Redundant braking system and method of redundant braking

Abstract

A kind of redundancy brake system and redundancy brake method, including EMB system and brake system, EMB system includes EMB control module, wheel speed acquisition processor, pedal stroke sensor and multiple brake actuators, EMB control module is electrically connected with brake system, pedal stroke sensor, wheel speed acquisition processor, multiple brake actuators respectively, EMB control module can obtain theoretical deceleration according to the corresponding relationship of brake master cylinder pressure and deceleration and the acceleration relationship corresponding to engine output torque, multiple wheel slip rates in braking process are calculated according to the signal detected by wheel speed acquisition processor, and the braking state of vehicle is judged according to pedal stroke, when the difference between theoretical deceleration and actual deceleration is greater than first threshold value, the difference of wheel slip rate on different oil circuit is greater than second threshold value and pedal stroke is greater than third threshold value, EMB control module controls brake actuator to intervene brake system and brake. It can solve the problem of instability when vehicle brake system fails.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of braking, in particular to a redundant braking system and a redundant braking method. BACKGROUND

[0002] In the event of an abnormal situation (abnormal pressure or valve body failure) in the operation of the electronic braking system, the vehicle will perform basic braking and will not have ABS and ESC functions, and the vehicle will rely on basic braking to decelerate.

[0003] When the vehicle electronic braking system fails, the vehicle can be decelerated by engine braking, parking braking, etc. However, this kind of braking still has the problems of insufficient deceleration and the need for driver reaction time. Moreover, this kind of braking strategy is too simple and rough on different adhesion coefficient road surfaces, the vehicle deceleration is not enough, and the vehicle is prone to instability. In addition, this kind of braking method will not have braking force in the automatic driving process. SUMMARY

[0004] Therefore, the present application provides a redundant braking system to solve the problems of instability and insufficient deceleration of the vehicle when the braking system fails.

[0005] A redundant braking system, comprising an EMB system and a braking system, the EMB system comprising an EMB control module, a wheel speed acquisition processor, a pedal stroke sensor and a plurality of brake actuators, the EMB control module being electrically connected with the braking system, the pedal stroke sensor, the wheel speed acquisition processor and the plurality of brake actuators, the EMB control module being capable of calculating a theoretical deceleration according to a brake master cylinder pressure and an engine output torque, calculating a plurality of wheel slip rates in a braking process according to signals detected by the wheel speed acquisition processor, and judging a braking state of the vehicle at the moment according to a pedal stroke detected by the pedal stroke sensor, the EMB control module controlling one or more brake actuators to intervene in the braking system for auxiliary braking when a difference between the theoretical deceleration of the vehicle and an actual deceleration of the vehicle is greater than a first threshold value, a difference between the wheel slip rates on different oil lines is greater than a second threshold value, and the pedal stroke is greater than a third threshold value.

[0006] In an embodiment of the present application, the above-mentioned braking system comprises an inertial sensor, a yaw angle sensor and a vehicle speed sensor, the inertial sensor, the yaw angle sensor and the vehicle speed sensor being electrically connected with the EMB control module, the EMB control module being capable of collecting signals detected by the inertial sensor, the yaw angle sensor, the vehicle speed sensor and the pedal stroke sensor and calculating when the braking system is not reporting a failure, the EMB control module controlling one or more brake actuators to brake according to the calculation results when the whole vehicle braking system is partially or totally invalid.

[0007] In the embodiment of the present application, the above-mentioned braking system comprises an electronic control unit, a hydraulic unit and a plurality of brakes, the electronic control unit is electrically connected with the inertial sensor, the yaw angle sensor, the vehicle speed sensor, the pedal stroke sensor, the hydraulic unit and the EMB control module respectively, the hydraulic unit is connected with the plurality of brakes respectively, and the plurality of brakes are used for braking the vehicle.

[0008] In the embodiment of the present application, the plurality of brakes comprise a left front wheel brake, a left rear wheel brake, a right front wheel brake and a right rear wheel brake, the hydraulic unit is connected with the left front wheel brake and the right rear wheel brake through a first oil path, and the hydraulic unit is connected with the right front wheel brake and the left rear wheel brake through a second oil path.

[0009] In the embodiment of the present application, the plurality of wheel slip rates comprise a left front wheel slip rate, a left rear wheel slip rate, a right front wheel slip rate and a right rear wheel slip rate, wherein the left front wheel and the right rear wheel are braked by the first oil path, and the left rear wheel and the right front wheel are braked by the second oil path.

[0010] When the left front wheel slip rate, the left rear wheel slip rate, the right front wheel slip rate and the right rear wheel slip rate are all greater than 0, and the difference between the wheel slip rates on different oil paths is greater than a second threshold value, the EMB control module controls one or more brake actuators to intervene in the braking system to assist braking, so that the vehicle deceleration reaches a target deceleration.

[0011] When the left front wheel slip rate and the right rear wheel slip rate are equal to 0, or the left rear wheel slip rate and the right front wheel slip rate are equal to 0, the oil path with a slip rate equal to 0 is closed, and the EMB control module controls one or more brake actuators to assist braking of the wheel with a slip rate equal to 0.

[0012] When the left front wheel slip rate, the left rear wheel slip rate, the right front wheel slip rate and the right rear wheel slip rate are all equal to 0, the EMB control module controls a plurality of brake actuators to brake each wheel according to the target deceleration corresponding to the pedal stroke.

[0013] The present application also provides a redundant braking method, which is used in the above-mentioned redundant braking system, and the redundant braking method comprises the following steps:

[0014] During braking, a theoretical deceleration of the vehicle is calculated according to a deceleration relationship corresponding to a brake master cylinder pressure and an acceleration relationship corresponding to an engine output torque;

[0015] During braking, a plurality of wheel slip rates are calculated;

[0016] The EMB system is communicated with the brake system to monitor the state of the brake system in real time, and the brake state of the vehicle at this time is judged by the pedal stroke of the brake pedal;

[0017] When the difference between the theoretical deceleration and the detected actual deceleration is greater than a first threshold value, the difference between the wheel slip rates on different oil lines is greater than a second threshold value, and the pedal stroke is greater than a third threshold value, one or more brake actuators are controlled to intervene in the brake system for auxiliary braking.

[0018] In an embodiment of the present application, the plurality of wheel slip rates include left front wheel slip rate, left rear wheel slip rate, right front wheel slip rate and right rear wheel slip rate, wherein the left front wheel and the right rear wheel are braked by the first oil line, and the left rear wheel and the right front wheel are braked by the second oil line, when the left front wheel slip rate, the left rear wheel slip rate, the right front wheel slip rate and the right rear wheel slip rate are all greater than 0, and the difference between the wheel slip rates on different oil lines is greater than a second threshold value, one or more brake actuators are controlled to intervene in the brake system for auxiliary braking, so that the vehicle deceleration reaches the target deceleration.

[0019] In an embodiment of the present application, the plurality of wheel slip rates include left front wheel slip rate, left rear wheel slip rate, right front wheel slip rate and right rear wheel slip rate, wherein the left front wheel and the right rear wheel are braked by the first oil line, and the left rear wheel and the right front wheel are braked by the second oil line, when the left front wheel slip rate and the right rear wheel slip rate are equal to 0, or the left rear wheel slip rate and the right front wheel slip rate are equal to 0, the oil line with a slip rate equal to 0 is closed, and one or more brake actuators are controlled to assist braking for the wheel with a slip rate equal to 0.

[0020] In an embodiment of the present application, the plurality of wheel slip rates include left front wheel slip rate, left rear wheel slip rate, right front wheel slip rate and right rear wheel slip rate, wherein the left front wheel and the right rear wheel are braked by the first oil line, and the left rear wheel and the right front wheel are braked by the second oil line, when the left front wheel slip rate, the left rear wheel slip rate, the right front wheel slip rate and the right rear wheel slip rate are all equal to 0, the plurality of brake actuators are controlled to assist braking for each wheel according to the target deceleration corresponding to the pedal stroke.

[0021] In an embodiment of the present application, when the EMB control module receives any one of the ESC fault signal, the TCS fault signal, the ABS fault signal, the EBD fault signal and the brake pressure signal sent by the brake system, the EMB control module controls one or more brake actuators to intervene in the brake system for auxiliary braking.

[0022] The redundant braking system of this invention solves the problems of vehicle instability and insufficient deceleration when the braking system fails, ensuring effective deceleration of the vehicle on road surfaces with different coefficients of friction. When vehicle instability occurs, the EMB system can intervene in time to control braking, ensuring that the vehicle can follow the driver's intentions normally and stably on road surfaces with different coefficients of friction. Moreover, the EMB system can avoid situations where braking system failure prevents deceleration during autonomous driving and has the capability to support Level 3 and above autonomous driving. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the redundant braking system of the present invention;

[0024] Figure 2 This is a schematic diagram of the redundant braking system of the present invention performing auxiliary braking of the EMB system when the slip rate of some wheels is zero;

[0025] Figure 3 This is a schematic diagram of the redundant braking system of the present invention braking the EMB system when the slip ratio of all wheels is zero. Detailed Implementation

[0026] This invention provides a redundant braking system.

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0028] To facilitate understanding by those skilled in the art, the present invention will illustrate the specific implementation process of the technical solution provided by the present invention through the following embodiments.

[0029] Figure 1 This is a schematic diagram of the redundant braking system of the present invention, as shown below. Figure 1As shown, the redundant braking system includes an EMB system and a braking system. The EMB system includes an EMB control module 11, a wheel speed acquisition processor (not shown), a pedal travel sensor 12, and multiple brake actuators 13. The EMB control module 11 is electrically connected to the braking system, the pedal travel sensor 12, the wheel speed acquisition processor, and the multiple brake actuators 13. The EMB control module 11 can calculate the theoretical deceleration of the vehicle based on the relationship between the brake master cylinder pressure and deceleration and the relationship between the engine output torque and acceleration. It can also calculate the slip ratio of multiple wheels during the braking process based on the signal detected by the wheel speed acquisition processor and determine the braking state of the vehicle based on the pedal travel detected by the pedal travel sensor 12. When the difference between the theoretical deceleration and the actual deceleration is greater than a first threshold, the difference between the wheel slip ratios on different oil circuits is greater than a second threshold, and the pedal travel is greater than a third threshold, the EMB control module 11 controls one or more brake actuators 13 to intervene in the braking system to perform auxiliary braking. In this embodiment, EMB is an electromechanical braking system; the braking system is, for example, an ESC system, an IPB system, or an MKCI system, but is not limited thereto. The ESC system is used as an example for explanation.

[0030] It is worth mentioning that the EMB system will only intervene in the braking system and replace or assist the braking system to brake when the difference between the vehicle's theoretical deceleration and the vehicle's actual deceleration is greater than the first threshold, the difference between the wheel slip rates on different oil circuits is greater than the second threshold, and the pedal travel is greater than the third threshold, all of which are met simultaneously. This is to avoid malfunctions. At the same time, the EMB system will issue an alarm signal.

[0031] The redundant braking system of this invention solves the problems of vehicle instability and insufficient deceleration when the braking system fails, ensuring effective deceleration of the vehicle on road surfaces with different coefficients of friction. When vehicle instability occurs, the EMB system can intervene in time to control braking, ensuring that the vehicle can follow the driver's intentions normally and stably on road surfaces with different coefficients of friction. Moreover, the EMB system can avoid situations where braking system failure prevents deceleration during autonomous driving and has the capability to support Level 3 and above autonomous driving.

[0032] Optionally, the values ​​of the first threshold, the second threshold, and the third threshold can be freely designed according to the actual situation. For example, the third threshold can be 30%, but it is not limited to this.

[0033] Optionally, the theoretical deceleration is calculated based on the deceleration relationship corresponding to the brake master cylinder pressure and the acceleration relationship corresponding to the engine output torque, and its kinematic equation is:

[0034] F(p) + Q(Torq) = target(a)

[0035] Where F(p) represents the deceleration relationship corresponding to the main cylinder pressure; Q(Torq) represents the acceleration relationship corresponding to the torque output; and target(a) represents the calculated theoretical deceleration.

[0036] The braking system is judged to have failed by comparing the theoretical deceleration target(a) with the actual deceleration du / dt of the vehicle. If there is a large difference between the actual deceleration du / dt and the calculated theoretical deceleration target(a) within a certain period, it is determined that there is an oil leak or air intake in the braking system. At this time, the EMB system is activated and intervenes in the braking system.

[0037] Optionally, the plurality of brake actuators 13 include a left front wheel actuator 131, a left rear wheel actuator 132, a right front wheel actuator 133, and a right rear wheel actuator 134. Each brake actuator 13 achieves braking by driving a ball screw through a planetary gear mechanism driven by a motor.

[0038] Optionally, the braking system includes an inertial sensor, a yaw angle sensor, and a vehicle speed sensor. The inertial sensor, yaw angle sensor, and vehicle speed sensor are all electrically connected to the EMB control module 11. When the braking system does not report a fault, the EMB control module 11 can collect and calculate the signals detected by the inertial sensor, yaw angle sensor, vehicle speed sensor, and pedal travel sensor 12. Based on the calculation results, the EMB control module 11 controls one or more brake actuators 13 to brake in real time when the vehicle brakes fail. In this embodiment, the EMB system can supply power to each sensor individually and collect signals detected by each sensor when the braking system fails to supply power. For example, it can autonomously collect and calculate signals such as inertial acceleration (lateral acceleration ax and longitudinal acceleration ay) detected by the inertial sensor (IMJ), yaw rate (Yaw_rate) detected by the yaw angle sensor, vehicle speed (Veh_speed) detected by the vehicle speed sensor, and pedal travel (brake_pedal) detected by the pedal travel sensor 12. When the braking system fails partially or completely (braking system or hydraulic line failure), the EMB system replaces the failed part to perform auxiliary braking, enabling the vehicle to decelerate smoothly and quickly, thus avoiding accidents.

[0039] Optionally, the braking system includes an electronic control unit 21 (ECU), a hydraulic unit 22, and multiple brakes 23. The ECU 21 is electrically connected to an inertial sensor, a yaw angle sensor, a vehicle speed sensor, a pedal travel sensor 12, the hydraulic unit 22, and an EMB control module 11. The hydraulic unit 22 is connected to the multiple brakes 23, which are used to brake the vehicle. In this embodiment, the hydraulic unit 22 includes a vacuum booster and hydraulic lines.

[0040] Optionally, the plurality of brakes 23 include a left front wheel brake 231, a left rear wheel brake 232, a right front wheel brake 233, and a right rear wheel brake 234. The hydraulic unit 22 is connected to the left front wheel brake 231 and the right rear wheel brake 234 respectively through a first oil circuit 24, and the hydraulic unit 22 is connected to the right front wheel brake 233 and the left rear wheel brake 232 respectively through a second oil circuit 25. In this embodiment, the first oil passage 24 and the second oil passage 25 are arranged in an X-shape. The hydraulic unit 22 provides brake oil pressure to the left front wheel brake 231 and the right rear wheel brake 234 through the first oil passage 24. The hydraulic unit 22 provides brake oil pressure to the right front wheel brake 233 and the left rear wheel brake 232 through the second oil passage 25. The left front wheel brake 231 is used to brake the left front wheel, the left rear wheel brake 232 is used to brake the left rear wheel, the right front wheel brake 233 is used to brake the right front wheel, and the right rear wheel brake 234 is used to brake the right rear wheel.

[0041] Optionally, the slip ratios of multiple wheels include the slip ratio of the left front wheel, the slip ratio of the left rear wheel, the slip ratio of the right front wheel, and the slip ratio of the right rear wheel. The left front wheel and the right rear wheel are braked by the first hydraulic circuit 24, and the left rear wheel and the right front wheel are braked by the second hydraulic circuit 25. When the vehicle is traveling on a road surface with the same coefficient of friction and the braking system is not faulty, the slip ratios of the left front wheel, the left rear wheel, the right front wheel, and the right rear wheel are all equal or have small differences. When there are significant differences in the slip ratios of the left front wheel, the left rear wheel, the right front wheel, and the right rear wheel, it can be determined that the braking system has failed. The formula for calculating the slip ratio of each wheel during braking is:

[0042] λ=(V spd -V wheel ) / V spd

[0043] Where λ is the wheel slip ratio; V wheel V is the wheel slip ratio; spd The vehicle speed.

[0044] It is worth mentioning that the wheel slip ratios on the same oil circuit are equal or have small differences between them, that is, the slip ratios of the left front wheel and the right rear wheel are equal or have small differences between them, or the slip ratios of the left rear wheel and the right front wheel are equal or have small differences between them; when the braking system is not failed, the slip ratios of each wheel are equal or have small differences between them; when the braking system fails (when there is an oil leak or air intake in the oil circuit), the wheel slip ratios of different oil circuits differ greatly.

[0045] like Figure 1As shown, when the slip ratios of the left front wheel, left rear wheel, right front wheel, and right rear wheel are all greater than 0, and the difference in wheel slip ratios on different oil lines is greater than a second threshold, the EMB control module 11 controls one or more brake actuators 13 to intervene in the braking system for auxiliary braking. This involves re-pressurizing the wheel ends of the oil lines with lower slip ratios to achieve the target deceleration. In this embodiment, the EMB control module 11 uses PWM periodic pulse current control, meaning it powers the brake actuators 13 for short periods (10ms cycle).

[0046] Figure 2 This is a schematic diagram of the redundant braking system of the present invention performing auxiliary braking when the slip ratio of some wheels is zero, as shown below. Figure 2 As shown, when the slip ratio of the left front wheel and the slip ratio of the right rear wheel are both 0, or when the slip ratio of the left rear wheel and the slip ratio of the right front wheel are both 0, the oil circuit with a slip ratio of 0 is closed. The EMB control module 11 controls one or more brake actuators 13 to perform auxiliary braking on the wheels with a slip ratio of 0. For example, when the slip ratio of the left front wheel and the slip ratio of the right rear wheel are both 0, the first oil circuit 24 is closed. At this time, the brake actuators 13 (left front wheel actuator 131 and right rear wheel actuator 134) replace the left front wheel brake 231 and the right rear wheel brake 234 to perform auxiliary braking. When the slip ratio of the left rear wheel and the slip ratio of the right front wheel are both 0, the second oil circuit 25 is closed. At this time, the brake actuators 13 (left rear wheel brake 132 and right front wheel brake 133) replace the left rear wheel brake 232 and the right front wheel brake 233 to perform auxiliary braking until the slip ratio of each wheel reaches the target value. When the wheels tend to lock up, the motor is controlled to reverse.

[0047] Figure 3 This is a schematic diagram of the redundant braking system of the present invention braking when the slip ratio of all wheels is zero, as shown. Figure 3 As shown, when the slip ratios of the left front wheel, left rear wheel, right front wheel, and right rear wheel are all equal to 0, the braking system completely fails. The EMB control module 11 controls multiple brake actuators 13 to brake each wheel based on the target deceleration corresponding to the pedal travel. In this embodiment, different pedal travels correspond to preset target decelerations, and the EMB control module 11 controls multiple brake actuators 13 to brake based on these target decelerations.

[0048] Optionally, when the EMB control module 11 receives any of the following signals from the braking system: ESC fault signal (ESC_failure), TCS fault signal (TCS_failure), ABS fault signal (ABS_failure), EBD fault signal (EBD_failure), or brake pressure signal (Brake_Pressure), the EMB control module 11 controls one or more brake actuators 13 to intervene in the braking system for auxiliary braking. That is, when the braking system actively issues a fault signal, the EMB system can respond to the braking request of the braking system and achieve independent control of the wheels. In this embodiment, when the braking system malfunctions, it actively reports the fault and disables the corresponding function, controlling the actuators 13 to operate by sending pressure commands to the EMB system.

[0049] The EMB system of the present invention determines the state of the braking system by mutual detection with the braking system. Different degrees of coupling and decoupling realize the deceleration and steady-state control of the vehicle, which can effectively avoid the occurrence of accidents. Especially when the brake failure is detected during autonomous driving, the brake actuator 13 can be controlled by electrical signals to achieve the target deceleration.

[0050] The redundant braking system of the present invention can solve the problem that the vehicle cannot provide sufficient deceleration when the brake line fails; when the braking system fails, it can ensure that the vehicle has a certain degree of stability by actively pressurizing through the EMB system when the vehicle is about to become unstable; at the same time, it solves the disadvantage that electric vehicles without a P gear locking mechanism cannot achieve parking on steep slopes; and it is compatible with L3 and above intelligent driving functions, with a high degree of redundancy, that is, in the event of brake system failure, it can request the brake actuator 13 (motor-driven planetary gear and ball screw transmission mechanism) to perform emergency braking.

[0051] The present invention also provides a redundant braking method for use in the aforementioned redundant braking system, the redundant braking method comprising:

[0052] During braking, the theoretical deceleration of the vehicle is calculated based on the deceleration relationship corresponding to the brake master cylinder pressure and the acceleration relationship corresponding to the engine output torque.

[0053] Multiple wheel slip ratios are calculated during braking;

[0054] The EMB system communicates with the braking system to monitor the status of the braking system in real time and determine the braking status of the vehicle at this time by the pedal travel of the brake pedal.

[0055] When the difference between the vehicle's theoretical deceleration and the vehicle's actual deceleration is greater than the first threshold, the difference between the wheel slip ratios on different oil circuits is greater than the second threshold, and the pedal travel is greater than the third threshold, one or more brake actuators 13 are controlled to intervene in the braking system to perform auxiliary braking.

[0056] Optionally, such as Figure 1 As shown, multiple wheel slip ratios include the left front wheel slip ratio, left rear wheel slip ratio, right front wheel slip ratio, and right rear wheel slip ratio. The left front wheel and right rear wheel are braked by the first oil circuit 24, and the left rear wheel and right front wheel are braked by the second oil circuit 25. When the left front wheel slip ratio, left rear wheel slip ratio, right front wheel slip ratio, and right rear wheel slip ratio are all greater than 0, and the difference between the wheel slip ratios on different oil circuits is greater than a second threshold, one or more brake actuators 13 are controlled to intervene in the braking system to perform auxiliary braking, so that the vehicle deceleration reaches the target deceleration.

[0057] Optionally, such as Figure 2 As shown, the multiple wheel slip ratios include the left front wheel slip ratio, the left rear wheel slip ratio, the right front wheel slip ratio, and the right rear wheel slip ratio. The left front wheel and the right rear wheel are braked by the first oil circuit 24, and the left rear wheel and the right front wheel are braked by the second oil circuit 25. When the left front wheel slip ratio and the right rear wheel slip ratio are equal to 0, or the left rear wheel slip ratio and the right front wheel slip ratio are equal to 0, the oil circuit with a slip ratio of 0 is closed, and one or more brake actuators 13 are controlled to perform auxiliary braking on the wheel with a slip ratio of 0.

[0058] Optionally, such as Figure 3 As shown, multiple wheel slip ratios include the left front wheel slip ratio, left rear wheel slip ratio, right front wheel slip ratio, and right rear wheel slip ratio. The left front wheel and right rear wheel are braked by the first hydraulic circuit 24, and the left rear wheel and right front wheel are braked by the second hydraulic circuit 25. When the left front wheel slip ratio, left rear wheel slip ratio, right front wheel slip ratio, and right rear wheel slip ratio are all equal to 0, the braking system completely fails. Multiple brake actuators 13 are then controlled to brake each wheel according to the target deceleration corresponding to the pedal travel. In this embodiment, different pedal travels correspond to preset target decelerations, and the EMB control module 11 controls the multiple brake actuators 13 to brake according to the target deceleration corresponding to the pedal travel.

[0059] Optionally, when the EMB control module 11 receives any of the following signals from the braking system: ESC fault signal (ESC_failure), TCS fault signal (TCS_failure), ABS fault signal (ABS_failure), EBD fault signal (EBD_failure), or brake pressure signal (Brake_Pressure), the EMB control module 11 controls one or more brake actuators 13 to intervene in the braking system for auxiliary braking. That is, when the braking system actively issues a fault signal, the EMB system responds to the braking system's braking request, achieving independent control of the wheels. In this embodiment, when the braking system malfunctions, it actively reports the fault and disables the corresponding function, controlling the actuators 13 to operate by sending pressure commands to the EMB system.

[0060] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention. The various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe the various possible combinations.

Claims

1. A redundant braking system, characterized in that, The system includes an EMB system and a braking system. The EMB system includes an EMB control module, a wheel speed acquisition processor, a pedal travel sensor, and multiple brake actuators. The EMB control module is electrically connected to the braking system, the pedal travel sensor, the wheel speed acquisition processor, and the multiple brake actuators. The EMB control module can calculate the theoretical deceleration of the vehicle based on the relationship between the brake master cylinder pressure and deceleration and the relationship between the engine output torque and acceleration. It can also calculate multiple wheel slip ratios during the braking process based on signals detected by the wheel speed acquisition processor and determine the braking state of the vehicle based on the pedal travel detected by the pedal travel sensor. When the difference between the theoretical deceleration and the actual deceleration of the vehicle is greater than a first threshold, the difference between the wheel slip ratios on different oil lines is greater than a second threshold, and the pedal travel is greater than a third threshold, the EMB control module controls one or more of the brake actuators to intervene in the braking system for auxiliary braking. The multiple wheel slip ratios include the left front wheel slip ratio, the left rear wheel slip ratio, the right front wheel slip ratio, and the right rear wheel slip ratio, wherein the left front wheel and the right rear wheel are braked by a first hydraulic circuit, and the left rear wheel and the right front wheel are braked by a second hydraulic circuit; When the slip ratio of the left front wheel and the slip ratio of the right rear wheel are equal to 0, or when the slip ratio of the left rear wheel and the slip ratio of the right front wheel are equal to 0, the oil circuit with a slip ratio of 0 is closed, and the EMB control module controls one or more of the brake actuators to perform auxiliary braking on the wheel with a slip ratio of 0.

2. The redundant braking system as described in claim 1, characterized in that, The braking system includes an inertial sensor, a yaw angle sensor, and a vehicle speed sensor. The inertial sensor, the yaw angle sensor, and the vehicle speed sensor are all electrically connected to the EMB control module. When the braking system does not report a fault, the EMB control module can collect and calculate the signals detected by the inertial sensor, the yaw angle sensor, the vehicle speed sensor, and the pedal travel sensor. Based on the calculation results, the EMB control module controls one or more of the brake actuators to brake when the vehicle's braking system fails partially or completely.

3. The redundant braking system as described in claim 2, characterized in that, The braking system includes an electronic control unit, a hydraulic unit, and multiple brakes. The electronic control unit is electrically connected to the inertial sensor, the yaw angle sensor, the vehicle speed sensor, the pedal travel sensor, the hydraulic unit, and the EMB control module. The hydraulic unit is connected to the multiple brakes, which are used to brake the vehicle.

4. The redundant braking system as described in claim 3, characterized in that, The plurality of brakes include a left front wheel brake, a left rear wheel brake, a right front wheel brake, and a right rear wheel brake. The hydraulic unit is connected to the left front wheel brake and the right rear wheel brake respectively through a first oil circuit, and the hydraulic unit is connected to the right front wheel brake and the left rear wheel brake respectively through a second oil circuit.

5. The redundant braking system as described in any one of claims 1 to 4, characterized in that, When the slip ratio of the left front wheel, the slip ratio of the left rear wheel, the slip ratio of the right front wheel, and the slip ratio of the right rear wheel are all greater than 0, and the difference in the slip ratio of the wheels on different oil lines is greater than the second threshold, the EMB control module controls one or more of the brake actuators to intervene in the braking system to perform auxiliary braking, so that the vehicle deceleration reaches the target deceleration. When the slip ratio of the left front wheel, the slip ratio of the left rear wheel, the slip ratio of the right front wheel, and the slip ratio of the right rear wheel are all equal to 0, the EMB control module controls multiple brake actuators to brake each wheel according to the target deceleration corresponding to the pedal travel.

6. A redundant braking method, characterized in that, The redundant braking method is used in the redundant braking system according to any one of claims 1 to 5, the redundant braking method comprising: During braking, the theoretical deceleration of the vehicle is calculated based on the deceleration relationship corresponding to the brake master cylinder pressure and the acceleration relationship corresponding to the engine output torque. Multiple wheel slip ratios are calculated during braking; The EMB system communicates with the braking system to monitor the status of the braking system in real time and determine the braking status of the vehicle at this time by the pedal travel of the brake pedal. When the difference between the vehicle's theoretical deceleration and its actual deceleration is greater than a first threshold, the difference between the wheel slip ratios on different oil lines is greater than a second threshold, and the pedal travel is greater than a third threshold, one or more of the brake actuators are controlled to intervene in the braking system to perform auxiliary braking.

7. The redundant braking method as described in claim 6, characterized in that, The multiple wheel slip ratios include the left front wheel slip ratio, the left rear wheel slip ratio, the right front wheel slip ratio, and the right rear wheel slip ratio. The left front wheel and the right rear wheel are braked by a first hydraulic circuit, and the left rear wheel and the right front wheel are braked by a second hydraulic circuit. When the left front wheel slip ratio, the left rear wheel slip ratio, the right front wheel slip ratio, and the right rear wheel slip ratio are all greater than 0, and the difference between the wheel slip ratios on different hydraulic circuits is greater than a second threshold, one or more of the brake actuators are controlled to intervene in the braking system to perform auxiliary braking, so that the vehicle deceleration reaches the target deceleration.

8. The redundant braking method as described in claim 6, characterized in that, The multiple wheel slip ratios include left front wheel slip ratio, left rear wheel slip ratio, right front wheel slip ratio, and right rear wheel slip ratio, wherein the left front wheel and right rear wheel are braked by a first hydraulic circuit, and the left rear wheel and right front wheel are braked by a second hydraulic circuit. When the left front wheel slip ratio and the right rear wheel slip ratio are equal to 0, or the left rear wheel slip ratio and the right front wheel slip ratio are equal to 0, the hydraulic circuit with a slip ratio of 0 is closed, and one or more of the brake actuators are controlled to perform auxiliary braking on the wheel with a slip ratio of 0.

9. The redundant braking method as described in claim 6, characterized in that, The multiple wheel slip ratios include the left front wheel slip ratio, the left rear wheel slip ratio, the right front wheel slip ratio, and the right rear wheel slip ratio. The left front wheel and the right rear wheel are braked by a first hydraulic circuit, and the left rear wheel and the right front wheel are braked by a second hydraulic circuit. When the left front wheel slip ratio, the left rear wheel slip ratio, the right front wheel slip ratio, and the right rear wheel slip ratio are all equal to 0, the multiple brake actuators are controlled to brake each wheel according to the target deceleration corresponding to the pedal travel.

10. The redundant braking method according to any one of claims 6 to 9, characterized in that, When the EMB control module receives any of the following signals from the braking system: ESC fault signal, TCS fault signal, ABS fault signal, EBD fault signal, or brake pressure signal, the EMB control module controls one or more of the brake actuators to intervene in the braking system to perform auxiliary braking.

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