JP7066261B2 - Transmission control device - Google Patents

Description

The present invention relates to a transmission control device.

A CVT (Continuously Variable Transmission) is widely known as a transmission mounted on a vehicle.

The CVT has a configuration in which an endless belt is wound around a primary pulley on the input side and a secondary pulley on the output side. When torque from a drive source such as an engine is input to the primary pulley, the frictional force between the primary pulley and the belt transfers torque from the primary pulley to the belt, and the frictional force between the secondary pulley and the belt causes the torque to be transmitted from the primary pulley to the belt. , Torque is transmitted from the belt to the secondary pulley.

Both the primary pulley and the secondary pulley are arranged so as to face each other with a belt sandwiched between the fixed sheave and the fixed sheave, and the movable sheave provided so as to be movable in the opposite direction thereof, and the movable sheave on the opposite side of the fixed sheave. It is provided with a piston that forms a piston chamber (oil chamber) with the movable sheave. The distance between the fixed sheave and the movable sheave is changed by controlling the hydraulic pressure acting on each movable sheave of the primary pulley and the secondary pulley. Along with this, the winding diameter of the belt with respect to the primary pulley changes, the distance between the fixed sheave and the movable sheave of the secondary pulley changes, and the winding diameter of the belt with respect to the secondary pulley changes. As a result, the gear ratio (pulley ratio) changes steplessly and continuously.

Japanese Unexamined Patent Publication No. 2004-176890

In the CVT shift control, a gear ratio target is set, and it acts on the control pressure according to the deviation between the gear ratio target and the actual gear ratio, that is, each movable sheave of the primary pulley and the secondary pulley. The command value of hydraulic pressure is set. Then, the operation of the valve included in the hydraulic circuit is controlled so that the control pressure acts on each movable sheave of the primary pulley and the secondary pulley.

However, there is room for various improvements in the conventional shift control, and improvement in followability is desired.

An object of the present invention is to provide a transmission control device capable of improving the followability of shift control.

In order to achieve the above object, the transmission control device according to the present invention has a fixed sheave and an endless belt on a pulley having a movable sheave whose distance from the fixed sheave is changed by the hydraulic pressure supplied from the hydraulic circuit. A transmission control device having a wound configuration, hydraulic pressure for controlling the position of a movable sheave, and a control pressure according to a deviation between a gear ratio target of the transmission and an actual gear ratio. It includes a control pressure setting means for setting the pressure, and a control pressure limiting means for limiting the control pressure set by the control pressure setting means based on the original pressure generated in the hydraulic circuit by the discharge pressure of the oil pump.

According to this configuration, the control pressure is set according to the deviation between the target of the gear ratio of the transmission and the actual gear ratio. By supplying the hydraulic pressure of this control pressure to the movable sheave, the actual gear ratio can be brought closer to the gear ratio target.

Since there is a limit to the original pressure generated in the hydraulic circuit due to the discharge pressure of the oil pump, there is an upper limit to the control pressure. If the control pressure is set beyond the upper limit, the deviation between the gear ratio target and the actual gear ratio will not be reduced, and if the control pressure setting includes integral operation (integral control), the deviation will be cumulative. Increase.

Therefore, the control pressure is limited based on the original pressure generated in the hydraulic circuit. As a result, even if the control pressure setting includes an integral calculation for ensuring control followability, it is possible to suppress the accumulation of deviations between the gear ratio target and the actual gear ratio. Therefore, it is possible to improve the followability of shift control.

When the control device of the transmission further includes a hydraulic pressure detecting means for detecting the hydraulic pressure supplied to the movable sheave and a principal pressure estimating means for estimating the original pressure from the hydraulic pressure detected by the hydraulic pressure detecting means, the control device is controlled. The pressure limiting means may limit the control pressure set by the control pressure setting means based on the source pressure estimated by the source pressure estimation means.

When the hydraulic pressure (actual pressure) supplied to the movable sheave does not follow the control pressure due to a decrease in the original pressure due to disturbance or the like, the hydraulic pressure detected by the hydraulic pressure detecting means decreases. Therefore, the original pressure can be estimated from the hydraulic pressure detected by the hydraulic pressure detecting means.

According to the present invention, it is possible to improve the followability of shift control.

It is a skeleton diagram which shows the structure of the drive system of a vehicle. It is a block diagram which shows the structure of the control system which concerns on one Embodiment of this invention. It is a block diagram which shows the structure of a sheave shift controller. It is a block diagram which shows the structure of the upper limit guard amount setting part. It is a flowchart which shows the flow of the process executed by a sheave shift controller. It is a figure which shows an example of time change of I control value, control pressure and an actual shift ratio.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Vehicle drive system>
FIG. 1 is a skeleton diagram showing the configuration of the drive system of the vehicle 1.

The vehicle 1 is an automobile whose drive source is the engine 2.

The engine 2 is provided with an electronic throttle valve for adjusting the amount of intake air into the combustion chamber of the engine 2, an injector (fuel injection device) that injects fuel into the intake air, an ignition plug that causes an electric discharge in the combustion chamber, and the like. Has been done. Further, the engine 2 is provided with a starter for starting the engine 2. The power of the engine 2 is transmitted to the differential gear 5 via the torque converter 3 and the belt-type CVT (Continuously Variable Transmission) 4, and is transmitted from the differential gear 5 via the left and right drive shafts 6L and 6R. It is transmitted to the left and right drive wheels 7L and 7R, respectively.

The torque converter 3 is a torque converter with a lock-up mechanism, and includes a front cover 11, a pump impeller 12, a turbine runner 13, and a lock-up clutch (lock-up piston) 14. The crankshaft of the engine 2 is connected to the front cover 11, and the front cover 11 rotates integrally with the crankshaft. The pump impeller 12 is arranged on the side opposite to the engine side with respect to the front cover 11. The pump impeller 12 is provided so as to be rotatable integrally with the front cover 11. The turbine runner 13 is arranged between the front cover 11 and the pump impeller 12 and is rotatably provided about a rotation axis common to the front cover 11. The lockup clutch 14 is arranged between the front cover 11 and the turbine runner 13.

The lockup clutch 14 is a differential pressure between the hydraulic pressure of the release side oil chamber 15 between the lockup clutch 14 and the front cover 11 and the hydraulic pressure of the engagement side oil chamber 16 between the lockup clutch 14 and the pump impeller 12. Engages / disengages with. That is, when the hydraulic pressure of the release side oil chamber 15 is higher than the hydraulic pressure of the engagement side oil chamber 16, the lockup clutch 14 is separated from the front cover 11 due to the differential pressure, and the lockup clutch 14 is released. It becomes an up-off state (released state). When the hydraulic pressure of the engaging side oil chamber 16 is higher than the hydraulic pressure of the releasing side oil chamber 15, the lockup clutch 14 is pressed against the front cover 11 due to the differential pressure, and the lockup clutch 14 is engaged with the lock. It becomes an up-on state (fastened state).

When the E / G output shaft is rotated in the lock-up / off state, the pump impeller 12 rotates. When the pump impeller 12 rotates, an oil flow from the pump impeller 12 to the turbine runner 13 is generated. This flow of oil is received by the turbine runner 13, and the turbine runner 13 rotates. At this time, the amplification action of the torque converter 3 occurs, and the turbine runner 13 generates a power larger than the power (torque) of the E / G output shaft.

In the lockup-on state, when the E / G output shaft is rotated, the E / G output shaft, the pump impeller 12 and the turbine runner 13 rotate together.

An oil pump 8 is provided between the torque converter 3 and the CVT 4. The oil pump 8 is a mechanical oil pump, and the pump shaft is provided so as to rotate integrally with the pump impeller 12 of the torque converter 3. As a result, when the pump impeller 12 is rotated by the power of the engine 2, the pump shaft of the oil pump 8 is rotated, and hydraulic pressure is generated from the oil pump 8.

The CVT 4 transmits the power input from the torque converter 3 to the differential gear 5. The CVT 4 includes an input shaft (input shaft) 21, an output shaft (output shaft) 22, a belt transmission mechanism 23, and a forward / backward switching mechanism 24.

The input shaft 21 is connected to the turbine runner 13 of the torque converter 3 and is provided so as to be integrally rotatable around the same rotation axis as the turbine runner 13.

The output shaft 22 is arranged in parallel with the input shaft 21. An output gear 25 is supported on the output shaft 22 so as to be relatively non-rotatable.

The belt transmission mechanism 23 includes a primary shaft 31 and a secondary shaft 32. The primary axis 31 and the secondary axis 32 are arranged on the same axis as the input axis 21 and the output axis 22, respectively.

The belt transmission mechanism 23 has a configuration in which an endless belt 35 is wound around a primary pulley 33 supported by a primary shaft 31 and a secondary pulley 34 supported by a secondary shaft 32.

The primary pulley 33 is arranged so as to face the fixed sheave 41 fixed to the primary shaft 31 with the belt 35 sandwiched between the fixed sheave 41, and is supported by the primary shaft 31 so as to be movable in the axial direction and non-relatively rotatable. It is equipped with 42. A piston 43 fixed to the primary shaft 31 is provided on the opposite side of the movable sheave 42 from the fixed sheave 41, and a piston chamber (oil chamber) 44 is formed between the movable sheave 42 and the piston 43. There is.

The secondary pulley 34 is arranged to face the fixed sheave 45 fixed to the secondary shaft 32 with the belt 35 sandwiched between the fixed sheave 45, and is supported by the secondary shaft 32 so as to be movable in the axial direction and non-relatively rotatable. It is equipped with a movable sheave 46. A piston 47 fixed to the secondary shaft 32 is provided on the opposite side of the movable sheave 46 from the fixed sheave 45, and a piston chamber 48 is formed between the movable sheave 46 and the piston 47.

Due to the movement of the movable sheave 42 of the primary pulley 33, the groove width, which is the distance between the fixed sheave 41 and the movable sheave 42, continuously changes. Due to the movement of the movable sheave 46 of the secondary pulley 34, the groove width, which is the distance between the fixed sheave 45 and the movable sheave 46, continuously changes. By continuously changing the groove widths of the primary pulley 33 and the secondary pulley 34, the winding diameter of the belt 35 with respect to the primary pulley 33 and the secondary pulley 34 can be changed, and the gear ratio (pulley ratio) can be steplessly changed. Can be changed continuously with.

Although not shown, a bias spring for applying an initial pinching pressure (initial thrust) to the belt 35 is interposed between the movable sheave 46 and the piston 47. The elastic force of the bias spring urges the movable sheave 46 and the piston 47 in a direction in which they are separated from each other.

The forward / backward switching mechanism 24 is interposed between the input shaft 21 and the primary shaft 31 of the belt transmission mechanism 23. The forward / backward switching mechanism 24 includes a planetary gear mechanism 51, a clutch C1 and a brake B1.

The planetary gear mechanism 51 includes a carrier 52, a sun gear 53, and a ring gear 54.

The carrier 52 is externally fitted to the input shaft 21 so as to be relatively rotatable. The carrier 52 rotatably supports a plurality of pinion gears 55. The plurality of pinion gears 55 are arranged on the circumference.

The sun gear 53 is supported by the input shaft 21 so as not to rotate relative to each other, and is arranged in a space surrounded by a plurality of pinion gears 55. The gear teeth of the sun gear 53 mesh with the gear teeth of each pinion gear 55.

The ring gear 54 is provided so that its rotation axis coincides with the axis of the primary shaft 31. The primary shaft 31 of the belt transmission mechanism 23 is connected to the ring gear 54. The gear teeth of the ring gear 54 are formed so as to collectively surround the plurality of pinion gears 55, and mesh with the gear teeth of each pinion gear 55.

The clutch C1 is hydraulically switched between an engaged state (on) in which the carrier 52 and the sun gear 53 are directly connected (coupled so as to be integrally rotatable) and an released state (off) in which the direct connection is released.

The brake B1 is provided between the carrier 52 and the transmission case accommodating the torque converter 3 and the CVT 4, and is in an engaged state (on) in which the carrier 52 is hydraulically braked and an released state (on) in which the carrier 52 is allowed to rotate (the brake B1). It can be switched to (off).

A shift lever (select lever) is arranged in the vehicle interior of the vehicle 1 at a position where the driver can operate the vehicle. In the movable range of the shift lever, for example, a P (parking) position, an R (reverse) position, an N (neutral) position, and a D (drive) position are provided in this order in a row.

When the shift lever is in the P position, both the clutch C1 and the brake B1 are released, and the parking lock gear (not shown) is fixed, so that the P range, which is one of the shift ranges of the CVT4, is configured. Will be done. Further, when the shift lever is in the N position, both the clutch C1 and the brake B1 are released and the parking lock gear is not fixed, so that the N range, which is one of the shift ranges of the CVT 4, is configured. When both the clutch C1 and the brake B1 are released, the input shaft 21 and the sun gear 53 idle, and the power of the engine 2 is not transmitted to the drive wheels 7L and 7R.

When the shift lever is in the D position, the brake B1 is engaged and the clutch C1 is released to form a forward range, which is one of the shift ranges of the CVT 4. In the forward range, when the power of the engine 2 is input to the input shaft 21, the sun gear 53 rotates integrally with the input shaft 21 while the carrier 52 is stationary. Therefore, the rotation of the sun gear 53 is transmitted to the ring gear 54 in reverse and decelerated. As a result, the ring gear 54 rotates, and the primary shaft 31 and the primary pulley 33 of the belt transmission mechanism 23 rotate integrally with the ring gear 54. The rotation of the primary pulley 33 is transmitted to the secondary pulley 34 via the belt 35 to rotate the secondary pulley 34 and the secondary shaft 32. Then, the output shaft 22 and the output gear 25 rotate integrally with the secondary shaft 32. The output gear 25 meshes with the differential gear 5 (the input gear of the differential gear 5). When the output gear 25 rotates, the drive shafts 6L and 6R extending to the left and right from the differential gear 5 rotate, and the drive wheels 7L and 7R rotate to advance the vehicle 1.

When the shift lever is in the R position, the brake B1 is released and the clutch C1 is engaged to form the R range, which is one of the shift ranges of the CVT 4. In the R range, when the power of the engine 2 is input to the input shaft 21, the carrier 52 and the sun gear 53 rotate integrally with the input shaft 21. Therefore, the rotation of the sun gear 53 is transmitted to the ring gear 54 without reversing the rotation direction. As a result, the ring gear 54 rotates, and the primary shaft 31 and the primary pulley 33 of the belt transmission mechanism 23 rotate integrally with the ring gear 54. The rotation of the primary pulley 33 is transmitted to the secondary pulley 34 via the belt 35 to rotate the secondary pulley 34 and the secondary shaft 32. Then, the output shaft 22 and the output gear 25 rotate integrally with the secondary shaft 32. When the output gear 25 rotates, the drive shafts 6L and 6R extending to the left and right from the differential gear 5 rotate, and the drive wheels 7L and 7R rotate, so that the vehicle 1 moves backward.

<Vehicle control system>
FIG. 2 is a block diagram showing the configuration of the control system of the vehicle 1.

The vehicle 1 is provided with an ECU (Electronic Control Unit) having a configuration including a microcomputer (microcontroller unit). The microcomputer has, for example, a built-in non-volatile memory such as a CPU and a flash memory, and a volatile memory such as a DRAM (Dynamic Random Access Memory). Although FIG. 2 shows only one ECU 101 for controlling the torque converter 3 and the CVT 4, the vehicle 1 is equipped with a plurality of ECUs having the same configuration as the ECU 101 in order to control each part. ing. A plurality of ECUs including the ECU 101 are connected so as to be capable of bidirectional communication by a CAN (Controller Area Network) communication protocol. Further, the ECU 101 is connected to a sensor required for control, for example, a pressure sensor 102 that detects the hydraulic pressure (actual pressure) supplied to the movable sheave 42 of the primary pulley 33 and the movable sheave 47 of the secondary pulley 34, respectively. ..

The ECU 101 functions as a sheave shift controller for shift control that controls the shift ratio of the CVT 4. In other words, the ECU 101 has a function as a sheave shift controller that controls the gear ratio of the CVT 4.

In the shift control by this function, first, the target rotation speed according to the accelerator opening and the vehicle speed is set based on the shift diagram. The shift line diagram is a map that defines the relationship between the accelerator opening degree and the vehicle speed and the target rotation speed, and is stored in, for example, the non-volatile memory of the ECU 101. Information on the accelerator opening degree and the vehicle speed is transmitted from the engine ECU that controls the engine 2 to the ECU 101, for example. When the target rotation speed is set, a gear ratio target that matches the rotation speed input to the input shaft 21 with the target rotation speed is set.

Next, a deviation E between the gear ratio target and the actual gear ratio, which is the actual gear ratio, is obtained, and the control pressures of the primary pulley 33 and the secondary pulley 34 are set according to the deviation E. Then, a valve included in the hydraulic circuit 111 for supplying hydraulic pressure to each part of the torque converter 3 and the CVT 4 is provided so that the control pressure acts on the movable sheave 42 of the primary pulley 33 and the movable sheave 46 of the secondary pulley 34. Be controlled.

The actual gear ratio is obtained, for example, by dividing the rotation speed of the primary pulley 33 by the rotation speed of the secondary pulley 34. The rotation speed of the primary pulley 33 is calculated from the detection signal of the primary rotation sensor that outputs a pulse signal synchronized with the rotation of the primary shaft 31 as a detection signal. Further, the rotation speed of the secondary pulley 34 is calculated from the detection signal of the secondary rotation sensor that outputs a pulse signal synchronized with the rotation of the secondary shaft 32 as a detection signal.

<Sheave shift controller>
FIG. 3 is a block diagram showing a configuration of a sheave shift controller.

The sheave shift controller has a deviation calculation unit 121 that obtains a deviation (control deviation) E between the shift ratio target and the actual shift ratio, and P control according to the deviation E by P operation (proportional operation) at P (Proportional) gain Kp. The P control unit 122 that outputs the value, the I control unit 123 that outputs the I control value according to the deviation E by the I operation (integral operation) at the I (Integral) gain Ki, and the D (differential) gain Kd. A D control unit 124 that outputs a D control value corresponding to a deviation E by a D operation (differential operation), and a control pressure output unit 125 that outputs an integral value of a P control value, an I control value, and a D control value as a control pressure. , The upper limit limiting unit 126 that limits the upper limit of the control pressure output by the control pressure output unit 125 and outputs the guard control pressure whose upper limit is limited, and the control pressure upper limit guard used for the limitation by the upper limit limiting unit 126. It is substantially provided with an upper limit guard amount setting unit 127 for setting the amount.

Further, the sheave shift controller has a windup amount calculation unit 128 that subtracts the guard control pressure output by the upper limit limiting unit 126 from the control pressure output by the control pressure output unit 125 and outputs the subtracted value as a windup amount. It is substantially provided with an amplification unit 129 that amplifies the windup amount output by the windup amount calculation unit 128 with a predetermined windup gain. Then, the I control unit 123 calculates the I control value by integrating the deviation between the multiplication value obtained by multiplying the deviation E by the I gain Ki and the amplification value of the windup amount output by the amplification unit 129.

<Upper limit guard amount setting unit>
FIG. 4 is a block diagram showing the configuration of the upper limit guard amount setting unit 127.

The upper limit guard amount setting unit 127 is the original pressure estimation unit 131 that estimates the original pressure of the hydraulic circuit 111 from the actual pressure detected by the pressure sensor 102 and outputs the estimated value (original pressure estimated value), and the actual shift ratio. The limit value calculation unit 132 that calculates the limit value according to the volume change amount of each piston chamber (oil chamber) 44, 48 of the primary pulley 33 and the secondary pulley 34 from the change amount of the primary pulley 33, and the original pressure of the hydraulic circuit 111 are generated. The subtraction unit 133, which subtracts the limit value calculated by the limit value calculation unit 132 from the pump shaft rotation speed of the oil pump 8 and outputs the subtraction value, and the primary pulley 33 and the secondary pulley 34 (movable sheaves 42, 46). The pump dischargeable pressure estimation unit 134 that estimates and outputs the dischargeable pressure of the oil pump 8 from the oil temperature of the supplied hydraulic oil and the subtraction value output by the subtraction unit 133, and the original pressure output by the original pressure estimation unit 131. The minimum value selection unit 135 that selects and outputs the minimum value of the estimated value and the discharge possible pressure estimated by the pump discharge possible pressure estimation unit 134, and the windup amount output by the windup amount calculation unit 128 (see FIG. 3). And 0 are compared, and the windup determination unit 136 for determining whether or not the windup amount is larger than 0, and the pump dischargeable pressure estimation unit according to the determination results of the windup determination unit 136. It is substantially provided with a selection output unit 137 that selects one of the dischargeable pressure output by the 134 and the minimum value output by the minimum value selection unit 135 and outputs it as the upper limit guard amount.

When the hydraulic pressure (actual pressure) supplied to the movable sheaves 42 and 46 does not follow the control pressure due to a decrease in the original pressure due to disturbance or the like, the actual pressure detected by the pressure sensor 102 decreases. Therefore, the original pressure estimation unit 131 can estimate the original pressure from the hydraulic pressure detected by the pressure sensor 102.

In the limit value calculation unit 132, the fluid inflow amount dQpri / dt, which is the inflow amount of hydraulic oil into the piston chamber 44 of the primary pulley 33, is calculated according to the following equation (1).

ただし、Apri：プライマリプーリ３３の可動シーブ４２の受圧面積
dPpri/dt：プライマリプーリ３３の可動シーブ４２の移動速度

However, Apri: The pressure receiving area of the movable sheave 42 of the primary pulley 33
dPpri / dt: Moving speed of movable sheave 42 of primary pulley 33

Since the position of the movable sheave 42 corresponds to the rotation speed ratio between the primary pulley 33 and the secondary pulley 34, that is, the gear ratio, the moving speed dPpri / dt of the movable sheave 42 is the rotation speed of each of the primary pulley 33 and the secondary pulley 34. It can be calculated from.

ただし、Qpump：オイルポンプ８の単位回転数あたりの吐出能力 Then, the pump rotation speed dNpri / dt required to generate the fluid inflow amount dQpri / dt is calculated according to the following equation (2).

However, Qpump: Discharge capacity per unit rotation speed of the oil pump 8

Further, in the limit value calculation unit 132, the fluid inflow amount dQsec / dt, which is the inflow amount of hydraulic oil into the piston chamber 48 of the secondary pulley 34, is calculated according to the following equation (3).

ただし、Asec：セカンダリプーリ３４の可動シーブ４６の受圧面積
dPsec/dt：セカンダリプーリ３４の可動シーブ４６の移動速度

However, Asec: The pressure receiving area of the movable sheave 46 of the secondary pulley 34
dPsec / dt: Moving speed of movable sheave 46 of secondary pulley 34

Since the position of the movable sheave 46 corresponds to the rotation speed ratio between the primary pulley 33 and the secondary pulley 34, that is, the gear ratio, the moving speed dPsec / dt of the movable sheave 46 is the rotation speed of each of the primary pulley 33 and the secondary pulley 34. It can be calculated from.

Then, the pump rotation speed dNsec / dt required to generate the fluid inflow amount dQsec / dt is calculated according to the following equation (2).

Therefore, the pump shaft rotation speed (pump rotation speed) dN / dt required when the hydraulic pressure supplied to the movable sheaves 42 and 46 is changed by the shift control described below is shown in the following equation (5). As described above, the addition of the pump rotation speed dNpri / dt required for the volume change due to the movement of the movable sheave 42 of the primary pulley 33 and the pump rotation speed dNsec / dt required for the volume change due to the movement of the movable sheave 46 of the secondary pulley 34. It becomes a value.

Then, the pump shaft rotation speed dN / dt is set as a limit value according to the volume change of the primary pulley 33 and the secondary pulley 34, and the pump dischargeable pressure estimation unit 134 determines the pump shaft rotation speed of the oil pump 8 from the pump shaft rotation speed. By estimating the dischargeable pressure of the oil pump 8 based on the value obtained by subtracting the limit value, the dischargeable pressure of the oil pump 8 can be estimated accurately. As can be understood from the above equations (1) and (3), the volume change on the side where the hydraulic oil flows out does not affect the capacity of the oil pump 8, so that the limit value (pump shaft rotation speed dN). / dt) is not considered.

<Shift control>
FIG. 5 is a flowchart showing a flow of processing executed by the sheave shift controller.

For shift control, the ECU 101, which functions as a sheave change controller, executes the process shown in FIG. 5 at predetermined control cycles.

In this process, first, the P control value by the P operation at the P gain Kp, the I control value by the I operation at the I gain Ki, and the D control value by the D operation at the D gain Kd are set, and these P controls are set. The control pressure is calculated by adding the value, the I control value, and the D control value (step S1).

Next, the determination by the windup determination unit 136, that is, whether or not the windup amount (previous windup amount) calculated at the time of control one cycle before the current control cycle is a value larger than 0 is determined. (Step S2).

When the previous windup amount is larger than 0 (YES in step S2), the upper limit guard amount setting unit 127 causes the upper limit guard amount to be the minimum value output by the minimum value selection unit 135, that is, the original pressure estimation unit 131. It is determined to be the smaller value of the estimated original pressure, which is the estimated original pressure, and the available discharge pressure estimated by the pump dischargeable pressure estimation unit 134 (step S3). When the previous windup amount is larger than 0, it means that the control pressure calculated at the time of control one cycle before the current control cycle exceeds the upper limit guard amount, and the control pressure is saturated. ..

On the other hand, when the previous windup amount is 0 or less (NO in step S2), it means that the control pressure calculated at the time of control one cycle before the current control cycle does not exceed the upper limit guard amount, and the control pressure. Is not saturated. In this case, the upper limit guard amount setting unit 127 sets the upper limit guard amount to the dischargeable pressure estimated by the pump dischargeable pressure estimation unit 134 (step S4).

After setting the upper limit guard amount, the upper limit guard amount 126 compares the set upper limit guard amount with the control pressure output by the control pressure output unit 125, and the smaller value among them is used as the guard control pressure. It is output (step S5).

After that, the windup amount is calculated by the windup amount calculation unit 128 for use in the processing in the next control cycle (step S6).

Then, the windup amount output by the windup amount calculation unit 128 is fed back to the I operation (step S7), and a series of processes is completed.

<Action effect>
As described above, the control pressure is set according to the deviation E between the target of the gear ratio of the CVT 4 and the actual gear ratio. By supplying the hydraulic pressure of this control pressure to the movable sheave 42 of the primary pulley 33 and the movable sheave 46 of the secondary pulley 34, the actual gear ratio can be brought closer to the gear ratio target.

Since the capacity of the oil pump 8 for generating the original pressure of the hydraulic circuit 111 is limited, there is an upper limit to the control pressure. When the control pressure is set beyond the upper limit, the deviation E between the target of the gear ratio and the actual gear ratio does not shrink, and the product of the deviation E multiplied by the I gain Ki is the calculation of the I control value by the I operation. That is, when used for integral calculation, the deviation E is cumulatively increased.

Therefore, the original pressure generated in the hydraulic circuit 111 and the dischargeable pressure of the oil pump 8 that generates the original pressure in the hydraulic circuit 111 are estimated, and the upper limit of the control pressure is limited to the estimated original pressure value or the dischargeable pressure. Therefore, the smaller the estimated original pressure or the dischargeable pressure, the smaller the guard control pressure, which is the control pressure after being limited by the estimated original pressure or the available discharge pressure. The larger the difference between the control pressure and the guard control pressure, the larger the windup amount obtained by subtracting the guard control pressure from the control pressure, and the product of the deviation E multiplied by the I gain Ki and the amplification unit 129. The I control value calculated by the integral calculation of the deviation from the amplification value of the windup amount output by is a small value. As a result, as is understood by comparing the solid line shown in FIG. 6 with the broken line and the alternate long and short dash line, the windup amount is not fed back to the I operation for calculating the I control value (without anti-windup) and control. In the configuration of the sheave shift controller described above, the I control value can be suppressed to a small value as compared with the configuration in which the windup amount obtained by subtracting the fixed upper limit amount from the pressure is fed back to the I operation. As a result, the limitation of the control pressure can be strengthened, the accumulation of the deviation E between the target of the gear ratio and the actual gear ratio can be suppressed, and therefore the followability of the shift control can be improved.

<Modification example>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other embodiments.

For example, in the above-described embodiment, the ECU 101 that controls the CVT 4 is taken up. However, the transmission to be controlled by the ECU 101 is not limited to the CVT4, and may be a power split type continuously variable transmission. The power split type continuously variable transmission is provided with, for example, a belt-type continuously variable transmission mechanism that changes power steplessly by changing the gear ratio, and splits power into two paths between an input shaft and an output shaft. It is a transmission that can be transmitted.

In addition, various design changes can be made to the above-mentioned configuration within the scope of the matters described in the claims.

4: CVT (transmission)
8: Oil pump 33: Primary pulley (pulley)
35: Belt 41: Fixed sheave 42: Movable sheave 101: ECU (control device)
102: Pressure sensor (hydraulic pressure detecting means)
111: Hydraulic circuit 121: Deviation calculation unit (control pressure setting means)
122: P control unit (control pressure setting means)
123: I control unit (control pressure setting means)
124: D control unit (control pressure setting means)
125: Control pressure output unit (control pressure setting means)
126: Upper limit limiting unit (control pressure limiting means)
131: Original pressure estimation unit (primary pressure estimation means)

Claims (2)

A transmission control device having a structure in which an endless belt is wound around a pulley having a movable sheave whose distance from the fixed sheave is changed by hydraulic pressure supplied from the fixed sheave and the hydraulic circuit.
A hydraulic pressure setting for controlling the position of the movable sheave, which sets a control pressure including an I control value according to a deviation between the target of the gear ratio of the transmission and the actual gear ratio by an integral calculation. Means and
Control that sets the control pressure upper limit guard amount based on the original pressure generated in the hydraulic circuit by the discharge pressure of the oil pump, and limits the control pressure set by the control pressure setting means with the control pressure upper limit guard amount. Pressure limiting means and
A windup amount calculation means that subtracts a guard control pressure, which is a control pressure whose upper limit is limited by the control pressure limiting means, from the control pressure set by the control pressure setting means, and outputs the subtracted value as a windup amount. Including and
The control pressure setting means calculates the I control value by integrating the deviation between the multiplication value obtained by multiplying the deviation by the I gain and the amplification value of the windup amount output by the windup amount calculation means. Control device . A hydraulic pressure detecting means for detecting the hydraulic pressure supplied to the movable sheave, and
Further including the original pressure estimating means for estimating the original pressure from the hydraulic pressure detected by the hydraulic pressure detecting means.
The control device according to claim 1, wherein the control pressure limiting means limits the control pressure set by the control pressure setting means based on the source pressure estimated by the source pressure estimation means.

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