Vehicle brake control method and device, vehicle and storage medium

Abstract

The embodiment of the application provides a vehicle braking control method, device, vehicle and storage medium, the method comprises: acquiring multi-source state data of a vehicle; performing torque distribution based on braking demand data, vehicle state data and battery state of charge data to obtain a basic braking torque; performing closed-loop compensation based on the braking demand data, the vehicle state data and the brake actuator feedback data to obtain a compensation braking torque; and performing braking control on the vehicle by using the basic braking torque and the compensation braking torque. The application solves the technical problems of insufficient braking smoothness, low control accuracy and poor working condition adaptability of the vehicle braking control method in the related art.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and more specifically, to a vehicle braking control method, device, vehicle, and storage medium. Background Technology

[0002] In the field of new energy vehicles, composite braking systems aim to balance energy recovery and driving safety through the coordinated operation of electric regenerative braking and friction braking. However, while electric braking offers a fast response, it is limited by battery capacity and engine speed, while friction braking provides significant braking force but suffers from inherent delays. The difference in their response characteristics makes coordinated allocation difficult. Related technical solutions mainly fall into categories such as rule-based static allocation, optimization algorithm-based dynamic allocation, and model predictive control. However, these solutions suffer from technical problems such as inability to adapt to dynamic operating conditions, poor robustness, and low control precision. Furthermore, during the transition from electric braking to friction braking, the response delay creates a "window period" in braking torque, severely impacting braking smoothness and safety.

[0003] There is currently no good solution to the above problems. Summary of the Invention

[0004] This application provides a vehicle braking control method, device, vehicle, and storage medium to at least solve the technical problems of insufficient braking smoothness, low control accuracy, and poor adaptability to operating conditions in related vehicle braking control methods.

[0005] According to one aspect of the embodiments of this application, a vehicle braking control method is provided, comprising: acquiring multi-source state data of a vehicle, wherein the multi-source state data includes at least: braking demand data, vehicle state data, battery state of charge data, and brake actuator feedback data; performing torque allocation based on the braking demand data, vehicle state data, and battery state of charge data to obtain a base braking torque, wherein the base braking torque is used to represent the vehicle's motor braking base torque and friction braking base torque; performing closed-loop compensation based on the braking demand data, vehicle state data, and brake actuator feedback data to obtain a compensated braking torque, wherein the compensated braking torque is used to represent the vehicle's motor braking compensation torque and friction braking compensation torque; and using the base braking torque and the compensated braking torque to perform braking control on the vehicle.

[0006] Optionally, the torque allocation based on braking demand data, vehicle status data, and battery state of charge data to obtain the basic braking torque includes: identifying the operating condition based on braking demand data, vehicle status data, and battery state of charge data to obtain the operating condition identification result; and allocating torque according to the operating condition identification result to obtain the basic braking torque.

[0007] Optionally, the braking demand data includes: brake pedal travel and brake pedal speed; the vehicle status data includes: current reference vehicle speed; and the multi-source status data also includes: motor temperature. Based on the braking demand data, vehicle status data, and battery state of charge data, the operating condition is identified, and the operating condition identification result is determined as follows: in response to the brake pedal travel being less than or equal to a first pedal travel threshold, and the absolute value of the brake pedal speed being less than or equal to a first pedal speed threshold, and the current reference vehicle speed being greater than the motor braking cutoff speed, the operating condition identification result is determined to be a normal braking condition.

[0008] Optionally, operating condition identification is performed based on braking demand data, vehicle status data, and battery state of charge data. The operating condition identification result includes: in response to the brake pedal travel being greater than the second pedal travel threshold, or the absolute value of the brake pedal speed being greater than the second pedal speed threshold, the operating condition identification result is determined to be an emergency braking condition, wherein the second pedal travel threshold is greater than the first pedal travel threshold, and the second pedal speed threshold is greater than the first pedal speed threshold.

[0009] Optionally, operating condition identification is performed based on braking demand data, vehicle status data, and battery state of charge data. The operating condition identification result includes: in response to the battery state of charge data being greater than a preset charge threshold, or the current reference vehicle speed being less than the motor braking cutoff speed, or the motor temperature being greater than a preset temperature threshold, the operating condition identification result is determined to be a transition braking condition.

[0010] Optionally, the vehicle braking control method further includes: in response to the vehicle being in a transition braking condition, sending a pre-pressure build-up request to the hydraulic control unit of the electro-hydraulic braking system; and controlling the hydraulic control unit to build up basic wheel cylinder pressure based on the pre-pressure build-up request so that the gap between the vehicle's friction brake pads and brake disc is less than a target gap value.

[0011] Optionally, closed-loop compensation based on braking demand data, vehicle status data, and brake actuator feedback data is performed to obtain the compensated braking torque, including: determining the total required braking torque of the vehicle based on braking demand data and vehicle status data, and determining the actual total braking torque of the vehicle based on brake actuator feedback data; determining the braking torque deviation based on the total required braking torque and the actual total braking torque; and, in response to the absolute value of the braking torque deviation being greater than a preset deviation threshold, performing closed-loop compensation based on the braking torque deviation and brake actuator feedback data to obtain the compensated braking torque.

[0012] Optionally, the brake actuator feedback data includes: the actual braking torque of the motor and the wheel brake cylinder pressure data. Determining the vehicle's actual total braking torque based on the brake actuator feedback data includes: determining the actual friction braking torque based on the wheel brake cylinder pressure data; and determining the actual total braking torque based on the actual friction braking torque and the actual braking torque of the motor.

[0013] Optionally, closed-loop compensation based on braking torque deviation and brake actuator feedback data is performed to obtain compensated braking torque, including: in response to a positive braking torque deviation, determining the motor torque margin based on the upper limit of motor torque and the actual motor braking torque; in response to a positive motor torque margin, determining the motor torque compensation amount based on the braking torque deviation and the motor torque margin, and incrementally compensating the actual motor braking torque using the motor torque compensation amount; and in response to the actual motor braking torque reaching the upper limit of motor torque, determining the friction braking torque compensation amount based on the first residual torque deviation.

[0014] Optionally, closed-loop compensation based on braking torque deviation and brake actuator feedback data is performed to obtain compensated braking torque, including: in response to a negative braking torque deviation, determining the reduction in motor braking torque based on the braking torque deviation and the actual motor braking torque, and using the reduction in motor braking torque to compensate for the reduction in the actual motor braking torque; in response to the actual motor braking torque reaching a preset value, determining the reduction in friction braking torque based on the second residual torque deviation.

[0015] Optionally, the vehicle status data includes: current reference vehicle speed, wheel angular velocity, and tire rolling radius. The vehicle braking control method further includes: determining the wheel slip ratios of multiple wheels based on the current reference vehicle speed, wheel angular velocity, and tire rolling radius; and controlling the first wheel to perform a braking torque redistribution operation in response to the wheel slip ratio of the first wheel among the multiple wheels being greater than a preset threshold value.

[0016] Optionally, controlling the first wheel to perform a braking torque redistribution operation includes: determining the total braking torque reduction corresponding to the first wheel based on the wheel slip ratio; determining a first target torque reduction amount based on the friction braking torque component of the first wheel and the total braking torque reduction amount; and adjusting the friction braking torque component based on the first target torque reduction amount; in response to the friction braking torque component reaching a preset value and the wheel slip ratio being greater than a preset threshold value, determining a second target torque reduction amount based on the wheel slip ratio; and adjusting the electric motor torque component of the first wheel based on the second target torque reduction amount.

[0017] Optionally, the vehicle braking control method further includes: transferring the total reduction of braking torque to the coaxial wheel corresponding to the first wheel, or transferring the total reduction of braking torque to the second wheel, wherein the wheel slip ratio of the second wheel is less than a preset threshold value.

[0018] Optionally, braking control of the vehicle using the base braking torque and the compensated braking torque includes: determining the motor braking command torque based on the motor braking base torque and the motor braking compensated torque, and generating a first control command based on the motor braking command torque; determining the friction braking command torque based on the friction braking base torque and the friction braking compensated torque, and generating a second control command based on the friction braking command torque; and using the first control command and the second control command to brake the vehicle.

[0019] Optionally, the torque change rate of the motor braking command torque is less than or equal to the first calibration value, and the torque change rate of the friction braking command torque is less than or equal to the second calibration value, wherein the second calibration value is less than the first calibration value.

[0020] Optionally, the vehicle braking control method further includes: determining that the vehicle's motor braking system is in a fault state in response to the vehicle's motor controller failing to respond to the first control command for multiple consecutive cycles, or the vehicle's motor temperature exceeding a preset protection threshold, or the battery state of charge data being in an abnormal state.

[0021] Optionally, the vehicle braking control method further includes: in response to a fault in the electric motor braking system, generating the vehicle's total braking torque using the vehicle's friction braking system.

[0022] Optionally, the vehicle braking control method further includes: determining that the vehicle's friction braking system is in a fault state in response to the wheel brake cylinder pressure data meeting a preset abnormal condition, or the vehicle's electro-hydraulic braking system being in a fault state.

[0023] Optionally, the vehicle braking control method further includes: in response to a fault in the friction braking system, generating the vehicle's total braking torque using the vehicle's electric braking system.

[0024] Optionally, the vehicle braking control method further includes: in response to a partial interruption of the vehicle network, determining a basic friction braking torque based on a preset safety braking mapping table and the brake pedal travel, and determining a basic motor braking torque based on a preset regenerative braking mapping table and the brake pedal travel; in response to a global interruption of the vehicle network, determining a target braking torque of the vehicle based on the pedal force of the vehicle brake pedal.

[0025] According to another aspect of the embodiments of this application, a vehicle braking control device is also provided, comprising: an acquisition module for acquiring multi-source state data of a vehicle, wherein the multi-source state data includes at least: braking demand data, vehicle state data, battery state of charge data, and brake actuator feedback data; an allocation module for performing torque allocation based on the braking demand data, vehicle state data, and battery state of charge data to obtain a base braking torque, wherein the base braking torque is used to represent the vehicle's motor braking base torque and friction braking base torque; a compensation module for performing closed-loop compensation based on the braking demand data, vehicle state data, and brake actuator feedback data to obtain a compensated braking torque, wherein the compensated braking torque is used to represent the vehicle's motor braking compensation torque and friction braking compensation torque; and a first control module for performing braking control of the vehicle using the base braking torque and the compensated braking torque.

[0026] Optionally, the allocation module is also used to: identify the operating condition based on braking demand data, vehicle status data, and battery state of charge data to obtain the operating condition identification result; and allocate torque according to the operating condition identification result to obtain the basic braking torque.

[0027] Optionally, the braking demand data includes: brake pedal travel and brake pedal speed; the vehicle status data includes: current reference vehicle speed; and the multi-source status data also includes: motor temperature. The allocation module is also used to: determine the operating condition identification result as a normal braking condition in response to the brake pedal travel being less than or equal to a first pedal travel threshold, and the absolute value of the brake pedal speed being less than or equal to a first pedal speed threshold, and the current reference vehicle speed being greater than the motor braking cutoff speed.

[0028] Optionally, the allocation module is further configured to: determine the operating condition identification result as an emergency braking condition in response to the brake pedal travel being greater than a second pedal travel threshold or the absolute value of the brake pedal speed being greater than a second pedal speed threshold, wherein the second pedal travel threshold is greater than a first pedal travel threshold and the second pedal speed threshold is greater than a first pedal speed threshold.

[0029] Optionally, the allocation module is also configured to: determine the operating condition identification result as transition braking condition in response to the battery state of charge data being greater than a preset charge threshold, or the current reference vehicle speed being less than the motor braking cutoff speed, or the motor temperature being greater than a preset temperature threshold.

[0030] Optionally, the vehicle braking control device further includes: a sending module for sending a pre-pressure build-up request to the hydraulic control unit of the electro-hydraulic braking system in response to the vehicle being in a transition braking condition; and a building module for controlling the hydraulic control unit to build up the base wheel cylinder pressure based on the pre-pressure build-up request, so that the gap between the vehicle's friction brake pads and brake disc is less than a target gap value.

[0031] Optionally, the compensation module is also used to: determine the total required braking torque of the vehicle based on braking demand data and vehicle status data, and determine the actual total braking torque of the vehicle based on brake actuator feedback data; determine the braking torque deviation based on the total required braking torque and the actual total braking torque; and, in response to the absolute value of the braking torque deviation being greater than a preset deviation threshold, perform closed-loop compensation based on the braking torque deviation and brake actuator feedback data to obtain the compensated braking torque.

[0032] Optionally, the brake actuator feedback data includes: the actual braking torque of the motor and the wheel brake cylinder pressure data. The compensation module is also used to: determine the actual friction braking torque based on the wheel brake cylinder pressure data; and determine the actual total braking torque based on the actual friction braking torque and the actual braking torque of the motor.

[0033] Optionally, the compensation module is further configured to: determine the motor torque margin based on the upper limit of the motor torque and the actual braking torque of the motor in response to a positive braking torque deviation; determine the motor torque compensation amount based on the braking torque deviation and the motor torque margin in response to a positive motor torque margin, and incrementally compensate the actual braking torque of the motor using the motor torque compensation amount; and determine the friction braking torque compensation amount based on the first residual torque deviation in response to the actual braking torque of the motor reaching the upper limit of the motor torque.

[0034] Optionally, the compensation module is also configured to: in response to a negative braking torque deviation, determine the reduction in motor braking torque based on the braking torque deviation and the actual braking torque of the motor, and use the reduction in motor braking torque to compensate for the reduction in the actual braking torque of the motor; and in response to the actual braking torque of the motor reaching a preset value, determine the reduction in friction braking torque based on the second residual torque deviation.

[0035] Optionally, the vehicle status data includes: current reference vehicle speed, wheel angular velocity, and tire rolling radius. The vehicle braking control device further includes: a first determining module, used to determine the wheel slip ratios of multiple wheels based on the current reference vehicle speed, wheel angular velocity, and tire rolling radius; and a second controlling module, used to control the first wheel to perform a braking torque redistribution operation in response to the wheel slip ratio of the first wheel among the multiple wheels being greater than a preset threshold value.

[0036] Optionally, the second control module is further configured to: determine the total reduction in braking torque corresponding to the first wheel based on the wheel slip ratio; determine a first target torque reduction based on the friction braking torque component of the first wheel and the total reduction in braking torque, and adjust the friction braking torque component based on the first target torque reduction; in response to the friction braking torque component reaching a preset value and the wheel slip ratio being greater than a preset threshold, determine a second target torque reduction based on the wheel slip ratio, and adjust the motor torque component of the first wheel based on the second target torque reduction.

[0037] Optionally, the vehicle braking control device further includes: a transfer module for transferring the total reduction in braking torque to the coaxial wheel corresponding to the first wheel, or transferring the total reduction in braking torque to the second wheel, wherein the wheel slip ratio of the second wheel is less than a preset threshold value.

[0038] Optionally, the first control module is further configured to: determine the motor braking command torque based on the motor braking base torque and the motor braking compensation torque, and generate a first control command based on the motor braking command torque; determine the friction braking command torque based on the friction braking base torque and the friction braking compensation torque, and generate a second control command based on the friction braking command torque; and use the first control command and the second control command to perform braking control on the vehicle.

[0039] Optionally, the torque change rate of the motor braking command torque is less than or equal to the first calibration value, and the torque change rate of the friction braking command torque is less than or equal to the second calibration value, wherein the second calibration value is less than the first calibration value.

[0040] Optionally, the vehicle braking control device further includes: a second determining module, used to determine that the vehicle's motor braking system is in a fault state in response to the vehicle's motor controller failing to respond to the first control command for multiple consecutive cycles, or the vehicle's motor temperature exceeding a preset protection threshold, or the battery state of charge data being in an abnormal state.

[0041] Optionally, the vehicle braking control device further includes: a first generation module, used to generate the vehicle's total braking torque using the vehicle's friction braking system in response to a fault in the electric motor braking system.

[0042] Optionally, the vehicle braking control device further includes: a third determining module, used to determine that the vehicle's friction braking system is in a fault state in response to the wheel brake cylinder pressure data meeting preset abnormal conditions, or the vehicle's electro-hydraulic braking system being in a fault state.

[0043] Optionally, the vehicle braking control device further includes: a second generation module, used to generate the vehicle's total braking torque using the vehicle's electric braking system in response to a fault in the friction braking system.

[0044] Optionally, the vehicle braking control device further includes: a fourth determining module, used to determine the friction braking base torque based on a preset safety braking mapping table and the brake pedal travel in response to a partial interruption of the vehicle network, and to determine the motor braking base torque based on a preset regenerative braking mapping table and the brake pedal travel; and a fifth determining module, used to determine the target braking torque of the vehicle based on the pedal force of the vehicle brake pedal in response to a global interruption of the vehicle network.

[0045] According to another aspect of the embodiments of this application, a vehicle is also provided, including: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods in various embodiments of this application when it runs.

[0046] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of this application.

[0047] According to another aspect of the embodiments of this application, a computer program product is also provided, including a computer program that, when executed by a processor, implements the methods of various embodiments of this application.

[0048] According to another aspect of the embodiments of this application, a computer program product is also provided, including a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, implements the methods in various embodiments of this application.

[0049] According to another aspect of the embodiments of this application, a computer program is also provided, which, when executed by a processor, implements the methods of the various embodiments of this application.

[0050] In this embodiment, by acquiring multi-source state data including braking demand, vehicle status, battery state of charge, and brake actuator feedback, a basic braking torque is first obtained by torque allocation based on braking demand, vehicle status, and battery state of charge. Then, a compensated braking torque is obtained by closed-loop compensation based on braking demand, vehicle status, and brake actuator feedback. Finally, the basic braking torque and the compensated braking torque are used to control the vehicle's braking, achieving the goal of precise control of braking torque by combining basic allocation and dynamic compensation. This improves braking smoothness, control accuracy, and adaptability to operating conditions, thereby solving the technical problems of insufficient braking smoothness, low control accuracy, and poor adaptability to operating conditions in related vehicle braking control methods. Attached Figure Description

[0051] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0052] Figure 1 This is a flowchart of an optional vehicle braking control method according to an embodiment of this application;

[0053] Figure 2 This is a schematic diagram of an optional vehicle braking control method according to an embodiment of this application;

[0054] Figure 3 This is a schematic diagram of another optional vehicle braking control method according to an embodiment of this application;

[0055] Figure 4 This is a structural block diagram of an optional vehicle braking control device according to an embodiment of this application;

[0056] Figure 5 This is a schematic diagram of an optional vehicle according to an embodiment of this application. Detailed Implementation

[0057] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0058] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0059] In the field of new energy vehicle technology, composite braking systems aim to balance driving safety and energy recovery efficiency by coordinating electric motor braking and mechanical friction braking. However, while electric braking systems offer rapid response (millisecond-level response and precise control), they are limited by the battery's state of charge (SOC) and the motor's speed range. In contrast, hydraulic / pneumatic friction braking systems, while providing large braking torque and high reliability, have an inherent pressure build-up delay of tens to hundreds of milliseconds. These significant differences in response characteristics pose challenges to the coordinated distribution of braking torque.

[0060] Related composite braking control technologies can be mainly categorized into rule-based static allocation, optimization algorithm-based dynamic allocation, and model predictive control. Static schemes are simple to implement but cannot adapt to dynamic operating conditions, and are prone to sudden changes in braking torque during mode switching, affecting ride smoothness. While optimization algorithms are theoretically optimal, they are computationally complex, making it difficult to meet the real-time requirements of mass-produced electronic control units and lacking robustness. Predictive control, on the other hand, suffers from decreased accuracy under highly nonlinear operating conditions.

[0061] Furthermore, most of the relevant solutions employ open-loop control, lacking an active compensation mechanism for the deviation between actual braking torque and demand. Especially during the transition from electric braking to friction braking, the delayed response of friction braking can easily generate a braking torque "window" of tens to hundreds of milliseconds, directly affecting braking safety and driving experience.

[0062] Therefore, the relevant methods still have technical problems such as insufficient braking smoothness, low control accuracy, and poor adaptability to operating conditions.

[0063] According to an embodiment of this application, a method embodiment for vehicle braking control is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0064] In one optional embodiment, the embodiments of this application can be applied to electric vehicles equipped with conventional electro-hydraulic braking systems and drive motors. The system configuration mainly includes an electro-hydraulic braking system (EHB), a drive motor and a motor control unit (MCU), wheel speed sensors, an inertial measurement unit (IMU), and a battery management system (BMS).

[0065] The electro-hydraulic braking system includes a brake pedal, brake pedal travel sensor, brake pedal speed sensor, hydraulic control unit (HCU), wheel cylinders, and brake lines. The system's pressure build-up response time is approximately 100-150ms. It can receive target wheel cylinder pressure commands and provide feedback on the actual wheel cylinder pressure via a Controller Area Network (CAN) bus. The drive motor and motor controller are mounted on the front or rear axle. During braking, the drive motor operates in regenerative braking mode, outputting negative torque to achieve regenerative braking with a response time better than 10ms. The motor controller provides real-time feedback on the maximum available regenerative braking torque and the actual regenerative braking torque. Wheel speed sensors are mounted on all four wheels, with a sampling frequency of at least 100Hz, outputting the angular velocity signal of each wheel. The inertial measurement unit is mounted near the vehicle's center of gravity, outputting longitudinal acceleration signals with a sampling frequency of at least 100Hz. The battery management system provides real-time feedback on the battery's state of charge to determine if the regenerative braking capability is limited. All the aforementioned sensor signals are collected via the CAN bus to the vehicle's domain controller or central computing unit, where the electronic control unit (ECU) executes the vehicle braking control method of this application embodiment.

[0066] This embodiment provides a vehicle braking control method. Figure 1 This is a flowchart of an optional vehicle braking control method according to an embodiment of this application, such as... Figure 1 As shown, the process includes the following steps:

[0067] Step S11: Obtain multi-source state data of the vehicle, wherein the multi-source state data includes at least: braking demand data, vehicle state data, battery state of charge data and brake actuator feedback data.

[0068] Step S12: Based on braking demand data, vehicle status data and battery state of charge data, torque is allocated to obtain the basic braking torque, wherein the basic braking torque is used to represent the basic motor braking torque and friction braking torque of the vehicle.

[0069] Step S13: Perform closed-loop compensation based on braking demand data, vehicle status data and brake actuator feedback data to obtain the compensation braking torque, wherein the compensation braking torque is used to represent the vehicle's motor braking compensation torque and friction braking compensation torque.

[0070] Step S14: Use the basic braking torque and the compensated braking torque to brake the vehicle.

[0071] The aforementioned multi-source state data can be a collection of various types of data collected from different subsystems of the vehicle, reflecting the current operating state of the vehicle and the driver's intentions. In the embodiments of this application, this data covers the driver's operating intentions, the vehicle's physical state, the energy system state, and the actual state of the actuators, serving as the fundamental information source for subsequent braking torque decisions and compensation.

[0072] The aforementioned braking demand data can be signal data reflecting the driver's braking intention, including but not limited to brake pedal travel. and brake pedal speed The total braking torque or total deceleration is typically collected by brake pedal travel sensors and brake pedal speed sensors, and is used to determine the total braking torque or total deceleration that the driver expects to obtain.

[0073] The aforementioned vehicle status data can reflect the vehicle's current kinematic characteristics and environmental conditions, including but not limited to reference vehicle speed. Four-wheel speed Longitudinal acceleration These are used to assess the current driving conditions and stability of a vehicle.

[0074] The aforementioned battery state of charge (SOC) data can reflect the current remaining charge level of the power battery, and is used to determine the available upper limit of the motor's regenerative braking capability to prevent battery overcharging or overload.

[0075] The aforementioned brake actuator feedback data can be the actual physical state data output in real time by the actual actuator of the braking system, such as the actual braking torque of the motor. Upper limit of electric motor driving torque Actual wheel cylinder pressure of each wheel These are used in closed-loop control to calculate the deviation between the actual output and the target requirement. The actual actuators of the braking system can include motor brake actuators and friction brake actuators.

[0076] For example, when acquiring multi-source vehicle status data, the electronic control unit (ECU) continuously collects braking demand data from the brake pedal sensor and brake pedal speed sensor at fixed intervals, such as 10ms, to reflect the driver's immediate braking intentions. It also collects vehicle status data from wheel speed sensors and the inertial measurement unit, as well as vehicle speed data from the vehicle control unit (VCU) or the electronic stability control system (ESC), to assess the vehicle's real-time motion state. The ECU also collects battery state-of-charge data from the battery management system to define the safety boundaries of electric braking. Simultaneously, it collects actuator feedback data from the motor controller and hydraulic control unit to understand the actual output capabilities of each braking source. By integrating the above data, a comprehensive and real-time status basis is provided for subsequent torque distribution and deviation compensation.

[0077] The aforementioned basic braking torque can be a theoretical braking torque allocation value initially calculated based on the driver's braking intention, the vehicle's current operating conditions, and battery energy recovery limitations, using a preset strategy or mapping relationship. The basic braking torque includes the basic electric motor braking torque and the basic friction braking torque, serving as the reference command for braking control.

[0078] The aforementioned basic braking torque of the motor can be the theoretical regenerative braking torque value allocated to the drive motor in the basic braking torque distribution.

[0079] The aforementioned friction braking base torque can be the theoretical braking torque value allocated to the mechanical friction braking system in the base braking torque distribution. For example, the mechanical friction braking system can use a hydraulic brake caliper.

[0080] For example, when allocating torque based on braking demand data, vehicle status data, and battery state of charge data to obtain the basic braking torque, the system determines the total target braking torque based on the braking demand data and, in conjunction with vehicle status data such as vehicle speed and adhesion coefficient estimation, judges the current operating condition. Simultaneously, referring to the battery state of charge data, it determines the maximum available capacity of the motor's regenerative braking. Under the above constraints, the system uses a preset allocation strategy, such as a lookup table or mapping relationship, to initially decompose the total required braking torque into the motor braking base torque and the friction braking base torque. This step provides a baseline control command that conforms to the energy recovery priority principle and meets battery safety limits.

[0081] The aforementioned compensating braking torque can be a corrective torque value calculated in real time using a closed-loop control algorithm based on the deviation between the actual actuator feedback and the demand. The compensating braking torque includes motor braking compensation torque and friction braking compensation torque, used to correct errors caused by the base distribution.

[0082] The aforementioned motor braking compensation torque can be the amount of motor braking torque correction that is added or reduced to meet the total braking torque requirement during the closed-loop compensation stage.

[0083] The aforementioned friction braking compensation torque can be the additional amount of friction braking torque correction that is added or reduced to meet the total braking torque requirement during the closed-loop compensation stage.

[0084] For example, when performing closed-loop compensation based on braking demand data, vehicle status data, and brake actuator feedback data to obtain the compensated braking torque, the system calculates the deviation between the total required braking torque and the actual total braking torque in real time. The actual total braking torque is obtained by summing the actual electric motor braking torque and the actual friction braking torque from the brake actuator feedback data. When this deviation exceeds a preset threshold, the closed-loop compensation mechanism is triggered. If the actual braking torque is insufficient, incremental compensation is preferentially performed using the rapid response characteristics of the electric motor braking system, or compensation is performed by the friction braking system when electric braking is limited. If the actual braking torque is excessive, the electric motor braking torque is preferentially reduced, or pressure relief compensation is performed by the friction braking system when electric braking has reached its lower limit. Through the above dynamic adjustments, the electric motor braking compensation torque and the friction braking compensation torque are obtained to eliminate the control accuracy loss caused by system delay, model error, or actuator nonlinearity.

[0085] For example, after obtaining the basic braking torque and the compensated braking torque, the system uses these two torques to control the vehicle's braking. The system superimposes the obtained basic braking torque and compensated braking torque to generate the final target control command sent to the electric motor brake actuator and the friction brake actuator. The electric motor brake actuator outputs torque based on the final electric motor braking torque, and the friction brake actuator outputs pressure based on the final friction braking torque. Through the combination of basic allocation and real-time compensation, the system ensures that the actual braking torque obtained by the vehicle closely follows the driver's needs, achieving a smooth and precise braking process.

[0086] Based on the above steps S11 to S14, this embodiment of the application acquires multi-source state data including braking demand, vehicle state, battery state of charge, and brake actuator feedback. First, it performs torque distribution based on braking demand, vehicle state, and battery state of charge to obtain a basic braking torque. Then, it performs closed-loop compensation based on braking demand, vehicle state, and brake actuator feedback to obtain a compensated braking torque. Finally, it uses the basic braking torque and the compensated braking torque to control the vehicle's braking, achieving the goal of precise control of braking torque by combining basic distribution and dynamic compensation. This improves braking smoothness, control accuracy, and adaptability to operating conditions, thereby solving the technical problems of insufficient braking smoothness, low control accuracy, and poor adaptability to operating conditions in related vehicle braking control methods.

[0087] In an optional embodiment, after acquiring the multi-source state data, preprocessing operations are performed on the data. For example, a moving average filter is applied to the wheel speed signals of each wheel to suppress high-frequency noise. For instance, embodiments of this application may employ a 5-point moving average filter, with the following formula:

[0088]

[0089] in, This represents the filtered wheel speed value of the i-th wheel. =10ms is the system sampling period.

[0090] In addition, the pressure signals of each wheel brake cylinder are also filtered to remove high-frequency noise components from the pressure sensors.

[0091] Optionally, the torque allocation based on braking demand data, vehicle status data, and battery state of charge data to obtain the basic braking torque includes: identifying the operating condition based on braking demand data, vehicle status data, and battery state of charge data to obtain the operating condition identification result; and allocating torque according to the operating condition identification result to obtain the basic braking torque.

[0092] The above-mentioned operating condition identification results can be the identification or status information after classifying the current braking scenario based on braking demand data, vehicle status data, and battery state of charge data, such as normal braking condition, emergency braking condition, or transitional condition, which can be used to guide subsequent torque distribution strategies.

[0093] When acquiring the basic braking torque, the system first identifies the operating condition based on braking demand data, vehicle status data, and battery state of charge data to obtain the operating condition identification result. For example, the system acquires braking demand data, vehicle status data, and battery state of charge data in real time, and then classifies and identifies the current braking scenario based on brake pedal travel, brake pedal speed, and current vehicle speed, combined with battery state of charge data. For instance, when the brake pedal travel is moderate and the pedal speed is gradual, it is identified as a normal braking condition. When the brake pedal speed is fast or the travel is large, it is identified as an emergency braking condition. When the battery state of charge is close to its upper limit or the vehicle speed drops below a certain threshold, it is identified as a transitional operating condition.

[0094] After identifying the operating condition, torque is allocated based on the identification results to obtain the basic braking torque. For example, after obtaining the operating condition identification results, the system calls the corresponding torque allocation strategy or mapping table according to the specific operating condition type identified. Under normal braking conditions, a larger amount of motor braking torque is allocated first to maximize energy recovery. Under emergency braking conditions, braking safety is prioritized, and friction braking torque is quickly allocated. Under transitional operating conditions, preparations for braking mode switching are made in advance. Finally, a matching basic braking torque is output based on the operating condition identification results to ensure that the basic allocation command can adapt to dynamically changing operating condition requirements.

[0095] Based on the above optional embodiments, this application embodiment identifies the operating conditions based on braking demand data, vehicle status data, and battery state of charge data to obtain the operating condition identification result. Then, torque is allocated according to the operating condition identification result to obtain the basic braking torque. This achieves the purpose of realizing the basic braking torque allocation based on dynamic adaptation of operating conditions. It realizes the technical effect that the braking force distribution strategy can be dynamically adjusted according to real-time operating conditions, and can achieve the optimal or suboptimal braking force distribution under normal braking, emergency braking, and transitional operating conditions. It solves the problem that related static braking force distribution schemes cannot adapt to dynamic operating condition changes and have poor robustness.

[0096] Optionally, the braking demand data includes: brake pedal travel and brake pedal speed; the vehicle status data includes: current reference vehicle speed; and the multi-source status data also includes: motor temperature. Based on the braking demand data, vehicle status data, and battery state of charge data, the operating condition is identified, and the operating condition identification result is determined as follows: in response to the brake pedal travel being less than or equal to a first pedal travel threshold, and the absolute value of the brake pedal speed being less than or equal to a first pedal speed threshold, and the current reference vehicle speed being greater than the motor braking cutoff speed, the operating condition identification result is determined to be a normal braking condition.

[0097] The above brake pedal travel It can be the amount of displacement of the brake pedal relative to its initial position, usually collected by a brake pedal travel sensor, used to quantify the extent to which the driver depresses the brake pedal.

[0098] The above brake pedal speed The rate of change of brake pedal travel over time, i.e., the derivative of brake pedal travel with respect to time, reflects how quickly the driver depresses or releases the brake pedal, thus determining the urgency of the braking request. Brake pedal speed is calculated by differentiating the brake pedal travel signal, using the following formula:

[0099]

[0100] in, =10ms is the system sampling period.

[0101] The above current reference speed This can be used as a reference value for the vehicle's current real-time speed, typically derived from wheel speed signals after filtering or by combining longitudinal acceleration. The speed obtained by integration is used as a reference speed for identifying operating conditions and calculating braking torque.

[0102] The motor temperature mentioned above represents the current thermal state parameter of the drive motor, monitored by a temperature sensor. Motor temperature affects the sustainability of the motor's overload capacity and regenerative braking capability, and is one of the important constraints for evaluating the available regenerative braking torque of the motor.

[0103] The aforementioned first pedal travel threshold This can be an upper limit value for the brake pedal travel used to define the boundary between normal braking and emergency braking. For example, this first pedal travel threshold can be 50% of the maximum pedal travel. When the brake pedal travel is less than or equal to this threshold, the braking depth is considered to be within the normal range.

[0104] The aforementioned first pedal speed threshold This can be a maximum brake pedal speed value used to define the boundary between normal braking and emergency braking. For example, this first pedal speed threshold could be 50 mm / s. When the absolute value of the brake pedal speed is less than or equal to this threshold, the braking action is considered to be gradual and not an emergency operation.

[0105] The above-mentioned motor braking stop speed This can be defined as the minimum vehicle speed threshold at which the electric motor braking system can operate normally. For example, the braking cutoff speed for this system can typically be 5-10 km / h. When the current reference vehicle speed is higher than this threshold, the motor has regenerative braking capability. When the vehicle speed is lower than this threshold, the regenerative braking effect of the motor weakens or stops, and it is necessary to switch to pure friction braking.

[0106] The above-mentioned conventional braking conditions can be classified as a specific vehicle operating state. Under these conditions, the driver's braking intention is relatively gentle, and the vehicle speed is within the effective range of electric motor braking. The control objective is primarily energy recovery, with braking smoothness as a secondary consideration. Regenerative braking torque is prioritized, while friction braking torque serves as a supplement.

[0107] When identifying the operating condition based on braking demand data, vehicle status data, and battery state of charge data, and obtaining the operating condition identification result, if the brake pedal travel is less than or equal to the first pedal travel threshold, and the absolute value of the brake pedal speed is less than or equal to the first pedal speed threshold, and the current reference vehicle speed is greater than the motor braking cutoff speed, the operating condition identification result is determined to be a normal braking condition.

[0108] For example, the system first acquires the brake pedal travel and brake pedal speed from the braking demand data, and the current reference vehicle speed from the vehicle status data. Next, the system compares the currently collected brake pedal travel with a preset first pedal travel threshold to determine if the braking depth is within a smooth range. Simultaneously, it calculates the absolute value of the brake pedal speed and compares it with a preset first pedal speed threshold to determine if the rate of change of braking action is within a smooth range. Furthermore, the system compares the current reference vehicle speed with the motor braking cutoff speed to determine if the current vehicle speed is higher than the effective lower limit of the motor braking system. Only when all three conditions are met—that is, the brake pedal travel does not exceed the first pedal travel threshold, the absolute value of the brake pedal speed does not exceed the first pedal speed threshold, and the current reference vehicle speed is higher than the motor braking cutoff speed—does the system determine that the current condition meets the characteristics of a normal braking condition and classifies the condition as a normal braking condition. If any condition is not met, the system proceeds to the judgment process for other conditions, such as emergency braking or transitional braking. Through the above logical judgment, the system can accurately identify smooth braking scenarios suitable for energy recovery as the primary objective.

[0109] Based on the above optional embodiments, this application embodiment determines the operating condition identification result as a normal braking condition in response to the brake pedal travel being less than or equal to a first pedal travel threshold, the absolute value of the brake pedal speed being less than or equal to a first pedal speed threshold, and the current reference vehicle speed being greater than the motor braking cutoff speed. This achieves the goal of accurate operating condition classification based on multi-parameter comprehensive judgment, and realizes the technical effect of accurately identifying normal braking conditions and prioritizing the execution of energy recovery strategies when ensuring that the vehicle is within the effective speed range of motor braking and the driver's operation is smooth. This solves the technical problem that related static allocation schemes cannot dynamically distinguish braking scenarios based on multi-dimensional real-time data such as pedal speed and vehicle speed, resulting in the failure to fully utilize electric braking energy recovery during non-emergency braking.

[0110] Optionally, operating condition identification is performed based on braking demand data, vehicle status data, and battery state of charge data. The operating condition identification result includes: in response to the brake pedal travel being greater than the second pedal travel threshold, or the absolute value of the brake pedal speed being greater than the second pedal speed threshold, the operating condition identification result is determined to be an emergency braking condition, wherein the second pedal travel threshold is greater than the first pedal travel threshold, and the second pedal speed threshold is greater than the first pedal speed threshold.

[0111] The aforementioned second pedal travel threshold This can be a brake pedal travel value used to define the lower limit of emergency braking conditions. For example, this second pedal travel threshold can be 80% of the maximum pedal travel. When the brake pedal travel exceeds this threshold, the system determines that the braking depth has entered the emergency braking range. This threshold is set to be greater than the first pedal travel threshold to ensure a clear distinction between normal braking and emergency braking, avoiding misjudgment of the operating condition.

[0112] The aforementioned second pedal speed threshold This can be a brake pedal speed value used to define the lower limit of emergency braking conditions. For example, this second pedal speed threshold can be 200 mm / s. When the absolute value of the brake pedal speed exceeds this threshold, the system determines that the braking action has changed drastically and constitutes an emergency operation. Setting this threshold to be greater than the first pedal speed threshold is also intended to provide a more sensitive triggering condition than normal braking conditions, in order to quickly respond to the driver's emergency braking needs.

[0113] The above-mentioned emergency braking conditions can be classified as a specific vehicle operating state. Under these conditions, the driver exhibits a strong braking intention, typically manifested as a large or rapid depressing of the brake pedal. The primary control objective is braking safety, with the friction braking system rapidly building up pressure and regenerative braking serving as an auxiliary measure.

[0114] When identifying the operating condition based on braking demand data, vehicle status data, and battery state of charge data, and obtaining the operating condition identification result, the operating condition identification result is determined to be an emergency braking condition if the brake pedal travel is greater than the second pedal travel threshold or the absolute value of the brake pedal speed is greater than the second pedal speed threshold.

[0115] For example, the system monitors the brake pedal travel and brake pedal speed in real time from the braking demand data. Then, the system compares the currently collected brake pedal travel with a preset second pedal travel threshold. Simultaneously, it calculates the absolute value of the brake pedal speed and compares it with a preset second pedal speed threshold. The system's determination logic uses an "OR" relationship. When either the brake pedal travel is greater than the second pedal travel threshold, or the absolute value of the brake pedal speed is greater than the second pedal speed threshold, the system determines that the driver is performing an emergency braking operation. In this case, the system directly identifies the condition as an emergency braking condition.

[0116] Furthermore, both the second pedal travel threshold and the second pedal speed threshold are greater than the first pedal travel threshold and the first pedal speed threshold corresponding to normal braking conditions, respectively. This hierarchical threshold setting ensures the hierarchical nature of the braking condition identification. Emergency braking conditions are only triggered when the braking depth is extremely deep or the braking speed is extremely high, thereby avoiding misjudging ordinary rapid braking as emergency braking. At the same time, it also ensures that in a real emergency, high-priority braking control strategies can be quickly identified and activated, such as prioritizing the establishment of friction braking torque to ensure the shortest braking distance.

[0117] Based on the above optional embodiments, this application embodiment determines the operating condition identification result as an emergency braking condition by responding to the brake pedal travel being greater than the second pedal travel threshold or the absolute value of the brake pedal speed being greater than the second pedal speed threshold. The second pedal travel threshold is greater than the first pedal travel threshold, and the second pedal speed threshold is greater than the first pedal speed threshold. This achieves the purpose of rapid emergency braking identification based on hierarchical threshold judgment, and realizes the technical effect of quickly switching to a control mode that prioritizes braking safety when the driver performs large or rapid braking operations, thereby reducing braking response delay. It solves the problem that related technologies have lagging or insufficient sensitivity in operating condition identification in emergency braking scenarios, resulting in the failure of braking force distribution to prioritize braking safety in a timely manner.

[0118] Optionally, operating condition identification is performed based on braking demand data, vehicle status data, and battery state of charge data. The operating condition identification result includes: in response to the battery state of charge data being greater than a preset charge threshold, or the current reference vehicle speed being less than the motor braking cutoff speed, or the motor temperature being greater than a preset temperature threshold, the operating condition identification result is determined to be a transition braking condition.

[0119] The aforementioned preset charge threshold can be an upper limit for the battery state of charge (SOC) set in the battery management system. For example, the preset charge threshold can be 95%. When the battery state of charge data exceeds this threshold, it indicates that the battery is close to being fully charged. Continuing to accept high-current charging may lead to overcharging or damage. Therefore, it is necessary to limit or stop motor braking and instead rely on friction braking.

[0120] The aforementioned preset temperature threshold can be the maximum allowable temperature limit for safe operation of the motor. When the motor temperature exceeds this threshold, it indicates that the motor is on the verge of overheat protection or has triggered overheat protection. The system needs to limit the motor braking power to prevent thermal damage to the motor.

[0121] The aforementioned transitional braking condition can be classified as a specific vehicle operating state. Under this condition, the availability of the electric motor braking system will be limited or completely lost, requiring the system to prepare in advance and smoothly replace the electric motor braking through the friction braking system to ensure the continuity and smoothness of the braking torque and avoid a "gap" in braking torque.

[0122] When identifying the operating condition based on braking demand data, vehicle status data, and battery state of charge data, and obtaining the operating condition identification result, if the battery state of charge data is greater than a preset charge threshold, or if the current reference vehicle speed is less than the motor braking cutoff speed, or if the motor temperature is greater than a preset temperature threshold, the operating condition identification result is determined to be a transition braking condition.

[0123] For example, the system monitors battery state of charge (SBC) data, current reference vehicle speed, and motor temperature in real time. Internally, three independent trigger conditions are set: the first condition is that the battery SBC data is greater than a preset SBC threshold, meaning the battery is fully charged and electric braking capability is limited; the second condition is that the current reference vehicle speed is less than the motor braking cutoff speed, meaning the vehicle speed is too low and the motor cannot effectively generate electricity; the third condition is that the motor temperature is greater than a preset temperature threshold, meaning the motor is overheating and electric braking needs to be limited. These three conditions are connected by a logical "OR" relationship. If any one of these conditions is met, the system determines that the current state is one where motor braking capability is about to be deactivated or limited, and identifies the operating condition as a transitional braking condition. When a transitional braking condition is identified, the subsequent control strategy will activate a pre-pressure build-up mechanism, allowing the friction braking system to intervene in advance to eliminate the braking torque gap when electric braking deactivates.

[0124] Based on the above optional embodiments, this application embodiment determines the operating condition identification result as a transitional braking condition in response to the battery state of charge data being greater than a preset charge threshold, or the current reference vehicle speed being less than the motor braking cutoff speed, or the motor temperature being greater than a preset temperature threshold. This achieves the purpose of multi-dimensional monitoring of the motor braking capacity limitation state, and realizes the technical effect of early identification of transitional operating conditions and initiation of friction braking pre-pressure building strategy in any scenario that leads to a decrease in electric braking capacity, such as a fully charged battery, low-speed driving, or motor overheating. This eliminates the braking torque switching gap, improves braking smoothness and safety, and solves the problem of sudden changes or delays in braking torque caused by the lack of a prediction mechanism during the switching process of limited electric braking capacity in related technologies.

[0125] Optionally, the vehicle braking control method further includes: in response to the vehicle being in a transition braking condition, sending a pre-pressure build-up request to the hydraulic control unit of the electro-hydraulic braking system; and controlling the hydraulic control unit to build up basic wheel cylinder pressure based on the pre-pressure build-up request so that the gap between the vehicle's friction brake pads and brake disc is less than a target gap value.

[0126] The aforementioned electro-hydraulic braking system can be the braking execution system used in the embodiments of this application, including components such as a hydraulic control unit, brake lines, and wheel cylinders, responsible for establishing frictional braking force through hydraulic means. This system has an inherent pressure build-up response delay, typically 100-150ms, and is the main target of the "pre-pressure build-up" strategy in this application.

[0127] The aforementioned hydraulic control unit can be the core actuator in an electro-hydraulic braking system. It is responsible for receiving hydraulic commands from the controller and adjusting the hydraulic pressure in the brake wheel cylinder through internal valves, thereby controlling the magnitude of the friction braking torque.

[0128] The aforementioned pre-pressure build-up request can be a specific control command generated by the control algorithm when the vehicle is identified as being in a transitional braking condition. This command is intended to instruct the hydraulic control unit to build up a certain initial hydraulic pressure in advance, rather than to execute the final braking pressure, in order to shorten the pressure build-up time during subsequent formal braking.

[0129] The aforementioned base wheel cylinder pressure can be the initial pressure value established in the brake wheel cylinder by the hydraulic control unit during the pre-pressure build-up phase. This pressure value is typically low, such as 0.5-1 MPa, insufficient to produce significant braking deceleration, but sufficient to bring the braking components close to contact.

[0130] The aforementioned friction brake pads can be components installed inside the brake caliper that move relative to the brake disc and generate friction. During the pre-pressure build-up process, the friction brake pads move towards the brake disc to eliminate the air gap between them.

[0131] The aforementioned brake disc can be a disc-shaped metal component that rotates with the wheel, and works in conjunction with friction brake pads to achieve friction braking.

[0132] The aforementioned target gap value can be a preset minimum distance threshold between the friction brake pads and the brake disc. When the gap between the two is less than this value, it is considered to be in a "standby" or "pre-contact" state. At this time, the hydraulic system does not need to go through the pressure build-up process from complete separation to contact, and can directly enter the linear pressure increase stage, thereby significantly shortening the response time.

[0133] In this embodiment, in response to the vehicle being in a transition braking condition, a pre-pressure build-up request is sent to the hydraulic control unit of the electro-hydraulic braking system. Exemplarily, the system monitors the vehicle status in real time. When the condition identification result is "transition braking condition," the control logic immediately triggers the pre-pressure build-up process. That is, the controller sends a pre-pressure build-up request command to the hydraulic control unit of the electro-hydraulic braking system.

[0134] Based on a pre-pressure build-up request, the hydraulic control unit establishes base wheel cylinder pressure to ensure the gap between the vehicle's friction brake pads and brake discs is less than a target gap value. For example, upon receiving this instruction, the hydraulic control unit starts the hydraulic pump or opens the corresponding valve to inject a small amount of brake fluid into the brake cylinders of each wheel, establishing base wheel cylinder pressure. As the pressure increases, the friction brake pads within the brake calipers are pushed against the rotating brake disc. The control logic continuously monitors or calculates based on a preset model until it is confirmed that the physical gap between the friction brake pads and the brake disc has decreased to less than the target gap value. In this state, the friction brake pads and brake discs are in a "pre-contact" state, about to make contact but without significant frictional force. This action utilizes the window of time when the electric braking has not yet fully disengaged and the friction braking still has a response time margin, completing the mechanical preparation of the hydraulic system in advance. This allows the friction braking to provide the required braking torque almost instantaneously when the electric braking finally disengages, without experiencing a lengthy pressure build-up delay.

[0135] Based on the above optional embodiments, this application embodiment, in response to the vehicle being in a transition braking condition, sends a pre-pressure build-up request to the hydraulic control unit of the electro-hydraulic braking system, and controls the hydraulic control unit to build up the basic wheel cylinder pressure based on the pre-pressure build-up request, so that the gap between the vehicle's friction brake pads and brake discs is less than the target gap value. This achieves the purpose of preparing for friction braking in advance by utilizing the time window before the electric braking is disengaged, realizing the technical effect of eliminating the "window period" of braking torque caused by the delay in hydraulic pressure build-up during the switching between electric braking and friction braking, and solving the problem of discontinuous braking torque and affecting braking smoothness and safety when switching braking modes in related technologies.

[0136] Optionally, closed-loop compensation based on braking demand data, vehicle status data, and brake actuator feedback data is performed to obtain the compensated braking torque, including: determining the total required braking torque of the vehicle based on braking demand data and vehicle status data, and determining the actual total braking torque of the vehicle based on brake actuator feedback data; determining the braking torque deviation based on the total required braking torque and the actual total braking torque; and, in response to the absolute value of the braking torque deviation being greater than a preset deviation threshold, performing closed-loop compensation based on the braking torque deviation and brake actuator feedback data to obtain the compensated braking torque.

[0137] The above total demand braking torque The total braking capacity that the driver expects the vehicle to achieve can be calculated based on the driver's braking intention and the vehicle's current driving state, such as brake pedal travel and vehicle speed, through a preset mapping relationship or algorithm. For example, in the embodiments of this application, the total required braking torque can be obtained through a preset mapping table. The mapping table was obtained through a real vehicle calibration. The total required braking torque is the ultimate target value pursued by the control system.

[0138] The above-mentioned actual total braking torque This can be the sum of the actual braking torques generated by all braking sources of the vehicle at a specific moment. In the embodiments of this application, this value is obtained by adding the regenerative braking torque actually output by the electric motor braking system and the braking torque actually output by the friction braking system.

[0139] The above-mentioned braking torque deviation This can be the difference between the total required braking torque and the actual total braking torque. This parameter reflects the gap between the current braking system output and the driver's needs. A positive deviation indicates insufficient actual braking force, while a negative deviation indicates excessive actual braking force. The formula for calculating the braking torque deviation is:

[0140]

[0141] The above-mentioned preset deviation threshold This can serve as an allowable error threshold for determining whether a compensation mechanism needs to be activated. The system only considers the error significant and requires intervention when the absolute value of the braking torque deviation exceeds this threshold. If the deviation is within this threshold range, the system control accuracy is considered acceptable, requiring no additional compensation and thus avoiding unnecessary control actions and noise interference. For example, this preset deviation threshold could be 50 Nm.

[0142] When performing closed-loop compensation based on braking demand data, vehicle status data, and brake actuator feedback data to obtain the compensated braking torque, the system first determines the total required braking torque of the vehicle based on the braking demand data and vehicle status data, and then determines the actual total braking torque of the vehicle based on the brake actuator feedback data. For example, the system uses braking demand data and vehicle status data, such as pedal travel and vehicle speed, to calculate the total required braking torque of the vehicle at the current moment through table lookup or function mapping. Simultaneously, the system reads brake actuator feedback data, including the actual regenerative torque of the motor and the wheel cylinder pressure of each wheel, and combines this with braking system parameters, such as the conversion coefficient from wheel cylinder pressure to torque, to calculate the vehicle's current actual total braking torque in real time.

[0143] Secondly, the braking torque deviation is determined based on the total required braking torque and the actual total braking torque. For example, the system subtracts the actual total braking torque from the total required braking torque to obtain the braking torque deviation.

[0144] After determining the braking torque deviation, in response to the absolute value of the braking torque deviation exceeding a preset deviation threshold, closed-loop compensation is performed based on the braking torque deviation and brake actuator feedback data to obtain the compensated braking torque. For example, after acquiring the braking torque deviation, the system determines whether the absolute value of the deviation is greater than the preset deviation threshold. If the absolute value is less than or equal to the threshold, no compensation is performed. If the absolute value is greater than the threshold, it indicates a significant error in the current braking torque, and the system triggers the closed-loop compensation mechanism. During closed-loop compensation, the system calculates the compensated braking torque according to the magnitude and direction of the braking torque deviation (positive or negative), combined with current brake actuator feedback data, such as motor torque margin and wheel cylinder pressure status, according to a preset compensation strategy. For example, when the deviation is positive, electric braking is preferentially increased; when the deviation is negative, electric braking is preferentially reduced or friction relief is increased. This compensated braking torque is then superimposed on the basic braking torque command to form the final execution command, thereby eliminating the deviation.

[0145] Based on the above optional embodiments, this application embodiment determines the total required braking torque of the vehicle based on braking demand data and vehicle status data, and determines the actual total braking torque of the vehicle based on brake actuator feedback data. It then determines the braking torque deviation based on the total required braking torque and the actual total braking torque. In response to the absolute value of the braking torque deviation exceeding a preset deviation threshold, closed-loop compensation is performed based on the braking torque deviation and brake actuator feedback data to obtain a compensated braking torque. This achieves the goal of real-time dynamic correction of the braking torque, realizing the technical effect of actively compensating for the deviation between the actual output and the demand by real-time monitoring, ensuring that the actual braking torque closely tracks the driver's demand. This significantly improves the accuracy, consistency, and responsiveness of braking control, and solves the problem that related control schemes cause the braking torque to deviate from the demand due to model errors, parameter drift, or actuator delay, affecting braking safety and smoothness.

[0146] Optionally, the brake actuator feedback data includes: the actual braking torque of the motor and the wheel brake cylinder pressure data. Determining the vehicle's actual total braking torque based on the brake actuator feedback data includes: determining the actual friction braking torque based on the wheel brake cylinder pressure data; and determining the actual total braking torque based on the actual friction braking torque and the actual braking torque of the motor.

[0147] The actual braking torque of the above motor This can be the actual regenerative braking torque output by the drive motor during the current control cycle. This data is fed back by the motor controller and reflects the current actual contribution value of the electric braking system, usually expressed in Newton-meters (Nm).

[0148] The above wheel brake cylinder pressure data The hydraulic pressure values ​​can be collected by pressure sensors installed on the brake cylinders of each wheel. This data reflects the working state of the hydraulic actuators in the friction braking system and is a key input parameter for estimating the friction braking torque.

[0149] The above-mentioned actual torque of friction braking This can be the actual braking torque generated at the current moment by a friction braking system, such as a disc brake. This torque cannot be measured directly and must be calculated using wheel brake cylinder pressure data combined with brake geometry parameters and friction coefficient models. The formula for calculating the actual friction braking torque is:

[0150]

[0151] in, For the first The braking efficiency factor of each wheel is calculated using brake parameters and friction coefficient.

[0152] Therefore, the actual total braking torque The calculation formula is:

[0153]

[0154] When determining the vehicle's actual total braking torque based on brake actuator feedback data, the actual friction braking torque is determined based on wheel brake cylinder pressure data. For example, the system extracts wheel brake cylinder pressure data from the brake actuator feedback data, which includes the real-time hydraulic pressure values ​​of each of the four wheels. Then, using a preset braking efficiency factor—the conversion coefficient between cylinder pressure and braking torque—the system converts the brake cylinder pressure data of each wheel into the corresponding wheel's friction braking torque, and adds the friction braking torques of the four wheels to obtain the actual friction braking torque at the vehicle level. Simultaneously, the system extracts the actual motor braking torque from the brake actuator feedback data, which directly represents the current output of the electric braking system.

[0155] After obtaining the actual friction braking torque and the actual motor braking torque, the actual total braking torque is determined based on these two values. For example, the system algebraically adds the calculated actual friction braking torque to the extracted actual motor braking torque to obtain the vehicle's actual total braking torque. This process achieves an accurate mapping from the raw data from the underlying sensors to the physical quantities required for upper-level control, providing a precise basis for subsequent deviation calculations.

[0156] Based on the above optional embodiments, this application embodiment determines the actual friction braking torque based on wheel brake cylinder pressure data, and determines the actual total braking torque based on the actual friction braking torque and the actual motor braking torque. This achieves the goal of accurately quantifying the vehicle's current real braking output, and realizes the technical effect of obtaining a high-precision actual total braking torque by separately estimating and summing the actual contributions of friction braking and electric braking. This provides a reliable benchmark for subsequent braking torque deviation calculation and closed-loop compensation, and solves the problem of decreased control accuracy due to the inability to accurately obtain the actual braking torque.

[0157] Optionally, closed-loop compensation based on braking torque deviation and brake actuator feedback data is performed to obtain compensated braking torque, including: in response to a positive braking torque deviation, determining the motor torque margin based on the upper limit of motor torque and the actual motor braking torque; in response to a positive motor torque margin, determining the motor torque compensation amount based on the braking torque deviation and the motor torque margin, and incrementally compensating the actual motor braking torque using the motor torque compensation amount; and in response to the actual motor braking torque reaching the upper limit of motor torque, determining the friction braking torque compensation amount based on the first residual torque deviation.

[0158] The above-mentioned upper limit of the driving torque of the electric motor This refers to the maximum regenerative braking torque that the motor braking system can output through the motor controller under current operating conditions, such as battery state of charge, motor temperature, and motor speed constraints. This value represents the physical boundary of the electric braking capability and is calculated and fed back by the motor controller in real time.

[0159] The above-mentioned motor torque margin This can be the difference between the maximum available capacity of the electric motor braking system and the currently used capacity. This parameter reflects how much incremental capacity the electric motor braking system still has to compensate for insufficient braking torque, and the calculation formula is:

[0160]

[0161] in, This is the actual braking torque of the motor.

[0162] The aforementioned motor torque compensation amount can be defined as the increased motor torque command value determined during the closed-loop compensation process to eliminate braking torque deviation. This value aims to bridge the gap between actual and demand by increasing the electric braking torque. The formula for calculating the motor torque compensation amount is:

[0163]

[0164] The aforementioned first residual torque deviation can be defined as the difference in braking torque deviation that cannot be compensated for by motor braking when the motor braking capacity has reached its upper limit, i.e., the motor braking torque margin is zero or negative. This value is equal to the total braking torque deviation minus the maximum compensation that motor braking can provide; this portion of the deviation must be borne by the friction braking system.

[0165] The aforementioned friction braking torque compensation amount can be a command allocated to the friction braking system to increase its output torque. When electric braking cannot fully meet the demand, this compensation amount is used to instruct the hydraulic control unit to increase the wheel cylinder pressure, thereby enhancing the friction braking force.

[0166] When performing closed-loop compensation based on braking torque deviation and brake actuator feedback data to obtain the compensated braking torque, in response to a positive braking torque deviation, the system determines the motor braking torque margin based on the upper limit of the motor braking torque and the actual braking torque of the motor. For example, the system determines whether the braking torque deviation is positive. If it is positive, it indicates that the actual braking force is insufficient and needs to be increased. The system then reads the upper limit of the motor braking torque and the actual braking torque of the motor from the motor brake feedback data, calculates the difference between the two, and obtains the motor braking torque margin, i.e., how much more torque can be added to the electric brake.

[0167] After calculating the motor's torque margin, in response to a positive motor torque margin, the system determines the motor torque compensation amount based on the braking torque deviation and the motor torque margin, and uses this compensation amount to incrementally compensate the actual braking torque of the motor. For example, the system determines whether the motor torque margin is positive. If it is positive, it indicates that there is still room for increased electric braking. The system calculates the motor torque compensation amount, which is typically the smaller of the braking torque deviation and the motor torque margin, to ensure that the motor's capacity limit is not exceeded. Subsequently, the system adds this compensation amount to the current actual braking torque of the motor and executes the incremental compensation command.

[0168] In response to the actual braking torque of the motor reaching the upper limit of the motor's braking torque, the friction braking torque compensation amount is determined based on the first residual torque deviation. For example, if the system determines that the motor's braking torque margin is not positive, meaning the actual braking torque of the motor has reached the upper limit of the motor's braking torque and electric braking cannot be increased further, then the friction braking compensation process begins. In this process, the system calculates the first residual torque deviation, which is the portion of the total braking torque deviation that has not been compensated by electric braking. Next, the system determines the friction braking torque compensation amount based on the first residual torque deviation and then sends a rapid pressure increase command to the hydraulic control unit of the friction braking system, such as the electro-hydraulic braking system (EHB). Upon receiving the command, the EHB controls the hydraulic pump and valves to rapidly increase the hydraulic pressure in the brake cylinders of each wheel, causing the friction braking torque to rise rapidly, thereby filling the torque gap left by electric braking.

[0169] Based on the above optional embodiments, this application embodiment achieves the coordinated control objective of prioritizing the use of fast-response electric braking on demand and replacing it with friction braking when the braking torque deviation is positive. This is achieved by responding to a positive braking torque deviation, determining the electric motor torque margin based on the upper limit of the electric motor torque and the actual braking torque of the motor, and using the electric motor torque compensation amount to incrementally compensate the actual braking torque of the motor. Finally, when the actual braking torque of the motor reaches the upper limit of the electric motor torque, the friction braking torque compensation amount is determined based on the first residual torque deviation. This achieves the technical effect of prioritizing the use of fast-response electric braking when needed and replacing it with friction braking when insufficient braking force is achieved. It fully utilizes the fast-response characteristics of electric braking for priority compensation when braking force is insufficient, and smoothly switches to friction braking to supplement when electric braking capacity is limited. This ensures that the total braking torque quickly and smoothly tracks the driver's needs, improving braking response speed and accuracy. It also solves the problem of braking torque fluctuation caused by large differences in the response characteristics of a single braking source and uneven switching.

[0170] Optionally, closed-loop compensation based on braking torque deviation and brake actuator feedback data is performed to obtain compensated braking torque, including: in response to a negative braking torque deviation, determining the reduction in motor braking torque based on the braking torque deviation and the actual motor braking torque, and using the reduction in motor braking torque to compensate for the reduction in the actual motor braking torque; in response to the actual motor braking torque reaching a preset value, determining the reduction in friction braking torque based on the second residual torque deviation.

[0171] The aforementioned reduction in electric motor torque can be defined as the amount removed from the current electric motor torque when there is excess braking torque. This value aims to eliminate the positive deviation between actual and demand by reducing the electric braking torque, bringing the actual braking torque back to the demand level. The formula for calculating the reduction in electric motor torque is:

[0172]

[0173] The aforementioned preset value can be the minimum allowable braking torque threshold for the motor braking system, typically 0 Nm. When the actual braking torque of the motor reaches this lower limit, it indicates that the electric braking has completely disengaged and cannot be further reduced to eliminate excess braking force.

[0174] The aforementioned second residual torque deviation can be the remaining braking torque difference when the electric braking torque has been reduced to a preset value but the excess braking torque still cannot be eliminated. This value is equal to the current braking torque deviation (negative value) plus the total amount of reduced electric braking torque. This excess braking torque must be eliminated by the friction braking system through pressure relief.

[0175] The aforementioned reduction in friction braking torque can be a command allocated to the friction braking system to reduce its output torque. When the electric braking cannot be reduced further, this reduction is used to instruct the hydraulic control unit to open the pressure relief valve, reducing the wheel cylinder pressure, thereby reducing the friction braking force to match the driver's required braking torque.

[0176] When performing closed-loop compensation based on braking torque deviation and brake actuator feedback data to obtain compensated braking torque, in response to a negative braking torque deviation, the system determines the reduction amount of motor braking torque based on the braking torque deviation and the actual motor braking torque, and uses this reduction amount to compensate for the decrease in the actual motor braking torque. For example, the system determines whether the braking torque deviation is negative. If it is negative, it indicates that the actual braking torque is greater than required, and the system needs to reduce the braking force. In this case, the system reads the actual motor braking torque and, combined with the magnitude of the braking torque deviation, calculates the reduction amount of motor braking torque. This reduction amount is typically the smaller of the absolute value of the braking torque deviation and the actual motor braking torque to ensure that the electric braking torque does not drop below the allowable minimum value, such as 0. Subsequently, the system applies this reduction amount of motor braking torque to the motor controller, executes a reduction compensation command, and rapidly reduces the electric braking torque.

[0177] In response to the actual braking torque of the motor reaching a preset value, the system determines the reduction amount of friction braking torque based on a second residual torque deviation. For example, the system monitors whether the actual braking torque of the motor has reached a preset value, such as 0 Nm. If the actual braking torque of the motor has reached the preset value, it indicates that the electric braking has been reduced to its minimum and cannot be further reduced to eliminate excess braking force. In this case, the system calculates the second residual torque deviation, which is the portion of the total braking torque deviation that has not yet been compensated by the reduction in electric braking. Next, the system determines the reduction amount of friction braking torque based on the second residual torque deviation and sends a command to the friction braking system, such as an electro-hydraulic braking system (EHB), to control its internal hydraulic regulating valve to perform a rapid pressure relief operation, for example, opening the outlet valve. After the hydraulic regulating valve actuates, the hydraulic pressure in the brake wheel cylinder drops rapidly, causing a decrease in the pressure of the friction brake pads on the brake disc, thereby rapidly reducing the friction braking torque until the vehicle's actual total braking torque matches the total required braking torque, eliminating the braking torque deviation.

[0178] Based on the above optional embodiments, this application embodiment, in response to a negative braking torque deviation, determines the reduction amount of motor braking torque based on the braking torque deviation and the actual braking torque of the motor, and uses the reduction amount of motor braking torque to compensate for the reduction in the actual braking torque of the motor. In response to the actual braking torque of the motor reaching a preset value, the reduction amount of friction braking torque is determined based on the second residual torque deviation. This achieves the goal of quickly and accurately eliminating excess braking force, realizes the technical effect of prioritizing the fast response of electric braking for rapid force release, and having friction braking take over the remaining force reduction task when the electric braking capacity is exhausted. This solves the braking shock and safety problems caused by lag in response or coarse adjustment when there is excess braking torque.

[0179] Optionally, the vehicle status data includes: current reference vehicle speed, wheel angular velocity, and tire rolling radius. The vehicle braking control method further includes: determining the wheel slip ratios of multiple wheels based on the current reference vehicle speed, wheel angular velocity, and tire rolling radius; and controlling the first wheel to perform a braking torque redistribution operation in response to the wheel slip ratio of the first wheel among the multiple wheels being greater than a preset threshold value.

[0180] The above wheel angular velocity This can be achieved by collecting angular velocity signals of the wheels rotating around the axle from wheel speed sensors installed on each wheel. This data reflects the rotational speed of an individual wheel and is a key variable for calculating the wheel's slip ratio.

[0181] The above tire rolling radius This is the equivalent radius value obtained by dividing the distance traveled by the wheel in one revolution under standard inflation pressure and no load by 2π. This parameter is used to convert the wheel angular velocity into linear velocity and is a geometric parameter for establishing the relationship between wheel kinematics and vehicle kinematics.

[0182] The above wheel slip ratio This refers to the relative difference between the linear velocity of the wheels and the longitudinal velocity of the vehicle during braking. In this embodiment, the wheel slip ratio is a dimensionless parameter calculated based on the current reference vehicle speed, wheel angular velocity, and tire rolling radius, used to assess the wheel's contact patch and the risk of wheel lockup. The formula for calculating the wheel slip ratio is:

[0183]

[0184] in, For reference vehicle speed, For the first The angular velocity of each wheel The tire's rolling radius, To prevent the denominator from being zero, use extremely small positive numbers.

[0185] The above preset threshold value A pre-calibrated safety threshold for wheel slip ratio can be used. When the wheel slip ratio exceeds this value, the system determines that the wheel is close to locking or instability, requiring intervention. This value is usually calibrated to a value less than 1, such as 0.15, to ensure that adjustment is made before the wheel locks up completely.

[0186] The aforementioned first wheel can be a specific target wheel among multiple wheels whose wheel slip ratio is detected to exceed a safety limit. This first wheel is used to designate the object requiring specific control actions in logical judgments, distinguishing it from other wheels in a normal state.

[0187] The aforementioned braking torque redistribution operation is a control action that adjusts the distribution ratio of electric braking torque and friction braking torque between the detected wheel and other wheels when an abnormal wheel slip ratio is detected. This operation aims to reduce the total braking torque of the high-risk wheel and transfer some torque to other wheels to restore vehicle stability.

[0188] When redistributing braking torque, this embodiment of the application determines the wheel slip ratios corresponding to multiple wheels based on the current reference vehicle speed, wheel angular velocity, and tire rolling radius. For example, the system extracts the current reference vehicle speed, the wheel angular velocity of each wheel, and the tire rolling radius from vehicle state data. Then, the system uses a preset slip ratio calculation formula to multiply the wheel angular velocity of each wheel by the tire rolling radius to obtain the linear velocity of that wheel. The linear velocity of the wheel is then subtracted from the current reference vehicle speed, and the difference is divided by the larger of the wheel linear velocity and the current reference vehicle speed to calculate the wheel slip ratio corresponding to each wheel.

[0189] In response to a wheel slip ratio exceeding a preset threshold among multiple wheels, the system controls the first wheel to perform a braking torque redistribution operation. For example, the system iterates through the wheel slip ratios of multiple wheels to determine if the wheel slip ratio of the first wheel exceeds the preset threshold. If the wheel slip ratio of the first wheel exceeds the preset threshold, it indicates that the wheel is prone to locking up or has insufficient traction. The system then triggers control logic to control the first wheel to perform a braking torque redistribution operation. This operation specifically includes reducing the total braking torque of the first wheel, i.e., prioritizing the reduction of friction braking torque while retaining electric braking torque, and redistributing the reduced braking torque to another wheel on the same axle or other axles to suppress wheel lock-up tendencies and maintain vehicle stability.

[0190] Based on the above optional embodiments, this application embodiment determines the wheel slip ratios corresponding to multiple wheels based on the current reference vehicle speed, wheel angular velocity, and tire rolling radius. In response to the first wheel's wheel slip ratio being greater than a preset threshold, the first wheel is controlled to perform a braking torque redistribution operation. This achieves the purpose of real-time monitoring of wheel adhesion status and dynamic adjustment of braking force distribution. It realizes the technical effect of identifying wheels at risk of locking by accurately calculating slip ratios and using a differentiated redistribution strategy to prioritize reducing friction braking force to protect grip, while retaining electric braking force to take into account energy recovery. This maximizes energy utilization efficiency while ensuring braking stability and solves the problem that traditional braking control is prone to wheel lock-up on wet or low-adhesion surfaces and cannot take energy efficiency into account.

[0191] Optionally, controlling the first wheel to perform a braking torque redistribution operation includes: determining the total braking torque reduction corresponding to the first wheel based on the wheel slip ratio; determining a first target torque reduction amount based on the friction braking torque component of the first wheel and the total braking torque reduction amount; and adjusting the friction braking torque component based on the first target torque reduction amount; in response to the friction braking torque component reaching a preset value and the wheel slip ratio being greater than a preset threshold value, determining a second target torque reduction amount based on the wheel slip ratio; and adjusting the electric motor torque component of the first wheel based on the second target torque reduction amount.

[0192] The above-mentioned total reduction in braking torque This can be defined as the total braking torque that needs to be removed from the first wheel in order to reduce its wheel slip ratio to a safe range, such as below 0.10. This value is calculated based on the difference between the current wheel slip ratio and the target slip ratio, combined with a vehicle dynamics model.

[0193] The above friction braking torque components This can be the portion of the braking torque currently provided to the first wheel by the hydraulic clamping force generated by a friction braking system, such as EHB. Because friction braking has a relatively slow response and is prone to causing complete wheel lock-up, it is typically a priority target for reduction in redistribution strategies.

[0194] The aforementioned first target torque reduction can be the planned reduction of torque from the friction braking torque component of the first wheel. This value is limited by the current magnitude of the friction braking torque component and the total torque to be reduced, aiming to eliminate the risk of wheel lock-up as much as possible by reducing friction braking force. The formula for calculating the first target torque reduction is:

[0195]

[0196] The aforementioned preset value can be the minimum allowable threshold for friction braking torque, typically 0 Nm. When the friction braking torque component drops to this value, it indicates that friction braking has been fully released, and it is no longer possible to further reduce the total braking force by decreasing the friction braking force.

[0197] The aforementioned second target torque reduction This can be defined as the torque value that needs to be further reduced from the motor's torque component after the friction braking torque component has reached a preset value, i.e., the friction braking has been fully released, but if the wheel slip ratio is still not lower than a preset threshold value. This value is equal to the remaining braking torque reduction requirement, i.e., the total braking torque reduction minus the first target torque reduction.

[0198] When controlling the first wheel to perform a braking torque redistribution operation, the total amount of braking torque reduction corresponding to the first wheel is determined based on the wheel slip ratio. For example, the system calculates the total amount of braking torque reduction that needs to be removed from the first wheel based on the deviation between the current wheel slip ratio and the target safe slip ratio, to ensure that the slip ratio falls back to a safe range.

[0199] The system determines a first target torque reduction based on the frictional braking torque component of the first wheel and the total reduction in braking torque, and adjusts the frictional braking torque component accordingly. For example, the system compares the total reduction in braking torque with the current frictional braking torque component of the first wheel. Then, the smaller value between the total reduction in braking torque and the frictional braking torque component is determined as the first target torque reduction to ensure that the frictional braking force is not excessively reduced, thus preventing other problems. Subsequently, the system sends a command to the friction brake actuator to reduce the frictional braking torque component of the first wheel according to the first target torque reduction.

[0200] In response to the friction braking torque component reaching a preset value and the wheel slip ratio exceeding a preset threshold, the system determines a second target torque reduction based on the wheel slip ratio and adjusts the motor torque component of the first wheel based on the second target torque reduction. For example, the system monitors whether the friction braking torque component has reached a preset value, such as 0 Nm, and simultaneously checks whether the wheel slip ratio is still greater than the preset threshold. If both conditions are met, it indicates that reducing the friction braking force alone is insufficient to eliminate the risk of wheel lockup, and the system enters the second stage of adjustment. In the second stage, the system calculates the second target torque reduction, i.e., the remaining torque to be reduced, which can be calculated by subtracting the first target torque reduction from the total braking torque reduction. Finally, the system sends a command to the motor controller to reduce the motor torque component of the first wheel based on the second target torque reduction, thereby further reducing the total braking torque until the wheel slip ratio returns to a safe range.

[0201] Based on the above optional embodiments, this application embodiment determines the total reduction of braking torque corresponding to the first wheel based on the wheel slip ratio, determines the first target torque reduction amount based on the friction braking torque component of the first wheel and the total reduction of braking torque, and adjusts the friction braking torque component based on the first target torque reduction amount. In response to the friction braking torque component reaching a preset value and the wheel slip ratio being greater than a preset threshold, a second target torque reduction amount is determined based on the wheel slip ratio, and the electric motor braking torque component of the first wheel is adjusted based on the second target torque reduction amount. This achieves the hierarchical control objective of prioritizing the rapid release of force by friction braking and fine adjustment by electric braking. Under the risk of wheel lock-up, it prioritizes the reduction of friction braking torque, which has a slow response and is prone to lock-up, to quickly reduce braking force. When friction braking is exhausted, it uses electric braking torque, which has a fast response and can be finely adjusted, to supplement the reduction. This maximizes the retention of energy recovery opportunities while ensuring braking stability. It solves the problem of response lag or energy waste caused by the single adjustment characteristics of the braking source in the control of traditional anti-lock braking systems (ABS).

[0202] Optionally, the vehicle braking control method further includes: transferring the total reduction of braking torque to the coaxial wheel corresponding to the first wheel, or transferring the total reduction of braking torque to the second wheel, wherein the wheel slip ratio of the second wheel is less than a preset threshold value.

[0203] The aforementioned coaxial wheel can be another wheel located on the same axle as the first wheel of the vehicle. For example, if the first wheel is the left front wheel, then the coaxial wheel is the right front wheel. Coaxial wheels typically have similar dynamic characteristics and road adhesion conditions.

[0204] The aforementioned second wheel can be the target wheel selected to receive the total reduction in braking torque during the implementation of braking torque transfer. In this embodiment, the selection criterion for the second wheel is that its wheel slip ratio is less than a preset threshold value, indicating that the wheel is in a stable adhesion state, has additional braking force reserve, and can withstand additional braking force without locking up.

[0205] In the torque transfer during braking torque redistribution, embodiments of this application transfer the total reduction in braking torque to the coaxial wheel corresponding to the first wheel, or transfer the total reduction in braking torque to the second wheel. Exemplarily, the system determines the total reduction in braking torque from the first wheel. Then, the system executes the torque transfer logic. The system can choose to transfer the total reduction in braking torque to the coaxial wheel corresponding to the first wheel, utilizing the remaining adhesion of the other coaxial wheel to compensate for the braking force lost due to the reduced force on the first wheel, thereby maintaining the braking performance of the entire vehicle. Alternatively, the system can choose to transfer the total reduction in braking torque to the second wheel, where the second wheel is defined as a wheel with a wheel slip ratio less than a preset threshold. The system identifies the second wheel that meets the condition by monitoring the wheel slip ratio of each wheel, and applies the braking torque command that originally needed to be removed from the first wheel to the second wheel. This process ensures that while reducing the braking force of the first wheel to restore stability, the loss of total braking force is offset by increasing the braking force of the second wheel, achieving a dynamic balance of the vehicle's braking torque.

[0206] Based on the above optional embodiments, this application embodiment achieves the goal of maintaining a constant total braking torque of the vehicle in single-wheel anti-slip control by transferring the total reduction of braking torque to the coaxial wheel corresponding to the first wheel, or by transferring the total reduction of braking torque to the second wheel, wherein the wheel slip ratio of the second wheel is less than a preset threshold value. This realizes the technical effect of maximizing the preservation of braking efficiency while ensuring vehicle braking stability, by flexibly selecting the coaxial wheel or the low slip ratio wheel as the torque receiving end, effectively compensating for the reduction in braking force due to the suppression of lock-up, and avoiding a significant increase in the overall braking distance due to the reduction in force of a single wheel. This solves the problem of a significant decrease in overall braking force during single-wheel anti-slip control in traditional braking control.

[0207] Optionally, braking control of the vehicle using the base braking torque and the compensated braking torque includes: determining the motor braking command torque based on the motor braking base torque and the motor braking compensated torque, and generating a first control command based on the motor braking command torque; determining the friction braking command torque based on the friction braking base torque and the friction braking compensated torque, and generating a second control command based on the friction braking command torque; and using the first control command and the second control command to brake the vehicle.

[0208] The above-mentioned motor braking command torque This can be the target regenerative braking torque command value ultimately sent to the motor controller MCU. This value is the motor braking base torque. Compensation torque for motor braking The superposition result represents the specific torque target that the electric motor braking system needs to execute. The formula for calculating the electric motor braking command torque is:

[0209]

[0210] The aforementioned first control command can be a specific control signal generated based on the motor braking torque command and sent to the motor braking execution end, such as the motor controller. This command drives the motor to output the corresponding regenerative braking torque.

[0211] The above-mentioned friction braking command torque This can be the target braking torque command value ultimately sent to the friction braking actuator, such as the EHB or Electro-Mechanical Brake (EMB) controller. This value is the friction braking base torque. Friction braking compensation torque The superposition result represents the specific torque target that the friction braking system needs to execute. The formula for calculating the friction braking command torque is:

[0212]

[0213] The aforementioned second control command can be a specific control signal generated based on the friction braking command torque and sent to the friction braking actuator, such as a hydraulic control unit or EMB actuator. This command drives the friction braking system to output the corresponding friction braking torque.

[0214] When controlling vehicle braking using a base braking torque and a compensated braking torque, the motor braking command torque is determined based on the base motor braking torque and the compensated motor braking torque, and a first control command is generated based on this command torque. For example, the system executes the electric braking command generation logic. The system superimposes the base motor braking torque determined under the current operating condition with the real-time calculated compensated motor braking torque to determine the motor braking command torque. Then, the system generates a first control command based on this command torque. This first control command typically includes a target torque value and a response rate requirement, and is sent to the motor controller of the vehicle's electric drive system.

[0215] The system determines the friction braking command torque based on the friction braking base torque and the friction braking compensation torque, and generates a second control command based on the friction braking command torque. For example, the system executes the friction braking command generation logic. The system superimposes the friction braking base torque determined under the current operating condition with the friction braking compensation torque calculated in real time to determine the friction braking command torque. Then, the system generates a second control command based on this friction braking command torque. This second control command typically includes a target wheel cylinder pressure value or clamping force value and is sent to the electro-hydraulic braking unit or electro-mechanical braking actuator of the vehicle's friction braking system.

[0216] After generating the first control command and the second control command, the system uses the first control command and the second control command to perform braking control on the vehicle. For example, the system simultaneously executes the first control command and the second control command to drive the motor to generate regenerative braking torque and the friction braking system to generate friction braking torque, respectively. The two work together to act on the vehicle and complete the braking control of the vehicle.

[0217] Based on the above optional embodiments, this application embodiment determines the motor braking command torque based on the motor braking base torque and the motor braking compensation torque, generates a first control command based on the motor braking command torque, determines the friction braking command torque based on the friction braking base torque and the friction braking compensation torque, generates a second control command based on the friction braking command torque, and uses the first and second control commands to perform braking control on the vehicle. This achieves the purpose of decoupling and superimposing the basic allocation strategy and the dynamic deviation compensation mechanism at the command layer, realizing the organic integration of the basic torque ensuring the adaptability of the working conditions and the compensation torque ensuring the control accuracy. It ensures that the electric braking and friction braking systems can simultaneously respond to the working condition allocation requirements and the real-time deviation correction requirements, thereby significantly improving the response speed and tracking accuracy of braking torque control while maintaining braking smoothness. This solves the problems of difficulty in coordinating basic allocation and dynamic compensation and the single command generation logic leading to control lag or inaccuracy in traditional control.

[0218] Optionally, the torque change rate of the motor braking command torque is less than or equal to the first calibration value, and the torque change rate of the friction braking command torque is less than or equal to the second calibration value, wherein the second calibration value is less than the first calibration value.

[0219] The aforementioned rate of change of torque can be considered as the magnitude of change of braking torque per unit time, i.e., the derivative of braking torque with respect to time. In the embodiments of this application, this parameter is used to limit the rate of increase of braking torque, preventing sudden torque changes from causing a jolt or affecting driving comfort.

[0220] The above first calibration value This can be a pre-calibrated maximum permissible rate of change threshold for the motor braking command torque. This value represents the upper limit of the maximum torque change rate that the motor braking system can safely and smoothly execute. For example, It can be set to 5000 Nm / s.

[0221] The above second calibration value This can be a pre-calibrated maximum permissible rate of change threshold for the friction braking command torque. This value represents the upper limit of the maximum torque change rate at which the friction braking system can safely and smoothly execute. For example, It can be set to 3000 Nm / s.

[0222] This application embodiment limits the rate of change of torque to ensure a smooth transition between electric braking and friction braking when outputting commands. Exemplarily, the system performs rate-of-change limitation processing on the generated motor braking command torque. The system calculates the change in the motor braking command torque relative to the previous control cycle and compares its rate of change with a first calibration value. If the calculated rate of change exceeds the first calibration value, the system will limit the amplitude or slope of the motor braking command torque to ensure that its actual rate of change is less than or equal to the first calibration value, i.e.:

[0223]

[0224] Next, the system performs rate-of-change limitation processing on the generated friction braking command torque. The system calculates the change in the friction braking command torque relative to the previous control cycle and compares its rate of change with a second calibration value. If the calculated rate of change exceeds the second calibration value, the system will limit the amplitude or slope of the friction braking command torque to ensure that its actual rate of change is less than or equal to the second calibration value, i.e.:

[0225]

[0226] In the above process, the system follows a preset relationship that the second calibration value is less than the first calibration value. That is, electric braking allows for more drastic torque changes to take advantage of its rapid response, while friction braking is limited to a more gradual rate of change to avoid torque shocks and braking irregularities caused by hydraulic or mechanical inertia.

[0227] Based on the above optional embodiments, this application embodiment achieves the purpose of limiting the torque change rate according to the difference in the response characteristics of the braking source by making the torque change rate of the electric braking command torque less than or equal to the first calibration value, and the torque change rate of the friction braking command torque less than or equal to the second calibration value, and the second calibration value less than the first calibration value. This realizes the use of the fast response capability of electric braking for fine adjustment, while strictly limiting the torque impact that may be caused by the response lag of friction braking. Thus, it effectively eliminates the braking impact feeling during the switching or cooperative operation of electric braking and friction braking, improves driving comfort, and solves the problem of poor braking smoothness caused by the failure to consider the dynamic response differences of different braking sources in traditional composite braking control.

[0228] Optionally, the vehicle braking control method further includes: determining that the vehicle's motor braking system is in a fault state in response to the vehicle's motor controller failing to respond to the first control command for multiple consecutive cycles, or the vehicle's motor temperature exceeding a preset protection threshold, or the battery state of charge data being in an abnormal state.

[0229] The motor controller described above can be the MCU mentioned in the embodiments of this application, which is responsible for receiving control commands and controlling the operation of the drive motor. The motor controller is the core execution control unit of the electric braking system.

[0230] The aforementioned multiple consecutive cycles can refer to the system performing multiple consecutive control loops with a fixed sampling period, such as 10ms. In the embodiments of this application, multiple consecutive cycles can be understood as a series of consecutive sampling time points.

[0231] The aforementioned preset protection threshold can be a pre-defined limit temperature or state value for the safe operation of the motor or battery. When the monitored value exceeds this threshold, the system determines that it is in a dangerous state and protective measures must be taken.

[0232] The abnormal state of the battery state of charge data mentioned above could be due to logical errors, jumps, exceeding the physical reasonable range, or communication interruptions, which would make it impossible to accurately determine the battery's rechargeability.

[0233] The aforementioned fault condition of the motor braking system indicates that the motor braking component is malfunctioning or poses a safety hazard. Once this condition is determined, the system will trigger a degradation strategy, ceasing reliance on the motor braking system.

[0234] This application embodiment monitors the health status of each subsystem in real time. In response to the vehicle's motor controller failing to respond to the first control command for multiple consecutive cycles, or the vehicle's motor temperature exceeding a preset protection threshold, or the battery state of charge data being in an abnormal state, it determines that the vehicle's motor braking system is in a fault state.

[0235] For example, the system monitors the response of the electric braking actuator. The system tracks the transmission and feedback of the first control command over multiple consecutive control cycles. If the motor controller fails to respond correctly to the first control command over multiple consecutive cycles, such as missing or severely deviating torque output, the system determines that the motor control link has failed. Secondly, the system monitors the physical state of the motor. The system acquires the vehicle motor's temperature data in real time and compares it with a preset protection threshold. If the vehicle motor temperature exceeds the preset protection threshold, it indicates that the motor is in an overheating danger state, and continued operation may damage the hardware; the system determines that the motor braking system has a thermal failure risk. Thirdly, the system monitors battery status data. The system acquires battery state of charge data in real time and analyzes its validity. If the battery state of charge data is in an abnormal state, such as a sudden change in value, an invalid value, or communication loss, making it impossible to determine whether the battery is suitable for charging, the system determines that there is a data-level fault in the electric braking energy recovery path. Finally, the system executes fault determination logic. The system performs a logical "OR" operation on the above three cases. If any of the following conditions are met: "the motor controller fails to respond to the first control command for multiple consecutive cycles", "the vehicle motor temperature is greater than the preset protection threshold", or "the battery state of charge data is in an abnormal state", the system will determine that the vehicle's motor braking system is in a faulty state.

[0236] Based on the above optional embodiments, this application embodiment determines that the vehicle's electric braking system is in a faulty state by responding to the vehicle's motor controller failing to respond to the first control command for multiple consecutive cycles, or the vehicle's motor temperature exceeding a preset protection threshold, or the battery state of charge data being in an abnormal state. This achieves the purpose of multi-dimensional and comprehensive monitoring of the health status of the electric braking system, realizing comprehensive fault detection covering communication response delay, hardware overheat protection, and data logic anomalies. This allows for the early detection of potential failure risks of the electric braking system, ensuring that a degradation strategy is triggered in a timely manner when the electric braking is unavailable, thus protecting vehicle braking safety and solving the safety hazards that may be caused by insufficient single fault detection dimensions.

[0237] Optionally, the vehicle braking control method further includes: in response to a fault in the electric motor braking system, generating the vehicle's total braking torque using the vehicle's friction braking system.

[0238] The aforementioned friction braking system can be an actuator used to generate braking force through mechanical friction in the embodiments of this application, including an electro-hydraulic braking system (EHB) or an electro-mechanical braking system (EMB) and its related actuators, such as brake calipers, brake discs, hydraulic control units, etc.

[0239] The aforementioned total braking torque can be considered as the total braking torque required by the vehicle as a whole to meet the driver's braking needs or safety requirements under specific braking conditions. In this embodiment, when the electric motor brake fails, the total braking torque is entirely borne by the friction braking system.

[0240] In response to a fault in the electric motor braking system, the vehicle's total braking torque is generated using the friction braking system. For example, when the system determines that the electric motor braking system is faulty, it executes braking torque reconstruction logic. Specifically, the system no longer sends a first control command to the motor controller to request regenerated braking torque. Instead, it fully allocates the vehicle's current total required braking torque, or the safety braking torque adjusted according to a degradation strategy, to the friction braking system. The system calculates the required friction braking torque value using the friction braking system's control algorithm, such as calculating the target pressure based on pedal travel or a preset mapping table, and sends a second control command to the friction braking actuator, such as the EHB or EMB controller. Finally, the friction braking system receives the command and acts, generating sufficient braking torque to replace the original electric motor braking contribution through the mechanical friction between the brake pads and the brake disc. This ensures that the vehicle can still achieve sufficient deceleration and safe stopping even if the electric motor braking fails. Simultaneously, a pre-pressure build-up strategy partially compensates for the response delay of the friction braking system, triggering pre-pressure build-up immediately upon detecting brake pedal movement, shortening the actual pressure build-up time.

[0241] Based on the above optional embodiments, this application embodiment, in response to the motor braking system being in a fault state, utilizes the vehicle's friction braking system to generate the vehicle's full braking torque, achieving the purpose of quickly switching to pure friction braking mode when electric braking fails. This realizes the use of the high reliability and large braking force characteristics of the friction braking system to compensate for the lack of electric braking, ensuring that the vehicle has basic braking capability under any fault conditions, thereby ensuring driving safety and solving the technical problem that electric braking failure may lead to severe insufficient braking force of the entire vehicle or even loss of braking function.

[0242] Optionally, the vehicle braking control method further includes: determining that the vehicle's friction braking system is in a fault state in response to the wheel brake cylinder pressure data meeting a preset abnormal condition, or the vehicle's electro-hydraulic braking system being in a fault state.

[0243] The aforementioned preset abnormal conditions can be pre-calibrated logical rules or threshold ranges used to determine abnormal wheel brake cylinder pressure data. These conditions typically include pressure values ​​exceeding physical limits, such as ±2MPa; pressure values ​​remaining unchanged for an extended period after the braking command is issued, such as 100ms; pressure values ​​deviating from the target command beyond the allowable tolerance; or pressure signals exhibiting jumps or loss.

[0244] The aforementioned fault state of the friction braking system indicates a specific system condition where the friction braking component is malfunctioning, failing to respond, or posing a safety hazard, such as when the EHB hydraulic unit reports a fault code. In this state, the system determines that the friction braking is unreliable and needs to trigger corresponding degradation or safety strategies.

[0245] In this embodiment, in response to wheel brake cylinder pressure data meeting preset abnormal conditions, or when the vehicle's electro-hydraulic braking system is in a fault state, the system determines that the vehicle's friction braking system is in a fault state. Exemplarily, the system monitors feedback data from the wheel brake actuators. The system acquires the pressure data of each wheel brake cylinder in real time and compares it with preset abnormal conditions. If the wheel brake cylinder pressure data shows conditions that meet the preset abnormal conditions, such as excessive pressure deviation, delayed response, or abnormal signals, the system determines that there is a data-level fault in the friction braking execution link.

[0246] Secondly, the system monitors the overall health status of the electro-hydraulic braking system. The system obtains the vehicle's electro-hydraulic braking system status codes or fault codes uploaded to the vehicle network via polling or interruption. If the vehicle's electro-hydraulic braking system is in a faulty state, such as a hydraulic pump failure, master cylinder leakage, or an internal control unit error, the system determines that there is a serious fault at the friction brake hardware level.

[0247] Finally, the system executes the fault determination logic. The system performs a logical "OR" operation on the two situations mentioned above. As long as either "the wheel brake cylinder pressure data meets the preset abnormal conditions" or "the vehicle's electro-hydraulic braking system is in a fault state" is met, the system determines that the vehicle's friction braking system is in a fault state.

[0248] Based on the above optional embodiments, this application embodiment determines that the vehicle's friction braking system is in a faulty state by responding to the wheel brake cylinder pressure data meeting preset abnormal conditions, or the vehicle's electro-hydraulic braking system being in a faulty state. This achieves the purpose of comprehensively judging the health status of friction braking from two dimensions: local pressure feedback and overall system status. It realizes accurate identification of friction braking system failure risks, thereby triggering a degradation strategy or alarm in a timely manner when friction braking is unavailable, ensuring vehicle braking safety, and solving the problem of misjudgment or omission that may be caused by single signal monitoring.

[0249] Optionally, the vehicle braking control method further includes: in response to a fault in the friction braking system, generating the vehicle's total braking torque using the vehicle's electric braking system.

[0250] The aforementioned motor braking system can be an execution system used in this application embodiment to generate negative torque by reverse power generation of the drive motor to achieve regenerative braking, including a drive motor, a motor controller (MCU) and related energy recovery paths.

[0251] In response to a fault in the friction braking system, the vehicle's electric motor braking system generates the vehicle's full braking torque. For example, when the system determines that the friction braking system is faulty, it executes braking torque reconstruction logic. Instead of sending a second control command to the friction braking actuator to request friction braking torque, the system allocates the vehicle's current total required braking torque, or a safety braking torque adjusted according to a degradation strategy (such as limiting maximum deceleration to avoid motor overload), entirely to the electric motor braking system. The system calculates the required regenerative braking torque value using the electric motor braking system's control algorithm and sends a first control command to the motor controller. Finally, the motor controller receives the command and controls the drive motor to operate in generator mode, producing the corresponding regenerative braking torque, thereby ensuring that the vehicle still has sufficient deceleration capability to achieve a safe stop in the event of friction braking failure. Additionally, the maximum braking intensity is limited, such as not exceeding 0.3g deceleration, to avoid motor overload, and the braking system fault warning light is illuminated.

[0252] Based on the above optional embodiments, this application embodiment, in response to a fault in the friction braking system, utilizes the vehicle's electric motor braking system to generate the vehicle's full braking torque, achieving the goal of quickly switching to pure electric motor braking mode when friction braking fails. This realizes the use of the electric motor braking system's rapid response characteristics and energy recovery advantages to compensate for the lack of friction braking, ensuring that the vehicle still has basic braking capability under friction braking failure conditions, thereby guaranteeing driving safety and solving the technical problem that friction braking failure may lead to severe insufficient braking force or even loss of braking function of the entire vehicle.

[0253] Optionally, the vehicle braking control method further includes: in response to a partial interruption of the vehicle network, determining a basic friction braking torque based on a preset safety braking mapping table and the brake pedal travel, and determining a basic motor braking torque based on a preset regenerative braking mapping table and the brake pedal travel; in response to a global interruption of the vehicle network, determining a target braking torque of the vehicle based on the pedal force of the vehicle brake pedal.

[0254] The aforementioned vehicle network can be a communication link used in this application embodiment to transmit data signals between various control units, sensors and actuators in the vehicle, including CAN or vehicle Ethernet, etc.

[0255] The aforementioned partial interruption state can occur when some nodes or communication links in the vehicle network fail, causing specific signals to be unable to be transmitted, while other parts of the network remain connected. In this state, affected functional modules may not be able to receive real-time commands, but basic mapping table data can still be accessed locally.

[0256] The aforementioned preset safety braking mapping table can be a pre-calibrated two-dimensional or multi-dimensional data table stored in the controller's local memory, establishing a correspondence between brake pedal travel and the desired frictional braking torque or electric braking torque. This mapping table is used to provide basic safety braking force distribution in the event of communication failure.

[0257] The aforementioned preset regenerative braking mapping table can be a pre-calibrated two-dimensional or multi-dimensional data table stored in the controller's local memory, establishing a correspondence between brake pedal travel and the desired basic motor braking torque. This mapping table is used to determine the magnitude of the regenerative braking force to be allocated based on the pedal position in normal or degraded modes.

[0258] The aforementioned global interruption state can be characterized by the failure of all communication links in the vehicle network, resulting in a complete loss of data exchange capabilities between all control units within the vehicle. In this state, centralized decision-making is lost, and the system must rely on local mechanical mechanisms or independent logic for safety degradation.

[0259] The pedal force of the aforementioned vehicle brake pedal can be the physical pressure applied by the driver to the brake pedal. In mechanical backup or complete power / network disconnection mode, this force is directly converted into brake fluid pressure through mechanical linkages or hydraulic master cylinders, thereby generating braking force.

[0260] The target braking torque mentioned above can be the total braking torque that the vehicle ultimately needs to generate under extreme fault conditions of a complete interruption of the vehicle network. This torque is directly determined by the pedal force through a mechanical or hydraulic path and is no longer subject to dynamic modulation by the electronic control unit.

[0261] In the event of a communication failure, responding to a partial interruption of the vehicle network, the system determines the basic friction braking torque based on a preset safety braking mapping table and the brake pedal travel, and the basic motor braking torque based on a preset regenerative braking mapping table and the brake pedal travel. For example, in a scenario where the vehicle network is partially interrupted, the system performs localized basic torque calculations. Upon detecting a partial interruption in network communication, the system no longer relies on dynamic real-time commands issued by the central controller. Instead, it reads the locally stored preset safety braking mapping table, using the currently collected brake pedal travel as an index to look up the table and obtain the basic friction braking torque. Simultaneously, the system reads the locally stored preset regenerative braking mapping table, also using the brake pedal travel as an index to look up the table and obtain the basic motor braking torque. At this point, each actuator outputs basic braking force based on the local mapping table, ensuring the availability of basic braking functions.

[0262] In response to a global network outage, the system determines the target braking torque based on the force applied to the vehicle's brake pedal. For example, in a scenario where the vehicle network is completely down, the system executes a mechanical / hydraulic backup mode. Upon detecting a global network outage, the electronic control functions become completely disabled. The system no longer relies on any electronic sensor signals or mapping tables, but instead directly senses the brake pedal force via mechanical linkages or a hydraulic master cylinder. This pedal force is directly converted into hydraulic pressure or mechanical clamping force, thereby generating the target braking torque. This process is entirely based on physical mechanics, ensuring that the vehicle can still decelerate and stop mechanically even when the network is completely paralyzed.

[0263] Based on the above optional embodiments, this application embodiment determines the basic friction braking torque according to a preset safety braking mapping table and brake pedal travel in response to a partial interruption of the vehicle network, and determines the basic motor braking torque according to a preset regenerative braking mapping table and brake pedal travel; in response to a global interruption of the vehicle network, it determines the target braking torque of the vehicle according to the pedal force of the vehicle brake pedal. This achieves the purpose of implementing a degradation strategy according to the severity of the communication failure, realizing the maintenance of basic electro-hydraulic coordinated braking function by using a locally stored mapping table during partial communication failure, and ensuring the most basic braking capability by using a mechanical / hydraulic path during complete communication failure. This ensures the braking safety of the vehicle under extreme communication failure conditions and solves the risk of complete paralysis of the braking system caused by reliance on a single communication.

[0264] For example, during system fault detection, the sensor fault detection logic identifies anomalies by monitoring the reasonableness of signals from the wheel speed sensor, brake pedal travel sensor, and inertial measurement unit. When the signals from these sensors are detected to be outside the reasonable range or remain unchanged, the corresponding sensor is determined to be faulty. In this case, the system adopts a degraded strategy of freezing the corresponding control function module and using redundant signals to maintain basic braking function. For example, the vehicle speed can be calculated using longitudinal acceleration integral to replace the faulty wheel speed signal, thereby ensuring the basic operation of braking control in the event of sensor failure.

[0265] The anomaly detection logic of the coordinated control algorithm is used to monitor the running status of the composite braking coordinated control algorithm. When the algorithm is determined to be abnormal, the system immediately switches to the preset safety distribution mapping table for open-loop control. This mapping table is generated based on a large amount of real vehicle calibration data and can provide safe and usable braking force distribution when the algorithm fails, ensuring the continuity and safety of the vehicle braking function.

[0266] Figure 2 This is a schematic diagram of an optional vehicle braking control method according to an embodiment of this application, such as... Figure 2 As shown. This method is applicable to systems containing EHB.

[0267] Step S21, Signal Acquisition and Preprocessing. The electronic control unit acquires signals such as brake pedal travel, pedal speed, four-wheel wheel speed, vehicle longitudinal acceleration, battery state of charge, actual motor braking torque and upper limit of motor braking torque, wheel cylinder pressure of each wheel, and reference vehicle speed at a period of 10ms. It also performs differential calculation on the pedal speed to identify braking intention, and performs moving average filtering on the wheel speed and pressure signals to suppress noise.

[0268] Step S22: Condition identification and mode prediction based on braking intention. The system categorizes braking conditions into three types: conventional braking, emergency braking, and transitional braking, based on brake pedal travel, pedal speed, and reference vehicle speed. Particularly in transitional braking conditions, the system sends a pre-pressure build-up command to the electro-hydraulic braking system in advance, putting the friction brake in a "standby" state, thereby eliminating the "window period" of braking torque when the electric brakes disengage.

[0269] Step S23: Closed-loop compensation based on the deviation between actual and required braking torque. The system obtains the total required braking torque according to a preset mapping table and calculates the deviation between the actual total braking torque and the actual braking torque in real time. When the deviation exceeds a threshold, the closed-loop compensation mechanism is triggered, prioritizing the use of the rapid response advantage of electric braking for incremental or decremental compensation. When the electric braking capacity is limited, friction braking is adjusted to ensure that the actual braking torque closely follows the driver's needs.

[0270] Step S24: Braking torque redistribution and anti-lock braking coordination based on slip ratio. The system calculates the slip ratio of each wheel in real time. When the slip ratio of a wheel exceeds a set threshold, anti-lock braking coordination and braking torque redistribution are triggered. The friction braking torque component that is slow to respond and prone to locking is reduced first, while the fast-responding and finely adjustable electric braking torque is retained. The reduced torque is then transferred to other unsaturated wheels to balance braking stability and energy recovery efficiency.

[0271] Step S25: Fusion Output and Smooth Mode Switching. The system superimposes the basic allocation command based on operating condition recognition and the closed-loop compensation command based on deviation detection to generate the final output, and introduces a torque change rate limit to ensure the smoothness of the switching and adjustment process between electric braking and friction braking torque, avoiding the generation of shock sensations, thereby improving driving comfort.

[0272] Step S26, System Fault Diagnosis and Degradation Strategy. The system monitors the system's operating status in real time. Once a fault is detected, the corresponding degradation control logic is immediately activated to ensure the safe operation of the vehicle under fault conditions, thereby forming an efficient, intelligent, and safe closed-loop vehicle braking control system.

[0273] In an optional embodiment, this application applies to electric vehicles equipped with a brake-by-wire system and a distributed drive motor. The system configuration includes an electromechanical braking system (EMB), a distributed drive motor, and the same sensors as described above. The EMB is equipped with independent actuators on each of the four wheels. Each actuator includes a brake motor, a reduction gear, and a brake caliper. The brake motor directly drives the brake caliper to perform friction braking. Compared to an electrohydraulic braking system, the response time of the EMB is further reduced to approximately 50-80 ms, and the braking torque of each wheel can be independently and precisely controlled. The distributed drive motor is equipped with independent hub motors or wheel-side motors on each of the four wheels. Each motor can independently perform regenerative braking, thereby achieving vector distribution of regenerative braking force across the four wheels. All sensor signals are collected via a controller area network or a higher-speed in-vehicle Ethernet to the vehicle's domain controller or central computing unit, where the electronic control unit executes the vehicle braking control method of this application embodiment.

[0274] Figure 3 This is a schematic diagram of another optional vehicle braking control method according to an embodiment of this application, such as... Figure 3 As shown. This method is applicable to systems that include EMB.

[0275] Step S31, Signal Acquisition and Preprocessing. The electronic control unit not only acquires the aforementioned signals such as brake pedal travel, pedal speed, four-wheel wheel speed, vehicle longitudinal acceleration, battery state of charge, actual motor braking torque and upper limit of motor braking torque, brake cylinder pressure of each wheel, and reference vehicle speed, but also acquires the actual clamping force of the electromechanical brake actuators of each wheel. The response status of each electromechanical brake actuator and the actual regenerative braking torque of each wheel hub motor. and their respective available upper limit torque The response states of each electromechanical brake actuator include ready, pressure building, pressure holding, and pressure releasing states.

[0276] By collecting the aforementioned high-precision local actuator status data, the system can more accurately grasp the real-time operating conditions of the four-wheel independent braking and drive units, providing the necessary data foundation for the subsequent realization of vector distribution of four-wheel independent braking torque, fault-tolerant redundancy control of distributed architecture, and deep integration of vehicle stability control system, thereby making full use of the hardware advantages of electromechanical braking system with short response time and independent and precise control of braking torque of each wheel.

[0277] Step S32, Vector distribution of independent braking torque for four wheels. This system utilizes the hardware advantages of distributed drive to perform vector distribution of independent braking torque for four wheels. First, based on the braking intensity and the estimated current road surface adhesion coefficient μ, the front and rear axle braking force distribution ratio is determined according to the ideal braking force distribution curve (I-curve). Under normal braking conditions, rear axle motor braking is prioritized to maximize energy recovery, while the front axle primarily uses friction braking. Under emergency braking conditions, the optimal distribution according to the I-curve ensures that both front and rear wheels reach their adhesion limits simultaneously. The formula for calculating braking intensity is:

[0278]

[0279] Where m is the mass of the vehicle, g is the acceleration due to gravity, and r is the tire rolling radius.

[0280] Secondly, under complex conditions such as steering or inconsistent road surface adhesion coefficients, the system uses feedback from steering wheel angle and yaw rate to differentiate braking force distribution between the left and right wheels on the same axle to generate the desired yaw torque, assisting in vehicle stability control. For example, when understeer is detected, the braking torque of the inner wheels is increased while the braking torque of the outer wheels is decreased, and vice versa when oversteer is detected. In the above process, the total braking torque of each wheel is composed of both electric braking torque and friction braking torque. The system prioritizes vector distribution by adjusting the faster and more precise electric braking torque, while the friction braking torque serves as a supplement and backup, thereby achieving optimal braking performance and energy recovery balance while ensuring vehicle stability.

[0281] Step S33: Fault-tolerant and redundant control based on a distributed architecture. Since each wheel is equipped with an independent EMB actuator and an independent hub motor, it possesses inherent actuator redundancy. When a failure is detected in the electromechanical brake actuator of a single wheel, the system automatically increases the remaining normal electric braking torque distribution coefficient of that wheel to compensate for the lack of friction braking force; conversely, if the hub motor of a single wheel fails, the system automatically increases the friction braking torque distribution coefficient of that wheel to compensate for the lack of electric braking force.

[0282] For more severe simultaneous failures of both wheels on the same axle, such as the failure of both front wheel electromechanical brake actuators, the system determines this as a serious fault, immediately illuminates the brake system warning light, and limits the vehicle speed to below 30 km / h, advising the driver to stop immediately for inspection. This fault-tolerant mechanism based on a distributed architecture not only improves the system's availability in the event of a single actuator failure but also ensures the continuity and safety of vehicle braking performance by dynamically adjusting the output of the remaining healthy actuators.

[0283] Step S34, coordination with the vehicle stability control system. This system deeply integrates the composite braking coordination control with the vehicle stability control system, such as ESC or Vehicle Dynamic Control (VDC). When the vehicle stability control system issues a stability intervention request such as yaw moment control or anti-lock braking, the request is treated as the highest priority command and directly superimposed on the final braking torque output. In terms of specific execution strategy, when it is necessary to increase the braking torque of a wheel, the fast-responding and finely adjusted electric braking torque is prioritized, and friction braking torque is only supplemented when electric braking is insufficient. When it is necessary to reduce the braking torque of a wheel, the slower-responding friction braking torque is reduced first to avoid the risk of over-braking due to the lag in friction braking response. If the friction braking torque is reduced to zero and still does not meet the requirements, then the electric braking torque is reduced. In addition, when the vehicle stability control system triggers the anti-lock braking function, the slip ratio control logic of the composite braking system completely obeys the pressure reduction, pressure holding, and pressure increase cycle control commands of the anti-lock braking system, thereby maximizing the advantages of the distributed drive system in stability assistance while ensuring vehicle dynamic stability.

[0284] Step S35: Degradation Strategy and Mode Switching. In this step, the aforementioned fault detection processes for the electric motor braking system, friction braking system, sensor, coordinated control algorithm, local communication interruption, and global communication interruption are executed. Furthermore, when a local fault occurs in the electromechanical braking system, such as the failure of some actuators, if the corresponding motor is functioning normally, the faulty wheel automatically switches to pure electric braking mode. If the corresponding motor fails but the actuators are functioning normally, the faulty wheel automatically switches to pure friction braking mode. Non-faulty wheels maintain the normal compound braking mode to maximize the retention of available braking capacity.

[0285] According to an embodiment of this application, a device embodiment for a vehicle braking control device is provided. It should be noted that the device can be used to execute the above-described vehicle braking control method. Figure 4 This is a structural block diagram of an optional vehicle braking control device according to an embodiment of this application, such as... Figure 4As shown. The device includes: an acquisition module 401 for acquiring multi-source state data of the vehicle, wherein the multi-source state data includes at least: braking demand data, vehicle state data, battery state of charge data, and brake actuator feedback data; an allocation module 402 for performing torque allocation based on the braking demand data, vehicle state data, and battery state of charge data to obtain a base braking torque, wherein the base braking torque represents the vehicle's motor braking base torque and friction braking base torque; a compensation module 403 for performing closed-loop compensation based on the braking demand data, vehicle state data, and brake actuator feedback data to obtain a compensated braking torque, wherein the compensated braking torque represents the vehicle's motor braking compensation torque and friction braking compensation torque; and a first control module 404 for performing braking control of the vehicle using the base braking torque and the compensated braking torque.

[0286] Optionally, the allocation module 402 is also used to: identify the operating condition based on braking demand data, vehicle status data and battery state of charge data, and obtain the operating condition identification result; and allocate torque according to the operating condition identification result to obtain the basic braking torque.

[0287] Optionally, the braking demand data includes: brake pedal travel and brake pedal speed, the vehicle status data includes: current reference vehicle speed, and the multi-source status data also includes: motor temperature. The allocation module 402 is also used to: determine the operating condition identification result as normal braking condition in response to the brake pedal travel being less than or equal to a first pedal travel threshold, and the absolute value of the brake pedal speed being less than or equal to a first pedal speed threshold, and the current reference vehicle speed being greater than the motor braking cutoff speed.

[0288] Optionally, the allocation module 402 is further configured to: determine the operating condition identification result as an emergency braking condition in response to the brake pedal travel being greater than a second pedal travel threshold or the absolute value of the brake pedal speed being greater than a second pedal speed threshold, wherein the second pedal travel threshold is greater than a first pedal travel threshold and the second pedal speed threshold is greater than a first pedal speed threshold.

[0289] Optionally, the allocation module 402 is further configured to: determine the operating condition identification result as transition braking condition in response to the battery state of charge data being greater than a preset charge threshold, or the current reference vehicle speed being less than the motor braking cutoff speed, or the motor temperature being greater than a preset temperature threshold.

[0290] Optionally, the vehicle braking control device further includes: a sending module for sending a pre-pressure build-up request to the hydraulic control unit of the electro-hydraulic braking system in response to the vehicle being in a transition braking condition; and a building module for controlling the hydraulic control unit to build up the base wheel cylinder pressure based on the pre-pressure build-up request, so that the gap between the vehicle's friction brake pads and brake disc is less than a target gap value.

[0291] Optionally, the compensation module 403 is further configured to: determine the total required braking torque of the vehicle based on braking demand data and vehicle status data, and determine the actual total braking torque of the vehicle based on brake actuator feedback data; determine the braking torque deviation based on the total required braking torque and the actual total braking torque; and, in response to the absolute value of the braking torque deviation being greater than a preset deviation threshold, perform closed-loop compensation based on the braking torque deviation and brake actuator feedback data to obtain the compensated braking torque.

[0292] Optionally, the brake actuator feedback data includes: the actual braking torque of the motor and the wheel brake cylinder pressure data. The compensation module 403 is also used to: determine the actual friction braking torque based on the wheel brake cylinder pressure data; and determine the actual total braking torque based on the actual friction braking torque and the actual braking torque of the motor.

[0293] Optionally, the compensation module 403 is further configured to: in response to a positive braking torque deviation, determine an electric motor torque margin based on the upper limit of the motor's braking torque and the actual braking torque of the motor; in response to a positive motor torque margin, determine an electric motor torque compensation amount based on the braking torque deviation and the motor's braking torque margin, and incrementally compensate the actual braking torque of the motor using the electric motor torque compensation amount; and in response to the actual braking torque of the motor reaching the upper limit of the motor's braking torque, determine a friction braking torque compensation amount based on a first residual torque deviation.

[0294] Optionally, the compensation module 403 is further configured to: in response to a negative braking torque deviation, determine the reduction in motor braking torque based on the braking torque deviation and the actual braking torque of the motor, and use the reduction in motor braking torque to compensate for the reduction in the actual braking torque of the motor; in response to the actual braking torque of the motor reaching a preset value, determine the reduction in friction braking torque based on the second residual torque deviation.

[0295] Optionally, the vehicle status data includes: current reference vehicle speed, wheel angular velocity, and tire rolling radius. The vehicle braking control device further includes: a first determining module, used to determine the wheel slip ratios of multiple wheels based on the current reference vehicle speed, wheel angular velocity, and tire rolling radius; and a second controlling module, used to control the first wheel to perform a braking torque redistribution operation in response to the wheel slip ratio of the first wheel among the multiple wheels being greater than a preset threshold value.

[0296] Optionally, the second control module is further configured to: determine the total reduction in braking torque corresponding to the first wheel based on the wheel slip ratio; determine a first target torque reduction based on the friction braking torque component of the first wheel and the total reduction in braking torque, and adjust the friction braking torque component based on the first target torque reduction; in response to the friction braking torque component reaching a preset value and the wheel slip ratio being greater than a preset threshold, determine a second target torque reduction based on the wheel slip ratio, and adjust the motor torque component of the first wheel based on the second target torque reduction.

[0297] Optionally, the vehicle braking control device further includes: a transfer module for transferring the total reduction in braking torque to the coaxial wheel corresponding to the first wheel, or transferring the total reduction in braking torque to the second wheel, wherein the wheel slip ratio of the second wheel is less than a preset threshold value.

[0298] Optionally, the first control module 404 is further configured to: determine the motor braking command torque based on the motor braking base torque and the motor braking compensation torque, and generate a first control command based on the motor braking command torque; determine the friction braking command torque based on the friction braking base torque and the friction braking compensation torque, and generate a second control command based on the friction braking command torque; and use the first control command and the second control command to perform braking control on the vehicle.

[0299] Optionally, the torque change rate of the motor braking command torque is less than or equal to the first calibration value, and the torque change rate of the friction braking command torque is less than or equal to the second calibration value, wherein the second calibration value is less than the first calibration value.

[0300] Optionally, the vehicle braking control device further includes: a second determining module, used to determine that the vehicle's motor braking system is in a fault state in response to the vehicle's motor controller failing to respond to the first control command for multiple consecutive cycles, or the vehicle's motor temperature exceeding a preset protection threshold, or the battery state of charge data being in an abnormal state.

[0301] Optionally, the vehicle braking control device further includes: a first generation module, used to generate the vehicle's total braking torque using the vehicle's friction braking system in response to a fault in the electric motor braking system.

[0302] Optionally, the vehicle braking control device further includes: a third determining module, used to determine that the vehicle's friction braking system is in a fault state in response to the wheel brake cylinder pressure data meeting preset abnormal conditions, or the vehicle's electro-hydraulic braking system being in a fault state.

[0303] Optionally, the vehicle braking control device further includes: a second generation module, used to generate the vehicle's total braking torque using the vehicle's electric braking system in response to a fault in the friction braking system.

[0304] Optionally, the vehicle braking control device further includes: a fourth determining module, used to determine the friction braking base torque based on a preset safety braking mapping table and the brake pedal travel in response to a partial interruption of the vehicle network, and to determine the motor braking base torque based on a preset regenerative braking mapping table and the brake pedal travel; and a fifth determining module, used to determine the target braking torque of the vehicle based on the pedal force of the vehicle brake pedal in response to a global interruption of the vehicle network.

[0305] Embodiments of this application also provide a vehicle, Figure 5 This is a schematic diagram of an optional vehicle according to an embodiment of this application, such as... Figure 5 As shown. The vehicle includes: a memory 501 storing an executable program; and a processor 502 for running the program, wherein the program executes the methods of various embodiments of this application during runtime.

[0306] Embodiments of this application also provide a computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the computer-readable storage medium is located to perform the methods of various embodiments of this application.

[0307] Embodiments of this application also provide a computer program product, including a computer program that, when executed by a processor, implements the methods of various embodiments of this application.

[0308] Embodiments of this application also provide a computer program product, including a non-volatile computer-readable storage medium for storing a computer program that, when executed by a processor, implements the methods in various embodiments of this application.

[0309] Embodiments of this application also provide a computer program that, when executed by a processor, implements the methods described in the various embodiments of this application.

[0310] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0311] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of the relevant data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and corresponding operation entry points are provided for users to choose to authorize or refuse.

[0312] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0313] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0314] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0315] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0316] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A vehicle braking control method, characterized in that, include: Acquire multi-source state data of the vehicle, wherein the multi-source state data includes at least: braking demand data, vehicle state data, battery state of charge data, and brake actuator feedback data; Based on the braking demand data, the vehicle status data, and the battery state of charge data, torque is allocated to obtain the basic braking torque, wherein the basic braking torque is used to represent the basic motor braking torque and the basic friction braking torque of the vehicle. Closed-loop compensation is performed based on the braking demand data, the vehicle status data, and the brake actuator feedback data to obtain the compensation braking torque, wherein the compensation braking torque is used to represent the motor braking compensation torque and friction braking compensation torque of the vehicle. The vehicle is braked using the base braking torque and the compensated braking torque.

2. The vehicle braking control method according to claim 1, characterized in that, Based on the braking demand data, the vehicle status data, and the battery state of charge data, torque allocation is performed to obtain the basic braking torque, which includes: Based on the braking demand data, the vehicle status data, and the battery state of charge data, operating condition identification is performed to obtain the operating condition identification result. Based on the identified operating conditions, torque is allocated to obtain the basic braking torque.

3. The vehicle braking control method according to claim 2, characterized in that, The braking demand data includes: brake pedal travel and brake pedal speed; the vehicle status data includes: current reference vehicle speed; the multi-source status data also includes: motor temperature; based on the braking demand data, vehicle status data, and battery state of charge data, operating condition identification is performed, and the operating condition identification results include: In response to the brake pedal travel being less than or equal to a first pedal travel threshold, and the absolute value of the brake pedal speed being less than or equal to a first pedal speed threshold, and the current reference vehicle speed being greater than the motor braking cutoff speed, the operating condition identification result is determined to be a normal braking condition.

4. The vehicle braking control method according to claim 3, characterized in that, Based on the braking demand data, the vehicle status data, and the battery state of charge data, operating condition identification is performed to obtain the following results: In response to the brake pedal travel being greater than a second pedal travel threshold, or the absolute value of the brake pedal speed being greater than a second pedal speed threshold, the operating condition identification result is determined to be an emergency braking condition, wherein the second pedal travel threshold is greater than the first pedal travel threshold, and the second pedal speed threshold is greater than the first pedal speed threshold.

5. The vehicle braking control method according to claim 3, characterized in that, Based on the braking demand data, the vehicle status data, and the battery state of charge data, operating condition identification is performed to obtain the following results: In response to the battery state of charge data being greater than a preset charge threshold, or the current reference vehicle speed being less than the motor braking cutoff speed, or the motor temperature being greater than a preset temperature threshold, the operating condition identification result is determined to be a transition braking condition.

6. The vehicle braking control method according to claim 5, characterized in that, The vehicle braking control method further includes: In response to the vehicle being in the transition braking condition, a pre-pressure build-up request is sent to the hydraulic control unit of the electro-hydraulic braking system. Based on the pre-build pressure request, the hydraulic control unit is controlled to establish a base wheel cylinder pressure so that the gap between the vehicle's friction brake pads and brake disc is less than the target gap value.

7. The vehicle braking control method according to any one of claims 1 to 6, characterized in that, Based on the braking demand data, the vehicle status data, and the brake actuator feedback data, closed-loop compensation is performed to obtain the compensated braking torque, which includes: The total required braking torque of the vehicle is determined based on the braking demand data and the vehicle status data, and the actual total braking torque of the vehicle is determined based on the feedback data from the brake actuator. The braking torque deviation is determined based on the total required braking torque and the actual total braking torque. In response to the absolute value of the braking torque deviation being greater than a preset deviation threshold, closed-loop compensation is performed based on the braking torque deviation and the feedback data from the brake actuator to obtain the compensated braking torque.

8. The vehicle braking control method according to claim 7, characterized in that, The brake actuator feedback data includes: the actual braking torque of the motor and the wheel brake cylinder pressure data. The actual total braking torque of the vehicle is determined based on the brake actuator feedback data, including: The actual friction braking torque is determined based on the wheel brake cylinder pressure data. The actual total braking torque is determined based on the actual friction braking torque and the actual braking torque of the motor.

9. The vehicle braking control method according to claim 8, characterized in that, Closed-loop compensation is performed based on the braking torque deviation and the brake actuator feedback data to obtain the compensated braking torque, which includes: In response to the positive value of the braking torque deviation, the motor torque margin is determined based on the upper limit of the motor torque and the actual braking torque of the motor. In response to the positive value of the motor torque margin, the motor torque compensation amount is determined based on the braking torque deviation and the motor torque margin, and the actual braking torque of the motor is incrementally compensated using the motor torque compensation amount; In response to the actual braking torque of the motor reaching the upper limit of the motor's braking torque, the friction braking torque compensation amount is determined based on the first residual torque deviation.

10. The vehicle braking control method according to claim 8, characterized in that, Closed-loop compensation is performed based on the braking torque deviation and the brake actuator feedback data to obtain the compensated braking torque, which includes: In response to the negative braking torque deviation, the reduction in motor braking torque is determined based on the braking torque deviation and the actual braking torque of the motor, and the reduction in motor braking torque is used to compensate for the reduction in the actual braking torque of the motor. In response to the actual braking torque of the motor reaching a preset value, the amount of reduction in friction braking torque is determined based on the second residual torque deviation.

11. The vehicle braking control method according to claim 1, characterized in that, The vehicle status data includes: current reference vehicle speed, wheel angular velocity, and tire rolling radius. The vehicle braking control method further includes: Based on the current reference vehicle speed, the wheel angular velocity, and the tire rolling radius, determine the wheel slip ratio corresponding to multiple wheels; In response to the first wheel's slip ratio being greater than a preset threshold, the first wheel is controlled to perform a braking torque redistribution operation.

12. The vehicle braking control method according to claim 11, characterized in that, Controlling the first wheel to perform a braking torque redistribution operation includes: The total reduction in braking torque corresponding to the first wheel is determined based on the wheel slip ratio. A first target torque reduction amount is determined based on the friction braking torque component of the first wheel and the total reduction of the braking torque, and the friction braking torque component is adjusted based on the first target torque reduction amount; In response to the friction braking torque component reaching a preset value and the wheel slip ratio being greater than the preset threshold value, a second target torque reduction amount is determined based on the wheel slip ratio, and the electric motor torque component of the first wheel is adjusted based on the second target torque reduction amount.

13. The vehicle braking control method according to claim 12, characterized in that, The vehicle braking control method further includes: The total reduction in braking torque is transferred to the coaxial wheel corresponding to the first wheel, or the total reduction in braking torque is transferred to the second wheel, wherein the wheel slip ratio of the second wheel is less than the preset threshold value.

14. The vehicle braking control method according to claim 1, characterized in that, Braking control of the vehicle using the base braking torque and the compensated braking torque includes: The motor braking command torque is determined based on the motor braking base torque and the motor braking compensation torque, and a first control command is generated based on the motor braking command torque. The friction braking command torque is determined based on the friction braking base torque and the friction braking compensation torque, and a second control command is generated based on the friction braking command torque. The vehicle is braked using the first control command and the second control command.

15. The vehicle braking control method according to claim 14, characterized in that, The torque change rate of the motor braking command torque is less than or equal to a first calibration value, and the torque change rate of the friction braking command torque is less than or equal to a second calibration value, wherein the second calibration value is less than the first calibration value.

16. The vehicle braking control method according to claim 14, characterized in that, The vehicle braking control method further includes: In response to the vehicle's motor controller failing to respond to the first control command for multiple consecutive cycles, or the vehicle's motor temperature exceeding a preset protection threshold, or the battery state-of-charge data being in an abnormal state, it is determined that the vehicle's motor braking system is in a fault state.

17. The vehicle braking control method according to claim 16, characterized in that, The vehicle braking control method further includes: In response to a malfunction in the electric motor braking system, the vehicle's full braking torque is generated using the vehicle's friction braking system.

18. The vehicle braking control method according to claim 14, characterized in that, The vehicle braking control method further includes: In response to the wheel brake cylinder pressure data meeting preset abnormal conditions, or the vehicle's electro-hydraulic braking system being in a fault state, it is determined that the vehicle's friction braking system is in a fault state.

19. The vehicle braking control method according to claim 18, characterized in that, The vehicle braking control method further includes: In response to a fault in the friction braking system, the vehicle's full braking torque is generated using the vehicle's electric braking system.

20. The vehicle braking control method according to claim 1, characterized in that, The vehicle braking control method further includes: In response to a partial interruption of the vehicle network, the friction braking base torque is determined based on a preset safety braking mapping table and the brake pedal travel, and the motor braking base torque is determined based on a preset regenerative braking mapping table and the brake pedal travel. In response to a global interruption of the vehicle network, the target braking torque of the vehicle is determined based on the pedal force of the vehicle's brake pedal.

21. A vehicle braking control device, characterized in that, include: The acquisition module is used to acquire multi-source status data of the vehicle, wherein the multi-source status data includes at least: braking demand data, vehicle status data, battery state of charge data and brake actuator feedback data. The allocation module is used to allocate torque based on the braking demand data, the vehicle status data and the battery state of charge data to obtain the basic braking torque, wherein the basic braking torque is used to represent the basic motor braking torque and the basic friction braking torque of the vehicle. The compensation module is used to perform closed-loop compensation based on the braking demand data, the vehicle status data and the brake actuator feedback data to obtain the compensation braking torque, wherein the compensation braking torque is used to represent the motor braking compensation torque and friction braking compensation torque of the vehicle. The first control module is used to perform braking control on the vehicle using the basic braking torque and the compensated braking torque.

22. A vehicle, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, performs the method according to any one of claims 1 to 20.

23. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored executable program, wherein, when the executable program is executed, it controls the device on which the storage medium is located to perform the method according to any one of claims 1 to 20.

24. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, implements the method according to any one of claims 1 to 20.

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