KR102709278B1 - Control apparatus and method of continuously variable transmission - Google Patents

Abstract

A control device of a continuously variable transmission according to a preferred embodiment of the present invention includes a vehicle speed detection unit that detects speed information of the vehicle, and a control unit that determines whether the vehicle is stopped using the speed information, and operates in a terrain mode that implements a second-gear start of the vehicle according to the operation of a terrain switch when the vehicle is determined to be stopped.

Description

CONTROL APPARATUS AND METHOD OF CONTINUOUSLY VARIABLE TRANSMISSION

The present invention relates to a control device and method for a continuously variable transmission.

The continuously variable transmission (CVT) commonly used in vehicles consists of a continuously variable speed belt mechanism and a forward/reverse control mechanism.

In a continuously variable speed belt mechanism, the rotational power of the engine is input to the driving pulley (primary pulley) and output through the driven pulley (secondary pulley). At this time, continuously variable speed is performed by varying the radius of the primary pulley and secondary pulley.

And the forward/reverse control mechanism is composed of a single or double pinion planetary gear set and a plurality of friction elements that control the planetary gear set, and converts the rotational power into a forward or reverse direction according to the control of the friction elements.

The forward/reverse control mechanism may be configured to simply perform forward and reverse control, but may be configured to perform control in two forward speeds and one reverse speed to improve power performance and fuel efficiency.

Meanwhile, various drive modes with various functions are applied as options in recent vehicles. Drive modes include Sports mode, Comfort mode, Echo mode, Smart mode, 4-wheel drive switching mode, Electric Vehicle mode, and Terrain mode.

Terrain Mode is used to control the vehicle's gear shifting status by considering road surface conditions such as snow, sand, and mud, and is usually applied to multi-speed transmissions.

For continuously variable transmissions, gear ratio control is limited because the terrain mode requires the 1st gear to start first.

Republic of Korea Patent No. 10-1602607

Accordingly, the present invention has been conceived in consideration of the above circumstances, and aims to provide a control device and method for a continuously variable transmission that prevents vehicle slippage by enabling a second gear start to secure a stable grounding state of the vehicle when the vehicle to which a continuously variable transmission is applied is operated in terrain mode.

In order to achieve the above object, a control device of a continuously variable transmission according to a preferred embodiment of the present invention comprises: a vehicle speed detection unit that detects speed information of a vehicle; and a control unit that determines whether the vehicle is stopped using the speed information, and if it is determined that the vehicle is stopped, operates in a terrain mode to change a pulley gear ratio of a continuously variable transmission according to the operation of a terrain switch to implement a second-stage start of the vehicle.

The above control unit, when operating in the terrain mode, can perform lock control of the parking gear of the vehicle and control disconnection of the engine of the vehicle and the continuously variable transmission.

The above control unit can change the first pulley gear ratio to the second pulley gear ratio when operating in the terrain mode, in a locked state of the parking gear and a disconnected state of the engine and the continuously variable transmission.

The above control unit, when operating in the terrain mode, can release the lock state of the parking gear and control the connection between the engine and the continuously variable transmission when the change to the two-stage pulley gear ratio is completed.

The invention further includes an accelerator pedal detection unit that detects an accelerator pedal value of the vehicle, and the control unit can determine whether the vehicle is stopped by further considering the accelerator pedal value.

The invention may further include a gear ratio output unit that outputs a pulley gear ratio change signal to implement a two-stage start of the vehicle under the control of the control unit.

The invention may further include a driving pulley speed detection unit that detects a driving pulley speed that occurs due to a second-stage start of the vehicle; and a driven pulley speed detection unit that detects a driven pulley speed that occurs due to a second-stage start of the vehicle.

According to a preferred embodiment of the present invention for achieving the above object, a control method of a continuously variable transmission includes a vehicle speed detection step of detecting speed information of a vehicle; and a first terrain mode determination step of confirming that the vehicle is stopped based on the speed information and operating in a terrain mode that implements a second-gear start of the vehicle depending on whether a terrain switch is operated.

The above terrain mode operation may further include a first parking lock step for locking the parking gear of the vehicle; a first clutch release step for disengaging the engine of the vehicle and the continuously variable transmission through clutch control in the locked state of the parking gear; and a first gear ratio change step for changing the pulley gear ratio of the continuously variable transmission to a two-stage pulley gear ratio.

After the first gear ratio changing step, the method may further include: a first clutch connecting step for connecting the engine and the continuously variable transmission through the clutch control; a first unlocking step for performing unlocking of the parking gear when the connection of the clutch is completed; and after the first unlocking step, a two-stage operation step for monitoring the speeds of the driven pulley and the driving pulley of the continuously variable transmission when the vehicle starts at the two-stage pulley gear ratio.

After the first terrain mode determination step, if the vehicle is not operating in the terrain mode and the vehicle starts at a first pulley gear ratio, the vehicle may further include a first operation step of monitoring the speeds of a driven pulley and a driving pulley of a continuously variable transmission that provides the first pulley gear ratio to the vehicle.

After the first operation step, the method may further include: a deceleration determination step for determining whether the speed of the vehicle is less than a preset maximum reference speed and greater than a preset minimum reference speed; a second terrain mode determination step for determining whether the vehicle is in a deceleration state and whether the terrain mode operates according to the operation of the terrain switch if the speed of the vehicle is less than the maximum reference speed and greater than the minimum reference speed; and an accelerator pedal determination step for determining whether the vehicle is decelerated based on an accelerator pedal value if the vehicle operates in the terrain mode after the second terrain mode determination step.

The method may further include a second gear ratio changing step of changing the pulley gear ratio of the continuously variable transmission to a two-stage pulley gear ratio when the vehicle is operating in the terrain mode in a state where the vehicle is judged to be in a deceleration state based on the speed of the vehicle and the accelerator pedal value.

The method may further include a stop determination step for determining whether to stop based on the speed of the vehicle; a second stop step for maintaining a second pulley gear ratio state if the vehicle is stopped after the stop determination step; and a third terrain mode determination step for determining whether to operate in terrain mode based on the operation of the terrain switch after the second stop step.

After the third terrain mode determination step, the method may further include: a second parking lock step for locking the parking gear of the vehicle when the terrain mode is not in operation; a second clutch release step for disengaging the engine of the vehicle and the continuously variable transmission through clutch control in the locked state of the parking gear; and a second gear ratio changing step for changing the pulley gear ratio of the continuously variable transmission to a first-stage pulley gear ratio.

After the second gear ratio changing step, the second clutch connecting step for connecting the engine and the continuously variable transmission through the clutch control; and when the connecting of the clutch is completed, the second unlocking step for performing unlocking of the parking gear may be further included.

According to a control device and method of a continuously variable transmission according to a preferred embodiment of the present invention, when a vehicle to which a continuously variable transmission is applied operates in terrain mode, it is possible to start in the second gear to secure a stable grounding state of the vehicle, thereby preventing slipping of the vehicle.

FIG. 1 is a block diagram of a control device of a continuously variable transmission according to a preferred embodiment of the present invention.
FIG. 2 is a first flowchart of a control method of a continuously variable transmission according to a preferred embodiment of the present invention.
FIG. 3 is a second flowchart of a control method for a continuously variable transmission according to a preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. First, when adding reference symbols to components of each drawing, it should be noted that, even if they are shown in different drawings, identical components are given the same symbols as much as possible. In addition, although preferred embodiments of the present invention will be described below, it should be understood that the technical idea of the present invention is not limited or restricted thereto and can be modified and implemented in various ways by those skilled in the art.

FIG. 1 is a block diagram of a control device of a continuously variable transmission according to a preferred embodiment of the present invention.

Referring to FIG. 1, a control device (100) of a continuously variable transmission according to a preferred embodiment of the present invention is characterized in that, when a vehicle to which a continuously variable transmission (70) is applied operates in the terrain mode, the vehicle is allowed to start in the second gear to ensure a stable grounding state of the vehicle, thereby preventing the vehicle from slipping on a low-friction road surface.

A control device (100) of a continuously variable transmission includes an accelerator pedal detection unit (110), a vehicle speed detection unit (120), a driving pulley speed detection unit (130), a driven pulley speed detection unit (140), a gear ratio detection unit (150), a control unit (160), and a gear ratio output unit (170).

The accelerator pedal detection unit (110) can receive an accelerator pedal value from a pedal angle sensor (not shown) of the vehicle. The accelerator pedal detection unit (110) can detect the user's driving intention from the accelerator pedal value. The accelerator pedal detection unit (110) can transmit the detected accelerator pedal value to the control unit (160).

The vehicle speed detection unit (120) receives vehicle speed information from the vehicle's wheel speed sensor (not shown). The vehicle speed detection unit (120) can transmit the vehicle speed information to the control unit (160).

The drive pulley speed detection unit (130) can receive drive pulley speed information from the speed sensor of the drive pulley (74) of the continuously variable transmission (70). The drive pulley speed detection unit (130) can transmit the drive pulley speed information to the control unit (160).

The driven pulley speed detection unit (140) can receive driven pulley speed information from the speed sensor of the driven pulley (72) of the continuously variable transmission (70). The driven pulley speed detection unit (430) can transmit the driven pulley speed information to the control unit (160).

The gear ratio detection unit (150) can receive the pulley gear ratio of the continuously variable transmission (70) output from the gear ratio output unit (170). The gear ratio detection unit (150) can transmit the pulley gear ratio of the continuously variable transmission (70) to the control unit (160).

The control unit (160) can determine whether the terrain mode is operated based on whether the terrain switch (10) is operated. If the terrain switch (10) is turned on by a user command, the control unit (160) can operate in the terrain mode. The terrain mode is a mode that implements a two-stage start of the vehicle to prevent the vehicle from slipping on a road surface with low friction such as a snowy road, a sandy road, or a muddy road.

The control unit (160) can operate in terrain mode when the vehicle speed received from the vehicle speed detection unit (120) is 0 kph and the vehicle is stopped, and the turn-on operation of the terrain switch (10) is detected according to a user command.

The control unit (160) can lock the parking gear (PG) when the terrain mode is operated. The control unit (160) can control the parking actuator (30) to pull the cable (CB) so that the parking gear (PG) can be locked. Through this, the stationary state of the vehicle before the train mode operation can be maintained.

The control unit (160) can disengage the clutch (60) that transmits the power of the engine (40) to the continuously variable transmission (70) to disconnect the engine (40) and the continuously variable transmission (70). That is, the clutch (60) disconnects the torque converter (50) and the continuously variable transmission (70).

The control unit (160) can change the first-stage target pulley gear ratio to the second-stage pulley gear ratio according to the terrain mode operation. The control unit (160) can output the changed second-stage pulley gear ratio as a signal through the gear ratio output unit (170). At this time, the pulley drive unit (80) can appropriately change the radius of the driven pulley (72) and the driving pulley (74) of the continuously variable transmission (70) according to the second-stage pulley gear ratio.

When the two-stage pulley gear ratio change is completed, the control unit (160) can engage the clutch (60) to connect the engine (40) and the continuously variable transmission (70).

The control unit (160) can perform unlocking of the parking gear (PG) when the connection of the clutch (60) is completed. The control unit (160) can perform unlocking of the parking gear (PG) by controlling the parking actuator (30) to release the cable (CB).

The control unit (160) can monitor the speed of the driven pulley (72) and the driving pulley (74) of the continuously variable transmission (70) when the continuously variable transmission (70) operates at a two-stage pulley gear ratio through the torque converted from the power of the engine (40). At this time, the vehicle can drive in second gear immediately from a stopped state, thereby enabling stable driving on low-friction roads such as snowy and sandy roads.

The gear ratio output unit (170) may be a type of gear ratio map device. The gear ratio output unit (170) may output a signal for changing the gear ratio according to the two-stage pulley gear ratio calculated by the control unit (160).

Fig. 2 is a first flow chart of a control method for a continuously variable transmission according to a preferred embodiment of the present invention. Fig. 3 is a second flow chart of a control method for a continuously variable transmission according to a preferred embodiment of the present invention.

Referring to FIGS. 1 to 3, a control method of a continuously variable transmission according to a preferred embodiment of the present invention includes steps S210 to S420.

In the vehicle speed detection step (S210), the vehicle speed detection unit (120) receives vehicle speed information from the wheel speed sensor of the vehicle. The vehicle speed detection unit (120) can transmit the vehicle speed information to the control unit (160).

In the first terrain mode judgment step (S220), the control unit (160) determines whether the terrain mode is operated according to the user's command. The control unit (160) determines that the vehicle speed received from the vehicle speed detection unit (120) is 0 kph and that the vehicle is stopped, and if the turn-on operation of the terrain switch (10) is detected according to the user's command, the control unit (160) operates in the terrain mode.

In the first parking lock step (S230), the control unit (160) performs locking of the parking gear when the terrain mode is operated. The control unit (160) controls the parking actuator (30) to pull the cable (CB), thereby performing the locking operation of the parking gear (PG). Through this, the stationary state of the vehicle before the train mode operation can be maintained.

In the first clutch disengagement step (S240), the control unit (160) disengages the clutch (60) that transmits the power of the engine (40) to the continuously variable transmission (70), thereby disconnecting the engine (40) and the continuously variable transmission (70). That is, the clutch (60) disconnects the torque converter (50) and the continuously variable transmission (70).

In the first gear ratio change step (S250), the control unit (160) changes the first-stage target pulley gear ratio to the second-stage pulley gear ratio according to the terrain mode operation. The control unit (160) outputs the changed second-stage pulley gear ratio through the gear ratio output unit (170). At this time, the pulley drive unit (80) can appropriately change the radius of the driven pulley (72) and the driving pulley (74) of the continuously variable transmission (70) according to the second-stage pulley gear ratio.

In the first clutch connection step (S260), when the two-stage pulley gear ratio change is completed, the control unit (160) engages the clutch (60) to connect the engine (40) and the continuously variable transmission (70).

In the first unlocking step (S270), the control unit (160) performs unlocking of the parking gear (PG) when the connection of the clutch (60) is completed. The control unit (160) controls the parking actuator (30) to release the cable (CB), thereby allowing the unlocking operation of the parking gear (PG) to be performed.

In the second operation step (S280), the control unit (160) monitors the speed of the driven pulley (72) and the driving pulley (74) of the continuously variable transmission (70) when the continuously variable transmission (70) operates at a two-stage pulley gear ratio through the torque converted from the power of the engine (40). At this time, the vehicle starts from a stopped state immediately in second gear, thereby enabling stable driving on low-friction road surfaces such as snowy and sandy roads.

Meanwhile, in the first operation step (S290), if the control unit (160) does not operate in the terrain mode after the first terrain mode judgment step (S220), it monitors the speed of the continuously variable transmission (70) operating at the first pulley gear ratio. At this time, the vehicle can start from a stopped state at the first pulley gear ratio.

In the deceleration judgment step (S310), the control unit (160) determines whether the vehicle is decelerating by using the vehicle speed while the vehicle is driving with a first-stage pulley gear ratio. The control unit (160) determines whether the vehicle speed is less than the maximum reference speed and greater than the minimum reference speed. In one embodiment, the maximum reference speed may be approximately 5 kph considering hysteresis. In one embodiment, the minimum reference speed may be approximately 2 kph.

In the second terrain mode judgment step (S320), if the control unit (160) determines that the vehicle is in a deceleration state, it determines whether the terrain mode is in effect based on the operation of the terrain switch (10) according to the user command. If the turn-on operation of the terrain switch (10) is detected, the control unit (160) determines that it is in terrain mode.

In the accelerator pedal judgment step (S330), the control unit (160) determines whether to decelerate based on the accelerator pedal value. If the accelerator pedal value is detected as 0, the control unit (160) determines that the vehicle is in a deceleration state.

In the second gear ratio change step (S340), the control unit (160) changes the first-stage target pulley gear ratio to the second-stage pulley gear ratio based on the vehicle speed and the accelerator pedal value when the vehicle is in a deceleration state and operates in terrain mode. The control unit (160) outputs the changed second-stage pulley gear ratio through the gear ratio output unit (170). At this time, the pulley drive unit (80) can appropriately vary the radius of the driven pulley (72) and the driving pulley (74) of the continuously variable transmission (70) according to the second-stage pulley gear ratio.

In the stop judgment step (S350), the control unit (160) determines that the vehicle is in a stopped state if the vehicle speed is 0 kph.

In the second stop stage (S360), the control unit (160) maintains the second pulley gear ratio state when the vehicle is stopped.

In the third terrain mode judgment step (S370), when the vehicle is stopped in a two-stage pulley gear ratio state, the control unit (160) determines the terrain mode based on whether the terrain switch (10) is operated. When the turn-on operation of the terrain switch (10) is detected according to a user command, the control unit (160) operates in the terrain mode. When the turn-off operation of the terrain switch (10) is detected, the control unit (160) does not perform the terrain mode operation.

In the second parking lock step (S380), the control unit (160) performs locking of the parking gear when the terrain mode is not in operation. The control unit (160) can perform the locking operation of the parking gear (PG) by controlling the parking actuator (30) to pull the cable (CB). Through this, the vehicle's stationary state before the train mode operation can be made more solid.

In the second clutch disengagement step (S390), the control unit (160) disengages the clutch (60) that transmits the power of the engine (40) to the continuously variable transmission (70), thereby disconnecting the engine (40) and the continuously variable transmission (70). That is, the clutch (60) disconnects the torque converter (50) and the continuously variable transmission (70).

In the second gear ratio change step (S400), the control unit (160) changes the second pulley gear ratio to the first pulley gear ratio according to the terrain mode non-operation. The control unit (160) outputs the changed first pulley gear ratio through the gear ratio output unit (170). At this time, the pulley drive unit (80) can appropriately change the radius of the driven pulley (72) and the driving pulley (74) of the continuously variable transmission (70) according to the first pulley gear ratio.

In the second clutch connection step (S410), when the first pulley gear ratio change is completed, the control unit (160) engages the clutch (60) to connect the engine (40) and the continuously variable transmission (70).

In the second unlocking step (S420), the control unit (160) performs unlocking of the parking gear (PG) when the connection of the clutch (60) is completed. The control unit (160) controls the parking actuator (30) to release the cable (CB), thereby performing the unlocking operation of the parking gear (PG). Thereafter, the vehicle runs at a first pulley gear ratio.

The above description is merely an illustrative description of the technical idea of the present invention, and those skilled in the art will appreciate that various modifications, changes, and substitutions may be made without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical idea of the present invention, but rather to explain it, and the scope of the technical idea of the present invention is not limited by these embodiments and the accompanying drawings.

The steps and/or operations according to the present invention may occur in other embodiments simultaneously, in other orders, in parallel, for other epochs, etc., as would be understood by one of ordinary skill in the art.

In some embodiments, some or all of the steps and/or operations may be implemented or performed at least in part using instructions, programs, interactive data structures, clients and/or servers stored on one or more non-transitory computer-readable media. The one or more non-transitory computer-readable media may be, for example, software, firmware, hardware, and/or any combination thereof. Furthermore, the functionality of a "module" discussed herein may be implemented in software, firmware, hardware, and/or any combination thereof.

100: Control unit of continuously variable transmission
110: Accelerator pedal detection unit
120: Vehicle speed detection unit
130: Drive pulley speed detection unit
140: Drive pulley speed detection unit
150: Gear ratio detection unit
160: Control Unit
170: Gear ratio output section

Claims (16)

A vehicle speed detection unit that detects vehicle speed information; and
A control unit that determines whether the vehicle is stopped using the above speed information, and if the vehicle is determined to be stopped, operates in a terrain mode to change the pulley gear ratio of a continuously variable transmission according to the operation of a terrain switch to implement a second-stage start of the vehicle;
Including,
The above control unit, if not operating in the terrain mode,
Determine whether the speed of the above vehicle is less than the preset maximum reference speed and more than the preset minimum reference speed,
If the speed of the above vehicle is less than the above maximum reference speed and greater than the above minimum reference speed, the vehicle is judged to be in a deceleration state,
Further determines whether the terrain mode is in operation based on the operation of the above terrain switch.
A control device for a continuously variable transmission, characterized in that it determines whether to decelerate based on the accelerator pedal value of the vehicle when further determining the terrain mode operation. In paragraph 1,
The above control unit,
A control device for a continuously variable transmission, characterized in that, when operating in the terrain mode, it performs lock control of the parking gear of the vehicle and disconnects the engine of the vehicle and the continuously variable transmission. In the second paragraph,
The above control unit,
A control device for a continuously variable transmission, characterized in that the first pulley gear ratio is changed to the second pulley gear ratio in a locked state of the parking gear and a disconnected state of the engine and the continuously variable transmission. In the third paragraph,
The above control unit,
A control device for a continuously variable transmission, characterized in that when the change to the above two-stage pulley gear ratio is completed, the lock state of the parking gear is released and the connection of the engine and the continuously variable transmission is controlled. In paragraph 1,
An accelerator pedal detection unit for detecting an accelerator pedal value of the above vehicle;
Including more,
A control device for a continuously variable transmission, characterized in that the control unit determines whether the vehicle is stopped by further considering the accelerator pedal value. In paragraph 1,
A gear ratio output unit that outputs a pulley gear ratio change signal to implement a two-stage start of the vehicle according to the control of the above control unit;
A control device for a continuously variable transmission, characterized by further including: In paragraph 1,
A drive pulley speed detection unit that detects the drive pulley speed generated by the second-stage start of the above vehicle; and
A driven pulley speed detection unit that detects the driven pulley speed generated by the second-stage start of the above vehicle;
A control device for a continuously variable transmission, characterized by further including: A vehicle speed detection step for detecting vehicle speed information; and
A first terrain mode determination step in which the vehicle is stopped based on the above speed information and operates in a terrain mode that implements a two-stage start of the vehicle depending on whether the terrain switch is operated;
Including,
After the first terrain mode determination step, if the vehicle is not operating in the terrain mode, a deceleration determination step for determining whether the speed of the vehicle is less than a preset maximum reference speed and greater than a preset minimum reference speed;
A second terrain mode determination step for determining whether the vehicle is in a deceleration state and whether the terrain mode is operated according to the operation of the terrain switch when the speed of the vehicle is less than the maximum reference speed and greater than the minimum reference speed; and
An accelerator pedal determination step for determining whether to decelerate based on the accelerator pedal value of the vehicle when operating in the terrain mode after the second terrain mode determination step;
A control method for a continuously variable transmission, characterized in that it further includes. In Article 8,
A first parking lock step for locking the parking gear of the vehicle when the terrain mode is in operation;
A first clutch release step for disengaging the engine of the vehicle and the continuously variable transmission through clutch control in the locked state of the parking gear; and
A first gear ratio changing step for changing the pulley gear ratio of the above continuously variable transmission to a two-stage pulley gear ratio;
A control method for a continuously variable transmission, characterized in that it further includes. In Article 9,
After the first gear ratio change step, a first clutch connection step for connecting the engine and the continuously variable transmission through the clutch control;
When the connection of the above clutch is completed, a first unlocking step is performed to unlock the parking gear; and
After the first unlocking step, if the vehicle starts with the second pulley gear ratio, a second operation step of monitoring the speeds of the driven pulley and the driving pulley of the continuously variable transmission;
A control method for a continuously variable transmission, characterized in that it further includes. In Article 10,
After the first terrain mode determination step, if the vehicle is not operating in the terrain mode, a first operation step of monitoring the speeds of the driven pulley and the driving pulley of the continuously variable transmission that provides the first pulley gear ratio to the vehicle when the vehicle starts at a first pulley gear ratio;
A control method for a continuously variable transmission, characterized in that it further includes. delete In Article 8,
A second gear ratio changing step of changing the pulley gear ratio of the continuously variable transmission to a two-stage pulley gear ratio when the vehicle is operating in the terrain mode in a state determined to be a deceleration state of the vehicle based on the speed of the vehicle and the accelerator pedal value;
A control method for a continuously variable transmission, characterized in that it further includes. In Article 13,
A stop determination step for determining whether to stop based on the speed of the vehicle;
If the vehicle is in a stopped state after the above-mentioned stop determination step, a second-stage stop step for maintaining a second-stage pulley gear ratio state; and
After the above two-stage stop step, a third terrain mode judgment step for judging whether the terrain mode is operated according to the operation of the terrain switch;
A control method for a continuously variable transmission, characterized in that it further includes. In Article 14,
After the third terrain mode determination step, a second parking lock step for locking the parking gear of the vehicle when the terrain mode is not in operation;
A second clutch release step for disengaging the engine of the vehicle and the continuously variable transmission through clutch control in the locked state of the parking gear; and
A second gear ratio changing step for changing the pulley gear ratio of the continuously variable transmission to a first-stage pulley gear ratio;
A control method for a continuously variable transmission, characterized in that it further includes. In Article 15,
After the second gear ratio change step, a second clutch connection step for connecting the engine and the continuously variable transmission through the clutch control; and
When the connection of the above clutch is completed, a second unlocking step is performed to unlock the parking gear;
A control method for a continuously variable transmission, characterized in that it further includes.

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