JPWO2019021535A1 - Brake system for vehicles - Google Patents

Abstract

The present invention provides a vehicle brake system including an electric brake. The vehicle brake system 1 includes electric brakes 16a to 16d including motors 80 to 85, and a plurality of controllers (30, 40, 41, 50) connected to each other and controlling the motors 80 to 85. The vehicle brake system 1 includes load sensors 6a to 6d that detect load values that act on the electric brakes 16a to 16d, and current sensors 70 to 75 that detect current values supplied to the motors 80 to 85. The controller (30, 40, 41, 50) can control the motors 80 to 85 based on the load values detected by the load sensors 6a to 6d, and is estimated from the current values of the current sensors 70 to 75. The motors 80 to 85 can be controlled based on the load value.

Description

The present invention relates to a vehicle brake system including an electric brake.

As a vehicle brake system, an electric brake system has been proposed in which an electric motor advances and retracts a pressing member relative to a friction pad (Patent Document 1). In this electric brake system, the supply current to the electric motor is controlled based on the detection value of the pressing force sensor, and the braking force according to the brake operation amount of the driver is obtained.

JP, 2000-213575, A

An object of the present invention is to provide a vehicle brake system including an electric brake.

The present invention has been made to solve at least a part of the problems described above, and can be realized as the following aspects or application examples.

[1]
One aspect of the vehicle brake system according to the present invention is
A vehicle brake system comprising: an electric brake including at least one electric actuator for pressing a friction pad toward a rotor; and a plurality of controllers that are mutually connected to control the electric actuator,
A load sensor for detecting a load value acting on the electric brake,
A current sensor for detecting a current value supplied to the electric actuator,
Including
The controller can control the electric actuator based on a load value detected by the load sensor, and can control the electric actuator based on an estimated load value estimated from a current value of the current sensor. It is characterized by

According to one aspect of the vehicle brake system described above, the controller can control the electric actuator based on the load value based on the load sensor and the estimated load value based on the current sensor. Therefore, redundancy of the system is improved and reliability is improved. Can be improved.

[2]
In one aspect of the vehicle brake system described above,
The electric actuator may be controllable based on the estimated load value corrected using the load value detected by the load sensor.

According to one aspect of the vehicle brake system described above, the estimation accuracy of the estimated load value is improved by correcting the estimated load value based on the current sensor, and the reliability of the system can be further improved.

[3]
In one aspect of the vehicle brake system described above,
The electric actuator may be controllable based on the estimated load value when the load sensor fails.

According to one aspect of the vehicle brake system described above, the electric actuator can be controlled based on the estimated load value even if the load sensor fails, and the redundancy of the system can be improved and the reliability can be improved. ..

FIG. 1 is an overall configuration diagram showing a vehicle brake system according to the present embodiment. FIG. 2 is a block diagram showing the master controller, the first and second sub-controllers, and the slave controller of the vehicle brake system according to the present embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The drawings used for this description are for convenience of description. It should be noted that the embodiments described below do not unduly limit the content of the invention described in the claims. Moreover, not all of the configurations described below are essential configuration requirements of the invention.

The vehicle brake system according to the present embodiment includes an electric brake that includes at least one electric actuator that presses the friction pad toward the rotor, and a plurality of controllers that are connected to each other and that control the electric actuator. The vehicle brake system includes a load sensor that detects a load value that acts on the electric brake, and a current sensor that detects a current value supplied to the electric actuator, and the controller detects the load sensor. It is possible to control the electric actuator based on a load value of the electric sensor and to control the electric actuator based on an estimated load value estimated from a current value of the current sensor.

1. Vehicle Brake System A vehicle brake system 1 according to the present embodiment will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is an overall configuration diagram showing a vehicle brake system 1 according to the present embodiment, and FIG. 2 is a master controller 30, first and second sub-controllers 40, 41 of the vehicle brake system 1 according to the present embodiment. 4 is a block diagram showing a slave controller 50. FIG.

As shown in FIG. 1, the vehicle brake system 1 and electric brakes 16a to 16d each including at least one motor 80 to 85, which is an electric actuator for pressing a friction pad (not shown) toward a rotor (not shown), are mutually connected. A plurality of controllers (master controller 30, first sub-controller 40, second sub-controller 41, slave controller 50) that are connected and control the motors 80 to 85 that are electric actuators are provided. The vehicle brake system 1 further includes drivers 60 to 65 that drive the motors 80 to 85, and control devices (10, 11) that include a plurality of controllers. A rotor (not shown) is provided on each wheel Wa to Wd of the vehicle VB, which is a four-wheeled vehicle, and rotates integrally with the wheels Wa to Wd. The vehicle VB is not limited to the four-wheeled vehicle. Further, one electric brake may be provided with a plurality of motors, and one wheel may be provided with a plurality of electric brakes.

1-1. Electric Brake The electric brake 16a provided on the front left wheel (FL) wheel Wa includes a brake caliper 5a, motors 80 and 81 fixed to the brake caliper 5a via a speed reducer 4a, and the electric brake 16a by the motors 80 and 81. A load sensor 6a for detecting a load value acting on the. The motor 80 includes a rotation angle sensor 90 that detects the relative position of the rotation shaft with respect to the stator itself. Since the motor 81 is coaxial with the motor 80, a rotation angle sensor is unnecessary. The detection signal of the load sensor 6a is input to the first sub controller 40 and also to the master controller 30 via the first sub controller 40. The detection signal of the rotation angle sensor 90 is input to the drivers 60 and 61.

The electric brake 16b provided on the front wheel right (FR) wheel Wb acts on the brake caliper 5b, the motors 82 and 83 fixed to the brake caliper 5b via the speed reducer 4b, and the motors 82 and 83. A load sensor 6b for detecting a load value to be applied. The motor 82 includes a rotation angle sensor 92 that detects the relative position of the rotation shaft with respect to the stator itself. Since the motor 83 is coaxial with the motor 82, a rotation angle sensor is unnecessary. The detection signal of the load sensor 6b is input to the slave controller 50 and also to the master controller 30, the first sub-controller 40, and the second sub-controller 41 via the slave controller 50. The detection signal of the rotation angle sensor 92 is input to the drivers 62 and 63.

The electric brake 16c provided on the rear wheel left (RL) wheel Wc includes a brake caliper 5c, a motor 84 fixed to the brake caliper 5c via a speed reducer 4c, and a load value applied to the electric brake 16c by the motor 84. And a load sensor 6c for detecting The motor 84 includes a rotation angle sensor 94 that detects the relative position of the rotation shaft with respect to the stator itself. The detection signal of the load sensor 6c is input to the second sub controller 41, and also to the master controller 30 and the first sub controller 40 via the second sub controller 41. The detection signal of the rotation angle sensor 94 is input to the driver 64.

The electric brake 16d provided on the rear wheel right (RR) wheel Wd includes a brake caliper 5d, a motor 85 fixed to the brake caliper 5d via a speed reducer 4d, and a load value applied to the electric brake 16d by the motor 85. And a load sensor 6d for detecting The motor 85 includes a rotation angle sensor 95 that detects the relative position of the rotation shaft with respect to the stator itself. The detection signal of the load sensor 6d is input to the second sub-controller 41 and also to the master controller 30 and the first sub-controller 40 via the second sub-controller 41. The detection signal of the rotation angle sensor 95 is input to the driver 65.

Each of the brake calipers 5a to 5d is integrally provided with a claw portion formed in a substantially C shape and extending to the opposite side across a rotor (not shown).

The speed reducers 4a to 4d are fixed to the brake calipers 5a to 5d and transmit the torque generated by the rotation of the motors 80 to 85 to a linear motion mechanism (not shown) incorporated in the brake calipers 5a to 5d.

As the linear motion mechanism, a known mechanism in an electric brake can be adopted. The linear motion mechanism converts the rotation of the motors 80 to 85 into the linear motion of the friction pad via the speed reducers 4a to 4d. The linear motion mechanism presses the friction pad against the rotor to suppress the rotation of the wheels Wa to Wd.

A well-known electric motor can be adopted as the motors 80 to 85, and is, for example, a brushless DC motor. By driving the motors 80 to 85, the friction pads are moved via the speed reducers 4a to 4d and the linear motion mechanism. An example in which a motor is adopted as the electric actuator will be described, but the present invention is not limited to this, and other known actuators may be adopted.

The load sensors 6a to 6d detect load values acting on the electric brakes 16a to 16d. The load sensors 6a to 6d are attached to predetermined positions of the electric brakes 16a to 16d, and may be, for example, those that detect a load value applied to a friction pad (not shown), or the brake calipers 5a to 5d. The acting reaction force may be detected as a load value. The load value may be a value corresponding to the braking force of the electric brakes 16a to 16d. As the load sensors 6a to 6d, known sensors such as strain gauge type and piezoelectric type can be used.

The current sensors 70 to 75 constantly detect the current value supplied to the motors 80 to 85. The current sensors 70-75 may be incorporated within the drivers 60-65.

1-2. Input Device The vehicle brake system 1 includes a brake pedal 2, which is an input device, and a stroke simulator 3 connected to the brake pedal 2. The brake pedal 2 includes a second stroke sensor 21 and a third stroke sensor 22 that detect the amount of operation of the brake pedal 2 by the driver. The stroke simulator 3 includes a first stroke sensor 20 that detects the operation amount of the brake pedal 2.

Each of the stroke sensors 20 to 22 independently generates an electrical detection signal corresponding to a stepping stroke and/or a pedaling force, which is a kind of the operation amount of the brake pedal 2. The first stroke sensor 20 transmits a detection signal to a master controller 30 described later, the second stroke sensor 21 transmits a detection signal to a first sub controller 40 described later, and the third stroke sensor 22 is a second sub controller described later. The detection signal is transmitted to 41.

The vehicle VB includes a plurality of control devices (hereinafter referred to as “other control device 1000”) provided in a system other than the vehicle brake system 1 as an input device to the vehicle brake system 1. The other control device 1000 is connected to the master controller 30 of the first control device 10 and the second sub-controller 41 of the second control device 11 by CAN (Controller Area Network), and communicates information regarding brake operation with each other. ..

1-3. Control Device The control device includes a first control device 10 and a second control device 11. The first control device 10 is arranged at a predetermined position of the vehicle VB independently of the second control device 11. The first control device 10 and the second control device 11 are electronic control units (ECU). Each of the first control device 10 and the second control device 11 is housed in a housing made of synthetic resin. Therefore, redundancy is provided by the two control devices, the first control device 10 and the second control device 11. Although an example in which two control devices are used will be described, the number may be one in consideration of the arrangement in the vehicle VB, or three or more in order to further increase redundancy.

The first control device 10 and the second control device 11 are connected by CAN and communication is performed. In CAN communication, unidirectional and bidirectional information is transmitted. The communication between ECUs is not limited to CAN.

The first control device 10 and the second control device 11 are electrically connected to three batteries 100, 101, 102 that are independent of each other. The batteries 100, 101, 102 supply electric power to electronic components included in the first control device 10 and the second control device 11. The batteries 100, 101, 102 of the vehicle brake system 1 are arranged at predetermined positions of the vehicle VB.

The first control device 10 includes at least one master controller 30 and at least one first sub-controller 40, and the second control device 11 includes at least one sub-controller (second sub-controller 41). By mounting the master controller 30 and the first sub-controller 40 on the first control device 10, redundancy and reliability of the first control device 10 are improved. The first controller 10 further includes a slave controller 50. The cost can be reduced by using the inexpensive slave controller 50. The combination of the master controller 30, the first sub controller 40, the second sub controller 41, and the slave controller 50 is an example, and the combination is not limited to this. For example, a first slave controller and a second slave controller may be provided instead of the first sub controller 40 and the second sub controller 41, a sub controller may be provided instead of the slave controller 50, and the first sub controller may be provided. Instead of the controller 40, the second sub controller 41, and the slave controller 50, a plurality of master controllers 30 can be provided.

The master controller 30, the first and second sub-controllers 40 and 41, and the slave controller 50 are each a microcomputer.

The first controller 10 includes a master controller 30, a first sub controller 40, and a slave controller 50. While achieving redundancy by using a plurality of controllers, cost reduction can be realized because a plurality of relatively expensive master controllers are not mounted. The master controller 30 requires a high performance in order to provide the behavior control unit 303 (the behavior control unit 303 will be described later), and is a relatively expensive controller as compared with the first and second sub-controllers 40 and 41.

As shown in FIGS. 1 and 2, the master controller 30 includes a driver control unit 301 that controls the drivers 61 and 63, a braking force calculation unit 302 that calculates the braking forces of the electric brakes 16a to 16d, and a behavior of the vehicle VB. A behavior control unit 303 that controls the load control unit and a load estimation unit 305 that estimates a load value acting on the electric brakes 16a and 16b.

The first sub-controller 40 includes a driver control unit 400 that controls the driver 60, a braking force calculation unit 402 that calculates braking forces of the electric brakes 16a to 16d, and a load estimation unit that estimates a load value that acts on the electric brake 16a. 405 and. The second sub-controller 41 estimates the driver control unit 410 that controls the drivers 64 and 65, the braking force calculation unit 412 that calculates the braking force of the electric brakes 16a to 16d, and the load value that acts on the electric brakes 16c and 16d. Load estimating unit 415 for

The slave controller 50 does not have a braking force calculation unit, and controls the driver 62 based on the braking force calculation result of the master controller 30 and at least one controller of the first and second sub-controllers 40 and 41. The unit 500 and a load estimating unit 505 that estimates a load value acting on the electric brake 16b are included. Since the slave controller 50 does not have a braking force calculator, a relatively inexpensive microcomputer can be adopted as compared with the first and second sub-controllers 40 and 41.

The drivers 60-65 control the driving of the motors 80-85. Specifically, the driver 60 controls the drive of the motor 80, the driver 61 controls the drive of the motor 81, the driver 62 controls the drive of the motor 82, the driver 63 controls the drive of the motor 83, and the driver 63 Reference numeral 64 controls the drive of the motor 84, and driver 65 controls the drive of the motor 85. The drivers 60 to 65 control the motors 80 to 85 by, for example, a sine wave driving method. Further, the drivers 60 to 65 are not limited to the sine wave driving method, and may be controlled by, for example, a rectangular wave current.

The driver 60 includes a current sensor 70 that detects a current value supplied to the motor 80, and a detection signal of the current sensor 70 is input to the first sub controller 40. The driver 61 has a current sensor 71 that detects a current value supplied to the motor 81, and a detection signal of the current sensor 71 is input to the master controller 30. The driver 62 has a current sensor 72 that detects a current value supplied to the motor 82, and a detection signal of the current sensor 72 is input to the slave controller 50. The driver 63 has a current sensor 73 that detects a current value supplied to the motor 83, and a detection signal of the current sensor 73 is input to the master controller 30. The driver 64 has a current sensor 74 that detects a current value supplied to the motor 84, and a detection signal of the current sensor 74 is input to the second sub controller 41. The driver 65 has a current sensor 75 that detects a current value supplied to the motor 85, and a detection signal of the current sensor 75 is input to the second sub controller 41.

The drivers 60-65 include power supply circuits and inverters that supply electric power to the motors 80-85 in accordance with commands from the driver control units 301, 400, 410, 500.

The braking force calculation units 302, 402, 412 calculate the braking force (required value) based on the detection signals of the stroke sensors 20 to 22 according to the operation amount of the brake pedal 2. Further, the braking force calculation units 302, 402, 412 can calculate the braking force (required value) based on signals from other control devices 1000.

Each controller (30, 40, 41, 50) can control the motors 80 to 85 based on the load values detected by the load sensors 6a to 6d, and is estimated from the current values of the current sensors 70 to 75. The motors 80 to 85 can be controlled based on the estimated load value. Since each controller (30, 40, 41, 50) can control the motors 80 to 85 by the load value based on the load sensors 6a to 6d and the estimated load value based on the current sensors 70 to 75, the load sensor 6a should be used. Even if ~6d fails, the motors 80-85 can be controlled based on the estimated load value, and the redundancy of the system can be improved and the reliability can be improved.

The driver control units 301, 400, 410, 500 drive the driver 60 based on the braking force (request value) calculated by the braking force calculation units 302, 402, 412 and the detection signals (load value) of the load sensors 6a to 6d. Control ~65. The drivers 60-65 supply the driving sine wave currents to the motors 80-85 in accordance with commands from the driver control units 301, 400, 410, 500. The current value supplied to the motors 80 to 85 is detected by the current sensors 70 to 75. The specific control of each controller (30, 40, 41, 50) is as follows.

The driver control unit 301 of the master controller 30 controls the drivers 61 and 63 based on the braking force (request value) calculated by the braking force calculation unit 302 and the detection signals (load value) of the load sensors 6a and 6b. The drivers 61 and 63 supply driving sine wave currents to the motors 81 and 83 in accordance with a command from the driver control unit 301. The current value supplied to the motors 81 and 83 is detected by the current sensors 71 and 73.

The driver control unit 400 of the first sub-controller 40 controls the driver 60 based on the braking force (request value) calculated by the braking force calculation unit 402 and the detection signal (load value) of the load sensor 6a. The driver 60 supplies a driving sine wave current to the motor 80 according to a command from the driver control unit 400. The current value supplied to the motor 80 is detected by the current sensor 70.

The driver control unit 410 of the second sub-controller 41 controls the drivers 64 and 65 based on the braking force (request value) calculated by the braking force calculation unit 412 and the detection signals (load value) of the load sensors 6c and 6d. To do. The drivers 64 and 65 supply driving sine wave currents to the motors 84 and 85 according to a command from the driver control unit 410. The current value supplied to the motors 84 and 85 is detected by the current sensors 74 and 75.

The driver control unit 500 of the slave controller 50 controls the driver 62 based on the braking force (request value) calculated by any of the braking force calculation units 302, 402, 412 and the detection signal (load value) of the load sensor 6b. Control. The driver 62 supplies a driving sine wave current to the motor 82 according to a command from the driver control unit 500. The current value supplied to the motor 82 is detected by the current sensor 72.

Here, the current value of the current sensors 70 to 75 is proportional to the output torque of the motors 80 to 85, and the output torque is proportional to the load value acting on the electric brakes 16a to 16d. Therefore, the load estimating units 305, 405, 415, 505 can estimate the load value acting on each of the electric brakes 16a to 16d from the current values of the current sensors 70 to 75.

Therefore, in a preset predetermined situation (for example, when the load sensor fails), the driver control units 301, 400, 410, 500 replace the detection signals (load value) of the load sensors 6a to 6d with the current sensor 70. The motors 80 to 85 can be controlled based on the estimated load value estimated from the current values of 75 to 75. Specifically, the driver control unit 301 is based on the braking force (request value) calculated by the braking force calculation unit 302 and the estimated load value estimated by the load estimation unit 305 from the current values of the current sensors 71 and 73. The driver control unit 400 controls the drivers 61 and 63 with the braking force (request value) calculated by the braking force calculation unit 402 and the estimated load value estimated by the load estimation unit 405 from the current value of the current sensor 70. The driver control unit 410 controls the driver 60 on the basis of the braking force (request value) calculated by the braking force calculation unit 412 and the estimated load estimated by the load estimation unit 415 from the current values of the current sensors 74 and 75. The driver control unit 500 controls the drivers 64 and 65 based on the value and the load based on the braking force (request value) calculated by one of the braking force calculation units 302, 402, and 412 and the current value of the current sensor 72. The driver 62 is controlled based on the estimated load value estimated by the estimation unit 505.

The estimated load value can be corrected using the load values detected by the load sensors 6a to 6d, and the motors 80 to 85 can control the motors 80 to 85 based on the corrected estimated load values. Specifically, in other than the predetermined situation, the load estimation units 305, 405, 415, 505 estimate the load values detected by the load sensors 6a to 6d and the current values of the current sensors 70 to 75. The load value is compared with, and the calculation formula for obtaining the estimated load value based on the current value is adjusted so that the difference between the load value and the estimated load value is eliminated. Then, in the predetermined situation, the motors 80 to 85 can be controlled based on the estimated load value corrected so as to be closer to the actual load value. As described above, according to the vehicle brake system 1, the estimation accuracy of the estimated load value is improved by correcting the estimated load value based on the current sensors 70 to 75, and the reliability of the vehicle brake system 1 is further improved. be able to.

The behavior control unit 303 outputs a signal for controlling the behavior of the vehicle VB to the driver control units 301, 400, 410, 500. The behavior is other than simple braking in accordance with the normal operation of the brake pedal 2. For example, ABS (Antilock Brake System) which is a control for preventing wheel lock, and TCS (a control for suppressing idling of the wheels Wa to Wd). (Traction Control System), which is behavior stabilization control that is control for suppressing sideslip of the vehicle VB.

The master controller 30 and the first and second sub-controllers 40, 41 include determination units 304, 404, 414 that compare the braking force calculation results of other controllers to determine the braking force.

The determination units 304, 404, and 414 compare the braking force calculation results of other controllers to determine the braking force. The other controllers are the first sub controller 40 and the second sub controller 41 for the determination unit 304, the master controller 30 and the second sub controller 41 for the determination unit 404, and the master controller 30 for the determination unit 414. And the first sub-controller 40. For example, the determination units 304, 404, and 414 determine the calculation result of the braking force calculation unit 302 of the master controller 30, the calculation result of the braking force calculation unit 402 of the first sub-controller 40, and the braking force calculation of the second sub-controller 41. The calculation result in the unit 412 is compared, and which calculation result is adopted as the braking force is determined by the majority vote. For example, if only the calculation result of the braking force calculation unit 402 is different from the other calculation results, the master controller 30 controls the driver 61 and the driver 63 based on the calculation results of the braking force calculation unit 302 and the braking force calculation unit 412.

According to the vehicle brake system 1 of the present embodiment, each controller (30, 40, 41, 50) uses the load value based on the load sensors 6a to 6d and the estimated load value based on the current sensors 70 to 75 to drive the motor 80. Since ~85 can be controlled, redundancy of the vehicle brake system 1 can be improved and reliability can be improved.

The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations having the same function, method, and result, or configurations having the same object and effect). Further, the invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. Further, the invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes configurations in which known techniques are added to the configurations described in the embodiments.

DESCRIPTION OF SYMBOLS 1... Vehicle brake system, 2... Brake pedal, 3... Stroke simulator, 4a-4d... Speed reducer, 5a-5d... Brake caliper, 6a-6d... Load sensor, 10... 1st control apparatus, 11... 2nd , 16a to 16d... Electric brake, 20... First stroke sensor, 21... Second stroke sensor, 22... Third stroke sensor, 30... Master controller, 301... Driver control unit, 302... Braking force calculation unit, 303... Behavior control unit, 304... Judgment unit, 305... Load estimation unit, 40... First sub-controller, 400... Driver control unit, 402... Braking force calculation unit, 404... Judgment unit, 405... Load estimation unit, 41... 2nd sub-controller, 410... Driver control part, 412... Braking force calculation part, 414... Judgment part, 415... Load estimation part, 50... Slave controller, 500... Driver control part, 505... Load estimation part, 60-65... Driver, 70-75... Current sensor, 80-85... Motor, 90, 92, 94, 95... Rotation angle sensor, 100-102... Battery, VB... Vehicle, Wa-Wd... Wheel

Claims (3)

A vehicle brake system comprising: an electric brake including at least one electric actuator for pressing a friction pad toward a rotor; and a plurality of controllers that are mutually connected to control the electric actuator,
A load sensor for detecting a load value acting on the electric brake,
A current sensor for detecting a current value supplied to the electric actuator,
Including
The controller can control the electric actuator based on a load value detected by the load sensor, and can control the electric actuator based on an estimated load value estimated from a current value of the current sensor. A vehicle braking system characterized by the above. In claim 1,
A vehicle brake system, wherein the electric actuator can be controlled based on the estimated load value corrected by using the load value detected by the load sensor. In claim 1 or claim 2,
A brake system for a vehicle, wherein the electric actuator can be controlled based on the estimated load value when the load sensor fails.

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