KR20190101131A - Electronic brake systme and control method thereof - Google Patents

Abstract

Disclosed are an electronic brake system and a control method thereof. According to an embodiment of the present invention, the electronic bake system comprises: an input unit receiving a brake pedal signal, and receiving a sensing value of a motor position sensor and a motor current sensor; and a control unit determining a target position of a motor by calculating a target motor speed value, wherein the motor is required for generating target braking pressure corresponding to the brake pedal signal when at least one of the motor position sensor or the motor current sensor is out of order.

Description

Electronic brake system and its control method {ELECTRONIC BRAKE SYSTME AND CONTROL METHOD THEREOF}

The present invention relates to an electronic brake system and a control method thereof.

In general, conventional motor position sensors sense the position of a motor to precisely generate braking pressure in the motor of the brake device.

For example, as described in Korean Patent Publication No. 10-1478070 (December 24, 2014), an electronically controlled brake booster for transmitting power for generating brake pressure in a motor and sensing a motor position using a motor position sensor is disclosed. It became.

However, the conventional electronically controlled brake booster has a limitation in stably driving the motor when the motor position sensor is in a failure state, and thus has a limitation in efficiently generating a braking pressure corresponding to the brake pedal signal.

Therefore, in recent years, studies of an improved brake device control device and a brake device control method for efficiently generating a braking pressure corresponding to the brake pedal signal even when the motor position sensor is in a broken state have been continuously conducted.

In addition, in recent years, researches on the improved brake device control device and the brake device control method for suppressing the noise phenomenon generated in the motor or the noise phenomenon generated differently have been continuously conducted.

In addition, in recent years, studies have been continuously conducted on improved brake device control devices and brake device control methods for efficiently generating a braking pressure corresponding to brake pedal signals even when a current sensor used in an electronic brake system has failed. Coming.

Republic of Korea Patent Publication 10-1478070 (2014.12.24)

According to an embodiment of the present invention, even without using the position sensor of the motor or the current sensor signal of the motor included in the electronic brake system, the motor is operated to accurately generate the braking pressure required by the driver.

Therefore, even when the position sensor of the motor or the current sensor signal of the motor is broken, the electronic brake system is intended to be stably operated.

In addition, to reduce the noise caused by the operation of the motor of the electronic brake system.

According to an aspect of the present invention, the input unit for receiving a brake pedal signal, the sensing value of the motor position sensor and the motor current sensor; and at least one or more of the motor position sensor or the motor current sensor, the brake, An electronic brake system may be provided that includes a controller configured to calculate and determine a target motor speed value of a target position of a motor required to generate a target braking pressure corresponding to a pedal signal.

The control unit may calculate the target motor speed value for compensating for an error between the target braking pressure and the actual braking pressure corresponding to the brake pedal signal.

The controller may calculate the motor target current using the torque constant of the motor and the safety factor of the motor when generating the motor target current.

The controller may return the position of the motor to an initial position when the brake pedal signal is smaller than a preset threshold.

The controller may further determine whether the piston is returned to an initial position when a step out of the motor occurs.

According to another aspect of the invention, the step of receiving a brake pedal signal, the sensing value of the motor position sensor and the motor current sensor; And calculating, by calculating a target motor speed value, a target motor position required for generating a target braking pressure corresponding to the brake pedal signal when at least one of the motor position sensor and the motor current sensor has failed. An electronic brake control method may be provided.

The method may further include calculating the target motor speed value for compensating for the error between the target braking pressure and the actual braking pressure corresponding to the brake pedal signal.

The method may further include generating a target current, and may calculate the motor target current by using the torque constant of the motor and the safety factor of the motor.

The method may further include returning the position of the motor to an initial position when the brake pedal signal is smaller than a preset threshold.

The method may further include determining whether the piston is returned to an initial position when a step out of the motor occurs.

According to an embodiment of the present invention, the braking pressure required by the driver may be accurately generated by operating the motor without using the position sensor of the motor or the current sensor signal of the motor included in the electronic brake system.

Therefore, even when the position sensor of the motor or the current sensor signal of the motor is broken, the electronic brake system can be stably operated.

In addition, it is possible to minimize the noise caused by the motor operation of the electronic brake system.

1 is a hydraulic circuit diagram illustrating a non-braking state of an electronic brake system according to an exemplary embodiment.
2 is a block 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.
4A to 4D are graphs showing braking pressure, motor speed, motor current, and motor position with time during emergency control of the electronic brake system according to one embodiment.
5 is a flowchart illustrating an emergency control entry decision of the electronic brake system according to an exemplary embodiment.
6 is a flowchart illustrating an emergency 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 embodiments are presented to sufficiently convey the spirit of the present invention to those skilled in the art. The present invention is not limited to the embodiments presented herein but may be embodied in other forms. The drawings may omit illustrations of parts not related to the description in order to clarify the present invention, and may be exaggerated to some extent in order to facilitate understanding.

1 is a hydraulic circuit diagram showing a state during non-braking of an electronic brake system 1 according to an embodiment of the present invention. However, the electronic brake system 1 shown in FIG. 1 is merely an embodiment, and some configurations of the circuit may be different.

Referring to FIG. 1, the electronic brake system 1 typically includes a master cylinder 20 for generating hydraulic pressure, a reservoir 30 coupled to an upper portion of the master cylinder 20 to store oil, and a brake pedal ( An input rod 12 for pressing the master cylinder 20 according to the stepping force of 10), a wheel cylinder 40 for braking the wheels RR, RL, FR, and FL by transmitting hydraulic pressure, and a brake pedal A pedal displacement sensor 11 for detecting a displacement of the 10 and a simulation device 50 for providing a reaction force according to the stepping force of the brake pedal 10 are provided.

The master cylinder 20 may be configured to have at least one chamber to generate hydraulic pressure. For 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 an input rod 12. ) Can be connected. 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.

On the other hand, the master cylinder 20 can ensure safety in the case of failure by having two chambers. For example, one of the two chambers may be connected to the right front wheel FR and the left rear wheel RL of the vehicle, and the other chamber may be connected to the left front wheel FL and the right rear wheel RR. As such, the two chambers may be independently configured to allow braking of the vehicle even when one chamber fails.

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 first spring 21b is provided between the second piston 22a and the end of the master cylinder 20. Two springs 22b may be provided.

The first spring 21b and the second spring 22b are respectively provided in the two chambers, and as the displacement of the brake pedal 10 is changed, the first piston 21a and the second piston 22a are compressed and thus the first spring 21b and the second spring 22b are compressed. An elastic force is stored in the spring 21b and the second spring 22b. When the force pushing the first piston 21a is smaller than the elastic force, the first and second pistons 21a and 22a are pushed back using the elastic force stored in the first spring 21b and the second spring 22b. Can be.

On the other hand, the input rod 12 for pressing the first piston 21a of the master cylinder 20 may be in close contact with the first piston 21a. That is, there may be no gap between the master cylinder 20 and the input rod 12. Therefore, releasing the brake pedal 10 can directly press the master cylinder 20 without a pedal invalid stroke section.

The simulation apparatus 50 may be connected to the first backup passage 251 to be described later to provide a reaction force according to the stepping force of the brake pedal 10. By providing reaction force as much as compensating for the driver's effort, the driver can adjust the braking force precisely as intended.

Referring to FIG. 1, the simulation apparatus 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 force spring 53 to elastically support 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 range of displacement in the simulation chamber 51 by oil flowing into the simulation chamber 51.

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 force piston 52 is returned, the oil of the reservoir 30 is introduced through the simulator valve 54 so that the entire interior of the simulation chamber 51 may be filled with oil.

Meanwhile, several reservoirs 30 are shown in the figure, and each reservoir 30 uses the same reference numeral. However, these reservoirs may be provided with the same parts 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.

On the other hand, the simulator valve 54 may be configured as a normally closed solenoid valve to maintain the normally closed state. The simulator valve 54 may be opened when the driver applies the pedal force to the brake pedal 10 to transfer 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 so as to be connected in parallel with the simulator valve 54. The simulator check valve 55 allows the oil of the reservoir 30 to flow into the simulation chamber 51, but the oil of the simulation chamber 51 flows to the reservoir 30 through a flow path in which the check valve 55 is installed. Can be blocked. Since the oil can be supplied into the simulation chamber 51 through the simulator check valve 55 when the pedal pedal 10 releases the pedal effort, a quick return of the pedal simulator pressure can be ensured.

The hydraulic pressure supply device 100 includes a hydraulic pressure providing unit 110 providing oil pressure transmitted to the wheel cylinder 40, a motor 120 generating a rotational force by an electrical signal of the pedal displacement sensor 11, and a motor. It may include a power conversion unit 130 for converting the rotational movement of the 120 to a linear movement to transmit to the hydraulic pressure providing unit (110). Alternatively, the hydraulic pressure providing unit 110 may operate by the pressure provided by the high pressure accumulator, not the driving force supplied from the motor 120.

The electronic brake system 1 according to an embodiment of the present invention is a hydraulic pressure supply device 100 which is mechanically operated by receiving a driver's braking will as an electrical signal from a pedal displacement sensor 11 for detecting a displacement of the brake pedal 10. ) And a hydraulic control unit comprising first and second hydraulic circuits 201 and 202 for controlling the flow of hydraulic pressure delivered to the wheel cylinder 40 provided on the two wheels RR, RL, FR, and FL, respectively. A first cut valve 261 provided at a first backup flow path 251 connecting the first hydraulic port 24a and the first hydraulic circuit 201 to the 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 the hydraulic pressure, and the hydraulic pressure based on the hydraulic pressure information and the pedal displacement information. To control supply 100 and valves 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, 243 It may comprise a control unit (2000).

Overall control of the electronic brake system 1 of the electronic control unit 2000 can be performed.

As shown in FIG. 1 again, the hydraulic pressure providing unit 110 includes a cylinder block 111 in which a pressure chamber is stored and supplied with oil, a hydraulic piston 114 accommodated in the cylinder block 111, and hydraulic pressure. Sealing members 115 (115a and 115b) provided between the piston 114 and the cylinder block 111 to seal the pressure chamber, and connected to the rear end of the hydraulic piston 114 to output the power output from the power conversion unit 130. It includes a drive shaft 133 for transmitting to the hydraulic piston (114).

The pressure chamber is located at the front of the hydraulic piston 114 (forward direction, left side in the drawing), and the first pressure chamber 112 and behind of the hydraulic piston 114 (forward direction, right direction in the drawing). It may include a second pressure chamber 113. That is, the first pressure chamber 112 is partitioned by the front end of the cylinder block 111 and the hydraulic piston 114, is provided to vary in volume according to the movement of the hydraulic piston 114, the second pressure chamber 113 ) Is partitioned by the rear end of the cylinder block 111 and the hydraulic piston 114, it is provided so that the volume varies according to the movement of the hydraulic piston (114).

The first and second pressure chambers 112 and 113 are connected to the reservoir 30 by dump passages 116 and 117, respectively, and receive or store oil from the reservoir 30 or store the first or second pressure chamber ( Oils 112 and 113 may be delivered to reservoir 30.

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

The second hydraulic passage 212 may communicate with the first hydraulic circuit 201, and the third hydraulic passage 213 may communicate with the second hydraulic circuit 202. Therefore, the 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 the embodiment of the present invention is provided in the second and third hydraulic flow paths 212 and 213, respectively, to control the flow of oil, the first control valve 231 and the second control valve ( 232).

The first and second control valves 231 and 232 allow only oil flow 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. May be provided as a check valve for blocking. That is, the first or second control valves 231 and 232 allow the hydraulic pressure of the first pressure chamber 112 to be transmitted to the first or second hydraulic circuits 201 and 202 while the first or second hydraulic valves are used. 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 passages 212 and 213.

On the other hand, the fourth hydraulic passage 213 may be branched into the fifth hydraulic passage 215 and the sixth hydraulic passage 216 on the way and may communicate with both the first hydraulic circuit 201 and the second hydraulic circuit 202. . For example, the fifth hydraulic passage 215 branched from the fourth hydraulic passage 214 communicates with the first hydraulic circuit 201, and the sixth hydraulic passage 216 branched from the fourth hydraulic passage 214 is It may be in communication with the second hydraulic circuit 202. Therefore, the hydraulic pressure may be transmitted to both the first hydraulic circuit 201 and the second hydraulic circuit 202 by reversing the hydraulic piston 114.

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

The third control valve 233 may be provided as a bidirectional control valve for controlling oil flow between the second pressure chamber 113 and the first hydraulic circuit 201. The third control valve 233 is normally closed and may be provided as a normal closed solenoid valve that operates to open the valve when the open control signal is received from the electronic control unit 2000.

In addition, 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 may prevent the hydraulic pressure of the second hydraulic circuit 202 from leaking into the second pressure chamber 113 through the sixth hydraulic channel 216 and the fourth hydraulic channel 214. Can be.

In addition, the electronic brake system 1 according to the embodiment of the present invention is provided in the seventh hydraulic passage 217 connecting the second hydraulic passage 212 and the third hydraulic passage 213 to control the flow of oil. And a fifth control valve 235 and a sixth control valve 236 provided in the eighth hydraulic passage 218 connecting the second hydraulic passage 212 and the seventh hydraulic passage 217 to control the flow of oil. can do. In addition, the fifth control valve 235 and the sixth control valve 236 may be provided as a normal closed solenoid valve that is normally closed but operates to open the valve when receiving an open signal from the electronic control unit. have.

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

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 passage 212 and the third hydraulic passage 213 are provided as check valves that allow only one-way oil flow.

In addition, the electronic brake system 1 according to an embodiment of the present invention is provided in the first and second dump passages 116 and 117, respectively, to control the flow of oil, the first dump valve 241 and the second dump valve ( 242 may be further included. 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 opposite directions. 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, the second dump valve 242 allows the oil to flow from the reservoir 30 to the second pressure chamber 113, the oil from the second pressure chamber 113 to the reservoir 30 Flowing may be a check valve to shut off.

In addition, the second dump flow path 117 may include a bypass flow path, and the bypass flow path may include a third dump valve 243 for controlling 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 for controlling bidirectional flow, and is normally open, but is normally open and operates to close the valve upon receiving 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 embodiment of the present invention may operate in a double-acting manner. That is, the hydraulic pressure generated in the first pressure chamber 112 while the hydraulic piston 114 is advanced is transmitted to the first hydraulic circuit 201 through the first hydraulic passage 211 and the second hydraulic passage 212 to the right. The wheel cylinder 40 installed on the front wheel FR and the left rear wheel LR may be actuated and transferred to the second hydraulic circuit 202 through the first hydraulic channel 211 and the third hydraulic channel 213. The wheel cylinder 40 is installed on the right rear wheel RR and the left front wheel FL.

Similarly, the hydraulic pressure generated in the second pressure chamber 113 while the hydraulic piston 114 is retracted is transmitted to the first hydraulic circuit 201 through the fourth hydraulic channel 214 and the fifth hydraulic channel 215 to the right. The wheel cylinder 40 installed on the front wheel FR and the left rear wheel LR can be actuated and transferred to the second hydraulic circuit 202 through the fourth hydraulic channel 214 and the sixth hydraulic channel 216. The wheel cylinder 40 is installed on the right rear wheel RR and the left front wheel FL.

In addition, the negative pressure generated in the first pressure chamber 112 while the hydraulic piston 114 is reversed sucks oil from the wheel cylinders 40 installed at the right front wheel FR and the left rear wheel LR, and thus the first hydraulic circuit. The wheel 201, the second hydraulic passage 212, and the first hydraulic passage 211 may be transferred to the first pressure chamber 112 and are provided on the right rear wheel RR and the left front wheel FL. The oil of the cylinder 40 may be sucked and transferred to the first pressure chamber 112 through the second hydraulic circuit 202, the third hydraulic channel 213, and the first hydraulic channel 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 for generating a rotational force by a signal output from the electronic control unit 2000 and may generate the rotational force in a forward or reverse direction. Rotational angular velocity and rotational angle of the motor 120 can be precisely controlled.

That is, the motor 120 may further include a motor position sensor MPS for measuring the rotational angular velocity and the rotational angle of the motor 120 to transmit the rotational angle or other position information of the motor 120 to the electronic control unit 2000.

On the other hand, the electronic control unit 2000 includes the motor 120, the valves 54, 60, 221a, 221b, constituting a plurality of valves 800 provided in the electronic brake system 1 of the present invention to be described later, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, and 243.

In addition, the operation of controlling the plurality of valves according to the displacement of the brake pedal 10 will be described later.

The driving force of the motor 120 generates the displacement of the hydraulic piston 114 through the power converter 130, and the hydraulic pressure generated while the hydraulic piston 114 slides in the pressure chamber is the first and second hydraulic flow paths. It is transmitted to the wheel cylinder 40 installed in each wheel RR, RL, FR, FL via 211, 212.

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

That is, while the displacement occurs in the brake pedal 10, a signal sensed by the pedal displacement sensor 11 is transmitted to the electronic control unit 2000, and the electronic control unit 2000 drives the motor 120 in one direction. By rotating the worm shaft 131 in one 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 forward to generate hydraulic pressure in the first pressure chamber 112.

On the contrary, when the stepping force is removed from the brake pedal 10, the electronic control unit 2000 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 generates negative pressure in the first pressure chamber 112 while the hydraulic piston 114 connected to the drive shaft 133 returns (reverses moving).

On the other hand, the hydraulic and negative pressure can be generated in the opposite direction. That is, while the displacement occurs in the brake pedal 10, a signal sensed by the pedal displacement sensor 11 is transmitted to the electronic control unit 2000, and the electronic control unit 2000 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 to generate hydraulic pressure in the second pressure chamber 113.

On the contrary, when the stepping force is removed from the brake pedal 10, the electronic control unit 2000 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 generates negative pressure in the second pressure chamber 113 while the hydraulic piston 114 connected to the drive shaft 133 is returned (moving forward).

As such, the hydraulic pressure supply device 100 serves to transfer the hydraulic pressure to the wheel cylinder 40 or to suck the hydraulic pressure to the reservoir 30 according to the rotational 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. Whether to release the brake by controlling the valves 54, 60, 221a, 221b, 221c, 221d, 222a, 222b, 222c, 222d, 233, 235, 236, and 243 constituting the plurality of valves 800. Can be determined.

And the power conversion unit 130 according to an embodiment of the present invention should be understood as being capable of employing any structure if the rotational motion in addition to the structure of the ball screw nut assembly can be converted to linear motion.

The first backup passage 251 may be provided with a first cut valve 261 for controlling the flow of oil, and the second backup passage 252 may be provided with a second cut valve 262 for controlling the flow of oil. have. 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 may be connected.

The first and second cut valves 261 and 262 may be provided as normal open type solenoid valves that are open in a normal state and operate to close the valve when the closing signal is received from the electronic control unit. have.

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

The hydraulic control unit 200 may be configured of a first hydraulic circuit 201 and a second hydraulic circuit 202 which receive hydraulic pressure to 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. . Each wheel FR, FL, RR, and RL has wheel cylinders 40 installed therein to be supplied with hydraulic pressure to perform braking.

The first hydraulic circuit 201 is connected to the first hydraulic passage 211 and the second hydraulic passage 212 to receive the hydraulic pressure from the hydraulic pressure supply device 100, and the second hydraulic passage 212 is the right front wheel FR And two flow paths connected to the left rear wheel RL. Similarly, the second hydraulic circuit 202 is connected to the first hydraulic passage 211 and the third hydraulic passage 213 to receive the hydraulic pressure from the hydraulic pressure supply device 100, and the third hydraulic passage 213 is the left front wheel. It branches into two flow paths connected to FL and the right rear wheel RR.

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

The inlet valve 221 is disposed upstream of the wheel cylinder 40 and is open in a normal state, and operates to close the valve upon receiving the closing signal from the electronic control unit 2000. It can be provided with a solenoid valve of.

In addition, the hydraulic circuits 201 and 202 may include check valves 223a, 223b, 223c, and 223d provided in a bypass flow path connecting the front and rear of the respective inlet valves 221a, 221b, 221c, and 221d. Can be. 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 the oil from the hydraulic pressure providing unit 110 toward the wheel cylinder 40. The flow of can be arranged to limit. The check valves 223a, 223b, 223c, and 223d are able to quickly release the braking pressure of the wheel cylinder 40, and the wheel cylinders when the inlet valves 221a, 221b, 221c, and 221d do not operate normally. The hydraulic pressure of the 40 may 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, and 222d connected to the reservoir 30 to improve performance when the brakes are released. The outlet valves 222 are connected to the wheel cylinders 40, respectively, to control the hydraulic pressure from the wheels RR, RL, FR, and FL. That is, the outlet valve 222 senses the braking pressure of each wheel (RR, RL, FR, FL) to selectively open when the decompression braking is required to control the pressure.

The outlet valve 222 is normally closed and may be provided as a normal closed solenoid valve that operates to open the valve upon receiving an open signal from the electronic control unit.

In addition, the hydraulic control unit 200 may be connected to the backup passage (251, 252). For example, the first hydraulic circuit 201 is connected to the first backup passage 251 to receive hydraulic pressure from the master cylinder 20, and the second hydraulic circuit 202 is connected to the second backup passage 252. The hydraulic pressure may be provided from the master cylinder 20.

In this case, 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 may be 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 may be supplied to the wheel cylinder 40 through the first and second backup passages 251 and 252. Can be. At this time, the plurality of inlet valves (221a, 221b, 221c, 221d) is an open state, it is not necessary to switch the operating state.

In particular, the first hydraulic circuit 201, the second hydraulic circuit 202, and the inlet valve 221 are disposed upstream of the wheel cylinder 40 and open in the normal state, and then closed in the electronic control unit 2000. A pressure sensor that measures the pressure of the circuit on the top of the inlet valves 221c and 221d of the second hydraulic circuit 202 when provided as a normal open solenoid valve that operates to close the valve upon receiving a signal. ps1 may be installed.

2 is an internal block diagram of the electronic brake system 1 according to an embodiment of the present invention, which is included in the electronic control unit 2000 and the electronic brake system 1 which collectively control the electronic brake system 1. It is a block diagram showing a state connected to the brake device 1000, Figure 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 may include an input unit 102, a determination unit 104, a calculation unit 106, and a control unit 108. Include.

The input unit 102 includes a motor position sensor 121, a motor current sensor 122, a motor 120, a brake pedal 10, a piston 114, a pressure sensor ps, and an inlet valve of the brake device 1000. 221, etc., receives an operation signal.

Here, the brake device 1000 may be an integrated dynamic brake (IDB) for generating the boosting pressure and the braking pressure with one motor 121, and may be all the brake means for generating the braking pressure with the motor. That is, the electronic brake system 1 shown in FIG. 1 may correspond to this.

Although not shown, the motor 121 may be a permanent magnet synchronous motor (not shown), and the permanent magnet synchronous motor (not shown) may be a permanent magnet synchronous motor (not shown) and a surface-mounted permanent magnet synchronous motor. It may be at least one of (not shown).

Next, the control unit 108 in the electronic control unit 2000 is a case in which the sensor value of the motor position sensor 121 and the sensor value of the motor current sensor 122 input through the input unit 102 are not obtained. According to an embodiment, the electronic brake system 1 normally generates a braking pressure.

For example, when the motor position sensor 121 or the motor current sensor 122 does not operate normally, the controller 108 may set the target pressure based on the pedal effort obtained through the pedal pedal effort of the brake pedal 10. have.

In addition, the controller 108 may secure the pressure according to the pedal effort, and monitor the pressure generated in the circuit based on the plurality of pressure sensors PS included in the brake device 1000.

Specifically, the controller 108 receives the target pressure set from the pedal effort of the brake pedal 10, the pressure value of the pressure sensor, and the chattering detection result of the DC link voltage, 1) a preparation mode, Determine 2) operation mode and 3) return mode.

At this time, detecting whether or not the DC link voltage chattering, if the piston is in contact with the rear wall in the process of returning the piston 112 to the initial position in the return mode to be described later ripple occurs in the DC link voltage It can be detected based on the occurrence of (Ripple).

First, the controller 108 1) drives the motor 120 in the idle state in the preparation mode, and monitors the target braking pressure corresponding to the pedal input of the driver in real time. At this time, the Idle state driving of the motor 120 means driving the drive voltage of the motor 120 to 0 [v] or driving the drive current of the motor 120 to 0 [A].

However, the controller 108 1) when the brake pedal 10 pedal force is applied from the driver in the ready mode state, 2) switches to the operation mode.

Next, the controller 108 starts controlling to follow the target pressure according to the brake pedal 10 pedaling force from the driver in the 2) operation mode. Specifically, the controller 108 may calculate the speed of the motor 120 for following the target pressure.

In addition, the calculation unit 106 calculates the torque of the motor 120 required to generate the target pressure generated from the driver's pedal input, and converts it to the current of the motor 120, from the value obtained by adding the safety factor and the offset current. The target pressure can be determined linearly.

However, instead of calculating the target pressure linearly, the calculator 106 may determine the target pressure to ensure that a current larger than the actual current required when driving the motor.

For example, when determining the target current of the motor 120, the controller 108 is 1) 0 [A] in the ready mode, 2) the motor required to generate the target pressure generated from the pedal input of the driver in the operation mode It is determined to output the current of 120, and 3) in the return mode, it may be determined to output a preset threshold current (for example, 10 [A]).

In addition, the controller 108 may output the speed of the motor 120 to compensate for the error by comparing the target pressure and the pressure sensor input. For example, the speed of the motor 120 according to the PID control technique may be adjusted. You can print

For example, when the controller 108 determines the target speed of the motor 120, the controller 108 1) compensates the error between the target pressure and the pressure sensor input in 0 [rpm] in the preparation mode and 2) in the operation mode. It is determined by the speed of the motor 120 calculated in order to, and 3) in the return mode can be determined to output a predetermined threshold speed (for example, 1000 [rpm]).

However, when the target speed of the motor 120 is input, the controller 108 limits the preset motor speed to the maximum rate of change of the maximum speed Max and the rate of change of the motor speed to a maximum rate of change of the motor speed. 120 may prevent synchronous outages from occurring.

In addition, the calculator 106 may calculate the position information of the motor through integration based on the speed of the motor 120.

Therefore, based on the following [Equation 1], the target voltage can be calculated through the target current and the target speed.

[Equation 1]

At this time, V _d Is the motor phase resistance, λ _f is the motor back EMF constant, L is the motor inductance, I _ref is the target motor current, ω is the target motor speed, and Vd is the target d-phase voltage of the motor. Vq means the target q-phase voltage of the motor.

Accordingly, the calculation unit 108 calculates the target d-phase voltage of the motor and the target q-phase voltage of the motor calculated based on [Equation 1], and based on [Equation 2], the target voltage of each phase of the three-phase motor. Convert to (V _an , V _bn , V _cn ).

[Equation 2]

In addition, the calculator 108 receives the target voltages V _an , V _bn , V _cn ) and the DC link voltage of each phase of the output three-phase motor, and synthesizes a PWM (Pulse Width Modulation) duty ratio. However, when synthesizing the PWM duty ratio, the duty ratio may be synthesized by applying various techniques such as Space Vector PulseWidth Modulation (SVWWM) or Discontinuous PulseWidth Modulation (DPWM).

In addition, the controller 108 may output the speed of the motor 120 to compensate for the error by comparing the target pressure and the pressure sensor input. For example, the speed of the motor 120 according to the PID control technique may be adjusted. You can print

Therefore, the controller 108 may drive the motor 120 according to the speed of the motor 120 calculated by the calculator 106 based on [Equation 1] to follow the target pressure.

In addition, the controller 108 starts to control the target pressure to 0 [bar] when the pedal effort of the brake pedal 10 disappears while following the target pressure. That is, in one embodiment, when the pedal effort is lost, the controller 108 controls the target pressure to 0 [bar], so that the pressure measured by the pressure sensor ps is set to a predetermined threshold pressure (for example, 5). lower than [bar]), 3) switch to return mode.

Next, the controller 108 returns the motor position to the initial position in the 3) return mode step. The initial position is to return the position of the piston 112 driven by the motor 120 of the electronic brake system 1 to the initial position, and when the piston is moved backward to come into contact with the rear wall, the initial position is assumed.

In particular, the control unit 108 retreats the piston for a preset movement time (critical movement time) at the set speed (critical motor speed) of the motor preset in the 3) return mode step, or when more than that has elapsed. The unit 104 determines that the motor 120 has reached the initial position. However, even if the control unit 108 reverses the piston at the critical motor speed during the critical movement time in the 3) return mode step, the piston 112 touches the rear wall to detect the synchronous outage of the permanent magnet synchronous motor. 104 may determine that motor 120 has reached its initial position.

Therefore, when the determination unit 104 determines that the motor 120 has reached the initial position, the controller 108 changes the 3) return mode to 1) the ready mode.

In addition, if the pedal 108 is re-applied during the 3) return mode step, the controller 108 may switch to the 2) operation mode.

Next, FIG. 4 is a graph illustrating braking pressure, motor speed, motor current, and motor position over time in emergency control of the electronic brake system according to an exemplary embodiment.

Specifically, Figure 4a is a graph showing the braking pressure with time during the emergency control, Figure 4b is a graph showing the motor speed with time during the emergency control, Figure 4c is a graph showing the motor current over time, Figure 4d is a graph showing the motor position over time.

At this time, the emergency control according to an embodiment of the present invention, when at least one or more of the motor position sensor 121 or the motor current sensor 122 included in the motor is a failure, the motor so that the braking control is normally performed It means a method for controlling.

The dotted line in FIG. 4A is the target pressure calculated by measuring the pedal force applied to the pedal by the driver at the target pressure, and the solid line is the generated pressure. The motor speed, the motor current, and the motor position control of FIGS. 6B to 6D are shown. The production pressure can be obtained.

In particular, the speed of the motor illustrated in FIG. 4B is that the controller 108 may compare the target pressure and the pressure sensor input to output the speed of the motor 120 to compensate for an error. It can output the speed of the motor 120 according to.

In addition, as the d-phase and q-phase currents of the motor shown in FIG. 4C, a phase current is calculated based on [Equation 1], and FIG. 4D is a graph showing the position of the motor obtained by integrating the motor speed.

It can be seen that the position of the motor is 1) the initial position of the piston in the ready mode, 2) the piston moves and is pressurized in the operation mode, and 3) the piston returns to the initial position in the return mode.

In the above, the structure which operates by receiving the sensor value of the various sensors contained in the brake apparatus 1000 of the electronic control unit 2000 was demonstrated.

Hereinafter, the operation of the electronic brake system 1 will be described. First, FIG. 5 is a flowchart illustrating an emergency control entry determination of an electronic brake system according to an embodiment, and FIG. 6 is a flowchart illustrating an emergency control method of an electronic brake system according to an embodiment.

First, as shown in FIG. 5, the electronic brake system 1 according to an exemplary embodiment obtains a motor position sensor value A from the motor position sensor 121 (500), and obtains the motor current sensor 122 from the motor current sensor 122. The motor current sensor value B is obtained (510). At this time, acquiring the motor position sensor value and acquiring the motor current sensor value may be performed in parallel.

Even if at least one of the motor current sensor and the motor position sensor has failed (Yes of 520), the electronic brake system may operate the motor normally to form a desired braking pressure.

Therefore, when the motor position sensor value A or the motor position sensor value B has failed, the emergency control described later in FIG. 6 is entered (530).

Specifically, when it is input 600 to perform the emergency control entry mode in the electronic control unit 2000 of the electronic brake system 1 according to an embodiment, the input unit 102 obtains a pedal effort (610), The controller 108 determines a target pressure corresponding to the obtained pedal effort (530).

In particular, the controller 108 calculates the current of the motor based on [Equation 1] and calculates the phase current value of the motor determined by [Equation 1] to control the motor speed according to the determined target pressure. In addition, the speed of the motor may be secured to determine the position of the motor according to the integration of the speed of the motor.

However, the controller 108 moves the motor position to the initial position when the pedal effort becomes less than the preset first pedal effort (Yes of 640).

Although one embodiment of the disclosed invention has been illustrated and described above, the disclosed invention is not limited to the specific embodiments described above, and those skilled in the art without departing from the scope of the claims. Of course, various modifications can be made by the above, and these modifications can not be individually understood from the disclosed invention.

Claims (10)

An input unit configured to receive a brake pedal signal and receive sensing values of a motor position sensor and a motor current sensor;
And a controller configured to calculate a target motor speed value and determine a target position of a motor required to generate a target braking pressure corresponding to the brake pedal signal when at least one of the motor position sensor and the motor current sensor is faulty. Electronic brake system. The method of claim 1,
The control unit,
And calculate the target motor speed value for compensating for an error between the target braking pressure and the actual braking pressure corresponding to the brake pedal signal. The method of claim 2,
The control unit,
The electronic brake system calculates the motor target current using the torque constant of the motor and the safety factor of the motor when generating the motor target current. The method of claim 3, wherein
The control unit,
And return the position of the motor to the initial position when the brake pedal signal is smaller than a preset threshold. The method of claim 4, wherein
The control unit,
And if it is in the state that out of the motor has occurred, it is further determined whether the piston is returned to the initial position. Receiving a brake pedal signal and receiving sensing values of a motor position sensor and a motor current sensor; And
Calculating a target motor speed value to determine a target position of a motor required to generate a target braking pressure corresponding to the brake pedal signal when at least one of the motor position sensor or the motor current sensor fails. Electronic brake control method. The method of claim 6,
And calculating the target motor speed value for compensating for an error between the target braking pressure and the actual braking pressure corresponding to the brake pedal signal. The method of claim 3, wherein
Generating a motor target current;
Electronic brake control method for calculating the target motor current by using the torque constant of the motor and the safety coefficient of the motor. The method of claim 8,
And returning the position of the motor to an initial position when the brake pedal signal is smaller than a preset threshold value. The method of claim 9,
And determining whether the piston is returned to an initial position when a step out of the motor occurs.

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