JP7036922B2 - Control device for automatic transmission - Google Patents

Description

The present invention relates to a control device for an automatic transmission equipped with a continuously variable transmission mechanism mounted on a vehicle.

Conventionally, Patent Document 1 describes a technique for performing feedback control using an integral compensator that integrates the deviation between the target gear ratio and the actual gear ratio when controlling a continuously variable transmission that continuously changes the gear ratio. It has been disclosed. Then, while the amount of change in the actual gear ratio is less than a predetermined value, the integral operation of the integral compensator is stopped to suppress the overshoot in the control.

Here, in feedback control of the continuously variable transmission, there is a disturbance (hereinafter referred to as a transient disturbance) that occurs only in the transitional period such as a hydraulic response delay and disappears in the stable period. Therefore, even if the integral compensator is stopped when the change in the actual gear ratio is small and the integral compensator is operated when the change in the actual gear ratio is large as in the prior art, the integral compensator is subjected to transient disturbance. Due to the integral compensation carried out in the above process, a new deviation is generated even in the stable period, and there is a problem that overshoot in control occurs.
The present invention has been made focusing on the above problems, and an object of the present invention is to provide a control device for an automatic transmission capable of ensuring the stability of shift control.

Japanese Unexamined Patent Publication No. 11-23319

In order to achieve the above object, in the control device of the automatic transmission that controls the speed change of the continuously variable transmission mechanism of the present invention, the target gear ratio of the continuously variable transmission mechanism is calculated based on the running state, and the continuously variable transmission mechanism of the above-mentioned stepless speed change mechanism is calculated. It has a feedback control unit that performs feedback control using an integral compensator based on the deviation from the actual gear ratio, and the feedback control unit operates the integral compensator when the occurrence of transient disturbance is estimated. When it is determined that the fluctuation of the deviation has converged after the stop, the operation of the stopped integral compensator is restarted.

That is, by stopping the integral compensator when the occurrence of a transient disturbance is estimated, the influence of the transient disturbance is suppressed, and after the deviation fluctuation has converged, the transient disturbance becomes small. Therefore, overshoot is not promoted even if the integral compensator is restarted at this stage, and stable feedback control can be realized. In addition, stable feedback control can be realized by eliminating the steady-state deviation by restarting the integral compensator.

It is a system diagram which shows the control device of the continuously variable transmission of Example 1. FIG. It is a control block diagram which shows the outline in the control unit of Example 1. FIG. It is a control block diagram which shows the structure of the feedback control part of Example 1. FIG. It is a time chart showing the change of the gear ratio at the time of sudden start when the accelerator is fully opened after the vehicle is stopped on the Hi side of the actual gear ratio ir. It is a flowchart which shows the integration stop entering determination process which determines whether or not the integration stop state of Example 1 is entered. It is a flowchart which shows the convergence experience determination process which determines whether or not the shift of Embodiment 1 has experienced convergence. It is a flowchart which shows the integration stop operation process of Example 1. FIG. It is a time chart which shows the integration stop operation process of Example 1. FIG.

[Example 1]
FIG. 1 is a system diagram showing a control device for the automatic transmission according to the first embodiment. The vehicle of the first embodiment has an engine 1 which is an internal combustion engine and an automatic transmission, and transmits a driving force to a tire 8 which is a driving wheel via a differential gear. The power transmission path connecting the automatic transmission to the tire 8 is collectively referred to as a power train PT.

The automatic transmission has a torque converter 2, an oil pump 3, a forward / backward switching mechanism 4, and a belt-type continuously variable transmission mechanism CVT. The torque converter 2 is connected to the pump impeller 2b, which is connected to the engine 1 and rotates integrally with the drive claw that drives the oil pump 3, and the input side of the forward / backward switching mechanism 4 (the input shaft of the belt-type continuously variable transmission mechanism CVT). It has a turbine runner 2c to be used, and a lockup clutch 2a capable of integrally connecting these pump impellers 2b and the turbine runner 2c. The forward / backward switching mechanism 4 is composed of a planetary gear mechanism and a plurality of clutches 4a, and switches between forward and reverse depending on the engaged state of the clutch 4a. The belt-type continuously variable transmission mechanism CVT has a primary pulley 5 connected to the output side (input shaft of the continuously variable transmission) of the forward / backward switching mechanism 4, a secondary pulley 6 that rotates integrally with the drive wheels, and a primary pulley 5. It has a belt 7 that is wound between the and a secondary pulley 6 to transmit power, and a control valve unit 20 that supplies control pressure to each hydraulic actuator.

The control unit 10 has a range position signal from the shift lever 11 that selects a range position by the operation of the driver (hereinafter, the range position signal is referred to as P range, R range, N range, and D range, respectively) and an accelerator. The accelerator pedal opening signal (hereinafter referred to as APO) from the pedal opening sensor 12, the brake pedal ON / OFF signal from the brake switch 17, and the primary pulley pressure from the primary pulley pressure sensor 15 that detects the hydraulic pressure of the primary pulley 5. The signal, the secondary pulley pressure signal from the secondary pulley pressure sensor 16 that detects the hydraulic pressure of the secondary pulley 6, the primary rotation speed signal Npri from the primary pulley rotation speed sensor 13 that detects the rotation speed of the primary pulley 5, and the secondary pulley. The secondary rotation speed signal Nsec from the secondary pulley rotation speed sensor 14 that detects the rotation speed of 6, the engine rotation speed Ne from the engine rotation speed sensor 18 that detects the engine rotation speed, and G that detects the front-rear acceleration G of the vehicle. Read the acceleration signal G from the sensor 19. In the case of the D range, the primary rotation speed signal Npri coincides with the turbine rotation speed by engaging the clutch 4a, and is therefore also referred to as the turbine rotation speed Nt below.

The control unit 10 controls the engaged state of the clutch 4a according to the range position signal. Specifically, if it is in the P range or N range, the clutch 4a is released, and if it is in the R range, a control signal is output to the control valve unit 20 so that the forward / backward switching mechanism 4 outputs reverse rotation, and the reverse clutch is used. (Or brake) is fastened. Further, in the D range, a control signal is output to the control valve unit 20 so that the forward / backward switching mechanism 4 rotates integrally and outputs a forward rotation, and the forward clutch 4a is engaged. In addition, the vehicle speed VSP is calculated based on the secondary rotation speed signal Nsec.

FIG. 2 is a block diagram showing a control configuration in the control unit of the first embodiment. The control unit 10 includes a target gear ratio calculation unit 101, a deviation calculation unit 102, a feedback control unit 103, a notch filter 104, an addition unit 105, a command signal divergence detection unit 106, and an oil vibration detection unit 107. It has a vehicle vibration detection unit 108, a phase compensation control unit 109, and a lockup control unit 110 that controls the engaged state of the lockup clutch 2a.

The target gear ratio calculation unit 101 calculates the target gear ratio ir * from the shift map that can achieve the optimum fuel consumption state based on the APO signal and the vehicle speed VSP. The deviation calculation unit 102 detects the actual gear ratio ir based on the primary rotation speed signal Npri and the secondary rotation speed signal Nsec, which are actual values indicating the state of the continuously variable transmission mechanism CVT, and detects the actual gear ratio ir and the target gear ratio ir. Calculate the deviation Δir from *. The feedback control unit 103 calculates a feedback command signal for the solenoid that controls the pulley hydraulic pressure so that the set target gear ratio ir * and the actual gear ratio ir, which is the actual value indicating the state of the continuously variable transmission mechanism CVT, match. do. The details of the feedback control unit 103 will be described later.

The notch filter 104 advances the phase of the frequency region corresponding to the resonance frequency region of the power train PT among the command signals calculated by the feedback control unit 103, and calculates the phase compensation signal with the gain on the high frequency side reduced. .. The addition unit 105 calculates the final command signal by adding the phase compensation signal to the feedback command signal. The command signal divergence detection unit 106 detects whether or not the final command signal vibrates at a frequency representing the low frequency region (for example, around 1 Hz), and if it does not vibrate, the vibration flag F1 is turned off. If it is diverging, turn on the vibration flag F1. Here, the divergence of the command signal is detected based on whether or not the state in which the amplitude is equal to or higher than the predetermined value continues for a predetermined time.

In the oil vibration detection unit 107, first, the voltage signal detected by the primary pulley pressure sensor 15 and the secondary pulley pressure sensor 16 is converted into a hydraulic signal, and the DC component (variable component according to the control command) is converted by the band bus filter processing. Remove and extract only the vibration component. Then, the amplitude of the vibration component is calculated, and when the amplitude of either the primary pulley pressure or the secondary pulley pressure continues to be equal to or higher than the predetermined amplitude for a predetermined time or longer, the oil vibration flag F2 is turned ON. On the other hand, when the oil vibration flag F2 is ON and the amplitude is less than the predetermined amplitude for a predetermined time or longer, the oil vibration flag F2 is turned OFF.

The vehicle vibration detection unit 108 extracts the vibration component of the front-rear acceleration G detected by the G sensor 19, and when the amplitude of the vibration component continues to be equal to or higher than a predetermined value for a predetermined time or longer, the resonance frequency of the power train PT. It is judged that the vibration is occurring in the region, and the resonance flag F3 is turned ON. On the other hand, if the amplitude of the vibration component is less than a predetermined time for a predetermined time or longer, the resonance flag F3 is turned off.

The phase compensation control unit 109 reads the information of the vibration flag F1, the oil vibration flag F2, and the resonance flag F3 and the range position signal, and calculates the operating point specified by VSP and APO. Then, when all the flags are OFF after the engine is started, a signal permitting the output of the phase compensation signal by the notch filter 104 is output. On the other hand, when any one of the flags is turned ON, a signal for prohibiting the output of the phase compensation signal in the notch filter 104 is output, and a command for releasing the lockup clutch 2a is output.

FIG. 3 is a control block diagram showing the configuration of the feedback control unit of the first embodiment. The feedback control unit 103 includes an integral compensator 301 that integrates the deviation Δir to calculate the integral value, an integral gain multiplication unit 302 that calculates the integral component by multiplying the integral value by the integral gain Ki, and a gain proportional to the deviation Δir. The proportional gain multiplication unit 303 that calculates the proportional component by multiplying by, the adder unit 304 that calculates the feedback control component by adding the integral component and the proportional component, and the integral stop determination that determines the operation / stop of the integral compensator 301. It has a part 305 and.

Next, the integration stop determination unit 305 will be described. The integral component in the feedback control unit eliminates the steady deviation. However, as shown in FIG. 4, when the target gear ratio ir * changes stepwise and a transient deviation occurs from the actual gear ratio ir as in the case of sudden shift, the integral component remains even after the deviation is eliminated. If it remains, the actual gear ratio ir may overshoot the target gear ratio ir * and affect the vehicle behavior. Therefore, it was decided to stop the integral compensator when the occurrence of transient disturbance is estimated.

In the first embodiment, when the occurrence of a transient disturbance is estimated, the integration is stopped, and it is determined that the deviation has converged before the integration is started.

FIG. 5 is a flowchart showing an integration stop entry determination process for estimating the occurrence of a transient disturbance of the first embodiment and determining whether or not to enter the integration stop state.
In step S1, it is determined whether or not the control is started, and if the control is started, the process proceeds to step S4 and the determination of entering the integration stop is established.
In step S2, it is determined whether or not it is at the time of control initialization, and at the time of control initialization, the process proceeds to step S4 to establish the integration stop entry determination, and at other times, the process proceeds to step S3.
In step S3, it is determined whether or not the shift speed exceeds the threshold value, and if it exceeds the threshold value, the process proceeds to step S4 to determine that the integration stop has been entered. In other cases, the process proceeds to step S5 to stop the integration. The entry judgment is unsuccessful. It should be noted that it is not always necessary to perform three steps S1, S2, and S3, and the integration stop entry determination may be performed based on any one or more.

FIG. 6 is a flowchart showing a convergence experience determination process for determining whether or not the shift of the first embodiment has experienced convergence.
In step S11, it is determined whether or not the absolute value of the velocity deviation VΔir, which is the differential value of the deviation, is the predetermined value a1 or more, and if it is the predetermined value a1 or more, the process proceeds to step S15 and the determination of the convergence experience is established. This is because the predetermined value a1 or more means that the deviation Δir fluctuates greatly once, and then it is considered to operate toward convergence. On the other hand, if the value is less than the predetermined value a1, the deviation Δir does not fluctuate, and it is considered that the user does not experience the operation toward convergence.
In step S12, it is determined whether or not the integration stop entry determination is established, and if it is established, the process proceeds to step S14 and the determination of the convergence experience is not established. This is because it is not necessary to determine the convergence if the integration is not stopped in order to determine the convergence after the integration is stopped.
In step S13, it is determined whether or not the determination of the convergence experience is established in the previous control cycle, and if it is established, the determination of the convergence experience is established in step S15. On the other hand, if the determination of the convergence experience is not established in the previous control cycle, the process proceeds to step S14 and the determination of the convergence experience is not established.
By determining the presence or absence of the above convergence experience, it is possible to avoid erroneously determining that the deviation has converged when the occurrence of a transient disturbance is estimated.

FIG. 7 is a flowchart showing the integration stop operation process of the first embodiment.
In step S21, it is determined whether or not the brake is activated, and if the brake is activated, the process proceeds to step S27 to activate the integral compensator 301. That is, in a situation where it is desired to rapidly shift to the Low side by sudden braking, the shift is prioritized even if overshoot is allowed.
In step S22, it is determined whether or not the absolute value of the velocity deviation VΔir is less than the predetermined value a1, and if it is less than the predetermined value a1, the process proceeds to step S23, and if not, the process proceeds to step S25.
In step S23, it is determined whether or not the acceleration deviation GΔir, which is a double derivative of the deviation Δir, is less than the predetermined value b1 indicating convergence. move on.
In step S24, it is determined whether or not the determination of the convergence experience is established, and if it is established, it is determined that the occurrence of a transient disturbance is not presumed, and the process proceeds to step S27.
In step S25, it is determined whether or not the integration stop entry determination is established, and if it is established, the process proceeds to step S28 to stop the integral compensator 301, and if not, the process proceeds to step S26.
In step S26, it is determined whether or not the integration has been stopped in the previous control cycle, and if it has stopped, the integration compensator 301 is stopped in step S28. On the other hand, if the integration has not been stopped in the previous control cycle, the process proceeds to step S27 to operate the integration compensator 301.

FIG. 8 is a time chart showing the integration stop operation process of the first embodiment. This time chart starts from a state where the target gear ratio ir * is Low, the actual gear ratio ir is Hi, and the deviation Δir is large.

When the occurrence of a transient disturbance is presumed, the condition shown in step S1 is satisfied, and the integration stop entry determination is satisfied. Then, since the absolute value of VΔir at the time of estimation of the occurrence of the transient disturbance is smaller than the predetermined value a1, it is determined that the determination of the convergence experience is unsuccessful. Further, since the absolute value of the acceleration deviation GΔir is smaller than the predetermined value b1, the process proceeds to steps S21 → S22 → S23 → S24 → S25 → S28 in the flowchart of FIG. 7, and the integral compensator 301 is stopped. As a result, feedback control is performed based on the proportional component, and overshoot is avoided. When the absolute value of the velocity deviation VΔir exceeds the predetermined value a1 with the integral compensator 301 stopped, the determination of the convergence experience is established.

When the velocity deviation VΔir becomes smaller than the predetermined value a1 at the time t1, the determination of entering the integration stop is not established in step S5. However, since the acceleration deviation GΔir is larger than the predetermined value b1, the process proceeds to step S22 → S23 → S25 → S26 → S28, and the integral compensator 301 is continuously stopped. This prevents the integral compensator 301 from resuming operation and increasing the overshoot.
Similarly, even if the acceleration deviation GΔir becomes smaller than the predetermined value b1 at time t2, since the absolute value of the velocity deviation VΔir is larger than the predetermined value a1, the process proceeds to step S22 → S25 → S26 → S28 and continues. Stop the integral compensator 301.

At time t3, although the steady-state deviation Δir remains, the velocity deviation VΔir and the acceleration deviation GΔir both become small, and when the deviation GΔir converges, the process proceeds to step S22 → S23 → S24 → S27, and the integral compensator 301 Resume operation. As a result, the steady-state deviation can be eliminated by the feedback control by the integral compensator 301 while avoiding the overshoot.

As described above, in the examples, the effects listed below can be obtained.
(1) A control unit 10 that controls the stepless speed change mechanism CVT that winds a belt between the primary pulley 5 and the secondary pulley 6 and controls the belt holding pressure between the primary pulley 5 and the secondary pulley 6 to change the speed. Therefore, feedback control is performed using the target gear ratio calculation unit 101 that calculates the target gear ratio ir * based on the running condition and the integral compensator 301 based on the deviation between the target gear ratio ir * and the actual gear ratio ir. It has a feedback control unit 103, and the integration stop determination unit 305 (feedback control unit) stops the operation of the integration compensator 301 when the occurrence of a transient disturbance is estimated, and then the fluctuation of the deviation Δir. When it is determined that has converged, the operation of the stopped integral compensator 301 is restarted.
That is, by stopping the integral compensator 301 when the occurrence of a transient disturbance such as when the control is started, when the control is initialized, or when a sudden shift is estimated, the influence of the transient disturbance is suppressed, and the influence of the transient disturbance is suppressed. After the fluctuation of the deviation Δir has converged, the transient disturbance becomes smaller, so overshoot is not promoted even if the integral compensator 301 is restarted at this stage, and stable feedback control is realized. can. In addition, stable feedback control can be realized by eliminating the steady-state deviation by restarting the integral compensator 301.

(2) The integration stop determination unit 305 changes the deviation Δir when the absolute value of the velocity deviation VΔir (deviation change rate) and the absolute value of the acceleration deviation GΔir (deviation change acceleration) are smaller than the predetermined values a1 and b1. Judges that has converged.
That is, if the convergence state is determined only by the absolute value of the velocity deviation VΔir, it may be erroneously determined that the convergence state has occurred even during the convergence. On the other hand, by using the absolute value of the acceleration deviation GΔir together, it is possible to prevent erroneous determination during convergence. Further, the erroneous determination that occurs when the convergence state is determined only by the absolute value of the acceleration deviation GΔir can be prevented from the erroneous determination during the convergence by using the absolute value of the velocity deviation VΔir together.

(3) The integration stop determination unit 305 determines that the fluctuation of the deviation Δir has converged after the absolute value of the velocity deviation VΔir becomes a predetermined value a1 or more after the start of the feedback control.
That is, when the occurrence of a transient disturbance is estimated, it is in a state where convergence has not started yet, and if it is judged using only the absolute value of the velocity deviation VΔir and the absolute value of the acceleration deviation GΔir at this stage, it converges. It will be misjudged that it is done. On the other hand, by determining the convergence state only after the absolute value of the velocity deviation VΔir becomes a predetermined value a1 or more, it is possible to avoid erroneous determination when the occurrence of transient disturbance is estimated.

Claims (5)

It is a control device for an automatic transmission that controls the speed change of a continuously variable transmission mechanism.
It has a feedback control unit that calculates the target gear ratio of the continuously variable transmission mechanism based on the running state and performs feedback control using an integral compensator based on the deviation from the actual gear ratio of the continuously variable transmission mechanism.
The feedback control unit stops the operation of the integral compensator when the occurrence of a transient disturbance is estimated, and then, when it is determined that the fluctuation of the deviation has converged, the integrated compensator is stopped. Resume operation ,
The feedback control unit is a control device for an automatic transmission that estimates that a transient disturbance occurs at the start of the feedback control . It is a control device for an automatic transmission that controls the speed change of a continuously variable transmission mechanism.
It has a feedback control unit that calculates the target gear ratio of the continuously variable transmission mechanism based on the running state and performs feedback control using an integral compensator based on the deviation from the actual gear ratio of the continuously variable transmission mechanism.
The feedback control unit stops the operation of the integral compensator when the occurrence of a transient disturbance is estimated, and then, when it is determined that the fluctuation of the deviation has converged, the integrated compensator is stopped. Resume operation ,
The feedback control unit is a control device for an automatic transmission that estimates that a transient disturbance occurs when the feedback control is initialized . It is a control device for an automatic transmission that controls the speed change of a continuously variable transmission mechanism.
It has a feedback control unit that calculates the target gear ratio of the continuously variable transmission mechanism based on the running state and performs feedback control using an integral compensator based on the deviation from the actual gear ratio of the continuously variable transmission mechanism.
The feedback control unit stops the operation of the integral compensator when the occurrence of a transient disturbance is estimated, and then, when it is determined that the fluctuation of the deviation has converged, the integrated compensator is stopped. Resume operation ,
The feedback control unit is a control device for an automatic transmission that estimates that a transient disturbance occurs when the absolute value of the change speed of the target gear ratio is larger than a predetermined value . It is a control device for an automatic transmission that controls the speed change of a continuously variable transmission mechanism.
It has a feedback control unit that calculates the target gear ratio of the continuously variable transmission mechanism based on the running state and performs feedback control using an integral compensator based on the deviation from the actual gear ratio of the continuously variable transmission mechanism.
The feedback control unit stops the operation of the integral compensator when the occurrence of a transient disturbance is estimated, and then, when it is determined that the fluctuation of the deviation has converged, the integrated compensator is stopped. Resume operation ,
The feedback control unit is a control device for an automatic transmission that determines that the fluctuation of the deviation has converged when the absolute value of the change speed of the deviation and the absolute value of the change acceleration of the deviation are smaller than a predetermined value . In the control device for the automatic transmission according to claim 4 ,
The feedback control unit is a control device for an automatic transmission that determines that the fluctuation of the deviation has converged after the absolute value of the change speed of the deviation becomes a predetermined value or more after the start of the feedback control.

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