of the F / B compensation means is limited due to the fluctuation of the slip rotation speed gain, the fluctuation width can be reduced by reducing the fluctuation width. The restriction on the gain design of the B compensator can be relaxed, and the optimum slip rotation speed gain can be set independently in the F / F compensation means and the F / B compensation means. At the same time, the F / F compensation means can maintain the compensation operation with the optimum gain according to the conventional control target.

  Hereinafter, an embodiment of the present invention will be described 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 interposed in a power transmission system such as an automatic transmission including a continuously variable transmission, and transmits power between input / output elements via an internal working fluid. .

  The torque converter 1 further includes a lockup clutch 2 that rotates together with the torque converter output element (turbine). The lockup clutch 2 inputs and outputs the torque converter 1 when fastened to the torque converter input element (impeller). A lockup state in which elements are directly connected is assumed.

  The lock-up clutch 2 responds to a differential pressure PA-PR between the torque converter apply pressure PA and the torque converter release pressure PR on both sides (front and rear), and when the release pressure PR is higher than the apply pressure PA, the lock-up clutch 2 When the release pressure PR is lower than the apply pressure PA without being directly connected between the torque converter input / output elements, the lockup clutch 2 is engaged and directly connected between the torque converter input / output elements.

  When the latter is engaged, the engagement force of the lockup clutch 2, that is, the lockup capacity, is determined by the differential pressure PA-PR, and the engagement force of the lockup clutch 2 increases as the differential pressure increases. Increase lockup capacity.

  The differential pressure PA-PR is controlled by a well-known lockup control valve 3, and the apply pressure PA and the release pressure PR are caused to act on the lockup control valve 3 so as to oppose each other. The urging force of the spring 3a is applied in the direction, the spring force is applied in the same direction as the release pressure PR, and the signal pressure Ps is applied in the same direction as the release pressure PR.

  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.

  Here, 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 using the pump pressure PP as an original pressure. 4 to control the differential pressure PA-PR.

  The controller 5 includes a signal indicating the running state of the vehicle and the driving situation of the driver, for example, a signal from the output shaft rotation sensor 9 provided in the automatic transmission, a turbine runner rotation speed (from the turbine rotation sensor 8 of the torque converter 1). A signal indicating an input shaft rotation speed or a primary rotation speed), a signal indicating a pump impeller rotation speed from an impeller rotation sensor 7 for detecting an input rotation speed (= engine rotation speed Ne) to the torque converter 1, a throttle opening sensor 10 The signal (throttle opening TVO or accelerator operation amount), the signal from the oil temperature sensor 11 and the like are input, and the control of the lockup clutch 2 such as engagement, disengagement or slip is performed by these detection signals. The vehicle speed VSP is obtained by multiplying the output shaft rotation speed detected by the output shaft rotation sensor 9 by a predetermined constant.

The controller 5 performs slip lockup by switching between open loop control and slip control (feed forward control + feedback control), and determines a lockup duty (S _{DUTY in} FIG. 2) for driving the lockup solenoid 4. At the same time, the lockup duty is corrected according to the power supply voltage signal 6.

  Next, slip control using a two-degree-of-freedom control system among the controls performed by the controller 5 will be described based on the control system configuration diagram of FIG. This slip control is executed by, for example, determining that a predetermined condition is satisfied when the deviation between the target slip rotation speed and the actual slip rotation speed becomes a predetermined value or less by increasing the lockup differential pressure by open control. .

The target slip rotation calculation unit S100, the vehicle speed VSP and throttle opening TVO (or accelerator operation amount) and on the basis of the oil temperature T _ATF, etc., determine the target slip rotational speed omega _SLPT at the least occurrence of torque fluctuation and the booming noise To do.

In the actual slip rotation calculation unit S103, the actual slip rotation speed ω _SLPR of the torque converter 1 is calculated by subtracting the rotation speed ω _TR of the turbine runner from the rotation speed ω _iR of the pump impeller.

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

In the precompensators (S101A and S101B), the target slip rotation correction value is calculated by passing the target slip rotation speed ω _SLPT through a compensation filter set so as to have a response intended by the designer.

First, the pre-compensator S101A calculates the first target slip rotation correction value ω _SLPTC1 by the following equation based on the target slip rotation speed ω _SLPT .

However, G _R (S) is a reference model, and a transfer function is set so as to obtain a target response intended by the designer. For example, when the reference model is configured with a first-order lag of the time constant Tt,

And

Next, in the pre-compensator S101B, the second target slip rotation correction value ω _SLPTC2 is

Calculate from However,

G _M (s) is a feedforward compensator. Further, P (s) is a transfer function that models the slip rotation part to be controlled, and is a first-order lag of the time constant Tt.

It becomes.

  The pre-compensator filter constant setting unit (S102) sets the above-mentioned reference model and filter constants (Tt, Tp) in the feedforward compensator. Since this control system is a two-degree-of-freedom control system, the time constant Tt of the reference model is set according to the driving state of the vehicle so as to obtain the response desired by the designer, and the feedforward compensator (S101B) The time constant Tp is set according to a slip rotation model that is a control target.

In the slip rotation speed deviation calculation unit S102, the slip rotation deviation ω _SLPER between the first target slip rotation correction value ω _SLPTC1 from the pre-compensator _S101A and the actual slip rotation speed ω _SLPR is _calculated .

Calculate from

In the feedback compensation calculation unit S105, in order to suppress the slip rotation deviation ω _SLPER , the feedback compensator G _CNT (s) configured by proportional / integral control (hereinafter referred to as PI control) uses the first slip rotation speed command value ω. _SLPTC1 is calculated by the following formula.

However, K _p: proportional control constant K _I: integral control constant s: the differential operator.

In feedforward slip speed gain calculation unit S106, determined by searching the slip rotation speed gain g _SLPCFF corresponding to the current turbine rotation speed omega _TR from the map shown in FIG. 3.

In the feedforward target converter torque calculation unit S107, in order to convert the second target slip rotation correction value ω _SLPTC2 into the converter torque command value t _CNVFF ,

Calculate from

Similarly, the feedback slip rotation speed gain calculation unit S108 searches and obtains the slip rotation speed gain g _SLPCFB corresponding to the current turbine rotation speed ω _TR from the map shown in FIG. At this time, if the range of the turbine rotational speed ω _TR to which the slip control is applied is in the range of NP1 to NP2 shown in the figure, and the range of the same gain for F / B is NP3 to NP4, Gain,

And treated as a fixed value. In the above equation (9), gs3 and gs4 are gains corresponding to feedback gain ranges NP3 and NP4 in the map of FIG.

In feedback target converter torque calculation unit S109, first slip rotation speed command value ω _SLPTC1 is converted to torque command value t _CNVCFB by the following equation.

In the target converter torque calculation unit S110, the target converter torque t _CNVC for achieving the first target slip rotation correction value ω _SLPTC1 is calculated from the following equation according to the turbine rotation speed ω _TR .

In the engine torque estimation unit (S111), the engine torque map value t _ES is searched from the engine speed Ne and the throttle opening TVO using the engine total performance map shown in FIG. The engine torque estimated value t _EH is calculated from the following equation by passing through a filter when the first-order lag of the time constant T _ED is passed.

The target lockup clutch tightening capacity computing unit S112, calculates the following equation a target lockup clutch tightening capacity t _LU by subtracting the target converter torque t _CNVC from the engine torque estimated value t _EH.

Lockup clutch engagement pressure command value calculating unit S113, searches the lock-up clutch engagement pressure command value P _LUC for achieving the current target lockup clutch tightening capacity t _LU from the lock-up clutch capacity map shown in FIG. 6 .

The solenoid drive signal calculation unit S114 determines a lockup duty S _DUTY for setting the actual lockup clutch engagement pressure to the lockup clutch engagement pressure command value _PLUC . Then, the lockup solenoid 4 is driven by the lockup duty, and the lockup clutch engagement pressure is controlled by controlling the differential pressure PA-PR.

As described above, when the converter torque command value is calculated by dividing the slip rotation speed command value by the slip rotation speed gain in the two-degree-of-freedom slip control, the F / F slip rotation speed command value (second target The slip rotation correction value ω _SLPTC2 ) is calculated using the slip rotation speed gain g _SLPCFF corresponding to the primary rotation speed in the same manner as in the prior art, and the F / B slip rotation speed command value (first slip rotation speed command value ω _SLPTC1). 7), a fixed gain is used, and the control system in the slip control is as shown in FIG.

The configuration of the control system in a conventional example slip control is as shown in FIG. 8, the slip rotation speed command value by the F / F (ω _SLPTC2) and F / slip rotation speed command value according to B (ω _SLPTC1) adding Then, since the gain is multiplied, there is a fluctuation element in the F / B loop as described above.

  On the other hand, according to the present invention, even if the degree of freedom in the gain design of the F / B compensator is limited due to the fluctuation of the slip rotation speed gain, this fluctuation width can be reduced. Thus, the restriction on the gain design of the F / B compensator can be relaxed, and the optimum slip rotation speed gain can be set independently in the F / F compensator and the F / B compensator. At the same time, the F / F compensator can maintain the compensation operation with the optimum gain according to the control target as in the conventional case.

  That is, in the above-described conventional example, even when the operating conditions are the same (slip control application range), when the slip rotation speed gain characteristic fluctuates up and down as shown by the broken line in FIG. 9, it does not fluctuate (GA in the figure). In the case of fluctuation (GB in the figure), the latter has a wider gain fluctuation range to be taken into consideration during design.

On the other hand, in the present invention, when the corresponding gain is searched from FIG. 4 in the F / B slip rotation speed gain calculation unit S108, the turbine rotation speed Np1 to Np2 which is the application range of the slip control is narrowed. An F / B gain in a range corresponding to a certain Np3 to Np4 is used, and the variation range is made smaller than the F / F gain. Specifically, the turbine rotational speed ω _TR when probing the map is limited to a range of Np3 to Np4. Then, as shown by the equation (9), the slip rotation speed gain g _SLPCFB is handled as a fixed value.

That is, in FIG. 7, when the F / B slip rotation speed command value ω _SLPTC1 = 10 and the FB slip rotation speed gain g _SLPCFB = 10, the F / B target converter torque t _CNVCFB = 1.

On the other hand, when the F / F slip rotation speed command value ω _SLPTC2 = 10 and the F / F slip rotation speed gain g _SLPCFF = 10, the F / F target converter torque t _CNVCFF = 1, so the total converter torque command value t _CNVC = 2.

Here, when the slip rotation speed gain changes from 10 to 5, only the g _SLPCFF on the F / F side changes, and t _CNVCFF changes to 2. However, since g _SLPCFB on the F / B side remains fixed at 10 and does not change, the total converter torque command value t _CNVC = 3 can be maintained while maintaining t _CNVCFB = 1 while ω _SLPTC1 = 10.

That is, since the output t _CNVCFB of the F / B control system does not change due to the change of the slip rotation speed gain, the output g _SLPCFB of the F / B compensator is not affected. Note that the F / F target converter torque t _CNVCFF changes because of the effect of F / F compensation by two-degree-of-freedom control, and does not limit the effect of the present invention.

  In this way, by reducing the gain fluctuation range in the F / B loop by F / F, the limitation of the gain design of the F / B compensator can be relaxed, and the F / F compensator and the F / B compensator are used. In the control system, the optimum optimum slip rotation speed gain can be set, and the F / F compensator can maintain the compensation operation with the optimum gain according to the control target as in the conventional case.

Further, according to the present invention, since the F / B slip rotation speed gain (g _SLPCFB ) is set to a fixed value as shown in the equation (9), the fluctuation element does not appear in the F / B loop. This increases the degree of freedom when designing / B gain. As a result, it is easy to perform gain design that prioritizes elimination of slip rotation errors, which are inputs to the F / B compensator, and an improvement in the performance of the entire control system can be expected.

FIG. 10 shows a timing chart showing the effects described above. However, the F / F slip rotation speed command value ω _SLPTC2 is assumed to be constant and the F / B slip rotation speed gain g _SLPCFB is a fixed value in a timing chart when model estimation in F / F control is correctly performed. .

At time t1, when the turbine rotational speed ωTR starts to increase as the throttle opening TVO increases, the F / F slip rotational speed gain ω _SLPCFF decreases according to the characteristics of the slip rotational speed gain shown in FIG. F converter torque command t _CNVCFF increases. However, according to the present invention, since the F / B slip rotation speed gain g _SLPCFB remains constant, the F / B converter torque command t _CNVCFB remains constant.

When the increase in the turbine rotational speed ω _TR stops at time t2, the decrease in the F / F slip rotational speed gain g _SLPCFF also stops. Increase in the converter torque command t _CNVC in from time t1 t2 is due to increase the F / F min of t _CNVCFF, F / B portion of t _CNVCFB are not involved.

That is, the fluctuation of the slip rotational speed gain from the time t1 to the time t2 affects only the F / F component, and the slip rotational speed command value ω _SLPTC1 which is the output of the F / B compensator is slip-rotated by the effect of the present invention. It is not affected by the speed gain variation and remains constant.

  As shown in FIGS. 4 and (9), the F / B slip rotation speed gain, which is a fixed value, is set to the median value of the expected fluctuation range in the operating condition to which the slip control is applied. It can be set to a value that matches the operating conditions to which the control is applied, and gain design that prioritizes elimination of slip rotation error, which is the input of the F / B compensator, is easier to perform, improving the overall performance of the control system Can be further advanced.

  FIG. 11 shows a second embodiment.

  The application range of the slip control shown in FIG. 4 of the first embodiment is specified by an actual use history or a prediction survey.

For example, if the slip control is often performed when the turbine rotational speed ω _TR is Np5 as shown in FIG. 11, the slip rotational speed set in the F / B slip rotational speed gain calculating unit S108 in the first embodiment. The gain is set to a value corresponding to this Np5.

  That is, by setting the F / B slip rotation speed gain, which is a fixed value, to a value based on the most frequently used operation condition in the operation condition to which the slip control is applied, the slip rotation speed gain is the slip rotation speed command value. Is converted to a converter torque command value, and fixing it to a value that matches the most frequently used operating conditions improves the accuracy of the conversion rate.

  As a result, the operational effects shown in the first embodiment can be further improved, facilitating gain design that prioritizes eliminating the slip rotation error that is the input of the F / B compensator, and the overall performance of the control system. The effect that improvement can be expected can be further enhanced.

  Next, FIG. 12 shows a third embodiment.

  FIG. 12 shows the F / B slip rotation speed gain calculation unit S108 shown in FIG. 2 of the first embodiment, the map search turbine rotation restriction unit S108A, and the limited F / B slip rotation speed gain calculation unit S108B. An example composed of

In the map search turbine rotation limiting unit S108A, the turbine rotation speed ω _TRL used when searching for the current slip rotation speed gain is limited in accordance with the current engine torque t _EH using the map of FIG.

That is, the upper limit Npmax and the lower limit Npmin of the limited rotation corresponding to the current engine torque t _EH are set, and the map search turbine rotational speed ω _TRL is limited to be between Npmax and Npmin.

Then, the limited F / B slip rotation speed gain calculation unit S108B uses the limited search turbine rotation speed ωTRL to correspond to the F / B slip rotation speed corresponding to the map of FIG. 4 as in the first embodiment. The gain g _SLPCFB is _obtained by searching. Since the search turbine rotational speed is limited, the obtained F / B slip rotational speed gain is a limited value.

  FIG. 14 shows a timing chart in the case of limiting the fluctuation range of the slip rotation speed gain according to the engine torque.

At time t1, when the turbine rotational speed ω _TR starts to increase as the throttle opening TVO increases, the F / F slip rotational speed gain ω _SLPCFF and the F / B slip according to the characteristics of the slip rotational speed gain shown in FIG. Rotational speed gain g _SLPCFB decreases.

Corresponding to the decrease in the slip rotation speed gain, the F / F converter torque command t _CNVCFF increases, but the F / B converter torque command value is the F / B slip rotation speed command that is the output of the F / B compensator. The value ω _SLPTC1 is kept constant by decreasing.

At time t2, since the turbine rotation speed in the map reference to omega _TR> Npmax become the F / B slip speed gain g _SLPCFB is limited to Npmax, also F / B slip speed gain g _SLPCFB limited .

In this time chart, since the F / B slip rotation speed gain g _SLPCFB is limited to a constant value after time t2, F for suppressing output fluctuation due to slip rotation speed gain fluctuation occurring between times t1 and t2. / B slip rotation speed command value ω _SLPTC1 stops decreasing, and the load on the F / B compensator decreases after time t2.

On the other hand, the F / F slip rotational speed gain g _SLPCFF is not limited, so the F / F converter torque command t _CNVCFF continues to increase.

  As described above, in the third embodiment, the same effects as those in the first embodiment can be obtained, and the following effects can be obtained.

  The slip rotation speed gain setting means makes the fluctuation range of the F / B slip rotation speed gain smaller than the fluctuation width of the F / F slip rotation speed gain as the input torque to the torque converter increases, and the input torque to the torque converter becomes The throttle opening and engine torque can be substituted.

  As a result, the larger the input torque to the torque converter, the greater the required engagement capacity in the lockup clutch, and the greater the slip rotation that occurs in the unlocked state. As a result, the target and actual slip rotation deviation in the F / B control are also increased, and the operating load of the F / B compensator itself is increased. In addition, in the control of the conventional example, the slip rotation speed gain fluctuates in response to the change of the operating condition accompanying the input torque change. Therefore, the output compensation operation by the slip rotation speed gain fluctuation mentioned above is performed. Thus, the original slip rotation deviation compensation operation is performed, and the original F / B control performance is difficult to be exhibited.

  Therefore, the degree of influence can be reduced by limiting the fluctuation range of the slip rotation speed gain to a small value according to the operating conditions as in the third embodiment, and the original operation of the F / B compensator is prioritized. Can be done.

  FIG. 15 shows the configuration of 43 (linearization compensator) according to the present invention, after adding an offset corresponding to the differential pressure variation to 44 (lock-up mechanism) in FIG. 6 of Japanese Patent No. 03240979 of the conventional example. It is a simulation result at the time of comprising according to 3 embodiment.

  As described with reference to the time chart of FIG. 14, even when the slip rotational speed gain to be controlled changes, the same rotational gain that divides the output of the F / B compensator is fixed, so the F / B output is a constant value. The operation amount does not change due to the differential pressure variation.

  Finally, as an effect of the entire slip rotation control system, a simulation result in the case where there is a differential pressure variation by changing the target slip rotation according to the throttle opening change is shown. In FIG. 16, which is the result of the conventional example, hunting occurs when the target converges, but in FIG. 17 which is the result of the present invention, hunting does not occur, and it can be seen that the target quickly converges.

  In the third embodiment of the present invention, the F / B slip rotational speed gain is constantly limited according to the input torque to the torque converter. However, depending on the application status of the present invention, the throttle A similar effect can be obtained even in a configuration in which a transient restriction such as a time restriction is added in accordance with the opening degree and the amount of change in engine torque.

  In each of the above embodiments, the F / B compensator is PI controlled. However, the same effect can be exhibited even if a higher-order controller is used according to the purpose.

Further, as described in the example of Japanese Patent No. 0330465, the slip rotation speed gain g _SLPC may also be a value g _SLPF that has been subjected to filter processing. In particular, when the slip rotation speed gain is limited according to the operating state as in the third embodiment, it is better to perform a filter process so that the values before and after that are smoothly connected.

  In each of the above-described embodiments, a torque map prepared in advance is used when performing engine torque estimation. However, any configuration that can receive a torque estimation value from an engine controller or the like using dedicated communication means such as CAN is used. The received value may be used.

  As described above, the slip converter for a torque converter according to the present invention can be applied to a transmission of a vehicle having excellent drivability.

The schematic block diagram of the torque converter which shows one Embodiment of this invention. The functional block diagram of the feedback control part of a controller. The map which shows the relationship between the turbine rotational speed of a torque converter, and F / F slip rotational speed gain. The map which shows the relationship between the turbine rotational speed of a torque converter, and F / B slip rotational speed gain. Map of engine torque according to throttle opening and engine speed. The map which shows the relationship between lockup clutch fastening pressure and lockup clutch capacity. The block diagram of the control system of this invention. The block diagram of the control system of a prior art example. The map which shows the relationship between the turbine rotational speed of a torque converter, and F / B slip rotational speed gain, and the relationship with the application range of slip control. A graph when slip control is performed when the throttle opening is gradually increased in the first and second embodiments, throttle opening, turbine rotational speed, F / F slip rotational speed gain, F / F slip The relationship between rotational speed command value, F / F converter torque command value, F / B slip rotational speed gain, F / B slip rotational speed command value, F / B converter torque command value, converter torque command value and time is shown. The graph which shows 2nd Embodiment and shows the relationship between the turbine rotational speed and the frequency of slip control. The block diagram which shows 3rd Embodiment and shows the other example of the slip rotational speed gain calculating part shown in FIG. The map which shows the relationship between the upper limit of engine torque and the turbine rotational speed for a search, and a lower limit. FIG. 6 is a graph when slip control is performed when the throttle opening is gradually increased in the third embodiment, and the throttle opening, the turbine rotation speed, the F / F slip rotation speed gain, and the F / F slip rotation speed command. The value, the F / F converter torque command value, the F / B slip rotation speed gain, the F / B slip rotation speed command value, the F / B converter torque command value, the converter torque command value, and the time are shown. The graph when the third embodiment is applied to the conventional example shows the relationship between rotation gain, slip rotation speed, F / B output, slip rotation speed deviation, and time. A conventional example is shown, and the relationship between slip rotation speed, engine torque, throttle opening, and time is shown in the case where the target slip rotation is changed according to the throttle opening change and there is a differential pressure variation. The third embodiment shows the relationship between the slip rotation speed, the engine torque, the throttle opening, and the time when the target slip rotation is changed according to the throttle opening change and there is a differential pressure variation.

Explanation of symbols

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

Claims (6)

A torque converter provided with a lock-up clutch and interposed between the prime mover and the automatic transmission;
Open control means for controlling the engagement state of the lockup clutch by open loop control based on the driving state of the vehicle;
A target slip rotation calculating unit for obtaining a target slip rotation speed of the lock-up clutch from a driving state of the vehicle;
An actual slip rotation speed detecting means for detecting an actual slip rotation speed from the pump impeller rotation speed and the turbine rotation speed of the torque converter;
Slip control means for controlling the engagement state of the lock-up clutch by feedback control based on the target slip rotation and the actual slip rotation;
In a torque control slip control device comprising: an engagement control means for switching from the open control means to a slip control means when a predetermined condition is satisfied when the lockup clutch is engaged;
The slip control means includes
F / F slip rotation speed gain is calculated by feedforward, and F / F compensation means for calculating F / F target converter torque based on the F / F slip rotation speed gain;
F / B compensation means for calculating an F / B slip rotation speed gain by feedback and calculating an F / B target converter torque based on the F / B slip rotation speed gain;
Target converter torque calculating means for calculating the target converter torque by adding the F / F target converter torque and the F / B target converter torque;
With
A slip control device for a torque converter, wherein a fluctuation range of the F / B slip rotation speed gain is set smaller than a fluctuation range of the F / F slip rotation speed gain. The F / F compensation means includes
F / F slip rotation speed command value calculating means for calculating a feed forward F / F slip rotation speed command value based on the target slip rotation speed;
F / F slip rotation speed gain calculating means for calculating an F / F slip rotation speed gain based on the turbine rotation speed;
F / F target converter torque calculation means for calculating the F / F target converter torque by feedforward by dividing the F / F slip rotation speed command value by the F / F slip rotation speed gain;
Have
The F / B compensation means includes
F / B slip rotation speed command value calculating means for calculating a feedback F / B slip rotation speed command value based on the target slip rotation speed and the actual slip rotation speed;
F / B slip rotation speed gain calculating means for calculating an F / B slip rotation speed gain based on the turbine rotation speed;
F / B target converter torque calculating means for calculating the F / B target converter torque by feedback by dividing the F / B slip rotation speed command value by the F / B slip rotation speed gain;
Have
2. The F / B slip rotation speed gain calculating unit sets the fluctuation range of the F / B slip rotation speed gain to be smaller than the fluctuation range of the F / F slip rotation speed gain. Slip control device for torque converter. The F / B slip rotation speed gain calculating means is
An input torque detecting means for detecting or estimating an input torque to the torque converter;
The slip control device for a torque converter according to claim 2, wherein a fluctuation range of the F / B slip rotation speed gain is set smaller than the F / F slip rotation speed gain as the input torque increases.   The slip control device for a torque converter according to claim 2 or 3, wherein the F / B slip rotation speed gain calculation means sets the F / B slip rotation speed gain to a fixed value.   The F / B slip rotation speed gain calculating means uses the fixed value as a median value of a fluctuation range of the F / B slip rotation speed gain assumed under an operation condition in which slip control is performed. 4. A slip control device for a torque converter according to 4.   5. The F / B slip rotation speed gain calculating means sets the fixed value to a value corresponding to an operating condition with the highest use frequency in an operating condition in which slip control is performed. The slip control apparatus of the torque converter as described.

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