Electronic mechanical braking system, vehicle controller and electric vehicle

Abstract

The invention provides an electronic mechanical braking system, a vehicle controller and an electric vehicle, and relates to the technical field of electric vehicles. The electronic mechanical braking system comprises a central controller and four wheel end braking devices, and the central controller is used for controlling the four wheel end braking devices to output clamping force to four wheels of the electric vehicle. Wherein the central controller is in communication with the whole vehicle CAN through two public CAN buses and is in communication with each of the four wheel end braking devices through two private CAN buses. In this way, redundant backup of the communication link is achieved, and the communication reliability of the electronic mechanical braking system is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric vehicles, and more particularly, to an electronic mechanical brake system, a vehicle controller and an electric vehicle. BACKGROUND

[0002] An electric vehicle equipped with an electronic mechanical brake system (EMB) usually realizes braking by controlling the wheel end brake device to output clamping force to the wheels in response to the driver operating the brake pedal, with the central controller in the electronic mechanical brake system. However, in the braking process of the electric vehicle, in some cases, the central controller is difficult to communicate with the whole vehicle and the wheel end brake device, which may cause the control failure of the brake system and affect the driving safety. SUMMARY

[0003] The present application provides an electronic mechanical brake system, a vehicle controller and an electric vehicle, in which each central controller in the electronic mechanical brake system communicates with the whole vehicle and the wheel end brake device through multiple CAN buses, realizes the redundant backup of the communication link, and improves the communication reliability of the electronic mechanical brake system.

[0004] In a first aspect, an embodiment of the present application provides an electronic mechanical brake system, which includes a central controller and four wheel end brake devices, and the central controller is configured to control the four wheel end brake devices to output clamping force to four wheels of an electric vehicle, wherein the central controller communicates with a whole vehicle CAN through two public CAN buses and communicates with each of the four wheel end brake devices through two private CAN buses.

[0005] In the embodiment, the central controller communicates with the whole vehicle CAN through multiple public CAN buses, which can be redundant to each other, thereby realizing the redundant backup of the communication link between the central controller and the whole vehicle. In the case of failure of one public CAN bus, communication can be realized through other public CAN buses, thereby avoiding the situation that the control failure of the electronic mechanical brake system occurs due to the failure of the link in the case of only one public CAN bus. In addition, the central controller communicates with each of the four wheel end brake devices through multiple private CAN buses, which can be redundant to each other, thereby realizing the redundant backup of the communication link between the central controller and the wheel end brake device. In the case of failure of one private CAN bus, communication can be realized through other private CAN buses, thereby avoiding the situation that the control failure of the electronic mechanical brake system occurs due to the failure of the link in the case of only one private CAN bus. In this way, the communication function of the electronic mechanical brake system is not failed, and the communication reliability and braking reliability of the electronic mechanical brake system are improved.

[0006] In an embodiment of the first aspect, each wheel end brake device comprises a wheel end controller and a wheel end actuator, the central controller sends a brake signal to one wheel end controller through two private CAN buses, and one wheel end controller controls one wheel end actuator to output a clamping force to the corresponding wheel after receiving the brake signal.

[0007] In the embodiment, each wheel end brake device comprises a wheel end controller and a wheel end actuator, the central controller sends a brake signal to one wheel end controller through two private CAN buses, which avoids the situation that the control of the electromechanical brake system fails due to the failure of the only private CAN bus, and then one wheel end controller controls one wheel end actuator to output a clamping force to the corresponding wheel after receiving the brake signal, thereby realizing braking and improving the communication reliability and braking reliability of the electromechanical brake system.

[0008] In an embodiment of the first aspect, the two public CAN buses comprise a first public CAN bus and a second public CAN bus, and the central controller receives signals through the first public CAN bus when the first public CAN bus is not faulty.

[0009] In the embodiment, the priority of the communication between the central controller and the whole vehicle through the first public CAN bus is higher than that through the second public CAN bus, so that the central controller receives signals through the first public CAN bus when the first public CAN bus is not faulty, thereby ensuring the certainty and predictability of signal reception and improving the reliability and fault tolerance of the electronic brake system.

[0010] In an embodiment of the first aspect, the central controller receives signals through the first public CAN bus and the second public CAN bus when the first public CAN bus has a first type of fault and the second public CAN bus is not faulty, and the first type of fault at least includes a data check fault and a communication timeout fault.

[0011] In the embodiment, the first type of fault at least includes a data check fault and a communication timeout fault, the first public CAN bus has the first type of fault, which means that the public CAN bus only fails when receiving the current signal, and does not fail when receiving other signals, and the second public CAN bus is not faulty, which means that the public CAN bus can be used to receive signals. In this case, the central controller receives signals through the first public CAN bus and the second public CAN bus, thereby ensuring the redundancy backup of the communication link and improving the communication reliability of the electromechanical brake system.

[0012] In an embodiment of the first aspect, when the first public CAN bus has a second type of fault and the second public CAN bus is not faulty, the central controller receives signals through the second public CAN bus, and the second type of fault at least includes a bus-off fault.

[0013] In the embodiment, the second type of fault at least includes a bus-off fault, and the first public CAN bus has the second type of fault, indicating that the communication of the public CAN bus is faulty. In this case, the central controller receives signals through the second public CAN bus, ensuring that the communication function of the electromechanical brake system is not disabled.

[0014] In an embodiment of the first aspect, when the first public CAN bus recovers from a fault within a target period, the central controller receives signals through the first public CAN bus.

[0015] In the embodiment, after automatically detecting that the first public CAN bus recovers from a fault within a target period, the central controller receives signals through the first public CAN bus, ensuring the certainty and predictability of receiving signals. The first public CAN bus and the second public CAN bus have been redundantly backed up to each other, improving the reliability and fault tolerance of the electronic brake system.

[0016] In an embodiment of the first aspect, the central controller sends signals to the whole vehicle through two public CAN buses.

[0017] In the embodiment, the central controller sends signals to the whole vehicle through two public CAN buses. The signals can be regarded as a detection signal when the public CAN bus is faulty, which is used to detect whether the public CAN bus has recovered to normal. This realizes accurate detection of whether the public CAN bus is in a fault state, and realizes redundant backup of the communication link, improving the communication reliability of the electromechanical brake system.

[0018] In an embodiment of the first aspect, the two private CAN buses include a first private CAN bus and a second private CAN bus, and when the first private CAN bus is not faulty, a wheel-end brake device receives signals through the first private CAN bus.

[0019] In the embodiment, the priority of communication between the central controller and the wheel-end brake device through the first private CAN bus is higher than that through the second private CAN bus. In the case that the first private CAN bus is not faulty, a wheel-end brake device receives signals through the first private CAN bus, ensuring the certainty and predictability of receiving signals, and improving the reliability and fault tolerance of the electronic brake system.

[0020] In an embodiment of the first aspect, when the first private CAN bus has a first type of fault and the second private CAN bus has no fault, the wheel end brake device receives the signal through the first private CAN bus and the second private CAN bus, and the first type of fault at least includes a data check fault and a communication timeout fault.

[0021] In the embodiment, the first type of fault at least includes a data check fault and a communication timeout fault, the first private CAN bus has the first type of fault, which means that the private CAN bus only has a fault when receiving the current signal, and has no fault when receiving other signals, and the second private CAN bus has no fault, which means that the private CAN bus can be used to receive signals. In this case, the wheel end brake device receives the signal through the first private CAN bus and the second private CAN bus, which ensures the redundancy backup of the communication link and improves the communication reliability of the electromechanical brake system.

[0022] In an embodiment of the first aspect, when the first private CAN bus has a second type of fault and the second private CAN bus has no fault, the wheel end brake device receives the signal through the second private CAN bus, and the second type of fault at least includes a bus shutdown fault.

[0023] In the embodiment, the second type of fault at least includes a bus shutdown fault, the first private CAN bus has the second type of fault, which means that the communication of the private CAN bus has a fault. In this case, the wheel end brake device receives the signal through the second private CAN bus, which ensures that the communication function of the electromechanical brake system does not fail.

[0024] In an embodiment of the first aspect, when the first private CAN bus recovers from a fault within a target period, the wheel end brake device receives the signal through the first private CAN bus.

[0025] In the embodiment, after automatically detecting that the first private CAN bus recovers from a fault within a target period, the wheel end brake device resumes receiving the signal through the first private CAN bus, which ensures the determinacy and predictability of receiving the signal. The first private CAN bus and the second private CAN bus have been mutually redundant, which improves the reliability and fault tolerance of the electronic brake system.

[0026] In an embodiment of the first aspect, the wheel end brake device sends a signal to the wheel end brake device through two private CAN buses.

[0027] In the embodiment, one wheel end brake device sends a signal to the central controller through two private CAN buses, and the signal can be regarded as a detection signal when the private CAN bus fails, which is used to detect whether the private CAN bus is restored to normal, so as to accurately detect whether the private CAN bus is in failure, realize the redundancy backup of the communication link, and improve the communication reliability of the electromechanical brake system.

[0028] In a second aspect, the embodiment of the application provides a vehicle controller, which communicates with a vehicle CAN through two public CAN buses and two private CAN buses and communicates with each of four wheel end brake devices through the two private CAN buses.

[0029] The vehicle controller can be the aforementioned central controller or a controller specially set for the application.

[0030] In an embodiment of the second aspect, the vehicle controller sends a signal to the vehicle through the two public CAN buses and sends a signal to the four wheel end brake devices through the two private CAN buses.

[0031] In a third aspect, the embodiment of the application provides an electric vehicle, which comprises an electromechanical brake system and four wheels, and the electromechanical brake system comprises a central controller and four wheel end brake devices, and the central controller is used to control the four wheel end brake devices to output clamping force to the four wheels of the electric vehicle.

[0032] The central controller communicates with a vehicle CAN through two public CAN buses and communicates with each of four wheel end brake devices through two private CAN buses.

[0033] The supplementary and technical effects of the solutions provided in the second aspect and the third aspect above can be referred to the corresponding description of the first aspect, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 FIG. 1 is a communication architecture schematic diagram of an electromechanical brake system;

[0035] Figure 2 FIG. 5 is a schematic diagram of an electric vehicle provided by the embodiment of the application;

[0036] Figure 3 FIG. 8 is a schematic diagram of an electromechanical brake system provided by the embodiment of the application;

[0037] Figure 4 FIG. 11 is a schematic diagram of a communication architecture of an electromechanical brake system provided by the embodiment of the application;

[0038] Figure 5This is a schematic diagram of a communication scenario of an electromechanical braking system provided in an embodiment of this application. Detailed Implementation

[0039] The technical solutions in this application will now be described in conjunction with the accompanying drawings. The detailed descriptions and drawings of the following embodiments are used to exemplarily illustrate the principles of this application, but should not be used to limit the scope of this application; that is, this application is not limited to the described embodiments.

[0040] The use of prefixes such as "first" and "second" in this application embodiment is solely for distinguishing different descriptive objects and does not limit the position, order, priority, quantity, or content of the described objects. The use of ordinal numbers and other prefixes to distinguish descriptive objects in this application embodiment does not constitute a limitation on the described objects. The description of the described objects is found in the claims or the context of the embodiments, and the use of such prefixes should not constitute unnecessary restrictions.

[0041] In electric vehicles, EMB has advantages over EHB (Electro-Hydraulic Brake System) such as fast response, high precision, and no fluid leakage. It also significantly improves safety performance while offering flexible layout and low maintenance costs. As a result, most braking systems now use EMB instead of EHB.

[0042] Electric vehicles equipped with an electronic mechanical brake (EMB) system typically achieve braking by a central controller within the EMB system responding to the driver's operation of the brake pedal and controlling the wheel-end brakes to apply clamping force to the wheels. However, during the braking process of electric vehicles, in some situations, the central controller may have difficulty communicating with the wheel-end brakes and the entire vehicle, leading to a failure of the braking system and compromising driving safety.

[0043] In one embodiment, see Figure 1 , Figure 1 A schematic diagram of the communication architecture of an electromechanical braking system is shown. Figure 1 The electromechanical braking system shown has two central controllers: a first central controller (main central controller) and a second central controller (auxiliary central controller). The first central controller communicates with the four wheel-end braking devices via communication link A, and the second central controller communicates with the four wheel-end braking devices via communication link B. Both the first and second central controllers communicate via communication link C, and also with other devices in the electric vehicle, such as the vehicle controller, through communication link C. However, if communication link C fails, both the first and second central controllers will be unable to receive signals from the vehicle controller, leading to a control failure of the braking system.

[0044] In view of this, this application provides an electromechanical braking system, a vehicle controller, and an electric vehicle. The electromechanical braking system includes a central controller and four wheel-end braking devices. The central controller controls the four wheel-end braking devices to output clamping force to the four wheels of the electric vehicle. The central controller communicates with the vehicle's CAN bus via two public CAN buses and with each of the four wheel-end braking devices via two private CAN buses. This achieves redundant backup of the communication links and improves the communication reliability of the electromechanical braking system.

[0045] Please see Figure 2 , Figure 2 A schematic diagram of an electric vehicle is shown. (For example...) Figure 2 As shown, the electric vehicle 100 includes four wheels 110, a braking system 120, and a power battery (…). Figure 2 (Not shown in the image). The braking system 120 includes a brake pedal 121, a central controller 122, and four wheel-end brake devices 123. The braking system 120 is used to brake the four wheels 110 to decelerate the electric vehicle, and the power battery supplies power to the braking system 120.

[0046] When braking is required on the electric vehicle 100, the driver presses the brake pedal 121. The central controller 122 receives the brake pedal signal from the brake pedal and outputs a brake signal to the four wheel-end braking devices 123 so that the four wheel-end braking devices 123 output clamping force to the brake disc of the electric vehicle to brake the four wheels 110 of the electric vehicle.

[0047] Among them, electric vehicle 100 can be any type of automobile such as car, truck, or passenger bus, or it can be a transportation device for carrying people or goods such as tricycle, two-wheeled vehicle, or train, or it can be other types of transportation driven by traditional power energy or other power batteries.

[0048] Please see Figure 3 , Figure 3 A schematic diagram of an electromechanical braking system is shown. Figure 3 As shown, the electromechanical braking system 120 (such as...) Figure 2 (As shown) It includes a central controller 122 and four wheel-end braking devices.

[0049] The central controller 122 is used to receive the brake pedal signal output by the brake pedal sensor and, in response to the brake pedal signal, control the four wheel-end braking devices to output clamping force to brake the four wheels of the electric vehicle.

[0050] A wheel end brake device 123 is configured to brake a wheel 110. Each wheel end brake device 123 includes a wheel end controller 1231 and a wheel end actuator 1232 (e.g. brake motor and brake caliper).

[0051] For each wheel, the central controller sends a brake signal to the wheel end controller in response to the brake pedal signal, and the wheel end controller 1231 controls the wheel end actuator 1232 of the wheel to output clamping force to the corresponding brake disc to brake the wheel according to the brake signal. For example, the wheel end controller 1231 controls the brake motor to output torque to drive the brake caliper to clamp the brake disc.

[0052] In an embodiment, the electromechanical brake system 120 (as shown in Figure 2 may include multiple central controllers, each of which is capable of receiving the brake pedal signal output by the brake pedal sensor and controlling the four wheel end brake devices to output clamping force to brake the four wheels of the electric vehicle in response to the brake pedal signal.

[0053] In an embodiment, the multiple central controllers can respectively receive brake pedal signals from different brake pedal sensors, and can also receive brake pedal signals from the same brake pedal sensor. Taking two central controllers as an example, the two central controllers (including a first central controller 1221 and a second central controller 1222) are one-to-one corresponding to two brake pedal sensors (a first brake pedal sensor 1241 and a second brake pedal sensor 1242), the first brake pedal sensor 1241 is connected to the first central controller 1221, and the second brake pedal sensor 1242 is connected to the second central controller 1222. The first central controller 1221 receives the first brake pedal signal output by the first brake pedal sensor 1241, and the second central controller 1222 receives the second brake pedal signal output by the second brake pedal sensor 1242.

[0054] The above describes the architecture of the embodiments of the present application. The electronic mechanical brake system provided by the present application will be described in combination with specific embodiments.

[0055] To solve the problem that the central controller is difficult to communicate with the wheel end brake device and the whole vehicle, the present application provides an electronic mechanical brake system, which includes a central controller and four wheel end brake devices. The central controller is configured to control the four wheel end brake devices to output clamping force to the four wheels of the electric vehicle.

[0056] In an embodiment, a plurality of public CAN buses can be configured, and the central controller communicates with the whole vehicle CAN through the plurality of public CAN buses. That is, the central controller has the ability to communicate with the whole vehicle CAN through the plurality of public CAN buses.

[0057] The public CAN bus is not exclusively used by the central controller, but is a communication channel shared with the whole vehicle. The whole vehicle refers to other controllers or components in the electric vehicle other than the central controller.

[0058] That is, the central controller can receive signals sent by the whole vehicle and send signals to the whole vehicle through the public CAN bus.

[0059] The signals received by the central controller through the multiple public CAN buses can be brake pedal signals, signals output by the whole vehicle controller, signals output by the intelligent driving controller, signals output by the electronic parking system, etc. The signals sent through the multiple public CAN buses can be signals sent to the instrument panel, signals sent to each gateway in the electric vehicle, signals sent to the intelligent driving controller, etc.

[0060] In an embodiment, there is a priority between the multiple public CAN buses. In the case of failure of the public CAN bus with higher priority, signals are received through the public CAN bus with lower priority.

[0061] In an embodiment, each signal is transmitted in the form of a message on the public CAN bus. The original information of the received message can be analyzed through the underlying software interface, and the fault information can be reported after the failure. The signals can be received and analyzed through the non-fault public CAN bus.

[0062] The CAN bus (including public CAN bus and private CAN bus) can be recovered in a single power-on cycle. After detecting the recovery of the fault, the message can still be received and analyzed according to the recovered CAN bus.

[0063] In an embodiment, the central controller can also set a filter to receive only signals carrying an identifier consistent with a preset identifier, thereby improving signal reception efficiency. The identifier can be a signal name, an identification bit, a signal ID, etc.

[0064] Further, the central controller can communicate with different controllers in the whole vehicle through different public CAN buses.

[0065] In the embodiments of the present application, if there are multiple central controllers, each central controller has the function of communicating with the whole vehicle CAN through multiple public CAN buses.

[0066] In the embodiment, the central controller communicates with the whole vehicle CAN through the multiple public CAN buses, the multiple public CAN buses can be redundant backup for each other, and the communication link between the central controller and the whole vehicle is redundantly backed up. In the case of failure of one public CAN bus, communication can be performed through other public CAN buses to ensure that the communication function of the electromechanical brake system does not fail, and the failure of the link causes the control of the electromechanical brake system to fail in the case of only one public CAN bus, thereby improving the communication reliability of the electromechanical brake system.

[0067] In an embodiment, multiple private CAN buses can be configured, and the central controller communicates with each of the four wheel-end brake devices through the multiple private CAN buses. That is, the central controller has the ability to communicate with each wheel-end brake device through the multiple private CAN buses.

[0068] In actual application, the central controller can select to communicate with part of the wheel-end brake devices (for example, any one of the two front wheels and any one of the two rear wheels), and the part of the wheel-end brake devices share the communication content to other wheel-end communication devices.

[0069] Among them, the private CAN bus is a communication channel between the central controller and the four wheel-end brake devices, which reduces the risk of being attacked or interfered by external networks.

[0070] That is, the central controller can receive signals sent by the wheel-end brake device and send signals to the wheel-end brake device through the private CAN bus.

[0071] The signals received by the wheel-end brake device through the multiple private CAN buses can be brake signals, life signals, reset signals, etc. The signals sent to the central controller through the multiple private CAN buses can be actual clamping force signals, motor signals, current signals, temperature signals, etc.

[0072] In an embodiment, there is a priority between the multiple private CAN buses, and in the case of failure of the private CAN bus with higher priority, signals are received through the private CAN bus with lower priority.

[0073] Further, the central controller can communicate with different wheel-end brake devices through different private CAN buses.

[0074] In the embodiment, the central controller is arranged to communicate with each of the four wheel-end brake devices through the multiple private CAN buses, the multiple private CAN buses can be redundant to each other, the communication link between the central controller and the wheel-end brake device is redundant, in the case of failure of one private CAN bus, communication can be realized through other private CAN buses, the communication function of the electromechanical brake system is ensured not to fail, the case that the control of the electromechanical brake system fails due to the failure of the link of one private CAN bus is avoided, and the communication reliability and braking reliability of the electromechanical brake system are improved.

[0075] In the case that the electromechanical brake system includes multiple central controllers, although each central controller has the function of communicating with the vehicle CAN through the multiple public CAN buses, only the effective central controller can receive signals, effectively process the received signals, and send effective signals to the vehicle or the wheel-end brake device.

[0076] Taking the first central controller and the second central controller as examples, the priority of the first central controller is higher than that of the second central controller.

[0077] When the first central controller is effective, the first central controller communicates with the vehicle CAN through the two public CAN buses and communicates with each of the four wheel-end brake devices through the two private CAN buses.

[0078] When the first central controller is ineffective and the second central controller is effective, the second central controller communicates with the vehicle CAN through the two public CAN buses and communicates with each of the four wheel-end brake devices through the two private CAN buses.

[0079] In one embodiment, whether the first central controller is totally ineffective or partially ineffective, as long as the first central controller is ineffective, the second central controller communicates with the vehicle CAN through the two public CAN buses and communicates with each of the four wheel-end brake devices through the two private CAN buses.

[0080] In another embodiment, whether the first central controller is totally ineffective or partially ineffective, if the first central controller is partially ineffective, the first central controller executes the non-inactive function, that is, the first central controller communicates with the controller corresponding to the non-inactive function through the public CAN bus and the private CAN bus, and the second central controller communicates with the controller corresponding to the inactive function through the public CAN bus and the private CAN bus.

[0081] After detecting that the first central controller is normal, the first central controller communicates with the vehicle CAN through two public CAN buses and communicates with each of the four wheel-end brake devices through two private CAN buses.

[0082] In this case, the two central controllers include a master central controller (i.e., the first central controller) and a slave central controller (i.e., the second central controller), so that when the master central controller is effective, the master central controller is responsible for communication with the vehicle and the wheel-end brake device, and when the master central controller is ineffective, the slave central controller is responsible for communication with the vehicle and the wheel-end brake device, thereby avoiding the failure of the electromechanical brake system due to the failure of the central controller.

[0083] It should be understood that the above only takes the communication link in the electromechanical brake system as an example of the CAN bus, which can also be a local interconnect network (LIN), automotive Ethernet (AE), etc.

[0084] That is, the central controller communicates with the vehicle LIN through two public LIN buses and communicates with each of the four wheel-end brake devices through two private LIN buses, or the central controller communicates with the vehicle AE through two public AE buses and communicates with each of the four wheel-end brake devices through two private AE buses.

[0085] The detailed process of the central controller communicating with the vehicle or the wheel-end brake device through LIN or AE can be referred to the detailed process of the central controller communicating with the vehicle or the wheel-end brake device through CAN.

[0086] The following will take two public CAN buses and two private CAN buses as an example to describe the electromechanical brake system proposed in the embodiments of the present application in detail.

[0087] In one embodiment, the central controller communicates with the vehicle CAN through two public CAN buses and communicates with each of the four wheel-end brake devices through two private CAN buses.

[0088] That is, the central controller has the ability to communicate with the vehicle CAN through two CAN buses, and communicate with each of the four wheel-end brake devices through two private CAN buses.

[0089] Referring to Figure 4 , taking the central controller including the first central controller and the second central controller as an example, Figure 4 a communication architecture schematic diagram of an electromechanical brake system is shown.

[0090] As Figure 4As shown, the two public CAN buses include a first public CAN bus and a second public CAN bus. The first central controller and the second central controller can communicate with each other through the first public CAN bus and the second public CAN bus, and can also communicate with the vehicle through the first public CAN bus and the second public CAN bus.

[0091] like Figure 4 As shown, the two private CAN buses include a first private CAN bus and a second private CAN bus. The four wheel-end braking devices can communicate with each other through the first private CAN bus and the second private CAN bus, and can also communicate with the first central controller and the second central controller through the first private CAN bus and the second private CAN bus.

[0092] In one embodiment, the central controller can communicate directly with the four wheel-end braking devices, or it can communicate with some of the four wheel-end braking devices.

[0093] In one embodiment, the central controller can actively select the public CAN and private CAN currently used for communication from two public CAN buses and two private CAN buses.

[0094] In this embodiment, by configuring the central controller to communicate with the vehicle's CAN bus via multiple public CAN buses, which can serve as redundant backups for each other, redundancy is achieved in the communication link between the central controller and the vehicle. In the event of a failure of one public CAN bus, communication can be maintained through other public CAN buses, preventing the electromechanical braking system from failing due to the failure of that link when only one public CAN bus is available. Similarly, by configuring the central controller to communicate with each of the four wheel-end braking devices via multiple private CAN buses, which can also serve as redundant backups for each other, redundancy is achieved in the communication link between the central controller and the wheel-end braking devices. In the event of a failure of one private CAN bus, communication can be maintained through other private CAN buses, preventing the electromechanical braking system from failing due to the failure of that link when only one private CAN bus is available. Thus, the communication function of the electromechanical braking system is guaranteed to remain functional, improving both communication and braking reliability.

[0095] In one embodiment, each wheel-end braking device includes a wheel-end controller and a wheel-end actuator. The central controller sends a braking signal to a wheel-end controller via two private CAN buses. After receiving the braking signal, the wheel-end controller controls a wheel-end actuator to output clamping force to the corresponding wheel.

[0096] The brake signal indicates a value of the clamping force output by a wheel end actuator to a corresponding wheel. The greater the clamping force indicated by the brake signal, the greater the clamping force output by the control wheel end actuator to the corresponding wheel.

[0097] In an embodiment, the brake signal is generated by the central controller. Specifically, the central controller calculates the clamping force output to the wheels of the electric vehicle based on the brake pedal signal received through the public CAN bus, the automatic brake signal from the intelligent driving controller, the stability control signal from the vehicle dynamics controller, and the like, and generates the brake signal.

[0098] The brake pedal signal indicates the motion state of the brake pedal, the automatic driving brake signal indicates the braking force of the electric vehicle calculated by the intelligent driving controller, and the stability control signal indicates the braking force of the electric vehicle in the case of maintaining the stability of the electric vehicle.

[0099] In an embodiment, the clamping force indicated by the brake signal received by the four wheel end controllers can be the same or different.

[0100] In another embodiment, when the clamping force output to two wheels needs to be the same, such as two front wheels or two rear wheels, the brake signal can be sent to the wheel end controller of one of the two wheels, and the brake signal is shared by the wheel end controller of the other wheel.

[0101] In an embodiment, in order to improve communication efficiency, the central controller can send the brake signal to the wheel end controllers corresponding to two wheels through the first private CAN bus and send the brake signal to the wheel end controllers corresponding to the other two wheels through the second private CAN bus.

[0102] In this embodiment, each wheel end brake device includes a wheel end controller and a wheel end actuator, and the central controller sends the brake signal to the wheel end controller through two private CAN buses, avoiding the situation that the control of the electromechanical brake system fails due to the failure of the only private CAN bus. Then, the wheel end controller controls the wheel end actuator to output the clamping force to the corresponding wheel after receiving the brake signal, realizes braking, and improves the communication reliability and braking reliability of the electromechanical brake system.

[0103] In an embodiment, the two public CAN buses include a first public CAN bus and a second public CAN bus, and when the first public CAN bus is not faulty, the central controller receives signals through the first public CAN bus.

[0104] The CAN bus fault can be a data check fault (E2E fault), a communication timeout fault (TimeOut fault), a bus off fault (BusOff fault), etc.

[0105] The E2E fault refers to a data transmission fault between a signal sender and a receiver, including data tampering, data loss, sequence disorder, and excessive delay, which does not directly affect CAN bus communication.

[0106] The TimeOut fault refers to a failure of the receiver to receive a signal within a predetermined time, including a sender downtime and configuration errors.

[0107] The BusOff fault refers to an internal error of a CAN bus node, which automatically disconnects the connection with the CAN bus, including hardware faults and electromagnetic interference, affecting CAN bus communication.

[0108] After excluding the physical layer fault of the CAN bus (such as power supply problems, line breakage, bus short circuit, and electromagnetic interference), the CAN bus can be determined to have a BusOff fault, a TimeOut fault, and an E2E fault in sequence.

[0109] In an embodiment, the process of determining that the CAN bus has an E2E fault can include performing E2E calculation on the received signal to obtain a calculation result, and determining that the CAN bus has an E2E fault if the calculation result is different from the calculation result of the sender.

[0110] In an embodiment, the received signal can also be subjected to cyclic redundancy check (CRC) (mismatch indicating data tampering or damage), counter check (the counter value of this reception is not exactly 1 greater than the last one, indicating message loss or sequence disorder), life cycle check (the life cycle value of this reception is not updated, indicating that the data can be obsolete), and freshness check (data is not received within the specified timeout), etc., to determine that the CAN bus has an E2E fault.

[0111] In an embodiment, the process of determining that the CAN bus has a TimeOut fault can include providing a timeout threshold and a timer for the signal at the receiver, resetting the corresponding timer after receiving the signal, checking the value of the timer at the expected reception time of the message, and determining that the CAN bus has a TimeOut fault if the value of the timer exceeds the predetermined timeout threshold.

[0112] The timeout threshold is greater than the period of the signal, for example, for a signal with a period of 10 ms, the timeout threshold can be set to 15 ms. When the value of the timer exceeds the preset timeout threshold, it indicates that the signal has not been received for more than one complete period.

[0113] In an embodiment, the process of determining that the CAN bus has a BusOff fault can include: reading a status register of the CAN controller, the register having a status bit indicating whether the node is currently in a BusOff state, and determining that the CAN bus has a BusOff fault.

[0114] In general, the CAN bus is determined to be not faulty when there is no physical layer fault, no BusOff fault, no TimeOut fault, and no E2E fault.

[0115] In addition, the CAN bus can also have a signal value dead fault (a certain signal value remains unchanged for a long time) and a relevance fault (signal values between different messages are logically contradictory).

[0116] In an embodiment, the priority of communication between the central controller and the vehicle through the first public CAN bus is higher than that through the second public CAN bus. In this way, when the first public CAN bus is not faulty, the central controller receives signals through the first public CAN bus.

[0117] In this embodiment, by setting the priority of communication between the central controller and the vehicle through the first public CAN bus higher than that through the second public CAN bus, when the first public CAN bus is not faulty, the central controller receives signals through the first public CAN bus, ensuring the certainty and predictability of signal reception and improving the reliability and fault tolerance of the electronic brake system.

[0118] In an embodiment, when the first public CAN bus has a first type of fault and the second public CAN bus is not faulty, the central controller receives signals through the first public CAN bus and the second public CAN bus together, and the first type of fault at least includes a data check fault and a communication timeout fault.

[0119] The first type of fault of the CAN bus indicates that the fault of the CAN bus only affects the reception of the current signal and does not affect the transmission of the current signal and the reception of other signals.

[0120] If the first public CAN bus has the first type of fault, it means that the first public CAN bus only has a fault in receiving the first signal and does not affect the communication through the public CAN bus. In this case, the first signal is received through the second public CAN bus, and the second signal is received through the first public CAN bus and the second public CAN bus together.

[0121] In this embodiment, the second signal represents a signal other than the first signal. The first signal and the second signal can be the same type of signal, such as the first brake pedal signal and the second brake pedal signal. The first signal and the second signal can also be different types of signals, such as the brake pedal signal and the stability control signal.

[0122] In this embodiment, the first type of fault includes at least data verification fault and communication timeout fault. If the first public CAN bus has the first type of fault, it means that the public CAN bus only has a fault in receiving the current signal and does not have a fault in receiving other signals. The second public CAN bus is not faulty, which means that the public CAN bus can be used to receive signals. In this case, the central controller receives signals through the first public CAN bus and the second public CAN bus together, ensuring the redundancy backup of the communication link and improving the communication reliability of the electromechanical brake system.

[0123] In one embodiment, when the first public CAN bus has the second type of fault and the second public CAN bus is not faulty, the central controller receives signals through the second public CAN bus. The second type of fault includes at least bus shutdown fault.

[0124] If the first public CAN bus has the second type of fault, it means that the communication of the first public CAN bus has a fault. In this case, the signal is received through the second public CAN bus.

[0125] In this embodiment, the second type of fault includes at least bus shutdown fault. If the first public CAN bus has the second type of fault, it means that the communication of the public CAN bus has a fault. In this case, the central controller receives signals through the second public CAN bus, ensuring that the communication function of the electromechanical brake system does not fail.

[0126] In one embodiment, when the first public CAN bus recovers from the fault within the target period, the central controller receives signals through the first public CAN bus.

[0127] In this embodiment, the target period refers to the power-on period of the electric vehicle. The power-on period refers to the complete process from the central controller being powered on (Ignition ON) to being powered off (Ignition OFF).

[0128] In an embodiment, when the first public CAN bus is recovered from failure in the target period, the state of the first public CAN bus can be first changed from "failure" to "running" or "to be verified", and after verification, the central controller receives signals through the first public CAN bus.

[0129] In an embodiment, the central controller can change the state of the first public CAN bus by receiving signals sent by the vehicle through the first public CAN bus in the target period and finding no errors by analyzing the signals.

[0130] In this embodiment, by automatically detecting that the first public CAN bus is recovered from failure in the target period, the central controller receives signals through the first public CAN bus, ensuring the certainty and predictability of receiving signals. The first public CAN bus and the second public CAN bus are redundant backups of each other, improving the reliability and fault tolerance of the electronic brake system.

[0131] In an embodiment, the central controller sends signals to the vehicle through two public CAN buses.

[0132] Even if the public CAN bus fails, the central controller can send signals through the public CAN bus. The signals sent through the failed public CAN bus can be regarded as a probe signal for detecting whether the public CAN bus has recovered to normal. The specific detection process can be performed by the vehicle or the CAN controller.

[0133] In this embodiment, the central controller sends signals to the vehicle through two public CAN buses. When the public CAN bus fails, the signal can be regarded as a probe signal for detecting whether the public CAN bus has recovered to normal. This realizes accurate detection of whether the public CAN bus is in failure, realizes redundant backup of the communication link, and improves the communication reliability of the electronic mechanical brake system.

[0134] In an embodiment, the two private CAN buses include a first private CAN bus and a second private CAN bus. When the first private CAN bus is not failed, a wheel-end brake device receives signals through the first private CAN bus.

[0135] Similarly, the failure of the private CAN bus can be determined by the aforementioned failure determination method.

[0136] In an embodiment, the priority of communication between the central controller and the wheel-end brake device through the first private CAN bus is higher than that through the second private CAN bus. In this way, when the first private CAN bus is not failed, the wheel-end brake device receives signals through the first private CAN bus.

[0137] In the embodiment, by setting the priority of the communication between the central controller and the wheel end brake device through the first private CAN bus higher than that through the second private CAN bus, in the case that the first private CAN bus is not faulty, one wheel end brake device receives signals through the first private CAN bus, ensuring the certainty and predictability of signal reception, and improving the reliability and fault tolerance of the electronic brake system.

[0138] In one embodiment, when the first private CAN bus has a first type of fault and the second private CAN bus is not faulty, one wheel end brake device receives signals through the first private CAN bus and the second private CAN bus together, and the first type of fault at least includes a data check fault and a communication timeout fault.

[0139] If the first private CAN bus has a first type of fault, it means that the first private CAN bus only has a fault in receiving the third signal, and does not affect the communication through the private CAN bus. In this case, the third signal is received through the second private CAN, and the fourth signal is received through the first private CAN bus and the second private CAN bus together.

[0140] Here, the fourth signal represents a signal other than the third signal.

[0141] In the embodiment, the first type of fault at least includes a data check fault and a communication timeout fault, the first private CAN bus has a first type of fault, which means that the private CAN bus only has a fault in receiving the current signal, and does not have a fault in receiving other signals, and the second private CAN bus is not faulty, which means that the private CAN bus can be used to receive signals. In this case, one wheel end brake device receives signals through the first private CAN bus and the second private CAN bus together, ensuring the redundancy backup of the communication link and improving the communication reliability of the electronic mechanical brake system.

[0142] In one embodiment, when the first private CAN bus has a second type of fault and the second private CAN bus is not faulty, one wheel end brake device receives signals through the second private CAN bus, and the second type of fault at least includes a bus shutdown fault.

[0143] If the first private CAN bus has a second type of fault, it means that the communication of the first private CAN bus has a fault. In this case, the signal is received through the second private CAN.

[0144] In the embodiment, the second type of fault at least includes a bus shutdown fault, and the first private CAN bus has a second type of fault, which means that the communication of the private CAN bus has a fault. In this case, one wheel end brake device receives signals through the second private CAN bus, ensuring that the communication function of the electronic mechanical brake system does not fail.

[0145] In an embodiment, when the first private CAN bus recovers from failure within the target period, a wheel-end brake device receives signals through the first private CAN bus.

[0146] In an embodiment, when the first private CAN bus recovers from failure within the target period, the state of the first private CAN bus can be first changed from “failure” to “running” or “to be verified”, and after verification, a wheel-end brake device receives signals through the first public CAN bus.

[0147] In an embodiment, a wheel-end brake device can change the state of the first private CAN bus by receiving signals sent by the central controller through the first private CAN bus within the target period and finding no error after analyzing the signals.

[0148] In this embodiment, by automatically detecting that the first private CAN bus recovers from failure within the target period, a wheel-end brake device resumes receiving signals through the first private CAN bus, ensuring the certainty and predictability of receiving signals. The first private CAN bus and the second private CAN bus are redundant backups for each other, improving the reliability and fault tolerance of the electronic brake system.

[0149] In an embodiment, a wheel-end brake device sends signals to the wheel-end brake device through two private CAN buses.

[0150] Even if the private CAN bus fails, a wheel-end brake device can still send signals through the private CAN bus. The signals sent through the failed private CAN bus can be regarded as a detection signal for detecting whether the private CAN bus has recovered to normal. The specific detection process can be performed by the wheel-end brake device or the CAN controller.

[0151] In this embodiment, a wheel-end brake device sends signals to the central controller through two private CAN buses. When the private CAN bus fails, the signals can be regarded as a detection signal for detecting whether the private CAN bus has recovered to normal. This embodiment realizes accurate detection of whether the private CAN bus is in failure, realizes redundant backup of the communication link, and improves the communication reliability of the electronic mechanical brake system.

[0152] For ease of understanding, refer to Figure 5 , Figure 5 a schematic diagram of a communication scenario of an electronic mechanical brake system is shown.

[0153] As Figure 5As shown, in the case that both the two public CAN buses and the two private CAN buses are not faulty, the central controller receives the first public message through the two public CAN buses and receives the first private message through the two private CAN buses.

[0154] In the case that the first public CAN bus has an E2E fault or a TimeOut fault, the central controller receives the first public message through the second public CAN bus and receives the second public message through the first public CAN bus and the second public CAN bus. The second public message is a message other than the first public message.

[0155] In the case that the first public CAN bus has a BusOff fault, the central controller receives the first public message through the second public CAN bus.

[0156] In the case that the first private CAN bus has an E2E fault or a TimeOut fault, the central controller receives the first private message through the second private CAN bus and receives the second private message through the first private CAN bus and the second private CAN bus. The second private message is a message other than the first private message.

[0157] In the case that the first private CAN bus has a BusOff fault, the central controller receives the first private message through the second private CAN bus.

[0158] In the case that each central controller sends a message through the two public CAN buses and the two private CAN buses, it is not necessary to consider whether the two public CAN buses and the two private CAN buses are faulty.

[0159] The application also provides a vehicle controller which communicates with a whole vehicle CAN through two public CAN buses and two private CAN buses and communicates with each of four wheel-end brake devices through two private CAN buses.

[0160] The vehicle controller can be the aforementioned central controller, such as the aforementioned first central controller or the second central controller, or a controller specially set for the application.

[0161] In an embodiment, the vehicle controller sends a signal to the whole vehicle through the two public CAN buses and sends a signal to the four wheel-end brake devices through the two private CAN buses.

[0162] The vehicle controller does not need to consider whether the CAN bus for sending the signal is faulty when sending the signal.

[0163] Similarly, the vehicle controller receives signals sent by the whole vehicle through two public CAN buses and receives signals sent by the four wheel-end braking devices through two private CAN buses.

[0164] When receiving signals, it is necessary to consider whether the CAN bus for receiving signals is faulty, which can be referred to the related content mentioned in the foregoing embodiments, and will not be repeated here.

[0165] The application also provides an electric vehicle, which comprises an electromechanical braking system and four wheels, and the electromechanical braking system comprises two central controllers and four wheel-end braking devices, one of the two central controllers is used to control the four wheel-end braking devices to output braking force to the four wheels of the electric vehicle, wherein:

[0166] Each wheel-end braking device comprises a wheel-end controller and a wheel-end actuator, and one wheel-end controller is used to control one wheel-end actuator to output clamping force to one wheel of the electric vehicle.

[0167] One wheel-end controller is specifically used to: in the braking process of at least one of the two central controllers being effective, receive a first braking signal output by the effective central controller, and control one wheel-end actuator to output clamping force to one wheel according to the indication of the first braking signal; when both of the two central controllers are invalid, control one wheel-end actuator to output clamping force to one wheel after receiving a second braking signal from outside the two central controllers.

[0168] It can be understood that all the related content of the electromechanical braking system involved in the above method embodiments can be cited to the embodiments of the electric vehicle and the embodiments of the vehicle controller, and the embodiments of the application will not be repeated here.

[0169] Finally, it should be pointed out that: the above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this, any change or replacement within the technical scope disclosed in the present application should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An electromechanical brake system characterized by, The electromechanical brake system comprises a central controller and four wheel-end brake devices, the central controller is configured to control the four wheel-end brake devices to output clamping force to four wheels of an electric vehicle, wherein: The central controller communicates with a vehicle CAN through two public CAN buses and communicates with each of the four wheel-end brake devices through two private CAN buses.

2. The electromechanical brake system of claim 1, wherein, The two public CAN buses comprise a first public CAN bus and a second public CAN bus, when the first public CAN bus is not faulty, the central controller receives signals through the first public CAN bus.

3. The electromechanical brake system of claim 2, wherein, When the first public CAN bus has a first type of fault and the second public CAN bus is not faulty, the central controller receives signals through the first public CAN bus and the second public CAN bus together, the first type of fault at least includes data check fault and communication timeout fault.

4. The electromechanical brake system of claim 2, wherein, When the first public CAN bus has a second type of fault and the second public CAN bus is not faulty, the central controller receives signals through the second public CAN bus, the second type of fault at least includes bus off fault.

5. The electromechanical brake system of claim 1, wherein, The central controller sends signals to the vehicle through the two public CAN buses.

6. The electromechanical brake system of claim 1, wherein, The two private CAN buses comprise a first private CAN bus and a second private CAN bus, when the first private CAN bus is not faulty, one wheel-end brake device receives signals through the first private CAN bus.

7. The electromechanical brake system of claim 6, wherein, When the first private CAN bus has a first type of fault and the second private CAN bus is not faulty, the one wheel-end brake device receives signals through the first private CAN bus and the second private CAN bus together, the first type of fault at least includes data check fault and communication timeout fault.

8. The electromechanical brake system of claim 6, wherein, When the first private CAN bus has a second type of fault and the second private CAN bus is not faulty, the one wheel-end brake device receives signals through the second private CAN bus, the second type of fault at least includes bus off fault.

9. The electromechanical brake system of claim 1, wherein, The one wheel-end brake device sends signals to the central controller through the two private CAN buses.

10. The electromechanical brake system according to claim 3 or 4, characterized in that, When the first public CAN bus recovers from fault within a target period, the central controller receives signals through the first public CAN bus.

11. The electromechanical brake system according to claim 7 or 8, characterized in that, When the first private CAN bus recovers from fault within a target period, the one wheel-end brake device receives signals through the first private CAN bus.

12. The electromechanical brake system of claim 1, wherein, Each of the wheel-end brake devices comprises a wheel-end controller and a wheel-end actuator, the central controller sends brake signals to the one wheel-end controller through two private CAN buses, and the one wheel-end controller controls the one wheel-end actuator to output clamping force to the corresponding wheel after receiving the brake signals.

13. A vehicle controller characterized by comprising: The vehicle controller communicates with a vehicle CAN through two public CAN buses and two private CAN buses and communicates with each of the four wheel-end brake devices through two private CAN buses.

14. The vehicle controller of claim 13, wherein, The vehicle controller sends signals to the whole vehicle through the two public CAN buses and sends signals to the four wheel-end braking devices through the two private CAN buses.

15. An electric vehicle characterized by comprising: The electric vehicle comprises an electromechanical braking system and four wheels, the electromechanical braking system comprises a central controller and four wheel-end braking devices, the central controller is used for controlling the four wheel-end braking devices to output clamping force to the four wheels of the electric vehicle, wherein: The central controller communicates with the whole vehicle CAN through two public CAN buses and communicates with each of the four wheel-end braking devices through two private CAN buses.

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