Electro-mechanical braking system for redundant braking, and vehicle

Abstract

An electro-mechanical braking system for redundant braking. The system comprises two front wheel end braking devices (401, 402) and two rear wheel end braking devices (403, 404); the front wheel end braking devices (401, 402) respectively brake two front wheels of a vehicle; each front wheel end braking device comprises two front wheel driving units which are mutually backed up, and one front wheel brake caliper; the two rear wheel end braking devices (403, 404) respectively brake two rear wheels of the vehicle; and each rear wheel end braking device comprises one rear wheel driving unit and one rear wheel brake caliper. When one front wheel driving unit in any front wheel end braking device fails, the other front wheel driving unit in the device still outputs a clamping force to a brake disk of one front wheel of the vehicle. In this way, at least one front wheel driving unit that works normally exists on the front wheels on both sides of the vehicle, so that sufficient braking force can be provided for the electric vehicle without using a diagonal braking strategy. Also provided is a vehicle.

Description

An electromechanical braking system with redundant braking and a vehicle

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411029803.X, filed on July 29, 2024, entitled "An Electromechanical Braking System and Vehicle with Redundant Braking", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of electric vehicle braking, and more particularly to an electromechanical braking system and vehicle with redundant braking. Background Technology

[0004] A car's braking system applies braking force to the wheels to achieve a certain degree of forced braking. With increasingly demanding braking performance requirements, traditional hydraulic or air braking systems, after incorporating numerous electronic control systems such as anti-lock braking systems (ABS) and traction control systems (TCS), have become increasingly complex in structure and piping layout. This increases the risk of leaks in hydraulic (air) circuits and also raises the difficulty of assembly and maintenance. Therefore, electro-mechanical braking systems (EMB), with their relatively simple structure and reliable integrated functions, are gaining popularity.

[0005] However, compared to traditional hydraulic braking systems, EMB has a higher electronic and electrical failure rate, and the resulting personal injury hazards are more prominent and complex. Single-point failure in EMB can lead to problems such as loss of braking force, insufficient braking force, or excessive yaw braking force. With the continuous development of automotive technology and increasingly stringent road safety standards, the requirements for vehicle braking deceleration are becoming increasingly stringent. Therefore, how to improve the braking capacity of the braking system to achieve greater braking deceleration after a single-point failure in EMB is an urgent problem to be solved. Summary of the Invention

[0006] This application provides a redundant electromechanical braking system and vehicle. By providing two drive units in each front wheel end braking device, even if one drive unit in the front wheel end braking device fails, the other drive unit in the front wheel end braking device can still work normally. Thus, the redundant electromechanical braking system provided by this application can still provide sufficient braking deceleration.

[0007] In a first aspect, this application provides a redundant electromechanical braking system, comprising two front wheel-end braking devices and two rear wheel-end braking devices. The two front wheel-end braking devices are used to brake the two front wheels of a vehicle, and each front wheel-end braking device includes a front wheel brake caliper and two backup front wheel drive units. During vehicle braking, the two front wheel drive units simultaneously drive one front wheel brake caliper to output clamping force to the brake disc of one front wheel of the vehicle, or one of the two front wheel drive units drives one front wheel brake caliper to output clamping force to the brake disc of the front wheel. The two rear wheel-end braking devices are used to brake the two rear wheels of the vehicle, and each rear wheel-end braking device includes a rear wheel drive unit and a rear wheel brake caliper. During vehicle braking, one rear wheel drive unit of each rear wheel-end braking device drives one rear wheel brake caliper to output clamping force to the brake disc of one rear wheel of the vehicle.

[0008] The redundant braking electromechanical braking system provided in this application ensures that even if one front-wheel drive unit in the front wheel end braking device fails, the other front-wheel drive unit in that device can still function normally, thereby driving the corresponding front brake caliper to output clamping force to the brake disc of one front wheel of the vehicle. Thus, at least one normally functioning front-wheel drive unit exists on each side of the vehicle's front wheels to output clamping force to the corresponding brake disc. Furthermore, since there are normally functioning drive units on both sides, a diagonal braking strategy is unnecessary. Therefore, even in the event of a single-point failure of any drive unit, the electromechanical braking system itself can provide sufficient braking deceleration.

[0009] In one possible implementation, each front-wheel drive unit includes a front-wheel brake controller and a front-wheel brake motor. The front-wheel brake controller of each front-wheel drive unit is used to control the front-wheel brake motor to drive a front-wheel brake caliper to output clamping force. Each rear-wheel drive unit includes a rear-wheel brake controller and a rear-wheel brake motor. The rear-wheel brake controller of each rear-wheel drive unit is used to control the rear-wheel brake motor to drive a rear-wheel brake caliper to output clamping force.

[0010] The front and rear wheel brake controllers respond to control signals to control the corresponding brake motors to drive the front wheel brake calipers to output clamping force. Furthermore, since there are two front wheel drive units in each front wheel end braking device, even if the brake controller or brake motor in one front wheel drive unit fails, the other front wheel drive unit can still work normally to provide sufficient braking deceleration.

[0011] As one possible implementation, during the braking of a front wheel by any one of the front wheel end brake devices, if one of the two front wheel drive units fails, the other front wheel drive unit is used to drive a front wheel brake caliper to output clamping force.

[0012] If a front-wheel drive unit of any front wheel end braking device drives a front wheel brake caliper to output clamping force during the process, and that front wheel drive unit fails, another front wheel drive unit of the same front wheel end braking device can drive a front wheel brake caliper to output clamping force, thereby ensuring that the front wheel on that side provides sufficient braking deceleration.

[0013] As one possible implementation, during the process of two front-wheel drive units of any front wheel end braking device jointly driving a front wheel brake caliper to output clamping force, if one of the two front-wheel drive units fails, the front wheel brake motor of the other front-wheel drive unit increases the braking torque output.

[0014] If, during the process of both drive units of any front wheel brake device jointly driving a front wheel brake caliper to output clamping force, one of the two front wheel drive units fails, the front wheel brake motor of the other front wheel drive unit can increase its braking torque output. In this way, the other front wheel drive unit can compensate for the braking torque originally output by the failed front wheel drive unit, thereby ensuring that the front wheel on that side provides sufficient braking deceleration.

[0015] As one possible implementation, when the electromechanical braking system is used to brake a vehicle, if any rear-wheel drive unit fails, each rear-wheel drive unit stops driving the rear wheel brake calipers to output clamping force, and the two front wheel end brake devices drive the two front wheel brake calipers to increase the clamping force output.

[0016] In order to provide sufficient braking deceleration to electric vehicles, after the rear-wheel drive unit of the other rear wheel end brake device stops driving one rear wheel brake caliper, it can also control each of the two front wheel end brake devices to drive one front wheel brake caliper to increase the clamping force output. Thus, the front wheel drive units on both sides alone can provide braking deceleration of more than 6.43 m / s2 to electric vehicles to support Level 3 and above intelligent driving functions.

[0017] As one possible implementation, during the process of one front-wheel drive unit of any front wheel end braking device driving one front wheel brake caliper to output clamping force, in response to the temperature of the front wheel drive unit driving one front wheel brake caliper being greater than a preset temperature value, the front wheel brake motor of the front wheel drive unit whose temperature is greater than the preset temperature value is controlled to reduce the braking torque output while the front wheel brake motor of the other front wheel drive unit outputs braking torque. Alternatively, during the process of two front wheel drive units of any front wheel end braking device jointly driving one front wheel brake caliper to output clamping force, in response to the temperature of one front wheel drive unit being greater than the preset temperature value, the front wheel brake motor of the front wheel drive unit whose temperature is greater than the preset temperature value is controlled to reduce the braking torque output while the front wheel brake motor of the other front wheel drive unit increases the output braking torque.

[0018] The solution provided in this application allows the front wheel brake motor of another front wheel drive unit to compensate for the braking torque originally output by the front wheel brake motor of the overheated front wheel drive unit, thereby preventing the front wheel drive unit from overheating and ensuring that the front wheel on that side provides sufficient braking deceleration.

[0019] In one possible implementation, two front wheel brake controllers for each front wheel brake device are used to receive clamping force signals, which indicate the magnitude of the clamping force output by each front wheel wheel-end brake device to the brake disc of one front wheel of the vehicle. In response to the clamping force indicated by the clamping force signal being less than a preset clamping force, one of the two front wheel drive units is used to drive one front wheel brake caliper to output clamping force. In response to the clamping force indicated by the clamping force signal being greater than or equal to the preset clamping force, the two front wheel drive units are used together to drive one front wheel brake caliper to output clamping force.

[0020] When the clamping force output by a front-wheel drive unit for a front-wheel brake caliper is small, this application can output the clamping force to the brake disc of one front wheel of the vehicle based on the clamping force signal indicating the clamping force of any front wheel wheel-end braking device. When the clamping force indicated by the clamping force signal is greater than or equal to the preset clamping force, it is difficult to meet the clamping force indicated by the clamping force signal using only one of the two front-wheel drive units. Therefore, it is necessary for both front-wheel drive units to work together to drive one front-wheel brake caliper to output the clamping force, thereby achieving the clamping force indicated by the clamping force signal and ensuring that the front wheel on that side provides sufficient braking deceleration.

[0021] As one possible implementation, the electromechanical braking system also includes two central controllers. At least one of the two central controllers is used to receive brake pedal signals from a pedal sensor. The brake pedal signals are used to indicate the movement state of the brake pedal. During the process of the electromechanical braking system braking the vehicle, at least one of the two central controllers is used to control the four wheel-end braking devices to output clamping forces to the brake discs corresponding to the four wheels of the vehicle, respectively, according to the indication of the brake pedal signals.

[0022] In the event of an abnormal failure of either of the two central controllers, the other central controller can continue to control the wheel-end braking device to output braking force, thereby providing sufficient braking force for the electric vehicle to avoid the failure of the entire electromechanical braking system due to the failure of one central controller, thus improving the safety and reliability of the braking system.

[0023] As one possible implementation, in the process of using an electromechanical braking system to brake a vehicle, a central controller is used to: in response to the failure of the other of the two central controllers, control the four wheel-end braking devices to output clamping forces to the brake discs corresponding to the four wheels of the vehicle respectively.

[0024] In one possible implementation, each front wheel braking device is used to receive power from two power sources, wherein one front wheel brake controller of each front wheel wheel-end braking device is used to receive power from one of the two power sources, and the other front wheel brake controller of each front wheel wheel-end braking device is used to receive power from the other of the two power sources.

[0025] By powering the wheel-end controller with two power supplies, even if one of the two power supplies fails, the other power supply can still power one front-wheel drive unit on each side of the front wheel. In this way, the front-wheel drive units on both sides can provide the electric vehicle with a braking deceleration of more than 6.43 m / s2 to support Level 3 and above intelligent driving functions.

[0026] As one possible implementation, a rear wheel brake controller is used to receive power from one power source, and another rear wheel brake controller is used to receive power from another power source; or, a rear wheel brake controller is used to receive power from two power sources, and another rear wheel brake controller is used to receive power from two power sources.

[0027] Since the front-wheel drive units on both sides can provide sufficient braking deceleration for the electric vehicle, the two power supplies only need to power one rear wheel brake device. Thus, even if one of the two power supplies fails, the electromechanical braking system provided in this application can still provide sufficient braking force for the electric vehicle, so that the vehicle can still maintain good handling stability and passenger comfort during emergency braking.

[0028] Secondly, this application provides an electromechanical braking system, which includes two backup left front wheel end braking devices, two backup right front wheel end braking devices, and two rear wheel end braking devices. The two left front wheel end braking devices are used to brake the left front wheels of a vehicle. Each left front wheel end braking device includes a left front wheel drive unit and a left front wheel brake caliper. One left front wheel drive unit drives one left front wheel brake caliper to output clamping force to the brake disc of the left front wheel of the vehicle. During vehicle braking, both left front wheel drive units simultaneously drive one left front wheel brake caliper to output clamping force to the brake disc of one left front wheel of the vehicle; alternatively, one of the two left front wheel drive units drives one left front wheel brake caliper to output clamping force to the brake disc of the left front wheel. The two right front wheel end braking devices are used to brake the vehicle... The vehicle's right front wheel, each right front wheel wheel-end braking device includes a right front wheel drive unit and a right front wheel brake caliper. One right front wheel drive unit is used to drive one right front wheel brake caliper to output clamping force to the brake disc of the right front wheel of the vehicle. During vehicle braking, two right front wheel drive units are used to simultaneously drive one right front wheel brake caliper to output clamping force to the brake disc of one right front wheel of the vehicle, or one of the two right front wheel drive units is used to drive one right front wheel brake caliper to output clamping force to the brake disc of the right front wheel. The two rear wheel wheel-end braking devices are used to brake the two rear wheels of the vehicle respectively. Each rear wheel wheel-end braking device includes a rear wheel drive unit and a rear wheel brake caliper. During vehicle braking, one rear wheel drive unit of each rear wheel wheel-end braking device is used to drive one rear wheel brake caliper to output clamping force to the brake disc of one rear wheel of the vehicle.

[0029] In one possible implementation, each left front wheel drive unit includes a left front wheel brake controller and a left front wheel brake motor. The left front wheel brake controller controls the left front wheel brake motor to drive the left front wheel brake caliper to output clamping force. Each right front wheel drive unit includes a right front wheel brake controller and a right front wheel brake motor. The right front wheel brake controller controls the right front wheel brake motor to drive the right front wheel brake caliper to output clamping force. Each rear wheel drive unit includes a rear wheel brake controller and a rear wheel brake motor. The rear wheel brake controller controls the rear wheel brake motor to drive a rear wheel brake caliper to output clamping force.

[0030] As one possible implementation, during the braking of a vehicle by an electromechanical braking system, if one of the two left front wheel end brake devices fails, the other left front wheel end brake device outputs clamping force to the brake disc of the left front wheel. Similarly, during the braking of a vehicle by an electromechanical braking system, if one of the two right front wheel end brake devices fails, the other right front wheel end brake device outputs clamping force to the brake disc of the right front wheel.

[0031] Thirdly, this application provides an electric vehicle, which includes a power battery, wheels, and an electromechanical braking system for redundant braking as described in the first aspect, or an electromechanical braking system for redundant braking as described in any of the second aspects. Attached Figure Description

[0032] Figure 1 is a structural schematic diagram of an electric vehicle;

[0033] Figure 2 is a schematic diagram of the wheel-end braking device;

[0034] Figure 3 is a schematic diagram of the current dual-redundant electromechanical braking system;

[0035] Figure 4 is a schematic diagram of the redundant braking electromechanical braking system of this application;

[0036] Figure 5 is a schematic diagram of the drive controller;

[0037] Figure 6 is a schematic diagram of the front wheel end braking device of this application;

[0038] Figure 7 is a schematic diagram of the structure of the two central controllers;

[0039] Figure 8 is a schematic diagram of the power supply of the electromechanical braking system.

[0040] Figure 9 is a schematic diagram of the power supply for the electromechanical braking system (II).

[0041] Figure 10A is a schematic diagram of braking after the failure of the electromechanical braking system;

[0042] Figure 10B is a schematic diagram of braking after the failure of the electromechanical braking system;

[0043] Figure 11 Schematic diagram of braking after the front wheel drive unit overheats;

[0044] Figure 12 is a schematic diagram of braking after the failure of the electromechanical braking system;

[0045] Figure 13 is a schematic diagram of braking after the failure of the electromechanical braking system;

[0046] Figure 14 is a schematic diagram of braking after the failure of the electromechanical braking system;

[0047] Figure 15 is a schematic diagram of braking after the failure of the electromechanical braking system.

[0048] Figure 16 is a schematic diagram of braking after the failure of the electromechanical braking system;

[0049] Figure 17 is a schematic diagram of braking after the failure of the electromechanical braking system.

[0050] Figure 18 is a schematic diagram of braking after the failure of the electromechanical braking system;

[0051] Figure 19 is a schematic diagram of another redundant braking electromechanical braking system of this application. Detailed Implementation

[0052] The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to also include expressions such as “one or more” unless the context clearly indicates otherwise.

[0053] References to "one embodiment" or "some embodiments" as used in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0054] Electromechanical braking systems offer numerous advantages, including simple layout and rapid response, making them a major direction for future technological development. Unlike traditional hydraulic braking, electromechanical braking systems transmit braking commands via electrical signals instead of hydraulic connections, which places higher demands on the functional safety standards of the entire braking system.

[0055] Figure 1 is a schematic diagram of the electric vehicle's structure. As shown in Figure 1, the electromechanical braking system in the electric vehicle 100 includes four wheel-end braking devices. The electric vehicle 100 also includes a brake pedal and a parking button (not shown in the figure), which the driver can use to control the driving state of the electric vehicle 100. The travel of the brake pedal and the state of the parking button can control the wheel-end braking devices to perform braking and / or parking. During the braking process of the electric vehicle 100, the electromechanical braking system is used to provide braking force to all four wheels.

[0056] Figure 2 is a schematic diagram of the wheel-end braking device. As shown in Figure 2, the wheel-end braking device includes a brake actuator 121 and a wheel-end controller 123. The brake actuator 121 includes a brake motor 1211 and a brake caliper 1212. During the braking process of the electric vehicle 100, the wheel-end controller 123 controls the brake motor 1211 to drive the brake caliper 1212 to clamp the brake disc 13 of the electric vehicle 100, thereby providing braking force to the electric vehicle 100. The specific structure of the wheel-end braking device is not limited to the structure shown in Figure 2, and can also be various other possible structures.

[0057] Most electric vehicles on the market today are equipped with an electromechanical braking system. While this design aligns with lightweight design principles, it also introduces potential safety hazards. When a single electromechanical braking system malfunctions in the brake pedal, electronic controller, or other critical components, it not only struggles to identify and locate the source of the problem in a timely manner but may also directly lead to the loss of braking function in the electric vehicle, seriously threatening its driving safety.

[0058] Currently, to ensure the reliability of electromechanical braking systems and maintain minimum braking capacity even in the event of a single component failure, a dual redundancy mechanism is employed. For example, the electromechanical braking system shown in Figure 3 utilizes a dual power supply, dual CAN bus communication, and a dual central controller architecture. This ensures that even if a component fails, the system can continue to provide necessary braking force through the redundant system, thus preventing single-point failures from jeopardizing driving safety or violating safety performance indicators, such as insufficient or excessive braking force, or causing vehicle yaw and loss of control.

[0059] While the aforementioned improvements can enhance the fault tolerance of electromechanical braking systems to some extent, higher-level autonomous driving scenarios (Level 3 and above) place even more stringent demands on them. According to Level 3 standards, when the braking system encounters a single point of failure, the electromechanical braking system must be able to provide at least 6.43 m / s². 2 The above braking deceleration is to ensure a safe stopping distance in emergency situations.

[0060] Under the current design, if the drive unit in one wheel-end brake fails (e.g., power semiconductor failure, three-phase wiring failure, or motor failure), and without relying on external auxiliary systems (such as steering or drive systems), the electromechanical braking system currently helps prevent vehicle yaw by implementing a diagonal braking strategy to maintain vehicle stability. The basic principle is to deactivate the other wheel-end brake that is diagonally opposite the failed wheel-end brake, while adjusting the braking force output of the other two wheel-end brakes (i.e., the left front wheel and the right rear wheel, or the right front wheel and the left rear wheel) to compensate for the braking force missing from the failed wheel-end brake, thereby ensuring the straight-line stability of the vehicle and reducing lateral forces, thus preventing yaw.

[0061] It should be noted that due to inertia, the weight of a vehicle will shift to the front axle. Therefore, the brake discs of the front wheels are larger than those of the rear wheels. The larger surface area of ​​the brake discs can increase the contact area with the brake pads, and consequently, the braking force that the front wheels can output is also greater than that that the rear wheels can output.

[0062] Specifically, assuming all wheel-end braking devices are functioning normally, the braking force provided by the drive unit in the wheel-end braking device of one front wheel for an electric vehicle is greater than the braking force provided by the drive unit in the wheel-end braking device of one rear wheel. When the drive units in both front wheel wheel braking devices are functioning normally, they can provide a braking force of 6.43 m / s². 2 The above braking deceleration is insufficient if the drive units in the wheel-end braking devices of both the front and rear wheels are functioning normally; otherwise, a braking deceleration exceeding 6.43 m / s² cannot be provided to the vehicle. Similarly, even if the drive units in the wheel-end braking devices of both rear wheels are functioning normally, a braking deceleration exceeding 6.43 m / s² cannot be provided. 2 The above braking deceleration.

[0063] In view of this, this application provides a redundant electromechanical braking system. By setting two front-wheel drive units in each front wheel end braking device, even if one front wheel drive unit in the front wheel end braking device fails, the other front wheel drive unit in the front wheel end braking device can still work normally. Thus, the redundant electromechanical braking system provided by this application can still provide sufficient braking deceleration.

[0064] Figure 4 is a schematic diagram of the redundant braking electromechanical braking system provided in the embodiment of this application. As shown in Figure 4, the redundant braking electromechanical braking system 400 includes a front wheel end braking device 401 and a front wheel end braking device 402, as well as a rear wheel end braking device 403 and a rear wheel end braking device 404.

[0065] The front wheel end braking device 401 is used to brake the left front wheel of the vehicle, and the front wheel end braking device 402 is used to brake the right front wheel of the vehicle. The front wheel end braking device 401 includes a front wheel brake caliper 4011, a front wheel drive unit 4012, and a front wheel drive unit 4013. The front wheel end braking device 402 includes a front wheel brake caliper 4021, a front wheel drive unit 4022, and a front wheel drive unit 4023. The rear wheel end braking device 403 includes a rear wheel brake caliper 4031 and a rear wheel drive unit 4032. The rear wheel end braking device 404 includes a rear wheel brake caliper 4041 and a rear wheel drive unit 4042.

[0066] During vehicle braking, at least one of the front-wheel drive units 4012 and 4013, which serve as backups for each other, drives the front brake caliper 4011 to output clamping force to the brake disc of one of the vehicle's left front wheels. At least one of the front-wheel drive units 4022 and 4023, which serve as backups for each other, drives the front brake caliper 4021 to output clamping force to the brake disc of one of the vehicle's right front wheels. The rear-wheel drive unit 4032 drives the rear brake caliper 4031 to output clamping force to the brake disc of one of the vehicle's left rear wheels. The rear-wheel drive unit 4042 drives the rear brake caliper 4041 to output clamping force to the brake disc of one of the vehicle's right rear wheels.

[0067] The specific structures of the front wheel end braking devices 401 and 402, as well as the rear wheel end braking devices 403 and 404, are not limited to the structures shown in Figure 5, and can be various other possible structures.

[0068] This application is mainly applied to vehicles during braking and parking, including but not limited to pure electric vehicles (pure EV / battery EV), hybrid electric vehicles (HEV), range-extended electric vehicles (REEV), plug-in hybrid electric vehicles (PHEV), and new energy vehicles (NEV).

[0069] The redundant braking electromechanical braking system 400 provided in this application ensures that, in the event of failure of any one of the drive units 4012 and 4013 in the front wheel end braking device 401, or 4022 and 4023 in the front wheel end braking device 402, the other drive unit in the device can still function normally and drive the front wheel brake caliper to output clamping force to the brake disc of one of the front wheels of the vehicle. Thus, since there are drive units functioning normally on both sides, there is no need to use a diagonal braking strategy (i.e., left front wheel and right rear wheel or right front wheel and left rear wheel), thereby providing greater braking deceleration for the vehicle.

[0070] The front wheel drive unit 4012, front wheel drive unit 4013, front wheel drive unit 4022 and front wheel drive unit 4023 include a front wheel brake controller and a front wheel brake motor. The front wheel brake controller is used to control the front wheel brake motor to drive a front wheel brake caliper to output clamping force.

[0071] The rear-wheel drive unit 4032 and the rear-wheel drive unit 4042 include a rear-wheel brake controller and a rear-wheel brake motor. The rear-wheel brake controller is used to control the rear-wheel brake motor to drive a rear-wheel brake caliper to output clamping force.

[0072] The front-wheel drive controller and the rear-wheel drive controller have the same structure, as shown in Figure 5. Figure 5 is a schematic diagram of the drive controller structure. The drive controller includes a control circuit 501 and a brake motor power circuit 502. The brake motor power circuit 502 includes a three-phase bridge arm, and the brake motor 503 includes a three-phase winding. The midpoints of the three-phase bridge arms of the brake motor power circuit 502 are used to connect the three-phase windings of the brake motor. The control circuit 501 is used to control the brake motor power circuit 502 to output the brake motor drive current to the three-phase windings of the brake motor. The brake motor drive current is used to control the brake motor to drive the brake caliper to clamp the brake disc.

[0073] Referring to Figure 6, which is a schematic diagram of the front wheel end braking device 401 of this application, it includes a front wheel drive unit 4012, a front wheel drive unit 4013, a reducer 601, a ball screw 602, a front wheel brake caliper 4011, and a front wheel brake disc 604. The structure of the front wheel end braking device 402 can be referenced from that of the front wheel end braking device 401, and will not be described again here.

[0074] In this system, the brake motor power circuit 502 in the front-wheel drive units 4012 and 4013 is controlled by the control circuit 501, driving the brake motor 503 to generate rotational force and provide sufficient torque. At least one brake motor 503 in the front-wheel drive units 4012 and 4013 transmits the generated rotational power to the reducer 601. The reducer 601 converts the high-speed, low-torque output generated by the brake motor 503 into a low-speed, high-torque output, making it more suitable for use with subsequent ball screw transmission components. The reducer 601 can be of various types, such as gear reducer, worm gear reducer, or planetary gear reducer.

[0075] The rotational torque output by reducer 601 can be transmitted to the ball screw through force transmission components such as couplings. The ball screw is a device that converts rotational motion into linear motion. It consists of a screw and a nut, with balls filling the space between the screw and the nut. When the screw rotates, the nut moves along the screw axis, and the linear motion of the screw is converted into a force that pushes or pulls the brake caliper.

[0076] The linear motion of the ball screw directly acts on the piston of the brake caliper or indirectly through the linkage mechanism, causing the brake pads inside the brake caliper to move to the sides or inside of the brake disc. The brake pads clamp the rotating brake disc, and the kinetic energy of the electric vehicle is converted into heat energy through friction, thereby achieving deceleration and braking.

[0077] The front-wheel drive unit 4012 and the front-wheel drive unit 4013 can be backups for each other. That is, in normal operation, each brake motor 503 in the front-wheel drive unit 4012 and the front-wheel drive unit 4013 is connected to the reducer 601. The front wheel brake caliper 4011 can be driven by either the front-wheel drive unit 4012 or the front-wheel drive unit 4013 to output clamping force, or the front-wheel drive unit 4012 and the front-wheel drive unit 4013 can jointly drive the front wheel brake caliper 4011 to output clamping force. The brake motors of the front-wheel drive unit 4012 and the front-wheel drive unit 4013 can be arbitrarily allocated to output braking torque.

[0078] When the braking torque output by either the front wheel brake motor of the front wheel drive unit 4012 or the front wheel drive unit 4013 is sufficient to enable the front wheel brake caliper 4011 to output sufficient clamping force, the front wheel brake caliper 4011 can be driven by either the front wheel drive unit 4012 or the front wheel drive unit 4013. If the front wheel drive unit 4012 fails during the process of driving the front wheel brake caliper 4011 to output clamping force, the front wheel drive unit 4013 of the front wheel brake device 401 can drive the front wheel brake caliper 4011 to output clamping force, thereby ensuring that the front wheel on that side provides sufficient braking deceleration.

[0079] Alternatively, if the front wheel drive unit 4013 fails during the process of the front wheel drive unit 4013 driving the front wheel brake caliper 4011 to output clamping force, the front wheel drive unit 4012 of the front wheel drive unit 4011 can drive the front wheel brake caliper 4011 to output clamping force, thereby ensuring that the front wheel on that side provides sufficient braking deceleration.

[0080] During the process where the front wheel drive units 4012 and 4013 of the front wheel end braking device 401 jointly drive the front wheel brake caliper 4011 to output clamping force, if the front wheel drive unit 4012 fails, the front wheel brake motor of the front wheel drive unit 4013 can increase the braking torque output. In this way, the front wheel drive unit 4013 can compensate for the braking torque originally output by the front wheel brake motor of the failed front wheel drive unit 4012, enabling the front wheel drive unit 4012 to drive the front wheel brake caliper 4011 to output clamping force, thereby ensuring that the front wheel on that side provides sufficient braking deceleration. All embodiments of this application use the front wheel end braking device 401 as an example; a similar control strategy applies to the front wheel end braking device 402, which will not be elaborated upon here.

[0081] During the process of the front-wheel drive unit driving the front wheel brake calipers to output clamping force, if the clamping force output to the front wheel brake calipers increases, the contact pressure between gears, bearings, and other transmission components will increase, leading to increased friction. The greater the friction, the more heat is generated. If this heat cannot be cooled in time, the front-wheel drive unit will overheat.

[0082] Based on the aforementioned overheating issue, if the braking torque output by either the front wheel brake motor of the front wheel drive unit 4012 or the front wheel brake motor of the front wheel drive unit 4013 is sufficient to enable the front wheel brake caliper 4011 to output sufficient clamping force, and if the temperature of the front wheel drive unit 4012 exceeds a preset temperature value during the process of the front wheel brake caliper 4011 being driven by the front wheel drive unit 4012 to output clamping force, the front wheel brake motor of the front wheel drive unit 4012 can reduce its output braking torque, and the front wheel brake motor of the front wheel drive unit 4013 can output braking torque. In this way, the front wheel drive unit 4013 can compensate for the braking torque originally output by the front wheel brake motor of the front wheel drive unit 4012, which is overheated. This not only avoids overheating of the front wheel drive unit 4012, but also ensures that the front wheel on that side provides sufficient braking deceleration.

[0083] During the process where the front wheel drive unit 4012 and the front wheel drive unit 4013 of the front wheel end braking device 401 jointly drive the front wheel brake caliper 4011 to output clamping force, if the temperature of the front wheel drive unit 4012 is greater than the preset temperature value, the front wheel brake motor of the front wheel drive unit 4012 with a temperature greater than the preset temperature value can reduce the output braking torque, and the front wheel drive unit 4013 can drive the front wheel brake motor of the front wheel brake caliper 4011 to increase the output braking torque. In this way, the front wheel drive unit 4013 can compensate for the braking torque originally output by the front wheel brake motor of the front wheel drive unit 4012 with an excessively high temperature, thereby avoiding overheating of the front wheel drive unit 4012 and ensuring that the front wheel on that side provides sufficient braking deceleration.

[0084] When the clamping force output by a front-wheel drive unit for the front brake caliper is small, this application can determine whether the clamping force is output by one front-wheel drive unit driving one front brake caliper or by two front-wheel drive units jointly driving one front brake caliper, based on the clamping force indicated by the clamping force signal.

[0085] Optionally, when the clamping force indicated by the clamping force signal is less than the preset clamping force, only one of the front wheel drive units 4012 and 4013 needs to output clamping force to one front wheel brake caliper. In this way, the number of front wheel drive units used can be reduced, thereby reducing the overall power consumption of the braking system.

[0086] When the clamping force indicated by the clamping force signal is greater than or equal to the preset clamping force, it is difficult to meet the clamping force indicated by the clamping force signal using only one of the front wheel drive units 4012 and 4013. Therefore, both front wheel drive units 4012 and 4013 are needed to jointly drive one front wheel brake caliper to output clamping force, thereby achieving the clamping force indicated by the clamping force signal and ensuring that the front wheel on that side provides sufficient braking deceleration. The preset clamping force can be freely set by those skilled in the art. For example, the preset clamping force is the maximum clamping force that one front wheel drive unit can drive the front wheel brake caliper to output.

[0087] As one possible implementation, the electromechanical braking system 400 further includes two central controllers. At least one of the two central controllers is used to receive brake pedal signals from a pedal sensor. The brake pedal signals are used to indicate the movement state of the brake pedal. During the braking process of the electromechanical braking system 400, at least one of the two central controllers is used to control the front wheel end brake devices 401 and 402, as well as the rear wheel end brake devices 403 and 404, to output clamping forces to the brake discs corresponding to the four wheels of the vehicle, respectively, according to the indication of the brake pedal signals.

[0088] Either of the two central controllers is used to receive a brake pedal signal from the pedal sensor. The brake pedal signal is used to indicate the movement state of the brake pedal. The two central controllers are used to send brake control signals to the wheel end controllers of the front wheel end brake devices 401 and 402, and the rear wheel end brake devices 403 and 404. The brake control signals are used to instruct the wheel end brake devices to output braking force to the brake disc.

[0089] As one possible implementation, the electromechanical braking system includes two pedal sensors that serve as backups for each other. The two pedal sensors include a first pedal sensor and a second pedal sensor. The two central controllers specifically include a first central controller and a second central controller. The first pedal sensor is connected to the first central controller, and the second pedal sensor is connected to the second central controller. The first central controller is used to receive a first brake pedal signal output by the first pedal sensor, and the second central controller is used to receive a second brake pedal signal output by the second pedal sensor.

[0090] Furthermore, either the front wheel brake controller or the rear wheel brake controller can also be used to receive the first brake pedal signal / second brake pedal signal from the first pedal sensor / second pedal sensor. After receiving the aforementioned brake pedal signal, the front wheel brake controller or the rear wheel brake controller is used to send brake control signals to the wheel-end controllers of other wheel-end braking devices. In this way, even if the central controller receiving the brake pedal signal fails, the front wheel brake controller or the rear wheel brake controller used to receive the brake pedal signal can still provide stable control for each wheel-end braking device, so that each wheel-end braking device provides the correct braking force, thereby improving the safety and reliability of electric vehicle braking.

[0091] The pedal sensor can be either a brake pedal displacement sensor or a brake pedal pressure sensor. A brake pedal displacement sensor monitors the angle of movement of the brake pedal. The central controller calculates the brake pedal travel based on the angle of movement from the brake pedal displacement sensor, thus obtaining the braking force requirement of the electric vehicle. A brake pedal pressure sensor monitors the pressure acting on the brake pedal. The central controller calculates the braking travel based on the pressure acting on the brake pedal, thus obtaining the braking force requirement of the electric vehicle.

[0092] As shown in Figure 7, both central controllers (referred to here as the first central controller 701 and the second central controller 702) are connected to the public CAN network of the electric vehicle. The first central controller 701 and the second central controller 702 can communicate with each other via the public CAN network or directly via a hardwired connection. Furthermore, the first central controller 701 and the second central controller 702 can also communicate with other controllers of the electric vehicle via the public CAN network. For example, the first central controller 701 and the second central controller 702 can communicate with the vehicle controller.

[0093] The first central controller 701 and the second central controller 702 in the electromechanical braking system provided in this application can also communicate using a dual-redundant public CAN network to realize information interaction between the main controller of the braking system and external ECUs such as automatic driving controllers, power steering controllers, and power domain controllers. The dual-redundant public CAN network can realize information interaction between the first central controller 701, the second central controller 702, and other drive units.

[0094] Each front and rear wheel brake controller communicates with the two central controllers via a chassis-owned private CAN network. On one hand, the two central controllers can send brake control signals to the front / rear wheel brake controllers via the chassis-owned private CAN network, thereby controlling the output braking force of the front wheel-end brake devices 401 and 402, and the rear wheel-end brake devices 403 and 404. On the other hand, the front / rear wheel brake controllers can also send status signals of the front wheel-end brake devices 401 and 402, and the rear wheel-end brake devices 403 and 404 to the two central controllers via the chassis-owned private CAN network, such as the current temperature of the brake motor, the current output torque of the brake motor, and the clamping force status signal of the brake calipers.

[0095] When both central controllers are functioning normally, either one of the two central controllers is responsible for controlling the output braking force of the front wheel end brake devices 401 and 402, as well as the rear wheel end brake devices 403 and 404. If either of the two central controllers fails abnormally, the other central controller can continue to control the output braking force of the front / rear wheel end brake devices, thereby avoiding the failure of the entire electromechanical braking system 400 due to the failure of one central controller, and improving the safety and reliability of the braking system.

[0096] In one possible implementation, each front / rear wheel brake controller includes a housing, the surface of which includes an internal bus interface, an external bus interface, and a power interface. The internal bus interface is used to connect to an internal bus, the external bus interface is used to connect to an external bus, and the power interface is used to connect to a power supply.

[0097] The internal bus receives signals from the braking devices at other wheels of the electric vehicle, while the external bus receives signals from external controllers, including at least one of the following: an autonomous driving controller, a power steering controller, a power domain controller, and inertial sensors, etc. Power is supplied to each front / rear wheel brake controller via a power interface.

[0098] Referring to Figure 8, which is a schematic diagram of the power supply of the electromechanical braking system, the electromechanical braking system 400 includes two power supplies, namely a first power supply 801 and a second power supply 802. The first power supply 801 is used to supply power to the front wheel drive unit 4012 of the front wheel end braking device 401, the front wheel drive unit 4022 of the front wheel end braking device 402, the rear wheel drive unit 4032 of the rear wheel end braking device 403, and the first central controller 701.

[0099] The second power supply 802 is used to supply power to the front wheel drive unit 4013 of the front wheel end braking device 401, the front wheel drive unit 4023 of the front wheel end braking device 402, the rear wheel drive unit 4042 of the rear wheel end braking device 404, and the second central controller 702.

[0100] This power supply method saves on power supply costs. Furthermore, even if one of the first power supply 801 and the second power supply 802 fails, the other power supply can still power one front-wheel drive unit on each side of the front wheels and another central controller. Even if one central controller loses power, the other central controller can still control other brake controllers. In addition, even if one rear-wheel brake controller loses power, the two front-wheel drive units alone can provide the electric vehicle with a braking deceleration of over 6.43 m / s², supporting Level 3 and above autonomous driving functions.

[0101] Referring to Figure 9, which is a second power supply schematic diagram of the electromechanical braking system, the first power supply 801 is used to supply power to the front wheel drive unit 4012 of the front wheel end braking device 401, the front wheel drive unit 4022 of the front wheel end braking device 402, the rear wheel drive unit 4032 of the rear wheel end braking device 403, the rear wheel drive unit 4042 of the rear wheel end braking device 404, the first central controller 701, and the second central controller 702.

[0102] The second power supply 802 is used to supply power to the front wheel drive unit 4013 of the front wheel end braking device 401, the front wheel drive unit 4023 of the front wheel end braking device 402, the rear wheel drive unit 4032 of the rear wheel end braking device 403, the rear wheel drive unit 4042 of the rear wheel end braking device 404, the first central controller 701, and the second central controller 702.

[0103] Using this power supply method, even if one of the first power supply 801 and the second power supply 802 fails, the other of the first power supply 801 and the second power supply 802 can still supply power to one front-wheel drive unit on each side of the front wheels. The rear-wheel drive units in the two rear wheel end braking devices can also be powered normally. Thus, the two front-wheel drive units and the two rear-wheel drive units can provide 6.43 m / s² to the electric vehicle. 2 The above braking deceleration enables Level 3 and above intelligent driving functions.

[0104] The electromechanical braking system 400 of this application provides sufficient braking deceleration for an electric vehicle by providing two redundant front-wheel drive units in each front wheel end braking device. Even if one front-wheel drive unit in a front wheel end braking device fails at a single point, the other front-wheel drive unit can still operate normally. In this case, since there are normally operating front-wheel drive units on both sides of the front wheels, there is no need to use a diagonal braking strategy for braking compensation. The front-wheel drive units on both sides and the two rear-wheel drive units can provide sufficient braking deceleration for the electric vehicle. When a single point of failure occurs in the rear-wheel drive unit in the rear wheel end braking device, since the front-wheel drive units on both sides of the front wheels are still operating normally, they can also provide sufficient braking deceleration for the electric vehicle.

[0105] The following detailed description of the different operating scenarios of the electromechanical braking system 400, using specific embodiments, is provided:

[0106] I. Normal working scenarios

[0107] When each front wheel-end brake unit and the rear wheel-end brake unit in the electromechanical braking system are operating normally, either of the two central controllers receives a brake pedal signal from the pedal sensor. This central controller calculates and distributes the braking force output by each front and rear wheel-end brake unit based on the brake pedal signal. Specifically, for each of the two front wheel-end brake units in each front wheel-end brake unit, the central controller can either cause both front wheel-end brake units in each unit to drive the brake calipers to output clamping force to the brake disc of one front wheel of the electric vehicle, or it can cause either one of the front wheel-end brake units in each unit to drive the brake calipers to output clamping force to the brake disc of one front wheel of the electric vehicle.

[0108] After determining the required braking force for each wheel-end braking unit, the central controller sends a braking control signal to the brake controller in each wheel-end braking unit. In response to the braking control signal, the control circuit 501 in each brake controller controls the brake motor power circuit 502 to output a corresponding current to drive the brake motor to output braking torque. The brake motor then drives the brake actuator (reducer 601 and ball screw 602) to drive the brake caliper to clamp the corresponding brake disc, thus outputting the braking force indicated by the braking control signal.

[0109] Specifically, for each front wheel brake unit, having the two front wheel brake units in each front wheel brake unit simultaneously drive the brake calipers to output clamping force to the brake disc of one front wheel of the electric vehicle can avoid insufficient braking force generated by a single front wheel brake unit, thereby providing the electric vehicle with greater braking deceleration to meet higher levels of intelligent driving and improve the user's driving experience.

[0110] II. Single point of failure scenarios

[0111] In this context, a single point of failure refers to the situation where, even if one device or component (other than the brake caliper) in the electromechanical braking system 400 fails, the electromechanical braking system 400 can still complete braking normally. Specifically, the following provides a detailed description of the specific circumstances of single point failure and the corresponding control methods in conjunction with specific embodiments.

[0112] 1. Front-wheel drive unit failure

[0113] When the front wheel drive unit 4012 in the front wheel end brake device 401 fails, the front wheel drive unit 4013 in the front wheel end brake device 401 is used to drive the front wheel brake caliper 4011 to output clamping force.

[0114] Specifically, during the process of the front wheel drive unit 4012 of the front wheel end braking device 401 driving the front wheel brake caliper 4011 to output clamping force, in response to the failure of the front wheel drive unit 4012, the front wheel drive unit 4013 of the front wheel end braking device 401 is used to drive the front wheel brake caliper 4011 to output clamping force.

[0115] During the process of the front wheel drive unit 4012 and the front wheel drive unit 4013 jointly driving the front wheel brake caliper 4011 to output clamping force in the front wheel end braking device 401, in response to the failure of the front wheel drive unit 4012, the braking torque output by the front wheel brake motor of the front wheel drive unit 4013 drives the front wheel brake caliper 4011 to output clamping force.

[0116] For example, if the front wheel drive unit 4012 in the front wheel end braking device 401 fails, the front wheel drive unit 4013 in the front wheel end braking device 401 drives the front wheel brake caliper 4011 to output clamping force, the front wheel drive unit 4022 or the front wheel drive unit 4023 in the front wheel end braking device 402 outputs sufficient clamping force to the front wheel brake caliper 4021, and the rear wheel drive units in the rear wheel end braking devices 403 and 404 output sufficient clamping force to their respective rear wheel brake calipers. A schematic diagram of braking after the failure of the electromechanical braking system 400 is shown in Figure 10A.

[0117] Alternatively, when the front-wheel drive unit 4012 in the front wheel end braking device 401 fails, the front wheel drive unit 4013 drives the front wheel brake caliper 4011 to output clamping force, the front wheel drive units 4022 and 4023 in the front wheel end braking device 402 output sufficient clamping force to the front wheel brake caliper 4021, and the rear wheel drive units in the rear wheel end braking devices 403 and 404 output sufficient clamping force to their respective rear wheel brake calipers. A second schematic diagram of braking after the failure of the electromechanical braking system 400 is shown in Figure 10B. It can provide sufficient braking force for electric vehicles to support Level 3 and above intelligent driving scenarios, providing greater braking deceleration.

[0118] When the temperature of the front wheel drive unit 4012 in the front wheel end braking device 401 exceeds a preset temperature value, the front wheel brake motor of the front wheel drive unit 4012, whose temperature exceeds the preset temperature value, reduces the output braking torque, and the front wheel brake motor of the front wheel drive unit 4013 outputs braking torque. A schematic diagram of braking after the front wheel drive unit overheats is shown in Figure 11.

[0119] 2. Rear-wheel drive unit failure

[0120] When the rear-wheel drive unit 4032 in the rear wheel-end braking device 403 fails, to avoid vehicle yaw caused by the unbalanced braking force resulting from the continued operation of the rear-wheel drive unit 4042 in the rear wheel-end braking device 404, it is necessary to stop the rear-wheel drive unit 4042 of the rear wheel-end braking device 404 from driving the rear wheel brake caliper 4041, and to allow the front-wheel drive units 4012 / 4013 in the front wheel-end braking device 401 to output sufficient clamping force to the front wheel brake caliper 4011, and the front-wheel drive units 4022 / 4023 in the front wheel-end braking device 402 to output sufficient clamping force to the front wheel brake caliper 4021. A schematic diagram of braking after the failure of the electromechanical braking system 400 is shown in Figure 12.

[0121] Furthermore, in order to provide sufficient braking deceleration to the electric vehicle, after the rear-wheel drive unit 4042 of the rear wheel end braking device 404 stops driving the rear wheel brake caliper 4041, the front wheel end braking device 401 can be controlled to drive the front wheel brake caliper 4011 to increase the clamping force output, and the front wheel end braking device 402 can drive the front wheel brake caliper 4021 to increase the clamping force output. Thus, the front wheel end braking devices 401 and 402 on both sides can provide the electric vehicle with a braking deceleration of more than 6.43 m / s2 to support Level 3 and above intelligent driving functions.

[0122] In one possible implementation, when the rear-wheel drive unit 4032 in the rear wheel-end braking device 403 fails, to avoid vehicle yaw caused by the unbalanced braking force resulting from the continued operation of the rear-wheel drive unit 4042 in the rear wheel-end braking device 404, the rear-wheel drive unit 4042 of the rear wheel-end braking device 404 stops driving the rear wheel brake caliper 4041. This allows the front-wheel drive units 4012 and 4013 in the front wheel-end braking device 401 to jointly output sufficient clamping force to the front wheel brake caliper 4011, and the front-wheel drive units 4022 and 4023 in the front wheel-end braking device 402 to jointly output sufficient clamping force to the front wheel brake caliper 4021. A schematic diagram of braking after the failure of the electromechanical braking system 400 is shown in Figure 13. Thus, using the above failure handling strategy can provide sufficient braking force for electric vehicles to support Level 3 and above intelligent driving scenarios, providing greater braking deceleration.

[0123] In one possible implementation, when the front wheel braking unit alone may not be sufficient to achieve the required braking deceleration, or when the braking force output by the front wheel braking unit is too large, causing excessive "nose-diving" of the vehicle, the electromechanical braking system 400 provided in this application will activate the rear-wheel drive unit in another undamaged rear wheel end braking device, thereby applying an appropriate amount of braking force to compensate for braking force or prevent vehicle imbalance. A schematic diagram of braking after the electromechanical braking system 400 fails is shown in Figure 14. When the rear wheel end braking device 403 fails, the rear wheel drive unit 4042 in the rear wheel end braking device 404 is activated, outputting a certain clamping force to the rear wheel brake caliper 4041.

[0124] In this way, the above method not only ensures the overall braking effect of the vehicle, but also avoids the yaw phenomenon caused by excessive braking force on one side of the rear wheel. It not only improves the control precision of the electromechanical braking system 400 during the braking process, but also effectively balances the braking force distribution between the front and rear wheels, so that the vehicle can still maintain good handling stability and passenger comfort during emergency braking, thereby better meeting the needs of Level 3 and above intelligent driving scenarios.

[0125] 3. Central controller failure

[0126] In the process of the electromechanical braking system 400 braking a vehicle, if either of the two central controllers fails abnormally, the other central controller can continue to control the front / rear wheel end braking devices to output braking force, thereby providing sufficient braking force for the electric vehicle, so as to avoid the failure of the entire electromechanical braking system 400 due to the failure of one central controller, thus improving the safety and reliability of the braking system.

[0127] 4. Power failure

[0128] Based on the power supply architecture shown in Figure 8, if the first power supply 801 supplies power to the rear wheel end brake device 403 and the second power supply 802 supplies power to the rear wheel end brake device 404, the rear wheel end brake device 403 will not function properly when the first power supply 801 fails. To avoid vehicle yaw caused by the unbalanced braking force resulting from the continued operation of the rear wheel drive unit 4042 of the rear wheel end brake device 404, it is necessary to control the rear wheel drive unit 4042 of the rear wheel end brake device 404 to stop driving the rear wheel brake caliper 4041, so that the front wheel drive unit 4012 / 4013 in the front wheel end brake device 401 outputs sufficient clamping force to the front wheel brake caliper 4011, and the front wheel drive unit 4022 / 4023 in the front wheel end brake device 402 outputs sufficient clamping force to the front wheel brake caliper 4021.

[0129] Figure 15 shows a schematic diagram of braking after the failure of the electromechanical braking system 400. Similarly, when the braking force of the front wheel braking unit is insufficient, or when the braking force output by the front wheel braking unit is too large, causing the vehicle to "nose-dive" excessively, the rear wheel drive unit 4042 in the rear wheel end braking device 404 can be activated to output a certain clamping force to the rear wheel brake caliper 4041 when the rear wheel end braking device 403 fails, thereby compensating for the braking force or preventing vehicle imbalance. Figure 16 shows a schematic diagram of braking after the failure of the electromechanical braking system 400. In this way, the above processing strategy can avoid power failure, thereby providing sufficient braking force for electric vehicles to support Level 3 and above intelligent driving scenarios and provide greater braking deceleration.

[0130] When the second power supply 802 fails, the rear wheel end brake device 404 cannot function properly. To avoid vehicle yaw caused by the unbalanced braking force resulting from the continued operation of the rear wheel drive unit 4032 of the rear wheel end brake device 403, it is necessary to control the rear wheel drive unit 4032 of the rear wheel end brake device 403 to stop driving the rear wheel brake caliper 4031, so that the front wheel drive units 4012 / 4013 in the front wheel end brake device 401 output sufficient clamping force to the front wheel brake caliper 4011, and the front wheel drive units 4022 / 4023 in the front wheel end brake device 402 output sufficient clamping force to the front wheel brake caliper 4021. A schematic diagram of braking after the failure of the electromechanical braking system 400 is shown in Figure 17. Similarly, when the front wheel braking unit's braking force is insufficient, or when the front wheel braking unit's output braking force is excessive, causing the vehicle to "nose-dive" excessively, the rear wheel drive unit 4032 in the rear wheel brake unit 403 can be activated to output a certain clamping force to the rear wheel brake caliper 4031 when the rear wheel brake unit 404 fails. This compensates for the braking force or prevents the vehicle from becoming unbalanced. A schematic diagram of braking after the electromechanical braking system 400 fails is shown in Figure 18. Thus, using the above-mentioned processing strategy can prevent power failure, thereby providing sufficient braking force for electric vehicles to support Level 3 and above intelligent driving scenarios and provide greater braking deceleration.

[0131] In addition, based on the same concept, this application also provides another electromechanical braking system, as shown in Figure 19. The difference between the electromechanical braking system 1900 and the one shown in Figure 4 is that the electromechanical braking system 1900 includes a left front wheel end braking device 1901, a left front wheel end braking device 1902, a right front wheel end braking device 1903, a right front wheel end braking device 1904, a rear wheel end braking device 1905, and a rear wheel end braking device 1906.

[0132] The left front wheel end braking device 1901 and the left front wheel end braking device 1902 are backups for each other, and the right front wheel end braking device 1903 and the right front wheel end braking device 1904 are backups for each other.

[0133] The left front wheel end braking device 1901 includes a left front wheel brake caliper 19011 and a left front wheel drive unit 19012; the left front wheel end braking device 1902 includes a left front wheel brake caliper 19021 and a left front wheel drive unit 19022; the right front wheel end braking device 1903 includes a right front wheel brake caliper 19031 and a right front wheel drive unit 19032; the right front wheel end braking device 1904 includes a right front wheel brake caliper 19041 and a right front wheel drive unit 19042; the rear wheel end braking device 1905 includes a rear wheel brake caliper 19051 and a rear wheel drive unit 19052; and the rear wheel end braking device 1906 includes a rear wheel brake caliper 19061 and a rear wheel drive unit 19062.

[0134] During vehicle braking, the left front wheel drive unit 19012 and the left front wheel drive unit 19022 are used to simultaneously drive the corresponding left front wheel brake caliper 19011 and the left front wheel brake caliper 19021 to output clamping force to the brake disc 191 of the left front wheel of the vehicle, or one of the left front wheel drive units 19012 and the left front wheel drive unit 19022 is used to drive the corresponding left front wheel brake caliper to output clamping force to the brake disc 191 of the left front wheel.

[0135] During vehicle braking, the right front wheel drive unit 19032 and the right front wheel drive unit 19042 are used to simultaneously drive the corresponding right front wheel brake caliper 19031 and the right front wheel brake caliper 19041 to output clamping force to the brake disc 192 of the right front wheel of the vehicle. Alternatively, one of the right front wheel drive units 19032 and the right front wheel drive unit 19042 is used to drive the corresponding left front wheel brake caliper to output clamping force to the brake disc 192 of the right front wheel.

[0136] In one possible implementation, each left front wheel drive unit includes a left front wheel brake controller and a left front wheel brake motor. The left front wheel brake controller is used to control the left front wheel brake motor to drive the left front wheel brake caliper to output clamping force.

[0137] Each right front wheel drive unit includes a right front wheel brake controller and a right front wheel brake motor. The right front wheel brake controller is used to control the right front wheel brake motor to drive the right front wheel brake caliper to output clamping force.

[0138] Each rear-wheel drive unit includes a rear-wheel brake controller and a rear-wheel brake motor. The rear-wheel brake controller is used to control the rear-wheel brake motor to drive a rear-wheel brake caliper to output clamping force.

[0139] As one possible implementation, during the braking of a vehicle by an electromechanical braking system, if one of the two left front wheel end brake devices fails, the other left front wheel end brake device outputs clamping force to the brake disc of the left front wheel. Similarly, during the braking of a vehicle by an electromechanical braking system, if one of the two right front wheel end brake devices fails, the other right front wheel end brake device outputs clamping force to the brake disc of the right front wheel.

[0140] Based on the same concept, this application provides an electric vehicle, which includes a power battery, wheels, and an electromechanical braking system for redundant braking as shown in FIG4, or an electromechanical braking system for redundant braking as shown in FIG19.

[0141] Although this application has been described in conjunction with specific features and embodiments, it will be apparent that various modifications and combinations can be made therein without departing from the scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined by the appended claims, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application.

[0142] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of protection of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. An electromechanical braking system with redundancy, characterized in that, The electromechanical brake system comprises two front wheel end brake devices and two rear wheel end brake devices, wherein: The two front wheel end brake devices are respectively used for braking two front wheels of the vehicle, each of the front wheel end brake devices comprises a front wheel brake caliper and two front wheel drive units which are backup to each other, during braking of the vehicle, the two front wheel drive units are used for simultaneously driving the front wheel brake caliper to output clamping force to the brake disc of one of the front wheels of the vehicle, or one of the two front wheel drive units is used for driving the front wheel brake caliper to output clamping force to the brake disc of the front wheel; The two rear wheel end brake devices are respectively used for braking two rear wheels of the vehicle, each of the rear wheel end brake devices comprises a rear wheel drive unit and a rear wheel brake caliper, during braking of the vehicle, the rear wheel drive unit of each of the rear wheel end brake devices is used for driving the rear wheel brake caliper to output clamping force to the brake disc of one of the rear wheels of the vehicle.

2. The electromechanical brake system of claim 1, wherein, Each of the front wheel drive units comprises a front wheel brake controller and a front wheel brake motor, the front wheel brake controller of each of the front wheel drive units is used for controlling the front wheel brake motor to drive the front wheel brake caliper to output the clamping force; Each of the rear wheel drive units comprises a rear wheel brake controller and a rear wheel brake motor, the rear wheel brake controller of each of the rear wheel drive units is used for controlling the rear wheel brake motor to drive the rear wheel brake caliper to output the clamping force.

3. The electromechanical brake system of claim 2, wherein, During braking of one of the front wheels by any one of the front wheel end brake devices, failure of one of the two front wheel drive units, the other front wheel drive unit is used for driving the front wheel brake caliper to output clamping force.

4. The electromechanical brake system of claim 3, wherein, During braking of one of the front wheels by the two front wheel drive units of any one of the front wheel end brake devices, failure of one of the two front wheel drive units, the front wheel brake motor of the other front wheel drive unit increases brake torque output.

5. The electromechanical brake system of claim 2, wherein, During braking of the vehicle by the electromechanical brake system, failure of any one of the rear wheel drive units, each of the rear wheel drive units stops driving the rear wheel brake caliper to output clamping force and the two front wheel end brake devices drive the two front wheel brake calipers to increase clamping force output.

6. The electromechanical brake system of claim 2, wherein, During braking of one of the front wheels by one of the front wheel drive units of any one of the front wheel end brake devices, in response to that the temperature of the front wheel drive unit driving the front wheel brake caliper is greater than a preset temperature value, the front wheel brake motor of the front wheel drive unit with the temperature greater than the preset temperature value is controlled to reduce brake torque output and the front wheel brake motor of the other front wheel drive unit outputs brake torque; Or, In the process that the two front wheel drive units of any one of the front wheel end brake devices jointly drive the one front wheel brake caliper to output the clamping force, in response to the temperature of one of the front wheel drive units being greater than a preset temperature value, the front wheel brake motor of the front wheel drive unit with the temperature greater than the preset temperature value is controlled to reduce the brake torque output, and the front wheel brake motor of the other front wheel drive unit is controlled to increase the brake torque output.

7. The electromechanical brake system of claim 2, wherein, The two front wheel brake controllers of each front wheel brake device are configured to receive a clamping force signal, the clamping force signal being configured to indicate the size of the clamping force output by each front wheel end brake device to the brake disc of one front wheel of the vehicle; In response to the clamping force indicated by the clamping force signal being less than a preset clamping force, one of the two front wheel drive units is configured to drive the one front wheel brake caliper to output the clamping force; In response to the clamping force indicated by the clamping force signal being greater than or equal to the preset clamping force, the two front wheel drive units are jointly configured to drive the one front wheel brake caliper to output the clamping force.

8. The electromechanical brake system of claim 2, wherein, The electromechanical brake system further comprises two central controllers, at least one of the two central controllers is configured to receive a brake pedal signal from a pedal sensor, the brake pedal signal being configured to indicate the movement state of the brake pedal, and in the process that the electromechanical brake system is used to brake the vehicle, at least one of the two central controllers is configured to control four wheel end brake devices to output clamping forces to the brake discs corresponding to the four wheels of the vehicle according to the indication of the brake pedal signal.

9. The electromechanical brake system of claim 8, wherein, In the process that the electromechanical brake system is used to brake the vehicle, one of the central controllers is configured to: In response to the failure of the other one of the two central controllers, control four wheel end brake devices to output clamping forces to the brake discs corresponding to the four wheels of the vehicle.

10. The electromechanical brake system of claim 2, wherein, Each front wheel brake device is configured to receive power from two power supplies, wherein one front wheel brake controller of each front wheel end brake device is configured to receive power from one of the two power supplies, and the other front wheel brake controller of each front wheel end brake device is configured to receive power from the other of the two power supplies.

11. The electromechanical brake system of claim 10, wherein, One of the rear wheel brake controllers is configured to receive power from one of the power supplies, and the other rear wheel brake controller is configured to receive power from the other of the power supplies; or, One of the rear wheel brake controllers is configured to receive power from both of the power supplies, and the other rear wheel brake controller is configured to receive power from both of the power supplies.

12. An electromechanical braking system with redundancy, characterized in that, The electromechanical brake system comprises two left front wheel end brake devices that back up each other, two right front wheel end brake devices that back up each other, and two rear wheel end brake devices; wherein, The two left front wheel end braking devices are used to brake the left front wheel of the vehicle. Each left front wheel end braking device includes a left front wheel drive unit and a left front wheel brake caliper. The left front wheel drive unit is used to drive the left front wheel brake caliper to output clamping force to the brake disc of the left front wheel of the vehicle. During the braking process of the vehicle, the two left front wheel drive units are used to simultaneously drive the corresponding left front wheel brake caliper to output clamping force to the brake disc of one of the left front wheels of the vehicle, or one of the two left front wheel drive units is used to drive the corresponding left front wheel brake caliper to output clamping force to the brake disc of the left front wheel. The two right front wheel end braking devices are used to brake the right front wheel of the vehicle. Each right front wheel end braking device includes a right front wheel drive unit and a right front wheel brake caliper. The right front wheel drive unit is used to drive the right front wheel brake caliper to output clamping force to the brake disc of the right front wheel of the vehicle. During the braking process of the vehicle, the two right front wheel drive units are used to simultaneously drive the corresponding right front wheel brake caliper to output clamping force to the brake disc of one of the right front wheels of the vehicle, or one of the two right front wheel drive units is used to drive the corresponding right front wheel brake caliper to output clamping force to the brake disc of the right front wheel. The two rear wheel end braking devices are used to brake the two rear wheels of the vehicle respectively. Each rear wheel end braking device includes a rear wheel drive unit and a rear wheel brake caliper. During the vehicle braking process, the rear wheel drive unit of each rear wheel end braking device is used to drive the rear wheel brake caliper to output clamping force to the brake disc of one rear wheel of the vehicle.

13. The electromechanical brake system of claim 12, wherein, Each of the left front wheel drive units includes a left front wheel brake controller and a left front wheel brake motor. The left front wheel brake controller is used to control the left front wheel brake motor to drive the left front wheel brake caliper to output the clamping force. Each of the right front wheel drive units includes a right front wheel brake controller and a right front wheel brake motor. The right front wheel brake controller is used to control the right front wheel brake motor to drive the right front wheel brake caliper to output the clamping force. Each of the rear-wheel drive units includes a rear-wheel brake controller and a rear-wheel brake motor, wherein the rear-wheel brake controller is used to control the rear-wheel brake motor to drive the rear-wheel brake caliper to output the clamping force.

14. The electromechanical brake system of claim 13, wherein, During the process of the electromechanical braking system braking the vehicle, if one of the two left front wheel end braking devices fails, the other left front wheel end braking device will output a clamping force to the brake disc of the left front wheel. During the braking of the vehicle by the electromechanical braking system, if one of the two right front wheel end braking devices fails, the other right front wheel end braking device will output clamping force to the brake disc of the right front wheel.

15. An electric vehicle characterized by comprising: The electric vehicle includes a power battery, wheels, and an electromechanical braking system for redundant braking as described in any one of claims 1-11, or an electromechanical braking system for redundant braking as described in any one of claims 12-14.

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