KR102633519B1 - Electric brake system and controlling method thereof - Google Patents

Abstract

An electronic brake system according to an embodiment of the disclosed invention includes a hydraulic pressure providing unit including a piston configured to move forward or backward; a drive unit that moves the piston; a storage unit that stores movement information regarding movement of the piston; And when a system drive (ON) signal is received, a control unit that determines a position to move the piston based on pre-stored movement information and controls the drive unit to move the piston to the determined position.

Description

Electronic brake system and its control method {ELECTRIC BRAKE SYSTEM AND CONTROLLING METHOD THEREOF}

The present invention relates to an electronic brake system, and more specifically, to an electronic brake system that generates braking force using an electrical signal corresponding to the displacement of the brake pedal.

Vehicles are essentially equipped with a brake system for braking, and recently, various types of systems have been proposed to achieve stronger and more stable braking force.

Examples of brake systems include the Anti-Lock Brake System (ABS), which prevents wheel slippage during braking, and the Brake Traction Control System (BTCS: Brake System), which prevents slippage of the driving wheels when the vehicle suddenly starts or accelerates. Traction Control System) and Electronic Stability Control System (ESC), which keep the vehicle's driving condition stable by controlling brake fluid pressure by combining an anti-lock brake system and traction control.

The conventional brake system used a mechanically connected booster to supply the hydraulic pressure needed for braking to the wheel cylinder when the driver stepped on the brake pedal, but recently, when the driver steps on the brake pedal, the driver's brake system uses a pedal displacement sensor that detects the displacement of the brake pedal. Electronic braking systems that include a hydraulic pressure supply device that receives the intention to brake as an electrical signal and supplies the hydraulic pressure necessary for braking to the wheel cylinder are widely used.

One aspect provides an electronic brake system and a control method thereof that provide a hydraulic pressure providing unit including a piston capable of moving forward or backward.

As a technical means for achieving the above-described technical problem, an electronic brake system according to one aspect includes a hydraulic pressure providing unit including a piston capable of moving forward or backward; a driving unit that moves the piston; a storage unit that stores movement information regarding movement of the piston; And when a system operation (ON) signal is received, a control unit that determines a position to move the piston based on pre-stored movement information and controls the drive unit to move the piston to the determined position.

In addition, it further includes a position sensor for detecting position information of the piston, wherein the control unit controls the driving unit to move the piston to a first position when a system OFF command is received, and the piston The storage unit may be controlled to identify whether movement to the first location has been completed, generate movement information including the identification result and the location information, and store the generated movement information.

Additionally, the control unit may identify whether the piston has completed moving to the first position at a first point in time after a predetermined time after the system off command is received.

Additionally, the control unit may control the storage unit to store movement information including the identification result and position information of the piston at the first point in time.

In addition, when the system driving signal is received, the control unit determines whether the piston has completed moving to the first position based on the identification result, and determines that the piston has completed moving to the first position. Once confirmed, the position to move the piston to can be determined as the second position.

In addition, when the system driving signal is received, the control unit determines whether the piston has completed moving to the first position based on the identification result, and determines whether the piston has not completed moving to the first position. If this is confirmed, the position to move the piston can be determined as the first position.

In addition, when it is confirmed that the piston has completed moving to the first position, the control unit checks whether the position information is within a predetermined range, and when the position information is within the predetermined range, the piston The position to move to can be determined as the second position.

Additionally, if the position information is not within a predetermined range, the control unit may determine a position to move the piston as the first position.

Additionally, the first point in time may be a predetermined time before the system is turned off.

An electronic brake system according to another aspect controls the drive unit to move the piston to a first position when a system OFF command is received; identify whether the piston has completed moving to the first position; generating movement information including the identification result and the location information, and storing the generated movement information; When a system operation (ON) signal is received, a position to move the piston is determined based on the movement information; and moving the piston to the determined position.

In addition, identifying whether the piston has completed moving to the first position refers to whether the piston has completed moving to the first position at a first point in time after a predetermined time after the system off command is received. It may include; identifying.

Additionally, storing the generated movement information may include storing movement information including the identification result and position information of the piston at the first point in time.

In addition, determining the position to move the piston includes, when the system driving signal is received, checking whether the piston has completed moving to the first position based on the identification result; And when it is confirmed that the piston has completed moving to the first position, determining a position to move the piston to the second position.

In addition, determining the position to move the piston includes, when the system driving signal is received, checking whether the piston has completed moving to the first position based on the identification result; And when it is confirmed that the piston has not completed moving to the first position, determining a position to move the piston to the first position.

In addition, determining a position to move the piston includes, when it is confirmed that the piston has completed moving to the first position, checking whether the position information is included in a predetermined range; and, if the position information is within a predetermined range, determining a position to move the piston to a second position.

Additionally, determining a position to move the piston may include determining a position to move the piston as a first position if the position information is not included in a predetermined range.

Additionally, the first point in time may be a predetermined time before the system is turned off.

According to an electronic brake system and its control method according to one aspect, the system initialization setup time can be shortened and the time delay that occurs in providing a braking function to the user can be shortened, thereby increasing user convenience.

1 is a hydraulic circuit diagram showing a non-braking state of an electronic brake system according to an embodiment.
Figure 2 is a control block diagram of an electronic brake system according to one embodiment.
Figure 3 is an enlarged view showing a hydraulic pressure providing unit according to an embodiment.
Figure 4 is a flowchart showing a control method of an electronic brake system according to an embodiment.
Figure 5 is a flowchart showing a control method of an electronic brake system according to an embodiment.

Like reference numerals refer to like elements throughout the specification. This specification does not describe all elements of the embodiments, and general content or overlapping content between the embodiments in the technical field to which the present invention pertains is omitted. The term 'unit, module, member, block' used in the specification may be implemented as software or hardware, and depending on the embodiment, a plurality of 'unit, module, member, block' may be implemented as a single component, or It is also possible for one 'part, module, member, or block' to include multiple components.

Throughout the specification, when a part is said to be “connected” to another part, this includes not only direct connection but also indirect connection, and indirect connection includes connection through a wireless communication network. do.

Additionally, when a part "includes" a certain component, this means that it may further include other components rather than excluding other components, unless specifically stated to the contrary.

Terms such as first and second are used to distinguish one component from another component, and the components are not limited by the above-mentioned terms.

Singular expressions include plural expressions unless the context clearly makes an exception.

The identification code for each step is used for convenience of explanation. The identification code does not explain the order of each step, and each step may be performed differently from the specified order unless a specific order is clearly stated in the context. there is.

Hereinafter, the operating principle and embodiments of the present invention will be described with reference to the attached drawings.

1 is a hydraulic circuit diagram showing a non-braking state of an electronic brake system according to an embodiment.

Referring to FIG. 1, the electronic brake system 1 typically includes a master cylinder 20 that generates hydraulic pressure, a reservoir 30 coupled to the upper part of the master cylinder 20 to store oil, and a brake pedal ( An input rod 12 that pressurizes the master cylinder 20 according to the pedal force of 10), a wheel cylinder 40 through which hydraulic pressure is transmitted to perform braking of each wheel (RR, RL, FR, FL), and a brake pedal It is equipped with a pedal displacement sensor 11 that detects the displacement of the brake pedal 10 and a simulation device 50 that provides a reaction force according to the pedal force of the brake pedal 10.

The master cylinder 20 is configured to have at least one chamber and can generate hydraulic pressure. As an example, the master cylinder 20 is configured to have two chambers, each chamber is provided with a first piston 21a and a second piston 22a, and the first piston 21a is the input rod 12. ) can be connected to. And the master cylinder 20 may form first and second hydraulic ports 24a and 24b through which hydraulic pressure is discharged from the two chambers, respectively.

In addition, a first spring 21b is provided between the first piston 21a and the second piston 22a of the master cylinder 20, and a spring 21b is provided between the second piston 22a and the end of the master cylinder 20. 2 Springs 22b may be provided.

The first spring 21b and the second spring 22b are provided in each of the two chambers, and as the displacement of the brake pedal 10 changes, the first piston 21a and the second piston 22a are compressed and the first spring 21b is compressed. Elastic force is stored in the spring 21b and the second spring 22b. And when the force pushing the first piston (21a) becomes smaller than the elastic force, the first spring (21b) and the second spring (22b) use the stored elastic force to push the first and second pistons (21a, 22a) to return to their original state. You can.

The simulation device 50 includes a simulation chamber 51 provided to store oil flowing out of the first hydraulic port 24a of the master cylinder 20, a reaction piston 52 provided in the simulation chamber 51, and an elastic support for the reaction piston 52. It includes a pedal simulator equipped with a reaction spring 53 and a simulator valve 54 connected to the rear end of the simulation chamber 51.

The reaction piston 52 and the reaction spring 53 are installed to have a certain range of displacement within the simulation chamber 51 due to oil flowing into the simulation chamber 51.

Meanwhile, the reaction spring 53 shown in the drawing is only one embodiment that can provide elastic force to the reaction piston 52, and may include various embodiments that can store elastic force by changing shape. For example, it includes various members that can store elastic force by being made of a material such as rubber or having a coil or plate shape.

The simulator valve 54 may be provided in a flow path connecting the rear end of the simulation chamber 51 and the reservoir 30. The front end of the simulation chamber 51 may be connected to the master cylinder 20, and the rear end of the simulation chamber 51 may be connected to the reservoir 30 through the simulator valve 54. Therefore, even when the reaction piston 52 returns, the oil in the reservoir 30 flows in through the simulator valve 54, so that the entire inside of the simulation chamber 51 can be filled with oil.

Meanwhile, several reservoirs 30 are shown in the drawing, and each reservoir 30 uses the same reference numeral. However, these reservoirs may be provided with the same parts or different parts. As an example, the reservoir 30 connected to the simulation device 50 may be the same as the reservoir 30 connected to the master cylinder 20, or may store oil separately from the reservoir 30 connected to the master cylinder 20. It may be a repository.

Meanwhile, the simulator valve 54 may be configured as a normally closed solenoid valve that maintains a normally closed state. The simulator valve 54 is opened when the driver applies pressure to the brake pedal 10 to transfer the oil in the simulation chamber 51 to the reservoir 30.

Additionally, a simulator check valve 55 may be installed between the pedal simulator and the reservoir 30 to be connected in parallel with the simulator valve 54. The simulator check valve 55 allows the oil in the reservoir 30 to flow into the simulation chamber 51, but allows the oil in the simulation chamber 51 to flow into the reservoir 30 through the passage in which the check valve 55 is installed. can be blocked. Since oil can be supplied into the simulation chamber 51 through the simulator check valve 55 when the brake pedal 10 is released, a quick return of the pedal simulator pressure can be guaranteed.

Since the inside of the simulation chamber 51 is always filled with oil, the friction of the reaction piston 52 is minimized when the simulation device 50 operates, which not only improves the durability of the simulation device 50 but also prevents foreign substances from entering from the outside. You may be blocked.

The electronic brake system 1 according to one embodiment includes a hydraulic pressure supply device 100 that receives the driver's intention to brake as an electrical signal from a pedal displacement sensor 11 that detects the displacement of the brake pedal 10 and operates mechanically; , a hydraulic control unit (200) consisting of first and second hydraulic circuits (201, 202) that control the flow of hydraulic pressure transmitted to the wheel cylinders (40) provided on two wheels (RR, RL, FR, FL), respectively. ), a first cut valve 261 provided in the first backup passage 251 connecting the first hydraulic port 24a and the first hydraulic circuit 201 to control the flow of hydraulic pressure, and a second hydraulic port A second cut valve 262 provided in the second backup passage 252 connecting (24b) and the second hydraulic circuit 202 to control the flow of hydraulic pressure, and a hydraulic pressure supply device based on hydraulic pressure information and pedal displacement information It may include an electronic control unit (ECU, not shown) that controls (100) and the valves (54, 60, 232, 233, 243, 250).

The hydraulic pressure supply device 100 includes a hydraulic pressure providing unit 110 that provides oil pressure transmitted to the wheel cylinder 40, a motor 120 that generates rotational force by an electrical signal from the pedal displacement sensor 11, and a motor. It may include a power conversion unit 130 that converts the rotational motion of 120 into linear motion and transmits it to the hydraulic pressure providing unit 110. Alternatively, the hydraulic pressure providing unit 110 may operate not by the driving force supplied by the motor 120 but by the pressure provided by the high pressure accumulator.

Next, passages 211, 212, 213, 214, 215 and valves 231, 232, 233, 241, 242, 243 connected to the first pressure chamber 112 and the second pressure chamber 113. Let's explain this.

The first hydraulic passage 211 branches into a second hydraulic passage 212 in communication with the first hydraulic circuit 201 and a third hydraulic passage 213 in communication with the second hydraulic circuit 202. Accordingly, hydraulic pressure can be transmitted to both the first hydraulic circuit 201 and the second hydraulic circuit 202 by the advancement of the hydraulic piston 114.

In addition, the electronic brake system 1 according to one embodiment includes a first control valve 231 and a second control valve 232 provided in the second and third hydraulic passages 212 and 213, respectively, to control the flow of oil. may include.

And the first control valve 231 allows only the oil flow in the direction from the first pressure chamber 112 to the first hydraulic circuit 201 and blocks the oil flow in the opposite direction. It can be provided as a check valve. . That is, the first control valve 231 allows the hydraulic pressure of the first pressure chamber 112 to be transmitted to the first hydraulic circuit 201, and the hydraulic pressure of the first hydraulic circuit 201 is transmitted to the second hydraulic passage 212. ) can be prevented from leaking into the first pressure chamber 112.

And the second control valve 232 may be provided as a solenoid valve capable of controlling the bidirectional flow of the third hydraulic passage 213. That is, the second control valve 232 allows the hydraulic pressure of the first pressure chamber 112 to be transmitted to the second hydraulic circuit 202 when braking, and the hydraulic pressure of the second hydraulic circuit 202 when braking is released. It can be allowed to flow into the first pressure chamber 112 through the third hydraulic oil passage 213.

Additionally, the second control valve 232 may be a normally closed solenoid valve that is normally closed and opens when an opening signal is received from the electronic control unit.

Additionally, the fourth hydraulic passage 214 may be provided to communicate with the second pressure chamber 113 and the third hydraulic passage 213.

Additionally, the electronic brake system 1 according to the first embodiment of the present invention may be provided with a fifth hydraulic passage 215 that communicates the first hydraulic circuit 201 and the second hydraulic circuit 202. As an example, the fifth hydraulic passage 215 may be provided to communicate with the second hydraulic passage 212 and the third hydraulic passage 213. Specifically, one side of the fifth hydraulic passage 215 is connected to the first control valve. It is connected to the downstream of (231), and the other side may be connected to the downstream of the second control valve (232).

In addition, the electronic brake system 1 according to one embodiment is provided in the fifth hydraulic passage 215 communicating with the first pressure chamber 112 and the second pressure chamber 113, and includes a circuit balance valve that controls the flow of oil. It may include (250). As an example, the circuit balance valve 250 may be installed in the fifth hydraulic passage 215 that communicates the second hydraulic passage 212 and the third hydraulic passage 213.

And the circuit balance valve 250 may be provided as a solenoid valve capable of controlling the bidirectional flow of the fifth hydraulic passage 215. That is, the circuit balance valve 250 allows the hydraulic pressure of the second hydraulic passage 212 to be transmitted to the third hydraulic passage 213, and at the same time, the hydraulic pressure of the third hydraulic passage 213 is transmitted to the second hydraulic passage 212. ) can be allowed to be transmitted.

In addition, the circuit balance valve 250 may be provided as a normally closed type solenoid valve that is normally closed and operates to open the valve when an opening signal is received from the electronic control unit.

Additionally, the second pressure chamber 113 may be in communication with both the first hydraulic circuit 201 and the second hydraulic circuit 202. That is, the fourth hydraulic passage 214 joins the third hydraulic passage 213 and communicates with the second hydraulic circuit 202, and branches off from the third hydraulic passage 213 to merge with the second hydraulic passage 212. It can be communicated with the first hydraulic circuit 201 through the fifth hydraulic oil path 215. Accordingly, hydraulic pressure can be transmitted to both the first hydraulic circuit 201 and the second hydraulic circuit 202 by the backward movement of the hydraulic piston 114.

Two operations are possible by the hydraulic piston 114 moving backwards. First, the braking force may be released by returning the oil in the first and second hydraulic circuits 201 and 202 to the first pressure chamber 112 using the negative pressure generated in the first pressure chamber 112. Second, braking force may be applied by transferring the oil in the second pressure chamber 113 to the first and second hydraulic circuits 201 and 202 using the hydraulic pressure generated in the second pressure chamber 113.

The second control valve 232 and the third control valve 233 enable selection of the above two operations by controlling the flows of the third hydraulic passage 213 and the fourth hydraulic passage 214, respectively. That is, when the second control valve 232 opens the third hydraulic passage 213 and the third control valve 233 closes the fourth hydraulic passage 214, the first and second hydraulic circuits 201, The oil in 202 can return to the first pressure chamber 112 to release the braking force, and conversely, the second control valve 232 closes the third hydraulic oil path 213, and the third control valve 233 When the fourth hydraulic oil path 214 is opened, the oil in the second pressure chamber 113 is delivered to the first and second hydraulic circuits 201 and 202 to apply braking force.

In addition, the electronic brake system 1 according to one embodiment includes a first dump valve 241 and a second dump valve 242 provided in the first and second dump passages 116 and 117, respectively, to control the flow of oil. may further include. The dump valves 241 and 242 may be check valves that open only the direction from the reservoir 30 to the first or second pressure chambers 112 and 113 and close the direction in the opposite direction. That is, the first dump valve 241 allows oil to flow from the reservoir 30 to the first pressure chamber 112, but blocks the oil from flowing from the first pressure chamber 112 to the reservoir 30. It may be a check valve, and the second dump valve 242 allows oil to flow from the reservoir 30 to the second pressure chamber 113, but does not allow oil to flow from the second pressure chamber 113 to the reservoir 30. It could be a check valve that blocks the flow.

In addition, the second dump passage 117 may include a bypass passage, and the bypass passage has a third dump valve 243 that controls the oil flow between the second pressure chamber 113 and the reservoir 30. Can be installed.

The third dump valve 243 may be provided as a solenoid valve capable of controlling two-way flow, and is a normally open type that is open in a normal state and operates to close the valve when it receives a closing signal from the electronic control unit. type) solenoid valve.

The hydraulic pressure providing unit 110 of the electronic brake system 1 according to the first embodiment of the present invention may operate in a double-acting manner. That is, as the hydraulic piston 114 advances, the hydraulic pressure generated in the first pressure chamber 112 is transmitted to the first hydraulic circuit 201 through the first hydraulic passage 211 and the second hydraulic passage 212 to the right side. It can actuate the wheel cylinder 40 installed on the front wheel (FR) and the left rear wheel (LR), and is transmitted to the second hydraulic circuit 202 through the first hydraulic passage 211 and the third hydraulic passage 213. This allows the wheel cylinders 40 installed on the right rear wheel (RR) and left front wheel (FL) to act.

Likewise, as the hydraulic piston 114 moves backward, the hydraulic pressure generated in the second pressure chamber 113 is transmitted to the first hydraulic circuit 201 through the fourth hydraulic passage 214 and the second hydraulic passage 212 to the right side. It can actuate the wheel cylinder 40 installed on the front wheel (FR) and the left rear wheel (LR), and is transmitted to the second hydraulic circuit 202 through the fourth hydraulic passage 214 and the third hydraulic passage 213. This allows the wheel cylinders 40 installed on the right rear wheel (RR) and left front wheel (FL) to act.

In addition, as the hydraulic piston 114 moves backwards, the negative pressure generated in the first pressure chamber 112 sucks oil from the wheel cylinder 40 installed on the right front wheel (FR) and left rear wheel (LR) to form the first hydraulic circuit. It can be delivered to the first pressure chamber 112 through (201) and the second hydraulic oil passage 212, and by sucking the oil from the wheel cylinder 40 installed on the right rear wheel (RR) and left front wheel (FL) It can be delivered to the first pressure chamber 112 through the second hydraulic circuit 202 and the third hydraulic passage 213.

Next, the motor 120 and the power conversion unit 130 of the hydraulic pressure supply device 100 will be described.

The motor 120 is a device that generates rotational force by a signal output from an electronic control unit (ECU, not shown), and can generate rotational force in the forward or reverse direction. The rotation angular speed and rotation angle of the motor 120 can be precisely controlled. Since this motor 120 is already a well-known technology, detailed description will be omitted.

Meanwhile, the electronic control unit includes the motor 120 and controls the valves 54, 60, 233, and 243 provided in the electronic brake system 1 of the present invention, which will be described later. The operation of controlling a plurality of valves according to the displacement of the brake pedal 10 will be described later.

The driving force of the motor 120 generates displacement of the hydraulic piston 114 through the power conversion unit 130, and the hydraulic pressure generated as the hydraulic piston 114 slides within the pressure chamber is supplied to the first and second hydraulic oils. It is transmitted to the wheel cylinder 40 installed on each wheel (RR, RL, FR, FL) through (211, 212).

The power conversion unit 130 is a device that converts rotational force into linear motion, and may be composed of, for example, a worm shaft 131, a worm wheel 132, and a drive shaft 133.

The worm shaft 131 may be formed integrally with the rotation axis of the motor 120, and a worm is formed on the outer peripheral surface and engages with the worm wheel 132 to rotate the worm wheel 132. The worm wheel 132 is connected to engage with the drive shaft 133 to move the drive shaft 133 in a straight line, and the drive shaft 133 is connected to the hydraulic piston 114 to slide the hydraulic piston 114 within the cylinder block 111. Move it.

To explain the above operations again, as displacement occurs in the brake pedal 10, the signal detected by the pedal displacement sensor 11 is transmitted to the electronic control unit, and the electronic control unit drives the motor 120 in one direction. Rotate the worm shaft (131) in one direction. The rotational force of the worm shaft 131 is transmitted to the drive shaft 133 through the worm wheel 132, and the hydraulic piston 114 connected to the drive shaft 133 moves forward to generate hydraulic pressure in the first pressure chamber 112.

Conversely, when the pedal force on the brake pedal 10 is removed, the electronic control unit drives the motor 120 in the opposite direction so that the worm shaft 131 rotates in the opposite direction. Accordingly, the worm wheel 132 also rotates in the opposite direction, and the hydraulic piston 114 connected to the drive shaft 133 returns (moves backward), generating negative pressure in the first pressure chamber 112.

Meanwhile, the generation of hydraulic pressure and negative pressure is also possible in the opposite direction. That is, as displacement occurs in the brake pedal 10, the signal detected by the pedal displacement sensor 11 is transmitted to the electronic control unit (ECU, not shown), and the electronic control unit drives the motor 120 in the opposite direction. to rotate the worm shaft (131) in the opposite direction. The rotational force of the worm shaft 131 is transmitted to the drive shaft 133 through the worm wheel 132, and the hydraulic piston 114 connected to the drive shaft 133 moves backward to generate hydraulic pressure in the second pressure chamber 113.

Conversely, when the pedal force on the brake pedal 10 is removed, the electronic control unit drives the motor 120 in one direction so that the worm shaft 131 rotates in one direction. Accordingly, the worm wheel 132 also rotates in the opposite direction, and the hydraulic piston 114 connected to the drive shaft 133 returns (moves forward), generating negative pressure in the second pressure chamber 113.

In this way, the hydraulic pressure supply device 100 transmits hydraulic pressure to the wheel cylinder 40 or suctions hydraulic pressure and transfers it to the reservoir 30 according to the rotation direction of the rotational force generated from the motor 120.

Meanwhile, when the motor 120 rotates in one direction, hydraulic pressure may be generated in the first pressure chamber 112 or negative pressure may be generated in the second pressure chamber 113. Should braking be performed using hydraulic pressure or negative pressure? Whether to release the brake can be determined by controlling the valves 54, 60, 233, and 243. This will be explained in detail later.

Although not shown in the drawing, the power conversion unit 130 may be composed of a ball screw nut assembly. For example, it consists of a screw that is integrally formed with the rotation axis of the motor 120 or connected to rotate with the rotation axis of the motor 120, and a ball nut that is screwed to the screw in a limited rotation state and moves linearly according to the rotation of the screw. It can be. The hydraulic piston 114 is connected to the ball nut of the power conversion unit 130 and pressurizes the pressure chamber by the linear movement of the ball nut. Since the structure of the ball screw nut assembly is a device that converts rotational motion into linear motion and is a well-known technology, detailed description will be omitted.

In addition, it should be understood that the power conversion unit 130 according to an embodiment of the present invention can be employed in any structure other than the structure of the ball screw nut assembly as long as it can convert rotational motion into linear motion.

In addition, the electronic brake system 1 according to one embodiment has first and It may further include a second backup flow path (251, 252).

A first cut valve 261 for controlling the flow of oil may be provided in the first backup passage 251, and a second cut valve 262 may be provided for controlling the flow of oil in the second backup passage 252. there is. In addition, the first backup passage 251 connects the first hydraulic port 24a and the first hydraulic circuit 201, and the second backup passage 252 connects the second hydraulic port 24b and the second hydraulic circuit ( 202) can be connected.

In addition, the first and second cut valves 261 and 262 are open in normal conditions and can be provided as solenoid valves of the normally open type that operate to close when a closing signal is received from the electronic control unit. there is.

The hydraulic control unit 200 may be composed of a first hydraulic circuit 201 and a second hydraulic circuit 202 that receive hydraulic pressure and control two wheels, respectively. As an example, the first hydraulic circuit 201 controls the right front wheel (FR) and the left rear wheel (RL), and the second hydraulic circuit 202 controls the left front wheel (FL) and the right rear wheel (RR). . And a wheel cylinder 40 is installed on each wheel (FR, FL, RR, RL) to receive hydraulic pressure and perform braking.

The first hydraulic circuit 201 is connected to the first hydraulic oil passage 211 and the second hydraulic oil passage 212 and receives hydraulic pressure from the hydraulic pressure supply device 100, and the second hydraulic circuit 202 is connected to the first hydraulic oil passage 212. It is connected to (211) and the third hydraulic passage 213 to receive hydraulic pressure from the hydraulic pressure supply device 100.

Additionally, the hydraulic control unit 200 may be connected to the backup passages 251 and 252. As an example, the first hydraulic circuit 201 is connected to the first backup passage 251 and receives hydraulic pressure from the master cylinder 20, and the second hydraulic circuit 202 is connected to the second backup passage 252. Hydraulic pressure can be provided from the master cylinder 20.

The unexplained reference number “PS2” is a backup oil pressure sensor that measures the oil pressure of the master cylinder (20). And “MPS” is a motor position sensor that measures the rotation angle of the motor 120 or the rotation speed of the motor.

Meanwhile, the conventional electronic brake system performs an operation of setting the position of the hydraulic piston to a preset initial position in order to generate braking force in the initial driving stage when the system starts driving.

This preset initial position may be set to have a predetermined distance value with respect to the reference position. Therefore, in order to move the position of the hydraulic piston to a preset initial position, it is necessary to move the position of the hydraulic piston to the reference position in advance.

However, in the operation of moving the hydraulic piston to the reference position, excessive time may be required for the hydraulic piston to move depending on the position of the hydraulic piston. Therefore, a time delay may occur in providing the braking function.

Hereinafter, the operation of the electronic brake system 1 according to an embodiment will be described in detail.

Figure 2 is a control block diagram of the electronic brake system 1 according to one embodiment.

Referring to FIG. 2, the electronic brake system 1 according to one embodiment includes a brake device 310 capable of generating braking force, a control unit 320 capable of overall controlling the components within the electronic brake system, and an electronic brake. It may include a storage unit 330 that can store various information related to the system.

The brake device 310 may include a hydraulic pressure providing unit 110, a driving unit 311, and a position sensor 312.

The hydraulic pressure providing unit 110 may provide oil pressure transmitted to the wheel cylinder 40 and may include a piston configured to move forward or backward. At this time, the piston may mean a hydraulic piston 114. The description of this is the same as that of FIG. 1.

The driving unit 311 may supply driving force to the hydraulic pressure providing unit 110. The driving unit 311 may drive the hydraulic pressure providing unit 110 by supplying driving force to the hydraulic pressure providing unit 110 according to a control signal from the control unit 320, which will be described later.

Specifically, the driving unit 311 may generate displacement of the hydraulic piston 114 of the hydraulic pressure providing unit 110. That is, the position of the hydraulic piston 114 can be moved.

For this purpose, the driving unit 311 may include a motor 120. Additionally, the drive unit 311 may further include a power conversion unit 130. The description of the motor 120 and the power conversion unit 130 is the same as that of FIG. 1.

The position sensor 312 can detect the position of the hydraulic piston 114. Through this, the position sensor 312 can measure the stroke value of the hydraulic piston 114.

Additionally, the position sensor 312 can detect whether the hydraulic piston 114 is located at a specific position. For example, the position sensor 312 detects the hydraulic piston 114 at a position where the volume of the second pressure chamber 113 is minimum or at a position where the volume of the first pressure chamber 112 is maximum, that is, the hydraulic piston 114 It is possible to detect whether the rear end of the cylinder block 111 is located in a position in contact with the rear end in the opening direction.

To this end, the position sensor 312 may be implemented as a motor position sensor (MPS in FIG. 1), but is not limited to this and may be implemented as a separate sensor capable of detecting the position of the hydraulic piston 114.

The position of the hydraulic piston 114 detected by the position sensor 312 can be the basis for controlling the control unit 320, which will be described later.

The control unit 320 may perform overall control of various components within the electronic brake system 1.

When a system operation (ON) signal is received, the control unit 320 determines a position to move the hydraulic piston 114 based on pre-stored movement information, and operates the drive unit 311 to move the hydraulic piston 114 to the determined position. ) can be controlled.

At this time, the system driving signal refers to an initialization command signal for the electronic brake system 1 and may include an ignition ON signal or a wake-up signal of the electronic brake system 1. For example, when the electronic brake system 1 according to an embodiment is implemented in a vehicle, not only when the vehicle's ignition is turned on, but also when the door is opened before the vehicle's ignition is turned on or the user applies the brake pedal 10. A wake-up signal may be generated when stepped on.

Movement information refers to information about the movement of the hydraulic piston 114 and may include location information of the hydraulic piston 114 and information related to whether the hydraulic piston 114 has moved to a preset position. Such movement information may be generated by the control unit 320 when a system startup-off command is received, and a detailed description of this will be provided later.

When a system OFF command is received, the control unit 320 may control the drive unit 311 to move the hydraulic piston 114 to the first position.

At this time, the system off command may mean a start turn-off command for the electronic brake system 1, and the first position (X1) is the position where the hydraulic piston 114 is in contact with the rear wall of the cylinder block 111. It can mean. In other words, it may mean a position where the rear end of the hydraulic piston 114 is in contact with the rear end of the cylinder block 111 in the opening direction. Additionally, the first position may be a position where the volume of the second pressure chamber 113 of the hydraulic piston 114 is minimum or a position where the volume of the first pressure chamber 112 is maximum.

Specifically, when a system OFF command is received, the control unit 320 transmits a control command to move the hydraulic piston 114 to the first position to the driving unit 311, thereby causing the hydraulic piston 114 to move to the first position. The driving unit 311 can be controlled to move to a certain position.

The system shutdown step of the electronic brake system 1 according to one embodiment may be completed after a predetermined time after the system OFF command is received, and the control unit 320 receives the system OFF command. After this is received, the drive unit 311 can be controlled so that the hydraulic piston 114 moves to the first position at a first point in time before the system is turned off. At this time, the first time may mean the time when a control command for moving the hydraulic piston 114 to the first position is transmitted to the drive unit 311.

Additionally, the control unit 320 may identify whether the hydraulic piston 114 has completed moving to the first position.

Specifically, the control unit 320 can identify whether the hydraulic piston 114 has completed moving to the first position after the system OFF command is received, and the system OFF command is received. It is possible to identify whether the hydraulic piston 114 has completed moving to the first position at a second point in time before the off is completed.

At this time, the second time may be a time after the first time when the control command for moving the hydraulic piston 114 to the first position is transmitted to the drive unit 311, and may be a predetermined time before the system off completion time. It may be at this point.

The control unit 320 may generate an identification result of whether the hydraulic piston 114 has completed moving to the first position and the position information of the hydraulic piston 114 as movement information, and a storage unit to store this movement information. (330) can be controlled.

Meanwhile, the control unit 320 has a memory (not shown) that stores data for an algorithm for controlling the operation of components in the electronic brake system 1 or a program that reproduces the algorithm, and uses the data stored in the memory to It may be implemented as a processor (not shown) that performs one operation. At this time, the memory and processor may each be implemented as separate chips. Alternatively, the memory and processor may be implemented as a single chip.

The storage unit 330 can store various information about the electronic brake system 1. Specifically, the storage unit 330 may store movement information related to the movement of the hydraulic piston 114. At this time, the movement information may include location information of the hydraulic piston 114 and information related to whether the hydraulic piston 114 has moved to a preset first position.

The storage unit 330 is a non-volatile memory device or RAM such as cache, read only memory (ROM), programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), and flash memory. It may be implemented as at least one of a volatile memory device such as (Random Access Memory) or a storage medium such as a hard disk drive (HDD) or CD-ROM, but is not limited thereto. The storage unit may be a memory implemented as a separate chip from the processor described above in relation to the control unit, or may be implemented as a single chip with the processor.

At least one component may be added or deleted in response to the performance of the components of the electronic brake system 1 shown in FIG. 2. Additionally, it will be easily understood by those skilled in the art that the mutual positions of the components may be changed in response to the performance or structure of the system.

Meanwhile, each component shown in FIG. 2 refers to software and/or hardware components such as Field Programmable Gate Array (FPGA) and Application Specific Integrated Circuit (ASIC).

Hereinafter, with reference to FIG. 3, the operation of the control unit 320 will be described in detail.

Figure 3 is an enlarged view showing a hydraulic pressure providing unit according to an embodiment.

Referring to FIG. 3, the hydraulic pressure providing unit 110 according to one embodiment includes a cylinder block 111 in which a pressure chamber in which oil is supplied and stored is formed, a hydraulic piston 114 accommodated in the cylinder block 111, and , a sealing member 115 (115a, 115b) provided between the hydraulic piston 114 and the cylinder block 111 to seal the pressure chamber, and a sealing member 115 (115a, 115b) connected to the rear end of the hydraulic piston 114 and output from the power conversion unit 130. It includes a drive shaft 133 that transmits power to the hydraulic piston 114.

When a system off command is received, the control unit 320 can control the drive unit 311 so that the hydraulic piston 114 moves to the first position (X1), and the hydraulic piston 114 moves to the first position (X1). You can identify whether the move has been completed.

At this time, the system off command may mean a start turn-off command for the electronic brake system 1, and the first position (X1) is the position where the hydraulic piston 114 is in contact with the rear wall of the cylinder block 111. It can mean. In other words, it may mean a position where the rear end of the hydraulic piston 114 is in contact with the rear end of the cylinder block 111 in the opening direction. Additionally, the first position may be a position where the volume of the second pressure chamber 113 of the hydraulic piston 114 is minimum or a position where the volume of the first pressure chamber 112 is maximum.

Specifically, when the system OFF command is received, the control unit 320 transmits a control command to move the hydraulic piston 114 to the first position (X1) to the drive unit 311, thereby The driving unit 311 can be controlled to move to this first position (X1).

The control unit 320 may control the drive unit 311 so that the hydraulic piston 114 moves to the first position (X1) at a first point in time after receiving the system OFF command and before the system OFF is completed. . At this time, the first time may mean the time when a control command for moving the hydraulic piston 114 to the first position (X1) is transmitted to the driving unit 311.

Additionally, the control unit 320 may identify whether the hydraulic piston 114 has completed moving to the first position (X1).

Specifically, the control unit 320 can identify whether the hydraulic piston 114 has completed moving to the first position (X1) after the system OFF command is received, and the system OFF command is received. After the system is turned off, it is possible to identify whether the hydraulic piston 114 has completed moving to the first position (X1) at a second point in time before the system is turned off.

At this time, the second time may be a time after the first time when a control command for moving the hydraulic piston 114 to the first position It may be before a certain time.

In this case, depending on the position of the hydraulic piston 114 at the first viewpoint, the hydraulic piston 114 may not be at the first position (X1) at the second viewpoint.

Accordingly, the control unit 320 may generate an identification result of whether the hydraulic piston 114 has completed moving to the first position (X1) and location information of the hydraulic piston 114 as movement information. At this time, the position information of the hydraulic piston 114 is the point at which the control unit 320 identifies whether the hydraulic piston 114 has completed moving to the first position (X1), and the hydraulic piston 114 detected at the second time point is ) may mean location information.

When the hydraulic piston 114 has completed moving to the first position (X1) at the second point in time, the control unit 320 may generate a completion flag as an identification result.

Specifically, when the position of the hydraulic piston 114 at the second viewpoint is the first position (X1), the control unit 320 detects a first position (X1) of the hydraulic piston 114 from the position sensor 312. When receiving, a completion flag can be generated as an identification result.

In addition, the control unit 320 operates when the hydraulic piston 114 does not complete movement to the first position ( ), an incomplete flag may be generated as an identification result.

Specifically, the control unit 320 detects the first position (X1) of the hydraulic piston 114 from the position sensor 312 or when the position of the hydraulic piston 114 at the second viewpoint is not the first position (X1). If a signal is not received, an incomplete flag may be generated as an identification result.

The movement information generated by the control unit 320 can be stored in the storage unit 330 and can be used as a control basis when the system drive signal is generated again and the initialization step is performed after the system is turned off. .

When a system operation (ON) signal is received, the control unit 320 can determine a position to move the hydraulic piston 114 based on the movement information, and operates the drive unit 311 to move the hydraulic piston 114 to the determined position. can be controlled.

Specifically, when the system operation (ON) signal is received, the control unit 320 determines whether to move the hydraulic piston 114 to one of the first position (X1) and the second position (X2) based on the movement information. You can.

At this time, the second position ( there is. For example, the second position (X2) may mean a position having a predetermined range of distance from the first position (X1) in the forward direction of the hydraulic piston 114.

To this end, when the system drive signal is received, the control unit 320 can check whether the hydraulic piston 114 has completed moving to the first position (X1) based on the identification result among the movement information. At this time, the movement information may refer to movement information generated in the system shutdown phase before the system operation signal is received and the system performs the initialization phase.

Specifically, the control unit 320 can check whether the identification result among the stored movement information is a completed flag or an incomplete flag.

If the identification result is a completion flag, the control unit 320 can confirm that the hydraulic piston 114 has completed moving to the first position (X1), and selects the position to move the hydraulic piston 114 to the second position (X2). ) can be determined. That is, the control unit 320 can omit the step of moving the position of the hydraulic piston 114 to the first position (X1).

In this case, the step of moving the position of the hydraulic piston 114 to the first position (X1) is omitted, and the position of the hydraulic piston 114 can be immediately determined to be the second position (X2). Therefore, when the hydraulic piston 114 is in the third position (X3) and the hydraulic piston 114 is moved to the first position (X1) and then moved again to the second position (X2), the initialization step is performed more easily. Time may be shortened. Accordingly, faster initialization settings can be performed. Additionally, since the time delay that occurs in providing the braking function to the user can be shortened, user convenience can be increased.

If the identification result is an incomplete flag, the control unit 320 can confirm that the hydraulic piston 114 has not completed moving to the first position (X1), and determines the position to move the hydraulic piston 114 to the first position (X1). X1) can be determined.

In this case, since it is confirmed that the position of the hydraulic piston 114 is not the first position (X1), the control unit 320 cannot immediately move the hydraulic piston 114 to the second position (X2) and moves it to the first position It can be moved to (X1) and then moved to the second location (X2).

However, even if it is confirmed that the hydraulic piston 114 has not completed its movement to the first position (X1), the movement of the hydraulic piston 114 to the first position (X1) is performed in the previous system termination step, so initialization The execution time of the step may be shorter than if the movement of the hydraulic piston 114 to the first position (X1) is not performed in the previous system shutdown step. Accordingly, faster initialization settings can be performed. Additionally, since the time delay that occurs in providing the braking function to the user can be shortened, user convenience can be increased.

Additionally, when it is confirmed that the hydraulic piston 114 has completed moving to the first position (X1), the control unit 320 may check whether the position information is within a predetermined range.

At this time, the position information may mean the position information of the hydraulic piston 114 at the second viewpoint, and the predetermined range may be an error range regarding the position having a predetermined distance from the first position (X1). For example, the predetermined range may be a range from the first position (X1) to a position having a predetermined range of distance in the forward direction of the hydraulic piston 114.

When the position information of the hydraulic piston 114 is included in the predetermined range, the position of the hydraulic piston 114 is within the error range, so the control unit 320 sets the position to move the hydraulic piston 114 to the second position ( X2) can be decided. That is, the control unit 320 can omit the step of moving the position of the hydraulic piston 114 to the first position (X1).

In this case, the step of moving the position of the hydraulic piston 114 to the first position (X1) is omitted, and the position of the hydraulic piston 114 can be immediately determined to be the second position (X2). Therefore, when the hydraulic piston 114 is in the third position (X3) and the hydraulic piston 114 is moved to the first position (X1) and then moved again to the second position (X2), the initialization step is performed more easily. Time may be shortened. Accordingly, faster initialization settings can be performed. Additionally, since the time delay that occurs in providing the braking function to the user can be shortened, user convenience can be increased.

If the position information of the hydraulic piston 114 is not included in the predetermined range, the position of the hydraulic piston 114 is outside the error range, so the control unit 320 sets the position to move the hydraulic piston 114 to the first position. It can be determined by (X1).

In this case, the control unit 320 cannot immediately move the hydraulic piston 114 to the second position (X2), but can move the hydraulic piston 114 to the first position (X1) and then to the second position (X2).

However, even if it is confirmed that the hydraulic piston 114 has not completed its movement to the first position (X1), the movement of the hydraulic piston 114 to the first position (X1) is performed in the previous system termination step, so initialization The execution time of the step may be shorter than if the movement of the hydraulic piston 114 to the first position (X1) is not performed in the previous system shutdown step. Accordingly, faster initialization settings can be performed. Additionally, since the time delay that occurs in providing the braking function to the user can be shortened, user convenience can be increased.

Figure 4 is a flowchart showing a control method of an electronic brake system according to an embodiment.

Referring to FIG. 4, the electronic brake system 1 according to one embodiment may check whether a system off command is received (401). At this time, the system off command may mean an engine turn-off command for the electronic brake system 1.

When a system OFF command is received (Yes at 401), the electronic brake system 1 may transmit a control command to move the hydraulic piston 114 to the first position (402). At this time, the first position may mean a position where the hydraulic piston 114 is in contact with the rear wall of the cylinder block 111. In other words, it may mean a position where the rear end of the hydraulic piston 114 is in contact with the rear end of the cylinder block 111 in the opening direction. Additionally, the first position may be a position where the volume of the second pressure chamber 113 of the hydraulic piston 114 is minimum or a position where the volume of the first pressure chamber 112 is maximum.

Afterwards, the electronic brake system 1 can identify whether the hydraulic piston 114 has moved to the first position (X1) (403).

The electronic brake system 1 can generate movement information based on the identification result and store the generated movement information (404).

At this time, the movement information refers to information about the movement of the hydraulic piston 114, and may include location information of the hydraulic piston 114 and information related to whether the hydraulic piston 114 has moved to the first position. . In particular, the position information of the hydraulic piston 114 is the hydraulic piston 114 detected at the time of identifying whether the hydraulic piston 114 has completed moving to the first position (X1), that is, when step 403 is performed. ) may mean location information.

Afterwards, the electronic brake system 1 may shut down the system (405). In other words, the system can be turned off (OFF).

Through this, since the movement of the hydraulic piston 114 to the first position is performed in the system termination step, the performance time of the subsequent system initialization step can be shortened.

That is, the execution time of the system initialization step can be shorter than when the movement of the hydraulic piston 114 to the first position is not performed in the previous system termination step. Accordingly, faster initialization settings can be performed. Additionally, since the time delay that occurs in providing the braking function to the user can be shortened, user convenience can be increased.

Figure 5 is a flowchart showing a control method of an electronic brake system according to an embodiment.

Referring to FIG. 5, the electronic brake system 1 according to one embodiment may check whether a system initialization signal is received (501). At this time, the system initialization signal may mean a system operation (ON) signal, that is, an initialization command signal for the electronic brake system 1. The system driving signal may include an ignition ON signal or a wake-up signal of the electronic brake system 1. For example, when the electronic brake system 1 is implemented in a vehicle, wakeup occurs not only when the vehicle's ignition is turned on, but also when the door is opened or the user steps on the brake pedal 10 before the vehicle's ignition is turned on. A signal can be generated.

When the system initialization signal is received (501), the electronic brake system 1 can check whether the hydraulic piston 114 has moved to the first position (502).

Specifically, the electronic brake system 1 may check whether the hydraulic piston 114 has completed moving to the first position based on the identification result among the movement information. At this time, the movement information may refer to movement information generated in the system termination step before the system drive signal is received and the system performs the initialization step, that is, movement information generated in step 404 of FIG. 4.

The electronic brake system 1 can check whether the identification result among the stored movement information is a completed flag or an incomplete flag. If the identification result is a completion flag, the electronic brake system 1 can confirm that the hydraulic piston 114 has completed moving to the first position. If the identification result is an incomplete flag, the electronic brake system 1 can confirm that the hydraulic piston 114 has not completed moving to the first position.

When it is confirmed that the hydraulic piston 114 has moved to the first position (yes at 502), the electronic brake system 1 can check whether the position information is within a predetermined range (503).

At this time, the position information may refer to the position information of the hydraulic piston 114 at the time of identifying whether the position of the hydraulic piston 114 is the first position, that is, when step 403 of FIG. 4 is performed. there is. Additionally, the predetermined range may be an error range regarding a position having a predetermined distance from the first position. For example, the predetermined range may be a range from the first position to a position having a distance of 0.05 mm in the forward direction of the hydraulic piston 114.

When the position information of the hydraulic piston 114 is included in a predetermined range (example of 503), the position of the hydraulic piston 114 is within the error range, so the electronic brake system 1 moves the hydraulic piston 114. The location to be processed can be determined as the second location. Thereafter, the electronic brake system 1 may move the hydraulic piston 114 to the second position (504) and end the system initialization step for providing the braking function.

That is, the electronic brake system 1 can omit the step of moving the position of the hydraulic piston 114 to the first position (X1). In this case, the electronic brake system 1 omits the step of moving the position of the hydraulic piston 114 to the first position, and the position of the hydraulic piston 114 can be immediately determined to be the second position. Therefore, the execution time of the initialization step can be shortened compared to when the hydraulic piston 114 is at a position with the maximum stroke value and the hydraulic piston 114 is moved to the first position and then moved to the second position. .

Accordingly, faster initialization settings can be performed. At the same time, since the time delay that occurs in providing the braking function to the user can be shortened, user convenience can be increased.

As another example, if it is confirmed that the hydraulic piston 114 has not completed moving to the first position (No in 502) or if the position information of the hydraulic piston 114 is not included in a predetermined range (No in 503) , the electronic brake system 1 may move the hydraulic piston 114 to the first position (505) and then move the hydraulic piston 114 to the second position (504).

In this case, since it is determined that the hydraulic piston 114 has not completed moving to the first position, the electronic brake system 1 cannot immediately move the hydraulic piston 114 to the second position, and the electronic brake system 1 cannot immediately move the hydraulic piston 114 to the first position. It can be moved to and then moved to the second location.

However, even if it is confirmed that the hydraulic piston 114 has not completed its movement to the first position, the movement of the hydraulic piston 114 to the first position is performed in the previous system termination step, so the execution time of the initialization step is The movement of the hydraulic piston to the first position can be shorter than if it were not carried out in a previous system shutdown step. Accordingly, faster initialization settings can be performed. Additionally, since the time delay that occurs in providing the braking function to the user can be shortened, user convenience can be increased.

Meanwhile, the disclosed embodiments may be implemented in the form of a recording medium that stores instructions executable by a computer. Instructions may be stored in the form of program code, and when executed by a processor, may create program modules to perform operations of the disclosed embodiments. The recording medium may be implemented as a computer-readable recording medium.

Computer-readable recording media include all types of recording media storing instructions that can be decoded by a computer. For example, there may be Read Only Memory (ROM), Random Access Memory (RAM), magnetic tape, magnetic disk, flash memory, optical data storage device, etc.

As described above, the disclosed embodiments have been described with reference to the attached drawings. A person skilled in the art to which the present invention pertains will understand that the present invention can be practiced in forms different from the disclosed embodiments without changing the technical idea or essential features of the present invention. The disclosed embodiments are illustrative and should not be construed as limiting.

1: Electronic brake system
110: Hydraulic pressure providing unit
310: brake device
311: driving unit
312: position sensor
320: control unit
330: storage unit

Claims (17)

When a system OFF command is received, the drive unit is controlled to move a piston capable of moving forward or backward to a first position;
identify whether the piston has completed moving to the first position;
generating movement information including the identification result and position information indicating a position to which the piston moves when the system is turned off, and storing the generated movement information;
When a system operation (ON) signal is received, a position to move the piston is determined based on the movement information; and
A control method of an electronic brake system comprising: moving the piston to the determined position. According to paragraph 1,
Identifying whether the piston has completed moving to the first position includes:
Identifying whether the piston has completed moving to the first position at a first time after a predetermined time after the system off command is received. According to paragraph 2,
Storing the generated movement information includes:
A control method of an electronic brake system comprising: storing movement information including the identification result and position information of the piston at the first point in time. According to paragraph 1,
Determining the position to move the piston is,
When the system driving signal is received, check whether the piston has completed moving to the first position based on the identification result; and
When it is confirmed that the piston has completed moving to the first position, determining a position to move the piston to a second position. According to paragraph 1,
Determining the position to move the piston is,
When the system driving signal is received, check whether the piston has completed moving to the first position based on the identification result; and
When it is confirmed that the piston has not completed moving to the first position, determining a position to move the piston to the first position. According to clause 4,
Determining the position to move the piston is,
When it is confirmed that the piston has completed moving to the first position, it is checked whether the position information is within a predetermined range; and
If the position information is within a predetermined range, determining a position to move the piston to a second position. According to clause 6,
Determining the position to move the piston is,
If the position information is not included in a predetermined range, determining a position to move the piston as a first position. According to paragraph 2,
The first time point is a control method of an electronic brake system that is a predetermined time before the system OFF is completed. delete delete delete delete delete delete delete delete delete

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