KR102516954B1 - Electric brake system and method thereof - Google Patents

Abstract

An electronic brake system is disclosed. An electronic brake system according to an embodiment of the present invention provides a hydraulic circuit for transmitting hydraulic pressure to a wheel cylinder provided in at least one wheel and a wheel cylinder provided in at least one wheel, an inlet valve for adjusting the hydraulic pressure of a wheel cylinder, and pressure of the hydraulic circuit. and a control unit that adjusts the degree of opening of the inlet valve based on the difference between the reference pressure and the pressure increase rate of the hydraulic circuit.

Description

Electronic brake system and control method {Electric brake system and method thereof}

The present invention relates to an electronic brake system, and more particularly, to an electronic brake system that generates braking force by following a target pressure.

A brake system for braking is essentially installed in a vehicle. Recently, various types of systems for obtaining stronger and more stable braking force have been proposed.

An example of the brake system is an anti-lock brake system (ABS) that prevents wheel slippage during braking, and a brake traction control system (BTCS: Brake Traction Control System), and an Electronic Stability Control System (ESC) that stably maintains the driving state of the vehicle by controlling brake hydraulic pressure by combining an anti-lock brake system and traction control.

In general, an electronic brake system includes a hydraulic pressure supply device that receives a driver's will to brake as an electrical signal from a pedal displacement sensor that detects the displacement of the brake pedal when the driver steps on the brake pedal and supplies pressure to the wheel cylinder.

An electronic brake system provided with the above hydraulic pressure supply device is disclosed in European Patent Registration No. EP 2 520 473. According to the disclosed literature, the hydraulic pressure supply device generates braking pressure by operating a motor according to a pressing force of a brake pedal. At this time, the braking pressure is generated by converting the rotational force of the motor into linear motion and pressurizing the piston.

In addition, the brake system includes a pedal simulator that provides a feeling of pedaling to the driver by receiving hydraulic pressure according to the driver's pedal effort in order to measure the driver's pedal effort.

Therefore, the electronic brake system provided with the hydraulic pressure supply device not only generates braking pressure based on the sensor value of the pedal position sensor obtained for the pedal force applied by the driver, but also operates the pedal simulator based on the pedal position sensor value. .

However, in the electronic brake system, when the target braking pressure to be transmitted to the wheel cylinder included in each wheel is different for each wheel, the opening amount of the inlet valve is adjusted to control the hydraulic pressure transmitted to the wheel. At this time, There is a problem in that it takes a long time to compensate for the desired pressure because the error between the pressure of the circuit and the target pressure is large.

EP 2 520 473 A1 (Honda Motor Co., Ltd.) 2012. 11. 7.

Embodiments of the present invention seek to accurately and quickly perform pressure compensation when a plurality of target pressures are to be provided to at least one wheel.

According to one aspect of the present invention, a hydraulic circuit for transmitting hydraulic pressure to a wheel cylinder provided on at least one or more wheels; and a wheel cylinder provided on the at least one or more wheels; And an inlet valve for adjusting the hydraulic pressure of the wheel cylinder; An electronic brake system including a; may be provided; and a control unit for adjusting the degree of opening of the inlet valve based on the difference between the pressure of the hydraulic circuit and the reference pressure and the pressure increase rate of the hydraulic circuit.

In addition, the electronic brake system includes: a master cylinder that discharges oil according to the pressure of the brake pedal; a reservoir connected to the master cylinder and storing oil; and a rotational force of a motor operated by an electrical signal output from a pedal position sensor. A hydraulic pressure supply device for generating hydraulic pressure using a hydraulic pressure supply device; and a first hydraulic circuit for transferring the hydraulic pressure discharged from the hydraulic pressure supply device to a wheel cylinder provided on at least one wheel; and a second hydraulic circuit that transfers the hydraulic pressure discharged from the hydraulic pressure supply device to a wheel cylinder provided on at least one wheel.

In addition, the control unit controls the degree of opening of the inlet valve based on the difference between the pressure of the hydraulic circuit and the reference pressure and the pressure increase rate of the hydraulic circuit when there are two or more target pressures in the at least one wheel. can

In addition, the control unit determines a compensation duty based on the difference between the pressure of the hydraulic circuit and the reference pressure and the pressure increase rate of the hydraulic circuit, and adjusts the degree of opening of the inlet valve by adding the compensation duty and the reference duty. The duty of the inlet valve can be calculated.

Also, when the target pressure is reached, the control unit may release the calculated duty control of the inlet valve and close (close) the inlet valve.

The controller may provide a negative compensation duty when the pressure increase rate of the hydraulic circuit is positive, and provide a positive compensation duty when the pressure increase rate of the hydraulic circuit is negative.

Further, the control unit may adjust the degree of opening of the inlet valve with the reference duty when the pressure increase rate of the hydraulic circuit is negative and the difference between the pressure of the hydraulic circuit and the reference pressure is positive.

In addition, if the pressure increase rate of the hydraulic circuit is positive, the difference between the pressure of the hydraulic circuit and the reference pressure is positive, and the difference between the target pressure and the current pressure of the wheel is greater than a preset threshold, the duty Threshold compensation control may be further performed.

According to another aspect of the present invention, an electronic brake comprising a wheel cylinder provided on at least one wheel, a hydraulic circuit for transmitting hydraulic pressure to the wheel cylinder provided on the at least one wheel, and an inlet valve for adjusting the hydraulic pressure of the wheel cylinder. An electronic brake control method of a system, comprising: estimating a pressure of the hydraulic circuit; and adjusting the degree of opening of the inlet valve based on the difference between the pressure of the hydraulic circuit and the reference pressure and the pressure increase rate of the hydraulic circuit.

In addition, the electronic brake system uses the rotational force of the motor operated by an electric signal output from a master cylinder that discharges oil according to the pedal force of the brake pedal, a reservoir connected to the master cylinder and storing oil, and a pedal position sensor. A hydraulic pressure supply device for generating hydraulic pressure and a first hydraulic circuit for transferring the hydraulic pressure discharged from the hydraulic pressure supply device to a wheel cylinder provided on at least one wheel and a hydraulic pressure discharged from the hydraulic pressure supply device are provided on at least one wheel A second hydraulic circuit for transmitting to the wheel cylinder may be further included.

In addition, adjusting the degree of opening of the inlet valve based on the difference between the pressure of the hydraulic circuit and the reference pressure and the pressure increase rate of the hydraulic circuit; An electronic brake control method may be provided in which the degree of opening of the inlet valve is adjusted based on the difference between the pressure of the hydraulic circuit and the reference pressure and the pressure increase rate of the hydraulic circuit.

In addition, determining a compensation duty based on the difference between the pressure of the hydraulic circuit and the reference pressure and the pressure increase rate of the hydraulic circuit; and calculating a duty of the inlet valve to adjust an opening degree of the inlet valve by summing the compensation duty and the reference duty.

The method may further include releasing the calculated duty control of the inlet valve and closing (closed) the inlet valve when the target pressure is reached.

In addition, determining a compensation duty based on the difference between the pressure of the hydraulic circuit and the reference pressure and the pressure increase rate of the hydraulic circuit; When the pressure increase rate of the hydraulic circuit is positive, a negative compensation duty may be provided, and when the pressure increase rate of the hydraulic circuit is negative, a positive compensation duty may be provided.

The method may further include adjusting the degree of opening of the inlet valve with the reference duty when the pressure increase rate of the hydraulic circuit is negative and the difference between the pressure of the hydraulic circuit and the reference pressure is positive.

In addition, if the pressure increase rate of the hydraulic circuit is positive, the difference between the pressure of the hydraulic circuit and the reference pressure is positive, and the difference between the target pressure and the current wheel pressure is greater than a preset threshold, duty threshold compensation control is performed. Performing; may further include.

According to the embodiments of the present invention, pressure compensation can be accurately and quickly performed when a plurality of target pressures are to be provided to at least one wheel.

1 is a hydraulic circuit diagram showing a non-braking state of an electronic brake system according to an embodiment of the present invention.
2 is a configuration diagram illustrating an electronic brake system according to an exemplary embodiment.
3 is an internal block diagram of an electronic brake system according to an embodiment.
4 is a graph for explaining a method for calculating the degree of pressure compensation in consideration of both the circuit pressure and the reference pressure error and the circuit pressure increase rate.
5 is a flowchart illustrating a control method of an electronic brake system according to an exemplary embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following examples are presented to sufficiently convey the spirit of the present invention to those skilled in the art. The present invention may be embodied in other forms without being limited to only the embodiments presented herein. In the drawings, in order to clarify the present invention, illustration of parts irrelevant to the description may be omitted, and the size of components may be slightly exaggerated to aid understanding.

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

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 portion 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 that brakes each of the wheels RR, RL, FR, and FL by transmitting hydraulic pressure, and a brake pedal It is provided with a pedal displacement sensor 11 that senses the displacement of (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 to generate hydraulic pressure. For example, the master cylinder 20 may include a first master chamber 20a and a second master chamber 20b.

Referring to FIG. 1, 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 and a reaction force piston provided in the simulation chamber 51 ( 52) and a pedal simulator having a reaction spring 53 for elastically supporting it, and a simulator valve 54 connected to the rear end of the simulation chamber 51.

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

On the other hand, the reaction spring 53 shown in the figure is only one embodiment capable of providing elastic force to the reaction force piston 52, and may include various embodiments capable of storing elastic force by shape deformation. For example, it includes various members capable of storing 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 passage connecting the rear end of the simulation chamber 51 and the reservoir 30 . A front end of the simulation chamber 51 may be connected to the master cylinder 20 , and a rear end of the simulation chamber 51 may be connected to the reservoir 30 through a simulator valve 54 . Therefore, even when the reaction force piston 52 returns, 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.

On the other hand, 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 part or different parts. For 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 can be a repository in

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 presses the brake pedal 10 to transfer the oil in the simulation chamber 51 to the reservoir 30 .

In addition, 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 oil in the reservoir 30 to flow into the simulation chamber 51, but the oil in the simulation chamber 51 flows into the reservoir 30 through a flow path in which the check valve 55 is installed. can block it

Referring to the operation of the pedal simulation device 50, the simulation chamber 51 in which the reaction force piston 52 of the pedal simulator compresses and pushes the reaction force spring 53 when the driver applies a pedal force to the brake pedal 10 The oil inside is transferred to the reservoir 30 through the simulator valve 54, and in this process, the driver is provided with a feeling of pedaling. In addition, when the driver releases the pedal force on the brake pedal 10, the reaction spring 53 pushes the reaction piston 52, and the reaction piston 52 returns to its original state, and the oil in the reservoir 30 returns to the simulator valve ( 54) is installed and the oil flows into the simulation chamber 51 through the flow path where the check valve 55 is installed, and the inside of the simulation chamber 51 may be filled with oil.

In this way, since the inside of the simulation chamber 51 is always filled with oil, the friction of the reaction force piston 52 is minimized when the simulation device 50 operates, thereby improving durability of the simulation device 50 and foreign matter from the outside. inflow can be blocked.

The electronic brake system 1 according to an embodiment of the present invention is a hydraulic pressure supply device 100 that mechanically operates by receiving a driver's braking will as an electrical signal from a pedal displacement sensor 11 that detects a displacement of a brake pedal 10 ) and first and second hydraulic circuits 201 and 202 that control the flow of hydraulic pressure transmitted to the wheel cylinders 40 provided on the two wheels RR, RL, FR, and FL, respectively. 200, 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; A second cut valve 262 provided in the second backup passage 252 connecting the hydraulic port 24b and the second hydraulic circuit 202 to control the flow of hydraulic pressure, and the hydraulic pressure based on hydraulic pressure information and pedal displacement information. An electronic control unit (ECU, not shown) that controls the supply device 100 and the valves 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 243 can include

The hydraulic pressure supply device 100 includes a hydraulic pressure supply unit 110 that provides oil pressure transmitted to the wheel cylinder 40, a motor 120 that generates rotational force by an electrical signal from a pedal displacement sensor 11, and a motor It may include a power converter 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 be operated not by driving force supplied by the motor 120 but by pressure supplied by the high-pressure accumulator.

Next, the flow paths 211, 212, 213, 214, 215, 216, and 217 connected to the first pressure chamber 112 and the second pressure chamber 113 and the valves 231, 232, 233, 234, 235, 236, 241, 242, 243) will be described.

The second hydraulic oil passage 212 may communicate with the first hydraulic circuit 201 , and the third hydraulic oil passage 213 may communicate with the second hydraulic circuit 202 . Accordingly, hydraulic pressure may be transmitted to 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 an embodiment of the present invention includes a first control valve 231 and a second control valve provided in the second and third hydraulic oil passages 212 and 213 respectively to control the flow of oil ( 232) may be included.

And, the first and second control valves 231 and 232 allow oil flow only in the direction from the first pressure chamber 112 to the first or second hydraulic circuits 201 and 202, and oil flow in the opposite direction. It may be provided as a check valve that blocks. That is, the first or second control valves 231 and 232 allow the hydraulic pressure of the first pressure chamber 112 to be transferred to the first or second hydraulic circuits 201 and 202, while allowing the first or second hydraulic pressure to be transferred. It is possible to prevent the hydraulic pressure of the circuits 201 and 202 from leaking into the first pressure chamber 112 through the second or third hydraulic oil passages 212 and 213 .

On the other hand, the fourth hydraulic oil passage 213 is branched into the fifth hydraulic oil passage 215 and the sixth hydraulic oil passage 216 on the way, and can communicate with both the first hydraulic oil circuit 201 and the second hydraulic oil circuit 202. . For example, the fifth hydraulic oil path 215 branching from the fourth hydraulic oil path 214 is in communication with the first hydraulic circuit 201, and the sixth hydraulic oil path 216 branching from the fourth hydraulic oil path 214 is It can communicate 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 backward movement of the hydraulic piston 114 .

In addition, the electronic brake system 1 according to an embodiment of the present invention is provided in the third control valve 233 provided in the fifth hydraulic oil passage 215 to control the flow of oil and provided in the sixth hydraulic oil passage 216 to control the flow of oil. A fourth control valve 234 for controlling the flow may be included.

The third control valve 233 may be provided as a two-way control valve that controls oil flow between the second pressure chamber 113 and the first hydraulic circuit 201 . In addition, the third control valve 233 may be provided as a normally closed type solenoid valve that is normally closed but opens when an open signal is received from the electronic control unit.

The fourth control valve 234 may be provided as a check valve that allows only oil flow in a direction from the second pressure chamber 113 to the second hydraulic circuit 202 and blocks oil flow in the opposite direction. . That is, the fourth control valve 234 prevents the hydraulic pressure of the second hydraulic circuit 202 from leaking into the second pressure chamber 113 through the sixth hydraulic oil passage 216 and the fourth hydraulic oil passage 214. can

In addition, the electronic brake system 1 according to an embodiment of the present invention is provided in the seventh hydraulic oil passage 217 connecting the second hydraulic oil passage 212 and the third hydraulic oil passage 213 to control the flow of oil. 5 includes a control valve 235 and a sixth control valve 236 provided in the eighth hydraulic oil passage 218 connecting the second hydraulic oil passage 212 and the seventh hydraulic oil passage 217 to control the flow of oil can do. In addition, the fifth control valve 235 and the sixth control valve 236 are normally closed type solenoid valves that operate to open when an open signal is received from the electronic control unit 2000 after being normally closed. can be provided.

The fifth control valve 235 and the sixth control valve 236 are operated to open when an abnormality occurs in the first control valve 231 or the second control valve 232, so that the first pressure chamber 112 Hydraulic pressure may be transmitted to both the first hydraulic circuit 201 and the second hydraulic circuit 202 .

In addition, the fifth control valve 235 and the sixth control valve 236 may operate to open when the hydraulic pressure of the wheel cylinder 40 is removed and sent to the first pressure chamber 112 . This is because the first control valve 231 and the second control valve 232 provided in the second hydraulic oil passage 212 and the third hydraulic oil passage 213 are provided as check valves allowing only one-way oil flow.

In addition, the electronic brake system 1 according to an embodiment of the present invention includes a first dump valve 241 and a second dump valve provided in the first and second dump passages 116 and 117 respectively to control the flow of oil ( 242) may be further included. The dump valves 241 and 242 may be check valves that open only in a direction from the reservoir 30 to the first or second pressure chambers 112 and 113 and close 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 flow of oil 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 the oil flows from the second pressure chamber 113 to the reservoir 30. Flowing may be a check valve shutting off.

In addition, the second dump passage 117 may include a bypass passage, and a third dump valve 243 controlling oil flow between the second pressure chamber 113 and the reservoir 30 is provided in the bypass passage. can be installed

The third dump valve 243 may be provided as a solenoid valve capable of controlling bidirectional flow, and is open in normal conditions, but operates to close the valve when a closing signal is received from the electronic control unit (Normal Open Type). type) of a solenoid valve.

The hydraulic pressure providing unit 110 of the electronic brake system 1 according to the embodiment of the present invention may operate in a double-acting manner. That is, while the hydraulic piston 114 moves forward, the hydraulic pressure generated in the first pressure chamber 112 is transmitted to the first hydraulic circuit 201 through the first hydraulic oil passage 211 and the second hydraulic oil passage 212, and is transmitted to the right side. The wheel cylinders 40 installed on the front wheels FR and the left rear wheel LR can act and are transmitted to the second hydraulic circuit 202 through the first hydraulic oil passage 211 and the third hydraulic oil passage 213. As a result, the wheel cylinders 40 installed on the right rear wheel RR and the left front wheel FL can act.

Similarly, the hydraulic pressure generated in the second pressure chamber 113 while the hydraulic piston 114 moves backward is transferred to the first hydraulic circuit 201 through the fourth hydraulic oil passage 214 and the fifth hydraulic oil passage 215, and is transmitted to the right side. The wheel cylinders 40 installed on the front wheels FR and the left rear wheel LR can be actuated and transmitted to the second hydraulic circuit 202 through the fourth hydraulic oil passage 214 and the sixth hydraulic oil passage 216. As a result, the wheel cylinders 40 installed on the right rear wheel RR and the left front wheel FL can act.

In addition, while the hydraulic piston 114 moves backward, the negative pressure generated in the first pressure chamber 112 sucks oil from the wheel cylinders 40 installed on the right front wheel (FR) and the left rear wheel (LR) to generate the first hydraulic circuit. 201, the second hydraulic oil passage 212, and the first hydraulic oil passage 211 can be transferred to the first pressure chamber 112, and the wheel is installed on the right rear wheel (RR) and the left front wheel (FL). Oil of the cylinder 40 may be sucked in and transferred to the first pressure chamber 112 through the second hydraulic circuit 202 , the third hydraulic oil passage 213 , and the first hydraulic oil passage 211 .

Next, the motor 120 and the power converter 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 the electronic control unit 2000, and can generate rotational force in a forward or reverse direction. The rotational angular velocity and rotational angle of the motor 120 can be precisely controlled. Since such a motor 120 is a well-known technology, a detailed description thereof will be omitted.

On the other hand, the electronic control unit includes the motor 120 and the valves 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 243). An operation in which a plurality of valves are controlled 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 while the hydraulic piston 114 slides in the pressure chamber is transferred to the first and second hydraulic fluids. Through (211, 212) is transmitted to the wheel cylinder 40 installed on each wheel (RR, RL, FR, FL).

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

The worm shaft 131 may be formed integrally with the rotating shaft of the motor 120, and a worm is formed on the outer circumferential surface to be engaged 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 linearly move the drive shaft 133, and the drive shaft 133 is connected to the hydraulic piston 114 to slide the hydraulic piston 114 within the cylinder block 111 move

To explain the above operations again, while displacement occurs in the brake pedal 10, the signal detected by the pedal displacement sensor 11 is transmitted to the electronic control unit 2000, and the electronic control unit drives the motor 120 in one direction. to rotate the worm shaft 131 in one direction. The rotational force of the worm shaft 131 is transmitted to the driving shaft 133 via the worm wheel 132, and the hydraulic piston 114 connected to the driving shaft 133 moves forward to generate hydraulic pressure in the first pressure chamber 112.

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

On the other hand, the generation of hydraulic pressure and negative pressure is also possible in the opposite direction. That is, while displacement occurs in the brake pedal 10, the signal detected by the pedal displacement sensor 11 is transmitted to an 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 via the worm wheel 132, and the hydraulic piston 114 connected to the drive shaft 133 moves backward while generating hydraulic pressure in the second pressure chamber 113.

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

As such, the hydraulic pressure supply device 100 serves to transfer the hydraulic pressure to the wheel cylinder 40 according to the rotational direction of the rotational force generated from the motor 120 or to suck the hydraulic pressure and transfer it to the reservoir 30.

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. Whether or not to release the braking by using the brake may be determined by controlling the valves 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, and 243. This will be described 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 formed integrally with the rotating shaft of the motor 120 or connected to rotate together with the rotating shaft of the motor 120, and a ball nut that is screwed with the screw in a state where rotation is limited 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 converter 130 and pressurizes the pressure chamber by the linear motion of the ball nut. Since the structure of the ball screw nut assembly is a well-known technology as a device for converting rotational motion into linear motion, a detailed description thereof will be omitted.

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

In addition, the electronic brake system 1 according to an embodiment of the present invention is capable of directly supplying the oil discharged from the master cylinder 20 to the wheel cylinder 40 when operating abnormally (fallback mode). First and second backup passages 251 and 252 may be further included.

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 for controlling the flow of oil may be provided in the second backup passage 252. there is. In addition, the first backup oil passage 251 connects the first hydraulic port 24a and the first hydraulic circuit 201, and the second backup oil 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 may be provided as normal open type solenoid valves that are open in normal conditions but close when a closing signal is received from the electronic control unit. there is.

Next, a hydraulic control unit 200 according to an embodiment of the present invention will be described with reference to FIG. 1 .

The hydraulic control unit 200 may include a first hydraulic circuit 201 and a second hydraulic circuit 202 that receive hydraulic pressure and control two wheels, respectively. For example, the first hydraulic circuit 201 may control the right front wheel FR and the left rear wheel RL, and the second hydraulic circuit 202 may control the left front wheel FL and the right rear wheel RR. . In addition, a wheel cylinder 40 is installed in each of the wheels FR, FL, RR, and RL to receive hydraulic pressure to perform braking.

The first hydraulic circuit 201 is connected to the first hydraulic oil passage 211 and the second hydraulic oil passage 212 to receive hydraulic pressure from the hydraulic pressure supply device 100, and the second hydraulic oil passage 212 is connected to the right front wheel (FR). ) and the left rear wheel (RL). Similarly, the second hydraulic circuit 202 is connected to the first hydraulic oil passage 211 and the third hydraulic oil passage 213 to receive hydraulic pressure from the hydraulic pressure supply device 100, and the third hydraulic oil passage 213 is connected to the left front wheel. (FL) and the right rear wheel (RR).

The hydraulic circuits 201 and 202 may include a plurality of inlet valves 221 (221a, 221b, 221c, 221d) to control the flow of hydraulic pressure. For example, the first hydraulic circuit 201 may be provided with two inlet valves 221a and 221b connected to the first hydraulic oil passage 211 and respectively controlling the hydraulic pressure transmitted to the two wheel cylinders 40. . In addition, the second hydraulic circuit 202 may be provided with two inlet valves 221c and 221d connected to the second hydraulic oil passage 212 and respectively controlling the hydraulic pressure transmitted to the wheel cylinder 40 .

In addition, the inlet valve 221 is disposed upstream of the wheel cylinder 40 and is open in a normal state, but operates to close the valve when a closing signal is received from the electronic control unit 2000 (Normal Open type) It can be provided as a solenoid valve of.

In addition, the hydraulic circuits 201 and 202 may include check valves 223a, 223b, 223c, and 223d provided in the bypass passage connecting the front and rear of the respective inlet valves 221a, 221b, 221c, and 221d. can The check valves 223a, 223b, 223c, and 223d allow only the flow of oil from the wheel cylinder 40 toward the hydraulic pressure providing unit 110, and oil flows from the hydraulic pressure providing unit 110 toward the wheel cylinder 40. The flow of may be arranged to limit. The check valves 223a, 223b, 223c, and 223d can quickly release the braking pressure of the wheel cylinder 40, and when the inlet valves 221a, 221b, 221c, and 221d do not operate normally, the wheel cylinder The hydraulic pressure of (40) can be introduced into the hydraulic pressure providing unit (110).

In addition, the hydraulic circuits 201 and 202 may further include a plurality of outlet valves 222 (222a, 222b, 222c, 222d) connected to the reservoir 30 to improve performance during braking release. The outlet valves 222 are connected to the wheel cylinders 40 to control hydraulic pressure escaping from the wheels RR, RL, FR, and FL. That is, the outlet valve 222 senses the braking pressure of each wheel RR, RL, FR, and FL, and is selectively opened to control the pressure when decompression braking is required.

In addition, the outlet valve 222 may be provided as a normally closed type solenoid valve that operates to open when an open signal is received from the electronic control unit 2000 after being normally closed.

Also, the hydraulic control unit 200 may be connected to the backup oil passages 251 and 252 . For example, the first hydraulic circuit 201 is connected to the first backup oil passage 251 to receive hydraulic pressure from the master cylinder 20, and the second hydraulic circuit 202 is connected to the second backup oil passage 252. Hydraulic pressure may be received from the master cylinder 20 .

At this time, the first backup passage 251 may join the first hydraulic circuit 201 upstream of the first and second inlet valves 221a and 221b. Similarly, the second backup passage 252 may join the second hydraulic circuit 202 upstream of the third and fourth inlet valves 221c and 221d. Therefore, when the first and second cut valves 261 and 262 are closed, the hydraulic pressure provided from the hydraulic pressure supply device 100 is supplied to the wheel cylinder 40 through the first and second hydraulic circuits 201 and 202. When the first and second cut valves 261 and 262 are opened, the hydraulic pressure provided from the master cylinder 20 is supplied to the wheel cylinder 40 through the first and second backup passages 251 and 252. can At this time, since the plurality of inlet valves 221a, 221b, 221c, and 221d are open, there is no need to change their operating state.

Meanwhile, unexplained reference numeral "PS11" denotes a first hydraulic oil pressure sensor that senses the hydraulic pressure of the first hydraulic circuit 201, and "PS12" denotes a second hydraulic oil that senses the hydraulic pressure of the second hydraulic circuit 202. is a pressure sensor, and "PS2" is a backup oil pressure sensor that measures the oil pressure of the master cylinder (20). And "MPS" is a motor control sensor that controls the rotation angle of the motor 120 or the current of the motor.

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

The hydraulic pressure supply device 100 may be used separately in a low pressure mode and a high pressure mode. The low pressure mode and the high pressure mode can be changed by differentiating the operation of the hydraulic control unit 200 . The hydraulic pressure supply device 100 can generate high hydraulic pressure without increasing the output of the motor 120 by using the high pressure mode. Therefore, it is possible to secure stable braking force while lowering the price and weight of the brake system.

More specifically, the hydraulic piston 114 generates hydraulic pressure in the first pressure chamber 112 while moving forward. As the hydraulic piston 114 advances from the initial state, that is, as the stroke of the hydraulic piston 114 increases, the amount of oil transferred from the first pressure chamber 112 to the wheel cylinder 40 increases, and the braking pressure increases. rise However, since there is an effective stroke of the hydraulic piston 114, there is a maximum pressure due to the advancement of the hydraulic piston 114.

At this time, the maximum pressure in the low pressure mode is smaller than the maximum pressure in the high pressure mode. However, in the high pressure mode, the pressure increase rate per stroke of the hydraulic piston 114 is small compared to the low pressure mode. This is because not all of the oil pushed out of the first pressure chamber 112 flows into the wheel cylinder 40, but some of it flows into the second pressure chamber 113.

Therefore, a low pressure mode with a large pressure increase per stroke may be used in the early stage of braking where braking response is important, and a high pressure mode with a large pressure may be used in the late stage of braking where maximum braking force is important.

When braking by the driver starts, the braking amount requested by the driver may be detected through information such as pressure of the brake pedal 10 pressed by the driver through the pedal displacement sensor 11 . The electronic control unit 2000 receives the electric signal output from the pedal displacement sensor 11 and drives the motor 120 .

In addition, the electronic control unit 2000 determines the amount of regenerative braking through the backup oil pressure sensor PS2 provided on the outlet side of the master cylinder 20 and the hydraulic oil pressure sensor PS1 provided in the second hydraulic circuit 202. , and the amount of friction braking is calculated according to the difference between the amount of braking requested by the driver and the amount of regenerative braking, thereby determining the amount of pressure increase or decrease of the wheel cylinder 40 .

Also, although not shown, the electronic brake system 1 may selectively brake a plurality of wheels, like an ABS operation. For example, the hydraulic piston 114 may selectively brake while moving forward, and as another example, the hydraulic piston 114 may selectively brake while moving backward.

First, the hydraulic piston 114 selectively brakes while moving forward, when the motor 120 operates according to the pedal force of the brake pedal 10, the rotational force of the motor 120 moves the power transmission unit 130. The hydraulic pressure is generated as it is transferred to the hydraulic pressure providing unit 110 through the liquid pressure supply unit 110 . At this time, the first and second cut valves 261 and 262 are closed so that the hydraulic pressure discharged from the master cylinder 20 is not transmitted to the wheel cylinder 40 .

While the hydraulic piston 114 moves forward, hydraulic pressure is generated in the first pressure chamber 112, and the fourth inlet valve 221d is provided in an open state through the first hydraulic oil passage 211 and the third hydraulic oil passage 213. The transmitted hydraulic pressure generates braking force by operating the wheel cylinder 40 located on the left front wheel FL.

At this time, the first to third inlet valves 221a, 221b, and 221c are switched to a closed state, and the first to fourth outlet valves 222a, 222b, 222c, and 222d remain closed. Also, the third dump valve 243 is provided in an open state and fills the second pressure chamber 113 with oil from the reservoir 30 .

As another example, selective braking while the hydraulic piston 114 moves backward generates hydraulic pressure in the second pressure chamber 113 while the hydraulic piston 114 moves backward, and the first inlet valve 221a is opened. The hydraulic pressure transmitted through the fourth hydraulic oil passage 214 and the second hydraulic oil passage 212 operates the wheel cylinder 40 located on the right front wheel FR to generate braking force.

At this time, the second to fourth inlet valves 221b, 221c, and 221d are switched to a closed state, and the first to fourth outlet valves 222a, 222b, 222c, and 222d remain closed.

That is, the electronic brake system 1 according to an embodiment of the present invention includes a motor 120 and each valve 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236 and 243), it is possible to selectively transmit or discharge hydraulic pressure to the wheel cylinder 40 of each wheel (RL, RR, FL, FR) according to the required pressure, enabling precise pressure control. do.

Next, FIG. 2 is an internal block diagram of the electronic brake system 1 according to an embodiment of the present invention, which includes an electronic control unit 2000 and an electronic brake system 1 that collectively control the electronic brake system 1. ) It is a block configuration diagram showing a state connected to the brake device 1000 included in, and FIG. 3 is a detailed block diagram.

Referring to FIG. 3 , the electronic control unit 2000 of the electronic brake system 1 according to an embodiment of the present invention includes an input unit 102, a determination unit 104, a calculation unit 106, and a control unit 108. include

The input unit 102 receives operation signals from the motor position sensor (MPS) of the brake device 1000, the brake pedal 10, the motor 120, the piston 114, the pressure sensor (PS), and the inlet valve 221. receive input

Here, the brake device 1000 may be an Integrated Dynamic Brake (IDB) that generates boosting pressure and braking pressure with one motor 120, or may be any brake unit that generates braking pressure with a motor. That is, the electronic brake system 1 shown in FIG. 1 may correspond to this.

Although the motor 120 is not shown, it may be a permanent magnet synchronous motor (not shown), and the permanent magnet synchronous motor (not shown) includes a buried permanent magnet synchronous motor (not shown) and a surface-attached permanent magnet synchronous motor. (not shown) may be at least one.

The determination unit 104 determines whether or not the pressure should be individually set for each wheel of the vehicle 1 . For example, when the pressure needs to be set individually for each wheel, when the TCS (Traction Control System) operates, such as in the case of performing posture control of the vehicle 1, or in the case of slow driving and rotational driving at the same time, etc. can be heard However, it is not limited thereto, and the determination unit 104 provides a control signal for setting a plurality of targets to the control unit 108 in all cases in which pressure is to be individually set for each wheel in the electronic brake system 1 of the vehicle. can send

Next, the control unit 108 determines the amount of current flowing through the inlet valve 221 when receiving a control signal for setting a plurality of targets from the determination unit 104 . Specifically, in order to determine the amount of current of the inlet valve 221, the amount of compensation current may be determined as shown in FIG. 4 . This will be described later with reference to FIG. 4 .

In addition, the control unit 108 applies electromagnetic force to the inlet valve 221 at a base duty (D _B ) to balance the circuit pressure and the wheel pressure in order to increase the pressure of the wheel to be controlled. do. In this case, the reference duty ( _DB ) may be set with reference to the estimated pressure of the wheel to be controlled by selecting the larger value between the highest pressure among the estimated wheel pressures and the highest pressure among the target pressures of the wheel as the reference pressure.

However, the control unit 108 individually controls each wheel by adding a compensation duty (D _c ) to the reference duty (D _B ). 4 is a graph for explaining a pressure compensation method in consideration of both an error between a circuit pressure and a reference pressure and a circuit pressure increase rate.

However, the direction of the compensation duty (D _c ) is determined by considering the error between the circuit pressure and the reference pressure and the circuit pressure increase rate.

For example, if the difference between the circuit pressure CP and the reference pressure RefP is greater than 0, the circuit pressure increase rate CP-rate is greater than 0, and the inlet valve 221 is open, the controller 108 performs a compensation duty (D _c ) in the negative direction. However, the control unit 108 limits the pressure rise rate of the corresponding wheel to be greater than the circuit pressure supply rate.

In addition, the control unit 108 compensates when the difference between the circuit pressure CP and the reference pressure RefP is less than or equal to 0, the circuit pressure increase rate CP-rate is greater than 0, and the inlet valve 221 is open. The duty (D _c ) is determined in the negative direction. However, the control unit 108 limits the pressure rise rate of the corresponding wheel to be smaller than the circuit pressure supply rate. In order to describe the operation of the control unit 108 to be described later, the corresponding control condition is referred to as “first phase control”.

In addition, the control unit 108 compensates when the difference between the circuit pressure CP and the reference pressure RefP is less than or equal to 0, the circuit pressure increase rate CP-rate is greater than 0, and the inlet valve 221 is open. The duty (D _c ) is determined in the negative direction. However, the control unit 108 limits the pressure rise rate of the corresponding wheel to be smaller than the circuit pressure supply rate. To describe the operation of the control unit 108 to be described later, the corresponding control condition is referred to as "second phase control".

In addition, the control unit 108 determines that the difference between the circuit pressure CP and the reference pressure RefP is greater than 0, the circuit pressure increase rate CP-rate is less than 0 (ie, the circuit pressure decreases), and the inlet valve 221 ) is in an open state, it is determined that there is no separate compensation duty (D _c ). However, the control unit 108 limits the pressure rise speed of the corresponding wheel to be smaller than the circuit pressure supply speed when controlling the inlet valve with a base duty (D _B ). In order to describe the operation of the controller 108 to be described later, the corresponding control condition is referred to as “fourth phase control”.

In addition, the control unit 108 determines that the difference between the circuit pressure CP and the reference pressure RefP is less than or equal to 0, the circuit pressure increase rate CP-rate is less than 0 (ie, the circuit pressure decreases), and the inlet valve When (221) is closed, the compensation duty (D _c ) is determined in a positive direction. In particular, the corresponding control condition is referred to as "third phase control", and the control unit 108 stands by in a waiting state for switching to the first phase, the second phase, or the fourth phase during the third phase control.

4 is a graph for explaining a method of determining the compensation duty (Dc) in more detail in the phase control determined by considering the difference between the circuit pressure and the reference pressure (CP-RefP) and the circuit pressure increase rate (CP-rate). .

First, in the first-phase control, the control unit 108 compares the difference between the circuit pressure and the reference pressure (CP-RefP) with the first threshold difference (diff1) to set a different compensation duty.

In addition, in the first phase control and the second phase control, the control unit 108 compares the circuit pressure increase rate (CP-rate) with the first threshold increase rate (rate1) and sets a different compensation duty.

Specifically, in the first-phase control, when the circuit pressure increase rate is greater than the first threshold increase rate, the control unit 108 determines that there is no circuit pressure margin, but the circuit pressure increases sufficiently quickly, and sets the compensation duty to D _ca1 to decide

In addition, in the first phase control, if the circuit pressure increase rate is less than the first threshold increase rate, the control unit 108 determines that there is no margin for circuit pressure, but the circuit pressure increases slowly, and determines the compensation duty as D _cb1 . do.

Specifically, in the second phase control, the control unit 108 controls the circuit pressure when the circuit pressure increase rate is greater than the first threshold increase rate and the difference between the circuit pressure and the reference pressure (CP-RefP) is less than the first threshold difference. Although the margin is not large, it is determined that the circuit pressure increases quickly enough, and the compensation duty is determined as _Dca2 .

Also, in the second phase control, if the circuit pressure increase rate is less than the first threshold increase rate and the difference between the circuit pressure and the reference pressure (CP-RefP) is less than the first threshold difference, the control unit 108 provides margin of circuit pressure. Although the margin is not large, it is judged that the circuit pressure increases slowly, and the compensation duty is determined as D _cb2 .

In addition, in the second phase control, if the circuit pressure increase rate is greater than the first threshold increase rate and the difference between the circuit pressure and the reference pressure (CP-RefP) is greater than the first threshold difference, the control unit 108 provides a circuit pressure margin. is sufficient and the circuit pressure increases rapidly enough, the compensation duty is determined as D _ca3 .

Also, in the second phase control, if the circuit pressure increase rate is less than the first threshold increase rate and the difference between the circuit pressure and the reference pressure (CP-RefP) is greater than the first threshold difference, the control unit 108 sets a margin for the circuit pressure. is sufficient, but it is judged that the circuit pressure increases slowly, and the compensation duty is determined as D _cb3 .

At this time, D _{ca1 ,} D _{cb1 ,} D _{ca2 ,} D _{cb2 ,} D ca3 _{, and} D _cb3 , which are compensation duties determined in the first-phase control and the second-phase control, are all determined in negative directions.

Next, in the third phase control, when the difference between the circuit pressure and the reference pressure (CP-RefP) is less than 0 and the circuit pressure increase rate is a negative value, the control unit 108 sets the second critical rate of increase (rate2) If it is less than, it is determined that there is no circuit pressure margin, but the circuit pressure is rapidly decreasing, and the compensation duty is determined as D _cd1 .

Further, in the third-phase control, the control unit 108 sets the second threshold rate of increase (rate2) when the difference between the circuit pressure and the reference pressure (CP-RefP) is less than 0 and the circuit pressure increase rate is a negative value. If it is large, it is determined that there is no circuit pressure margin, but the circuit pressure is slowly decreasing, and the compensation duty is determined as _Dcc1 .

Also, in the fourth-phase control, the control unit 108 does not assign a compensation duty.

Next, the duty compensation control cycle of the controller 108 will be described.

The duty compensation control cycle of the control unit 108 may largely consist of the first to fourth steps. The duty compensation control cycle of the control unit 108 starts in the first step, and completely closes the inlet valve 221 in the fourth step. Thereafter, after the fourth step, control may be started again with the first step.

First, in the first step, the control unit 108 starts to determine a compensation duty to be added to the reference duty when the pressure of the wheel increases through the circuit pressure value obtained from the input unit 102. That is, by determining the initial duty value, the controller 108 determines the initial duty D1 as the sum of the reference duty D _B and the compensation duty D _c .

At this time, as described above, when the first-phase control condition is satisfied, the initial duty (D1) is the negative compensation duty (Dc) added to _DB , and at this time, the compensation duty is Dca2, Dcb2, Dca3, or at least one of Dcb3.

In addition, when the second-phase control condition is satisfied, the initial duty D1 is obtained by adding a negative compensation duty Dc to D _B , and in this case, the compensation duty may be set to at least one of Dca1 and Dcb1.

In addition, when the third-phase control condition is satisfied, the initial duty D1 is obtained by adding a positive compensation duty Dc to _DB , and at this time, the compensation duty may be set to at least one of Dcc1 and Dcd1.

In addition, when the fourth-phase control condition is satisfied, the initial duty D1 may be set as the reference duty D _B .

Then, after calculating the initial duty D1, the control unit 108 determines that the second step has entered, and calculates the second step duty D2.

Upon entering the second step, the control unit 108 determines whether there is a transition in the phase of the first duty (D1).

If it is the same as the phase determined during the initial duty (D1), the initial duty (D1) is maintained.

However, in the case where the initial duty (D1) is the 3rd phase control or the 4th phase control, if the circuit pressure reduction becomes larger and the reduction amount is greater than the second critical increase rate (moving from ⓒ to ⓓ in the same phase in FIG. 4), the th The 2 duty (D2) is updated by adding the compensation duty (D _cc1 ) to the reference duty (D _B ).

However, if the initial duty D1 maintains the first phase during the first phase control, the controller 108 may additionally compensate for the negative compensation duty by comparing the target pressure with the estimated pressure. This is to increase the insufficient wheel pressure due to the previous initial duty D1.

For example, if the initial duty (D1) is during the first phase control and the error between the target pressure and the estimated pressure is smaller than the preset first threshold pressure, the final duty (D _fin ) continues with the current initial duty (D1). keep

However, if the error between the target pressure and the estimated pressure is greater than the preset first threshold pressure while the initial duty D1 is in the first phase control, the final duty D _fin is set to the first phase duty of the current state. It is determined by adding up the duty (Dth1).

In addition, when the initial duty D1 is larger than the second critical pressure, which is greater than the preset first critical pressure, during the first phase control, the error between the target pressure and the estimated pressure is larger than the first critical pressure, the final duty D _fin is set to the first It is determined by adding the second critical duty (Dth2) to the phase duty.

If the first duty (D1) determined phase is switched to another phase, the controller 108 resets the duty. Specifically, the control unit 108 is in the third phase control when the initial duty (D1) is set, and then, when the first, second, or fourth phase is controlled, the duty to increase the pressure of the wheel reset the In addition, the control unit 108 resets the duty to prevent a drop in circuit pressure when switching from another phase to a third phase.

For example, when the second phase, the third phase, or the fourth phase is converted to the first phase, the second duty D2 is the sum of the reference duty _DB and the negative compensation duty Dc. The compensation duty may be at least one of Dca2, Dca3, Dcb1, and Dcb3.

In addition, when the first phase, the third phase, or the fourth phase is switched to the second phase, the second duty D2 is the sum of the reference duty D _B and the negative compensation duty Dc. At this time, The compensation duty of may be at least one of Dca1 and Dcb1.

In addition, when switching from the first phase, the second phase, or the fourth phase to the third phase, the second duty D2 is the sum of the reference duty DB and the positive compensation duty _Dc . At this time, The compensation duty of may be at least one of Dcc1 and Dcd1.

Also, when switching from the first phase, the second phase, or the third phase to the fourth phase, the second duty D2 becomes the reference duty _DB .

Thereafter, when the control unit 108 determines that the wheel pressure increase control is completed, a third step of closing and controlling the corresponding inlet valve 221 is entered.

Thereafter, as a fourth step, the control unit 108 waits whether to enter the next first step during inlet valve closing control.

In the above, the duty control method of the inlet valve with respect to the configuration of the electronic brake system 1 according to the present invention has been described.

Hereinafter, a comprehensive control method of the electronic brake system 1 according to the present invention will be described.

Specifically, FIG. 5 is a flowchart illustrating a control method of an electronic brake system according to an exemplary embodiment.

First, the electronic brake system 1 measures circuit pressure (500). Specifically, the circuit pressure may be measured through at least one pressure sensor PS included in the circuit.

Then, based on the measured pressure, the determination unit 104 in the electronic control unit 2000 determines whether individual target pressure settings for each wheel FL, FR, RR, and RL are necessary (510). If it is necessary to set a plurality of target pressures (YES in 510), a plurality of target pressure providing process is entered (520). Specifically, the control unit 108 may determine the duty of the inlet valve 221 for each wheel through the above-described FIG. 4 and the first to fourth steps (530).

Next, when the control unit 108 determines that the target pressure for each wheel has been increased (YES in 540), as a fourth step, the process of providing a plurality of target pressures is canceled (550).

However, unlike the above description, if the determination unit 104 determines that individual target pressure setting for each wheel is not necessary (No in 510), general braking control may be performed (560). That is, the control of the inlet valve according to the standard duty is performed, and pressure control is performed for each wheel during braking without calculating an additional compensation duty.

Although an embodiment of the disclosed invention has been shown and described above, the disclosed invention is not limited to the specific embodiment described above, and those skilled in the art to which the disclosed invention belongs without departing from the subject matter claimed in the claims Of course, various modifications are possible by this, and these modifications cannot be individually understood from the disclosed invention.

10: brake pedal 11: pedal displacement sensor
20: master cylinder 30: reservoir
40: wheel cylinder 50: simulation device
54: simulator valve 60: inspection valve
100: hydraulic pressure supply unit 110: hydraulic pressure supply unit
120: motor 130: power conversion unit
200: hydraulic control unit 201: first hydraulic circuit
202: second hydraulic circuit 211: first hydraulic oil path
212: second hydraulic oil path 213: third hydraulic oil path
214: fourth hydraulic oil path 215: fifth hydraulic oil path
216: sixth hydraulic oil passage 217: seventh hydraulic oil passage
218: eighth hydraulic oil 221: inlet valve
222: outlet valve 223: check valve
231: first control valve 232: second control valve
233: third control valve 234: fourth control valve
235: fifth control valve 236: sixth control valve
241: first dump valve 242: second dump valve
243: third dump valve 251: first backup passage
252: second backup flow path 261: first cut valve
262: second cut valve

Claims (16)

a wheel cylinder provided on at least one wheel;
a hydraulic circuit for transmitting hydraulic pressure to the wheel cylinder;
a pressure sensor for sensing pressure in the hydraulic circuit;
an inlet valve for adjusting the hydraulic pressure of the wheel cylinder;
The pressure of the wheel cylinder is estimated, a reference pressure is determined based on the estimated pressure of the wheel cylinder and a target pressure for braking the wheel, and the difference between the detected pressure of the hydraulic circuit and the reference pressure and the hydraulic pressure An electronic brake system comprising: a control unit that adjusts the degree of opening of the inlet valve based on the increase rate of the pressure detected in the circuit. According to claim 1,
The electronic brake system,
A master cylinder that discharges oil according to the pressure of the brake pedal;
a reservoir connected to the master cylinder and storing oil;
a hydraulic pressure supply device generating hydraulic pressure using rotational force of a motor operated by an electrical signal output from a pedal position sensor;
a first hydraulic circuit for transferring the hydraulic pressure discharged from the hydraulic pressure supply device to a wheel cylinder provided on at least one wheel; and
The electronic brake system further includes a second hydraulic circuit that transfers the hydraulic pressure discharged from the hydraulic pressure supply device to a wheel cylinder provided on at least one wheel. The method of claim 1, wherein the control unit,
In at least two wheels, when the target pressure is two or more, the electronic brake system controls the opening degree of the inlet valve based on the difference between the pressure of the hydraulic circuit and the reference pressure and the pressure increase rate of the hydraulic circuit. The method of claim 1, wherein the control unit,
Determine a reference duty based on the reference pressure, determine a compensation duty based on a difference between the sensed pressure of the hydraulic circuit and the reference pressure and an increase rate of the sensed pressure of the hydraulic circuit, and determine the compensation duty and the reference duty The electronic brake system for calculating the duty of the inlet valve to adjust the degree of opening of the inlet valve by summing . The method of claim 4, wherein the control unit,
When the target pressure is reached, the calculated duty control of the inlet valve is released and the electronic brake system closes (closes) the inlet valve. The method of claim 4, wherein the control unit,
If the increase rate of the sensed pressure of the hydraulic circuit is positive, a negative compensation duty is provided, and if the rate of increase of the sensed pressure of the hydraulic circuit is negative, a positive compensation duty is provided. The method of claim 4, wherein the control unit,
If the pressure increase rate of the hydraulic circuit is negative and the difference between the pressure of the hydraulic circuit and the reference pressure is positive, the electronic brake system controls the degree of opening of the inlet valve with the reference duty. The method of claim 5, wherein the control unit,
If the increase rate of the sensed pressure of the hydraulic circuit is positive and the difference between the sensed pressure of the hydraulic circuit and the reference pressure is positive, the difference between the target pressure and the current estimated pressure of the wheel cylinder is greater than a preset threshold. If large, the electronic brake system further performs duty threshold compensation control. In the electronic brake control method of an electronic brake system including a wheel cylinder provided on at least one wheel, a hydraulic circuit for transmitting hydraulic pressure to the wheel cylinder, and an inlet valve for adjusting the hydraulic pressure of the wheel cylinder,
estimating the pressure of the wheel cylinder;
sensing the pressure in the hydraulic circuit;
determining a reference pressure based on an estimated pressure of the wheel cylinder and a target pressure for braking the wheel; and
and adjusting an opening degree of the inlet valve based on a difference between the detected pressure of the hydraulic circuit and the reference pressure and an increase rate of the detected pressure of the hydraulic circuit. 10. The method of claim 9, wherein the electronic brake system
A master cylinder that discharges oil according to the pressure of the brake pedal, a reservoir that is connected to the master cylinder and stores oil, and a hydraulic pressure supply device that generates hydraulic pressure using the rotational force of a motor operated by an electrical signal output from a pedal position sensor. and a first hydraulic circuit for transferring the hydraulic pressure discharged from the hydraulic pressure supply device to a wheel cylinder provided on at least one wheel, and a second hydraulic circuit for transferring the hydraulic pressure discharged from the hydraulic pressure supply device to a wheel cylinder provided on at least one wheel. Electronic brake control method further comprising a circuit According to claim 9,
adjusting the degree of opening of the inlet valve based on a difference between the detected pressure of the hydraulic circuit and the reference pressure and an increase rate of the detected pressure of the hydraulic circuit;
In at least two wheels, when the target pressure is two or more, the electronic brake control method of adjusting the opening degree of the inlet valve based on the difference between the pressure of the hydraulic circuit and the reference pressure and the pressure increase rate of the hydraulic circuit. According to claim 9,
determining a compensation duty based on a difference between the sensed pressure of the hydraulic circuit and the reference pressure and an increase rate of the sensed pressure of the hydraulic circuit; and
and calculating a duty of the inlet valve to adjust an opening degree of the inlet valve by summing the compensation duty and the reference duty. According to claim 12,
The electronic brake control method further comprising releasing the calculated duty control of the inlet valve and closing (closed) the inlet valve when the target pressure is reached. According to claim 12,
determining a compensation duty based on a difference between the sensed pressure of the hydraulic circuit and the reference pressure and an increase rate of the sensed pressure of the hydraulic circuit; Is
If the increase rate of the sensed pressure of the hydraulic circuit is positive, a negative compensation duty is provided, and if the increase rate of the sensed pressure of the hydraulic circuit is negative, a positive compensation duty is provided. According to claim 12,
adjusting the degree of opening of the inlet valve with the reference duty when the increase rate of the detected pressure of the hydraulic circuit is negative and the difference between the detected pressure of the hydraulic circuit and the reference pressure is positive; brake control method. According to claim 13,
If the increase rate of the sensed pressure of the hydraulic circuit is positive and the difference between the sensed pressure of the hydraulic circuit and the reference pressure is positive, the difference between the target pressure and the current estimated pressure of the wheel cylinder is greater than a preset threshold. If it is large, performing duty threshold compensation control; electronic brake control method further comprising.

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