JP2002267006A - Shift control device of automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish the responsiveness to a target rotating speed and converging stability in a high degree of compatibility in a shift control to make feedback control of a turbine rotating speed to the target value during an inertial phase. SOLUTION: A max. value of the deviation or an integrated value of deviation is computed during the feedback by a sliding mode control. In accordance with the size of the max. value or integrated value of the deviation, learning is made for either of the feedback gain, the width of boundary layer, and the initial value of the deviation integrated value included in the conditional amount which defines the changeover function, and at the time of next feedback control, the sliding mode control is performed using the result of learning.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission, and more particularly to a sliding mode control technique suitable for feedback control of an input shaft rotation speed during an inertia phase.

[0002]

2. Description of the Related Art Conventionally, feedback is performed by proportional / integral / differential operation based on a deviation between a target value and an actual value so that an input shaft rotation speed during a gear shift or a rate of change of the input shaft rotation speed follows a target. 2. Description of the Related Art There is known a shift control device for an automatic transmission configured to perform control (see Japanese Patent Application Laid-Open Nos. 2000-110924 and 11-31317).

In the feedback control based on the above-described proportional / integral / differential operation (PID control), A
Since the requirements of the feedback gain differ depending on the conditions such as the temperature of TF (Automatic Transmission Fluid) and the vehicle speed, a gain map adapted for each condition such as the ATF temperature and the vehicle speed is provided. Is searched for and used.

[0004] Therefore, there is a problem that the number of feedback gains that need to be adapted is large and the number of adaptation steps becomes enormous.
Since the gain is fixed, it is not possible to cope with a state change during gear shifting, and there is a possibility that convergence to a target may be deteriorated. As a control for compensating for the above-mentioned disadvantages of the PID control, a sliding mode control which has excellent robustness and a relatively simple controller design is known (Japanese Patent Laid-Open No. 2000-2000).
-35120).

[0005]

However, in the above-mentioned sliding mode control, it is difficult to set control parameters such as a feedback gain and a boundary layer width so as to achieve both high responsiveness and high stability. For example, if the boundary layer width is set to be large with priority given to stability, there is a problem that responsiveness to a target is reduced when a large deviation occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a responsiveness and stability of a shift control device for an automatic transmission in which a state quantity (input shaft rotation speed) during shifting is made to coincide with a target by sliding mode control. The purpose is to be able to balance sex with a high level.

[0007]

According to the first aspect of the present invention, the hydraulic pressure supply to the friction engagement element is controlled by a sliding mode control based on a deviation between a state quantity during shifting and a target value of the state quantity. The control signal is calculated, and the control parameter used in the next sliding mode control is learned based on the deviation during the sliding mode control.

With this configuration, it is determined from the magnitude of the deviation during the sliding mode control whether priority should be given to responsiveness or stability in the next sliding mode control, and the next sliding mode control should be performed in the next sliding mode control. Determine the control parameters to be used. According to the second aspect of the present invention, the maximum value of the deviation during the sliding mode control is obtained, and the control parameter used in the next sliding mode control is learned from the maximum value.

According to such a configuration, based on the deviation at the most distant from the target during the sliding mode control,
The control parameters to be used in the next sliding mode control are determined. In the invention according to claim 3, an integrated value of the deviation during the sliding mode control is obtained,
The control parameter used in the next sliding mode control is learned from the integrated value.

According to this configuration, the deviation is integrated during the sliding mode control, and the control parameter used in the next sliding mode control is determined based on the integrated value of the deviation. According to a fourth aspect of the present invention, the state parameter x defining the switching function σ in the sliding mode control includes an integral value of the deviation, and the control parameter to be learned is set to an initial value of the integral value. .

With this configuration, it is determined from the magnitude of the deviation during the sliding mode control whether to prioritize responsiveness or stability in the next sliding mode control, and determine the state quantity of the switching function σ. The initial value (the value at the start of feedback) of the integrated value of the deviation included in is determined. According to a fifth aspect of the invention, the control parameter to be learned is a feedback gain in the sliding mode control.

According to this configuration, when the deviation is large, the responsiveness is improved by increasing the feedback gain, and when the deviation is relatively small, the convergence stability is improved by reducing the feedback gain. In the invention according to claim 6, the control parameter to be learned is a boundary layer width in the sliding mode control.

According to such a configuration, in the sliding mode control, the discontinuous function is continuously approximated by the saturation function or the like, so that when the boundary layer is introduced to the switching surface, the width of the boundary layer is set to the previous value. Is changed according to the magnitude of the deviation during the sliding mode control. According to a seventh aspect of the present invention, the hydraulic pressure supplied to the friction engagement element is feedback-controlled so that the input shaft rotation speed matches the target rotation speed in the inertia phase during the shift.

According to this configuration, when the input shaft rotation speed (turbine rotation speed) is feedback-controlled to the target rotation speed by the sliding mode control during the inertia phase, the feedback gain is determined based on the deviation of the rotation speed during the feedback control. And control parameters such as the boundary layer width are determined, and the next feedback control is performed using the determined control parameters.

[0015]

According to the first aspect of the present invention, it is determined whether to prioritize responsiveness or stability based on whether the deviation is large, and the control parameters in the sliding mode control are determined. Responsiveness and stability in feedback control can be made compatible at a high level, and there is an effect that shift controllability can be improved.

According to the second aspect of the present invention, there is an effect that the appropriate value of the control parameter can be easily determined from the maximum deviation during the sliding mode control and reflected in the next sliding mode control. According to the third aspect of the present invention, there is an effect that the appropriate value of the control parameter can be accurately determined from the integrated value of the deviation during the sliding mode control and reflected in the next sliding mode control.

According to the fourth aspect of the present invention, the switching function σ
The effect that the initial value of the integral value when starting the sliding mode control can be set to an appropriate value that can achieve both responsiveness and stability at a high level in the configuration that includes the integral value of the deviation as the state quantity of There is. Claim 5
According to the invention described above, by changing the feedback gain in accordance with the deviation, there is an effect that an appropriate value can be set in which responsiveness and stability can be compatible at a high level.

According to the sixth aspect of the present invention, by changing the width of the boundary layer according to the deviation, there is an effect that it is possible to set an appropriate value capable of achieving both high responsiveness and high stability. . According to the seventh aspect of the present invention, the input shaft rotation speed during the inertia phase can be feedback-controlled near the target rotation speed with good response and stability, and the speed ratio can be smoothly changed. .

[0019]

Embodiments of the present invention will be described below. FIG. 1 shows a transmission mechanism of an automatic transmission according to an embodiment, in which an output of an engine (not shown) is transmitted to a transmission mechanism 2 via a torque converter 1.

The transmission mechanism 2 has two sets of planetary gears G1,
G2, 3 sets of multiple disc clutches H / C, R / C, L / C, 1
A set of brake bands 2 & 4 / B, a set of multiple disc brakes L & R / B, and a set of one-way clutch L / OWC. The two sets of planetary gears G1 and G2 are simple planetary gears including sun gears S1 and S2, ring gears r1 and r2, and carriers c1 and c2, respectively.

The sun gear S1 of the planetary gear set G1 is configured to be connectable to the input shaft IN by a reverse clutch R / C, and is configured to be fixed by a brake band 2 & 4 / B. Sun gear S2 of the planetary gear set G2
Are directly connected to the input shaft IN. The carrier c1 of the planetary gear set G1 is configured to be connectable to the input shaft I by a high clutch H / C, while the ring gear r2 of the planetary gear set G2 is connected to the planetary gear set G1 by a low clutch L / C.
And the carrier c1 of the planetary gear set G1 can be fixed by the low & reverse brake L & R / B.

A ring gear r1 of the planetary gear set G1 and a carrier c2 of the planetary gear set G2 are directly and integrally connected to the output shaft OUT. In the speed change mechanism 2 having the above-described configuration, as shown in FIG.
This is realized by a combination of the release states.

In FIG. 2, a circle indicates a fastened state, and a part without a symbol indicates a released state. In particular, the low & reverse brake L at the first speed is used.
A fastening state indicated by a black circle of & R / B indicates fastening in only one range. Each of the clutches and brakes (friction engagement elements) is engaged and disengaged by supply hydraulic pressure. The supply hydraulic pressure for each clutch and brake is controlled by a solenoid valve unit 11 shown in FIG.
Are individually controlled by a solenoid valve included in the control unit.

An A / T controller 12 for controlling each solenoid valve of the solenoid valve unit 11 includes an A / T oil temperature sensor 13, an accelerator opening sensor 14,
Detection signals from the vehicle speed sensor 15, the turbine rotation sensor 16, the engine rotation sensor 17, the air flow meter 18, and the like are input, and the hydraulic pressure in each friction engagement element is controlled based on the detection results.

In FIG. 3, reference numeral 20 denotes an engine combined with the automatic transmission. Here, A /
The state of the shift control by the T controller 12 will be described with reference to the time chart of FIG. 5 by taking an example of an upshift (hereinafter, referred to as a power-on upshift) in a state where the driving torque of the engine 20 is applied. This will be described with reference to the flowchart of FIG.

In the flowchart of FIG. 4, in step S1, a shift determination for a power-on upshift is performed.
The A / T controller 12 previously stores a shift map in which a shift stage is set according to the vehicle speed VSP and the accelerator opening (throttle opening). For example, a search is made from the current shift stage and the shift map. Different from the gear stage, and
If it is the upshift direction and the accelerator is not fully closed, it is determined as a power-on upshift.

When the shift of the power-on upshift is determined, the process proceeds to step S2, where the output shaft rotation speed No [rpm] of the transmission mechanism is changed to the gear ratio before the shift (gear ratio = turbine rotation speed Nt (input shaft rotation speed). ) / Output shaft rotation speed No)
The shift to the torque phase is determined by determining whether or not the turbine rotation speed Nt [rpm] is higher than the sum of the reference turbine rotation obtained by multiplying the reference turbine speed and the hysteresis value HYS stored in advance. I do.

In the present embodiment, the release control is advanced earlier than the engagement control to induce the idling, and the shift to the torque phase is determined based on the occurrence of the idling. is there. Until the transition to the torque phase is determined in step S2, step S3
To execute the preparation phase process.

In the preparation phase process of step S3, the command oil pressure of the friction engagement element (hereinafter, referred to as a release-side friction engagement element) to be released from the engaged state before the shift is gradually reduced to the release initial pressure in a predetermined time. Then, while gradually decreasing the release initial pressure at a predetermined speed from the release initial pressure, the command oil pressure of the friction engagement element (hereinafter, referred to as engagement-side friction engagement element) to be engaged from the release state before the shift is changed to the standby pressure after the precharge. To be held.

When the shift to the torque phase is determined in step S2, the process proceeds to step S4, where the gear ratio is set to F / B.
(Feedback) It is determined whether or not the gear ratio has changed in the upshift direction beyond the start gear ratio. Then, the torque phase process of step S5 is performed until the gear ratio exceeds the F / B start gear ratio and changes in the upshift direction.

In the torque phase process, following the preparation phase process, the command oil pressure of the disengagement side frictional engagement element is gradually reduced, and the command oil pressure of the engagement side frictional engagement element is gradually increased from the standby pressure. If it is determined in step S4 that the gear ratio has exceeded the F / B start gear ratio, the process proceeds to step S6, in which the gear ratio is changed to the F / B end gear ratio (<F / B start gear ratio).
Is determined.

When the gear ratio is between the F / B start gear ratio and the F / B end gear ratio, an inertia phase process in step S7 is performed. In the inertia phase process, the command oil pressure of the disengagement side frictional engagement element is decreased stepwise to 0, while the command oil pressure of the engagement side frictional engagement element is set at the target turbine rotation speed Nt (input shaft rotation speed). Feedback control is performed so as to match the rotation speed.

If it is determined in step S6 that the gear ratio has become smaller than the F / B end gear ratio, the process proceeds from step S6 to step S8, where the gear ratio is smaller than the F / B end gear ratio for the first time. A predetermined time TI
It is determined whether or not MER7 has elapsed. If it is within the predetermined time TIMER7, the process proceeds to step S9,
Perform end phase processing.

In the end phase process, the command oil pressure of the disengagement side frictional engagement element is maintained at the oil pressure at the end of the inertia phase (= 0), while the command oil pressure of the engagement side frictional engagement element is increased to the maximum pressure. Let it. Here, step S7
Rotation speed N in the inertia phase process
The feedback control of t will be described in detail.

FIG. 6 is a block diagram of a system for performing the feedback control.
1 is a deviation err between a signal indicating the actual turbine rotation speed Nt extracted from the drive system 102 and the target rotation speed.
, And calculates a feedback control signal (control input u) to be output to the hydraulic system 103 (a solenoid valve that controls the hydraulic pressure of the engagement side frictional engagement element) by sliding mode control based on the deviation err.

As described above, the feedback control of the turbine rotational speed by the sliding mode control enables a control system having excellent robustness to be constructed, and the man-hour for gain matching is greatly reduced. It can be done easily. In addition, the minimum dimension observer 1
04 (Corona “Sliding mode control” 1996
(See pages 160-178, issued April 10, 2008)
A mechanism for estimating, from measurable data, a state quantity that cannot be directly measured among system state quantities (state variables) required for realizing the sliding mode control, and outputs the estimation result to the SMC controller 101. I do.

In designing the SMC controller 101, the drive system 102 and the hydraulic system 103 were modeled as follows. [Hydraulic system model]

[0038]

(Equation 1)

The hydraulic system model has an ATF temperature of 80.
° C as the nominal model of the hydraulic system. [Drive system model]

[0040]

(Equation 2)

[0041] Note that in Equation 2, T _t is turbine torque, T _REV is reverse clutch torque, the T _HC is high clutch torque, T _LC is low clutch torque, Omegaod
ot indicates output shaft angular acceleration, ωtdot indicates turbine angular acceleration (input shaft angular acceleration), and I indicates inertia. FIG. 7 shows a system block diagram based on the above model formula.

In FIG. 7, Frtn is the return spring pressure of the engagement side frictional engagement element, u is the control input, r is the target rotation speed, and err is the turbine rotation speed Nt and the target rotation speed r.
Is the deviation from In the above system model, the state variable (state quantity) x used for the switching function σ = Cx is

[0043]

(Equation 3)

[0044] By including x5 which is an integral value of the deviation in the state variable (state quantity) x, the steady deviation can be absorbed. Note that x1, x2, x3, x4 are state variables shown on the system block diagram of FIG.

At this time, the state equation is described as follows.

[0046]

(Equation 4)

X1, x2, x3, x4 of the above state variables x
Cannot be measured directly, so that the minimum dimension observer 10
4 Then, the switching function σ is calculated as follows: σ = Cx + βr C = [c1, c2, c3, 1, c4], x = [x1, x2, x3, x4, x5] σ = (c1 · x1 + c2 · x2 + c3 · x3 + x4 + c4 · x5) +
βr.

The second term βr of the switching function σ is a term for adding a zero point, and the control parameter β for multiplying the target rotation speed r is changed according to the ATF temperature.
In a controller that does not add a zero point, the turbine torque T
Since the influence of t cannot be suppressed and the transient response deteriorates, the transient response is improved by adding a zero point by βr and increasing the gain in the high frequency region.

The control input u was set as follows. u = _ueq + _unl + _uf

[0050]

(Equation 5)

_Ueq is an equivalent control input when the effects (disturbance) of the return spring pressure, turbine torque, low clutch torque and output shaft angular acceleration are ignored. Wherein u _nl is an operation for restraining the system switching surface (nonlinear control input), where, by introducing a boundary layer switching surface, suppresses chattering by successive approximation the switching function in the boundary layer The saturation function was used.

It should be noted that a configuration using a smoothing function instead of the saturation function may be adopted. Further, _uf is an offset input (disturbance compensation input) for eliminating the effects of the return spring pressure, the turbine torque, the low clutch torque, and the output shaft angular acceleration, which are assumed as disturbances. The _unl is
Assuming that the feedback gain is q, outside the saturation region (σ>
Φ), u _nl = −q · σ / | σ |, within the saturation region (σ <
Φ), it is expressed as u _nl = − (q / Φ) · σ.

Note that Φ is a value that defines the boundary layer width (inside and outside of the saturated layer) as described above. The switching function σ = Cx
Differentiating both sides of + βr,

[0054]

(Equation 6)

And solving for u at σdot = 0 gives:

[0056]

(Equation 7)

Is as follows. Therefore, the control input is separated into the equivalent control input u _eq and the disturbance offset input _uf ,
Further, a non-linear control input u _nl which is continuously approximated by a saturation function is employed to suppress chattering. When the switching function σ and the control input u are set as described above, the system when the sliding mode occurs is as follows.

[0058]

(Equation 8)

The transfer function G (s) from the target rotation speed r to the actual turbine rotation speed Nt is

[0060]

(Equation 9)

Is obtained. Here, the transfer function G of Equation 9 is obtained.
So that the response in (s) is the response characteristic of the request,
The control parameters c1, c2, c3, c4 (switching parameters) are determined. Specifically, it was designed such that the closed-loop dynamics was −60 (heavy pole) −80 (heavy pole) [rad / s] at an ATF temperature of 80 ° C. The zero point was set to -5 [rad / s].

At this time, in the present embodiment, the control parameters c1, c2, c3, c4 are as follows. c1 = -0.00467 c2 = 29200 c3 = 280 c4
= −0.00838 FIG. 8 shows a control input u = u _eq based on the switching function σ.
SMC controller 101 for calculating + u _nl + u _f and minimum dimension observer 104 for estimating x1, x2, x3, x4
FIG. 3 is a block diagram showing the configuration of FIG.

The minimum dimension observer 104 has an actual turbine rotation speed Nt, a control input u of a friction engagement element,
The return spring pressure, the estimated value of the turbine torque, the low clutch torque, and the output shaft angular acceleration are input, and the state variables x1, x2, x3, x4 are estimated based on these data. The estimated state variables x1, x2, x3, x4 are:
Target turbine speed r, estimated turbine torque, low clutch torque, output shaft angular acceleration, shift up / down signal Up / Down, power on / off signal PowerOn / Off,
A rotation error err, which is a difference between the actual turbine rotation speed Nt and the target r, and a phase signal Ph-flg are input to the SMC controller 101, and a control input u is calculated based on these signals.

FIG. 9 shows an operation block of the control input u in the SMC controller 101, in which the state parameters x1, x2, x3, x5 and the target rotational speed r have control parameters c1, c2, c3, c4, c4, respectively. is multiplied by β, and the result of the multiplication and the state variable x4 are summed to calculate the value of the switching function σ = Cx + βr. Then, the _unl is calculated using a saturation function based on the value of the switching function.

The return spring pressure F which is a disturbance
rtn, turbine torque Tt, the low clutch torque T _LC and the output shaft angle disturbance offset which is calculated by the acceleration ωodot is summed with the u _f is calculated, and further, error er
The equivalent control input _ueq is calculated by multiplying r, the state quantities x2, x3, x4, and the target rotational speed r by the respective gains and summing them.

FIG. 10 is a flowchart showing the flow of the feedback control of the turbine rotational speed Nt by the above-mentioned sliding mode control. Step S21
Then, it is determined whether or not the shift is being performed, and when the shift is started, the process proceeds to step S22. In step S22, it is determined whether or not the inertia phase has been reached. When the inertia phase has been reached, the process proceeds to step S23, where the integral value of the deviation err (state variable x5) is reset to an initial value.

As the initial value, as will be described later, a value learned at the time of the previous feedback control is used, but at the time of the first feedback control, a previously stored reference value is used. . Thereafter, in step S24, and the input hydraulic pressure control signal of the engagement side frictional engagement element (control input u), the return spring pressure Frtn, turbine torque Tt, the low clutch torque T _LC and the output shaft angular acceleration Omegaodot, in step S25, The state variables x1, x2, x3, x4 are estimated based on these.

In step S26, a deviation err (err = Nt-N) between the actual turbine rotational speed Nt and the target rotational speed r is obtained.
r) is calculated, and in step S27, the deviation err is added to the integration result up to that time to update the integration value (state variable x5). In step S28, the state variables x1, x2,
The control input u is calculated based on disturbances such as x3, x4, x5, the target rotation speed r, and the return spring pressure Frtn, and the control input u (feedback control signal) is output in step S29.

In step S30, the maximum absolute value of the deviation err during the sliding mode control is calculated. Note that the deviation err is used for learning the initial value of the integral value described later.
If the maximum value is not used, the processing in step S30 is omitted. In step S31, the end of the inertia phase is determined.
Then, the feedback control (sliding mode control) is continued.

If it is determined in step S31 that the inertia phase has been completed, the process proceeds to step S32, where the deviation er is set at the start of the next sliding mode control.
Learn the initial value to reset the integral value of r. Specifically, as shown in FIG. 11, the larger the maximum value of the deviation err during the sliding mode control or the greater the integral value of the deviation err at the end of the inertia phase, the smaller the initial value.

In the present embodiment, the direction of increase and change of the initial value is closer to Cx = 0. Therefore, when the initial value is reduced, the control surface reaches the switching surface with a relay gain (non-linear control) from outside the saturation region at the start of control. And the convergence response of large deviations is improved. Conversely, when the maximum value of the deviation err during the sliding mode control or the integral value of the deviation err at the end of the inertia phase is small, the initial value is increased and the control is started in a state closer to Cx = 0. By doing so, the sliding mode motion starts to appear immediately after the start of the control, and the target can be brought close to the target with the intended transient response, so that the convergence stability is improved.

The flowchart of FIG. 12 shows the second embodiment. In the second embodiment, the maximum value of the deviation err during the sliding mode control or the deviation err at the end of the inertia phase is described. Based on the integral value, a feedback gain q used in the next sliding mode control is learned. In the flowchart of FIG. 12 showing the second embodiment, step S2
Steps other than 3A and step S32A perform the same processes as those in the flowchart of FIG. 10, and a detailed description thereof will be omitted.

In the flowchart of FIG. 12, in step S23A, the integral value is reset to a constant reference value. In step S32A executed at the end of the inertia phase, the larger the integrated value of the deviation err at the end of the inertia phase or the greater the integral value of the deviation err at the end of the inertia phase, the larger the value used at the next sliding mode control. Increase the value of the feedback gain q (see FIG. 13).

When the maximum value of the deviation err or the integral value of the deviation err is large, the response to the target is improved by increasing the feedback gain q. Conversely, the maximum value of the deviation err or When the integrated value of the deviation err is small, the convergence stability is improved by reducing the feedback gain q. Note that the reference value shown in FIG. 13 indicates a feedback gain q used in the first feedback control in which no learning value exists.

Further, the flowchart of FIG. 14 shows the third embodiment. In the third embodiment,
Based on the maximum value of the deviation err during the sliding mode control or the integral value of the deviation err at the end of the inertia phase, the boundary layer width Φ used in the next sliding mode control is learned. In the flowchart of FIG. 14 showing the third embodiment, each step other than step S23A and step S32B performs the same processing as that of the flowchart of FIG. 10, and thus detailed description is omitted.

In the flowchart of FIG. 14, in step S23A, the integral value is reset to a constant reference value. In the step S32B executed at the end of the inertia phase, the larger the integrated value of the deviation err at the end of the inertia phase or the greater the integral value of the deviation err at the end of the inertia phase, the larger the value used at the next sliding mode control. Decrease the boundary layer width Φ (see FIG. 15).

When the maximum value of the deviation err or the integral value of the deviation err is large, by reducing the boundary layer width Φ, the relay gain control region is expanded, and the response to the target is improved. When the maximum value of the deviation err or the integral value of the deviation err is small, by increasing the boundary layer width Φ, the region constrained by the switching surface is enlarged and the convergence stability is improved.

The reference value shown in FIG. 15 indicates the boundary layer width Φ used at the time of the first feedback control in which no learning value exists. In the above embodiment, any one of the initial value of the integral value, the feedback gain q, and the boundary layer width Φ is set to the deviation
The learning is performed in accordance with the maximum value of err or the integral value of the deviation err. However, a configuration in which two or more of the initial value of the integral value, the feedback gain q, and the boundary layer width Φ are simultaneously changed may be adopted.

In the above embodiment, feedback control of the turbine rotational speed in the inertia phase at the time of an upshift has been described as an example. However, feedback control of the turbine rotational speed in the inertia phase at the time of a downshift can be performed in a similar manner. Is clear.

[Brief description of the drawings]

FIG. 1 is a diagram showing a transmission mechanism of an automatic transmission according to an embodiment.

FIG. 2 is a diagram showing a correlation between a combination of engagement states of frictional engagement elements in the transmission mechanism and a shift speed.

FIG. 3 is a system diagram showing a control system of the automatic transmission.

FIG. 4 is a flowchart illustrating shift control in the embodiment.

FIG. 5 is a time chart showing changes in each phase and a command oil pressure in the shift control according to the embodiment;

FIG. 6 is a block diagram illustrating a feedback control system of the turbine rotational speed according to the embodiment.

FIG. 7 is a block diagram showing a model of the feedback control system.

FIG. 8 is a block diagram showing input / output signals of the feedback control system.

FIG. 9 is a block diagram showing an arithmetic circuit of a control input in an SMC controller constituting the feedback control system.

FIG. 10 is a flowchart illustrating a first embodiment of feedback control.

FIG. 11 is a diagram showing a correlation between a maximum value or an integral value of a deviation and an initial value of the integral value.

FIG. 12 is a flowchart showing a second embodiment of the feedback control.

FIG. 13 is a diagram showing a correlation between a maximum value or an integral value of a deviation and a feedback gain.

FIG. 14 is a flowchart showing a third embodiment of the feedback control.

FIG. 15 is a diagram showing a correlation between a maximum value or an integral value of a deviation and a boundary width.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Torque converter 2 ... Transmission mechanism 11 ... Solenoid valve unit 12 ... A / T controller 13 ... A / T oil temperature sensor 14 ... Accelerator opening degree sensor 15 ... Vehicle speed sensor 16 ... Turbine rotation sensor 17 ... Engine rotation sensor 18 ... Air flow Meter 20 Engine 101 SMC controller 102 Drive system 103 Hydraulic system 104 Minimum dimension observer G1, G2 Planetary gear H / C High clutch R / C Reverse clutch L / C Low clutch 2 & 4 / B 2 Speed / 4 speed band brake L & R / B ... Low & reverse brake

Claims (7)

[Claims] 1. A sliding mode control based on a deviation between a state quantity during a shift and a target value of the state quantity, wherein a control signal for controlling hydraulic pressure supply to a friction engagement element is calculated. A shift control device for an automatic transmission, wherein a control parameter used in the next sliding mode control is learned based on a deviation during control. 2. The shift of the automatic transmission according to claim 1, wherein a maximum value of the deviation during the sliding mode control is obtained, and a control parameter used in the next sliding mode control is learned from the maximum value. Control device. 3. The automatic transmission according to claim 1, wherein an integrated value of the deviation during the sliding mode control is obtained, and a control parameter used in the next sliding mode control is learned from the integrated value. Control device. 4. The method according to claim 1, wherein the state variable x defining the switching function σ in the sliding mode control includes an integral value of the deviation, and the control parameter to be learned is an initial value of the integral value. A shift control device for an automatic transmission according to any one of Items 1 to 3. 5. The shift control device for an automatic transmission according to claim 1, wherein the control parameter to be learned is a feedback gain in a sliding mode control. 6. The shift control device for an automatic transmission according to claim 1, wherein the control parameter to be learned is a boundary layer width in the sliding mode control. 7. The system according to claim 1, wherein the hydraulic pressure supplied to the friction engagement element is feedback-controlled so that the input shaft rotation speed matches the target rotation speed in the inertia phase during the shift. A shift control device for an automatic transmission according to any one of the above.