Brake control method

Abstract

The application relates to a brake control method. The method comprises the following steps: acquiring a unified slope value, an attribute data set and a state data set of a vehicle; decomposing the unified slope value according to the attribute data set and the state data set to obtain a target tire slope corresponding to each tire in the vehicle; constructing a brake torque model of the tire according to the target tire slope, and outputting a minimum tracking expected deceleration, a minimum brake torque change amount and a maximum energy recovery rate in the case that the brake torque model meets a preset constraint condition; and determining a brake torque of the tire based on the minimum tracking expected deceleration, the minimum brake torque change amount, the maximum energy recovery rate and the target tire slope. The method can improve the accuracy of the brake torque.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to a brake control method. BACKGROUND

[0002] During driving, vehicles often encounter different road conditions. For example, in the case of continuous ups and downs or sudden slope changes, in order to ensure the stability of the vehicle, the central controller of the vehicle will distribute brake forces according to the slope at which the vehicle is currently located, so as to control the vehicle to move forward according to the distributed brake torques.

[0003] In the conventional technology, the central controller receives map data of the current location of the vehicle. The map data contains a uniform slope value of the location where the vehicle is currently located. Then, the central controller corrects the total brake force according to the uniform slope value, and distributes the corrected total brake force to each tire according to a fixed proportion to obtain each brake torque. The brake torque is used to control the vehicle to move forward.

[0004] However, in the conventional technology, the consideration factor for determining the brake torque of each tire according to the overall uniform slope value and the fixed proportion value is single. Therefore, the accuracy of the current brake control method is low. SUMMARY

[0005] Therefore, it is necessary to provide a brake control method aiming at the above technical problems.

[0006] In a first aspect, the present application provides a brake control method, comprising:

[0007] obtaining a uniform slope value, an attribute data set and a state data set of a vehicle;

[0008] decomposing the uniform slope value according to the attribute data set and the state data set to obtain a target tire slope corresponding to each tire in the vehicle;

[0009] constructing a brake torque model of the tire according to the target tire slope, and outputting a minimum tracking expected deceleration, a minimum brake torque change amount and a maximum energy recovery rate in the case that the brake torque model meets a preset constraint condition;

[0010] determining a brake torque of the tire based on the minimum tracking expected deceleration, the minimum brake torque change amount, the maximum energy recovery rate and the target tire slope.

[0011] In one embodiment, the decomposing the uniform slope value according to the attribute data set and the state data set to obtain a target tire slope corresponding to each tire in the vehicle comprises:

[0012] According to the attribute data set, decompose the uniform slope value to obtain a tire environment slope of each tire in the vehicle;

[0013] According to the attribute data set and the state data set, update the tire environment slope to obtain a target tire slope of the tire.

[0014] In one of the embodiments, the attribute data set comprises a wheelbase and a track of the vehicle, and the decomposing the uniform slope value to obtain the tire environment slope of each tire in the vehicle comprises:

[0015] Decompose the uniform slope value to obtain an environment longitudinal slope pitch angle and an environment lateral slope roll angle;

[0016] According to the environment longitudinal slope pitch angle, the environment lateral slope roll angle, the wheelbase and the track of the vehicle, determine the tire environment slope of each tire in the vehicle.

[0017] In one of the embodiments, the updating the tire environment slope to obtain the target tire slope of the tire according to the attribute data set and the state data set comprises:

[0018] According to the state data set and the attribute data set, determine a tire state slope of each tire;

[0019] Based on an extended Kalman filter, fuse the tire state slope of the tire and the tire environment slope to obtain the target tire slope of the tire and a confidence of the target tire slope.

[0020] In one of the embodiments, the state data set comprises a longitudinal acceleration of the vehicle, a wheel speed and a driving force of each tire, and the determining the tire state slope of each tire according to the state data set and the attribute data set comprises:

[0021] According to the driving force of each tire, a mass of the vehicle and the longitudinal acceleration, determine an equivalent slope angle of the vehicle;

[0022] According to the equivalent slope angle, the mass and the longitudinal acceleration, determine a total longitudinal force of the vehicle on a slope;

[0023] For each tire, according to a pitch angle and a suspension displacement of the tire, determine an initial tire state slope of the tire, and according to the initial tire state slope, the mass and the total longitudinal force, determine the tire state slope of the tire.

[0024] In one of the embodiments, the constructing the brake torque model of the tire according to the target tire slope comprises:

[0025] For each of the tires, a target function is constructed according to a target tire slope of the tire, aiming at minimizing a tracking expected deceleration, minimizing a brake torque variation amount, and maximizing an energy recovery rate;

[0026] According to attribute information of an actuator in the vehicle, available adhesion of the tire, and a charging power threshold of a battery, each constraint condition of the target function is constructed;

[0027] The target function and each of the constraint conditions are combined to obtain a brake torque model of the tire.

[0028] In one of the embodiments, the attribute information of the actuator includes a regenerative brake torque threshold and a friction brake torque threshold, and the construction of each constraint condition of the target function according to the attribute information of the actuator in the vehicle, the available adhesion of the tire, and the charging power threshold of the battery includes:

[0029] A skid prevention constraint condition is constructed aiming at the brake force of the tire not exceeding the available adhesion;

[0030] An attribute constraint condition is constructed aiming at the brake torque of the tire not exceeding the regenerative brake torque threshold and the total regenerative brake power of each of the tires not exceeding the charging power threshold of the battery;

[0031] A demand constraint condition is constructed aiming at the brake torque of each of the tires meeting a driving demand.

[0032] In one of the embodiments, the output of the minimum tracking expected deceleration, the minimum brake torque variation amount, and the maximum energy recovery rate in the case that the brake torque model meets a preset constraint condition includes:

[0033] An effective slope average value is determined according to each of the target tire slopes;

[0034] The brake torque model is analyzed according to a linear solver, the effective slope average value, the attribute data set, and the state data set to obtain values of the tracking expected deceleration, the brake torque variation amount, and the energy recovery rate.

[0035] In one of the embodiments, the determination of the effective slope average value according to each of the target tire slopes includes:

[0036] A conservative adjustment coefficient is determined according to a confidence degree of the target tire slope of each of the tires;

[0037] An effective slope angle of the tire is determined based on the target tire slope, the confidence degree, and the conservative adjustment coefficient;

[0038] The effective slope angles of each of the tires are averaged to obtain an effective slope average value.

[0039] In one of the embodiments, after determining the brake torque of the tire based on the minimum tracking expected deceleration, the minimum brake torque variation, the maximum energy recovery rate and the target tire slope, the method further comprises:

[0040] sending the brake torque of the tire to an angle module controller of the tire; the angle module controller is configured to distribute the brake torque into a regenerative brake torque and a friction brake torque based on a coordination distribution strategy;

[0041] receiving the regenerative brake torque and the friction brake torque returned by the angle module controller, and determining a target slip ratio;

[0042] constructing a control instruction according to the target slip ratio, the brake torque, the regenerative brake torque and the target tire slope, and sending the control instruction to the angle module controller; the control instruction is configured to instruct the angle module controller to control the vehicle to operate.

[0043] In a second aspect, the present application further provides a brake control device, comprising:

[0044] an acquisition module configured to acquire a unified slope value, an attribute data set and a state data set of a vehicle;

[0045] a decomposition module configured to decompose the unified slope value according to the attribute data set and the state data set to obtain a target tire slope corresponding to each tire in the vehicle;

[0046] a construction module configured to construct a brake torque model of the tire according to the target tire slope, and output a minimum tracking expected deceleration, a minimum brake torque variation and a maximum energy recovery rate in a case where the brake torque model meets a preset constraint condition;

[0047] a determination module configured to determine the brake torque of the tire based on the minimum tracking expected deceleration, the minimum brake torque variation, the maximum energy recovery rate and the target tire slope.

[0048] In a third aspect, the present application further provides a computer device, comprising a memory and a processor, the memory stores a computer program, and the processor realizes the following steps when executing the computer program:

[0049] acquiring a unified slope value, an attribute data set and a state data set of a vehicle;

[0050] According to the attribute data set and the state data set, the uniform slope value is decomposed to obtain a target tire slope corresponding to each tire in the vehicle;

[0051] According to the target tire slope, a braking torque model of the tire is constructed, and in a case where the braking torque model satisfies a preset constraint condition, a minimum tracking expected deceleration, a minimum braking torque change amount and a maximum energy recovery rate are outputted;

[0052] Based on the minimum tracking expected deceleration, the minimum braking torque change amount, the maximum energy recovery rate and the target tire slope, a braking torque of the tire is determined.

[0053] In a fourth aspect, the present application further provides a computer readable storage medium, which has a computer program stored thereon, and the computer program is executed by a processor to implement the following steps:

[0054] A uniform slope value, an attribute data set and a state data set of a vehicle are acquired;

[0055] According to the attribute data set and the state data set, the uniform slope value is decomposed to obtain a target tire slope corresponding to each tire in the vehicle;

[0056] According to the target tire slope, a braking torque model of the tire is constructed, and in a case where the braking torque model satisfies a preset constraint condition, a minimum tracking expected deceleration, a minimum braking torque change amount and a maximum energy recovery rate are outputted;

[0057] Based on the minimum tracking expected deceleration, the minimum braking torque change amount, the maximum energy recovery rate and the target tire slope, a braking torque of the tire is determined.

[0058] In a fifth aspect, the present application further provides a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the following steps:

[0059] A uniform slope value, an attribute data set and a state data set of a vehicle are acquired;

[0060] According to the attribute data set and the state data set, the uniform slope value is decomposed to obtain a target tire slope corresponding to each tire in the vehicle;

[0061] According to the target tire slope, a braking torque model of the tire is constructed, and in a case where the braking torque model satisfies a preset constraint condition, a minimum tracking expected deceleration, a minimum braking torque change amount and a maximum energy recovery rate are outputted;

[0062] determine the brake torque of the tire based on the minimum tracking expected deceleration, the minimum brake torque change amount, the maximum energy recovery rate, and the target tire slope.

[0063] The brake control method described above obtains a unified slope value of a vehicle, an attribute data set, and a state data set; decomposes the unified slope value according to the attribute data set and the state data set to obtain a target tire slope corresponding to each tire in the vehicle; constructs a brake torque model of the tire according to the target tire slope, and outputs a minimum tracking expected deceleration, a minimum brake torque change amount, and a maximum energy recovery rate in a case where the brake torque model meets a preset constraint condition; and determines the brake torque of the tire based on the minimum tracking expected deceleration, the minimum brake torque change amount, the maximum energy recovery rate, and the target tire slope. With this method, the unified slope value of the vehicle is decomposed according to the attribute and state of the vehicle, which increases the two factors of vehicle attribute and state compared with the unified slope value, and improves the accuracy of the target tire slope. Furthermore, the brake torque of the tire is determined by comprehensively considering the tracking expected deceleration, the energy recovery rate, the brake torque change amount, and the target tire slope of each tire, which increases the factors of tracking expected deceleration, energy recovery rate, and target tire slope of each tire, improves the accuracy of the brake torque, and further improves the accuracy of the brake control method. BRIEF DESCRIPTION OF DRAWINGS

[0064] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed to be used in the description of the embodiments of the present application or the related art will be briefly introduced. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other related drawings can also be obtained without creative labor.

[0065] Figure 1 An application environment diagram of the brake control method in an embodiment;

[0066] Figure 2 A flowchart of the brake control method in an embodiment;

[0067] Figure 3 A flowchart of determining the target tire slope in an embodiment;

[0068] Figure 4 A flowchart of determining the tire environment slope in an embodiment;

[0069] Figure 5 A flowchart of determining the target tire slope and the confidence in an embodiment;

[0070] Figure 6 Flowchart for determining the slope of the tire state in one embodiment;

[0071] Figure 7 Flowchart for building the model of the braking torque in one embodiment;

[0072] Figure 8 Flowchart for building the constraints in one embodiment;

[0073] Figure 9 Flowchart for resolving the model of the braking torque in one embodiment;

[0074] Figure 10 Flowchart for determining the average of the effective slopes in one embodiment;

[0075] Figure 11 Flowchart for sending the control instructions in one embodiment;

[0076] Figure 12 Architectural diagram of the braking system in one exemplary embodiment;

[0077] Figure 13 Structural block diagram of the braking control device in one embodiment;

[0078] Figure 14 Internal structural diagram of the computer device in one embodiment. DETAILED DESCRIPTION

[0079] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0080] It should be noted that the terms "first", "second", and the like used herein can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "include" and "have" and any variations thereof used herein are intended to cover the non-exclusive inclusion. The term "multiple" used herein refers to two or more. The term "and / or" used herein refers to one of the options or any combination of multiple options.

[0081] The corner module has a large number of drive-by-wire actuators and high control freedom, four-wheel independent control, and the mechanical constraint between the wheels and the traditional configuration is cancelled. Based on the characteristics of this configuration, the braking coordination control requirements of the four wheels will become more stringent; at the same time, in the context of vehicle development, it is necessary to design a more refined energy recovery scheme during driving to improve energy recovery capability and utilization, and achieve the purpose of energy saving and emission reduction. Therefore, the application provides a braking control method applicable to a corner module controller.

[0082] The braking control method provided by the embodiment of the application can be applied to the braking control system 100 as shown in the figure. Figure 1 The braking system is applied to a vehicle. Optionally, the vehicle can be an electric vehicle or a fuel cell hybrid vehicle. The braking system 100 includes a central controller 110 (Vehicle Control Unit, VCU for short), four corner module controllers 120 (Local Module Controller, LMC for short), a perception system 130, and a force battery management system 140 (Battery Management System, BMS for short).

[0083] The central controller 110 is configured to receive a driver braking request or an automatic driving braking instruction, calculate a total braking force demand, and execute a braking control method (also referred to as an upper layer model predictive control (Model Predictive Control, MPC) algorithm).

[0084] The corner module controller 120: Each corner module integrates a drive motor, a friction brake actuator, a suspension actuator, and a steering actuator, and can independently collect operating parameters (such as the rotational speed of the tire, the steering angle, the vertical load, etc.) of the module where the corner module controller is located.

[0085] The perception system 130 includes an inertial measurement unit (IMU (Inertial Measurement Unit) for measuring longitudinal acceleration, lateral acceleration, and yaw rate), a wheel sensor, and an environment perception sensor (such as a camera and a laser radar), and is configured to provide road slope state information.

[0086] The force battery management system 140 is responsible for monitoring the battery state (such as SOC (State Of Charge), temperature, and maximum allowed charging power), and performing charging control during energy recovery.

[0087] The central controller 110 communicates with the corner module controller 120, the perception system 130 and the force battery management system 140 respectively. Among them, the central controller 110 and the corner module controller 120 communicate through high-speed Ethernet. In the case of communication exception, the central controller 110 can independently maintain the braking safety function of this round based on the last valid instruction or local sensor information.

[0088] In an exemplary embodiment, as shown in Figure 2 , a brake control method is provided, and the method is applied to Figure 1 the central controller 110 (hereinafter referred to as the central controller) in the example is described, including the following steps 202 to step 208. Among them:

[0089] Step 202, obtaining a unified slope value, an attribute data set and a state data set of the vehicle.

[0090] Among them, the unified slope value is the slope of the vehicle environment.

[0091] In implementation, the central controller obtains the environment data set of the vehicle environment, and extracts features from the environment data set through the environment slope recognition model to obtain the unified slope value of the vehicle. At the same time, the central controller obtains the attribute data set and the state data set of the vehicle. Among them, the attribute data set contains attribute data representing the inherent attributes of the vehicle, such as the weight of the vehicle. The state data set contains the state data of the current driving condition of the vehicle. For example, tire speed, longitudinal acceleration, etc.

[0092] Specifically, an intelligent driving perception module is provided in the vehicle. In the process of vehicle driving, the intelligent driving perception module will collect image data set and point cloud data set in front of the vehicle, and construct the environment data set according to the image data set and the point cloud data set. Then, the central controller inputs the environment data set into the environment slope recognition model, extracts geometric features from the environment data set through the environment slope recognition model, and identifies the slope features of the road in front of the vehicle, so as to output the unified slope value of the vehicle. The unified slope value is also a preliminary global slope reference value At the same time, the central controller obtains the attribute data set of the vehicle. The central controller obtains the current state data of the vehicle through the perception system, the force battery management system and each corner module controller, and obtains the state data set.

[0093] In an exemplary embodiment, the visual perception model is preset in the central controller. The intelligent driving perception module includes a camera device and a laser radar. During the continuous driving of the vehicle, the camera device continuously collects images in front of the vehicle to obtain an image dataset. At the same time, the laser radar collects laser point cloud data around the vehicle to obtain a point cloud dataset. The central controller constructs an environment dataset according to the image dataset and the point cloud dataset, and inputs the environment dataset into the preset visual perception model to extract geometric features of the environment dataset through the visual perception model, identify the slope feature of the road in front of the vehicle, and output a unified slope value of the vehicle . The unified slope value is a two-dimensional vector. At the same time, the central controller obtains an attribute dataset of the vehicle from the perception system. At the same time that the central controller obtains the attribute dataset, the central controller obtains state data representing the state of the vehicle, such as longitudinal acceleration, transverse acceleration, rotation speed of each tire, steering angle of each tire, and remaining power of the vehicle, from the angle module controller, the perception system, and the force battery management system, to obtain a state dataset.

[0094] In an optional embodiment, the perception visual model is a pre-trained neural network architecture BEVFormer (a visual perception model). That is, the central controller inputs the environment dataset into the BEVFormer, extracts geometric features in the bird's eye view space through the pre-trained neural network architecture BEVFormer, identifies the slope feature of the road in front of the vehicle, and outputs a preliminary global slope reference value , that is, a unified slope value. The unified slope value is a two-dimensional vector.

[0095] Optionally, the attribute dataset can include but is not limited to the mass of the vehicle, the wheelbase of the vehicle, and the track of the vehicle. The state dataset can include but is not limited to the longitudinal acceleration of the vehicle, the wheel speed of each tire, and the driving force. The present embodiment does not limit the data included in the attribute dataset and the state dataset.

[0096] Step 204, decompose the unified slope value according to the attribute dataset and the state dataset to obtain a target tire slope corresponding to each tire in the vehicle.

[0097] In implementation, the central controller decomposes the unified slope value according to the attribute dataset to obtain a tire environment slope of each tire in the vehicle. Then, the central controller updates the tire environment slope according to the attribute dataset and the state dataset to obtain a target tire slope corresponding to the tire.

[0098] Specifically, the central controller decomposes the uniform slope value, and performs coordinate transformation and geometric projection on the decomposed uniform slope value according to the attribute data set to obtain a tire environment slope of each tire. Then, the central controller determines a tire state slope of each tire according to the attribute data set and the state data set, and updates the tire environment slope according to the tire state slope to obtain a target tire slope of the tire.

[0099] In step 206, a braking torque model of the tire is constructed according to the target tire slope, and the minimum tracking expected deceleration, the minimum braking torque change amount, and the maximum energy recovery rate are output in a case where the braking torque model satisfies a preset constraint condition.

[0100] In the attribute data set, attribute information of the actuator and a charging power threshold are included.

[0101] In implementation, the central controller constructs a target function of each tire according to the target tire slope of the tire, and constructs a constraint condition of the target function according to the state data set and the attribute data set. The central controller constructs a braking torque model of the tire according to the target function and the constraint condition. In a case where the braking torque model satisfies the constraint condition, the central controller analyzes the target function in the braking torque model to obtain the minimum tracking expected deceleration, the minimum braking torque change amount, and the maximum energy recovery rate.

[0102] Specifically, the central controller constructs a target function according to the target tire slope for each tire, with the goal of minimizing the tracking expected deceleration, minimizing the braking torque change amount, and maximizing the energy recovery rate. The central controller constructs constraint conditions of the target function according to attribute information of the actuator in the vehicle, available adhesion of the tire, and a charging power threshold of the battery. Then, the central controller combines the target function and the constraint conditions to obtain the braking torque model. The central controller determines an effective slope average value according to the target tire slopes. Then, in a case where the braking torque model satisfies the constraint condition, the central controller analyzes the braking torque model according to a linear solver, the effective slope average value, the attribute data set, and the state data set to obtain values of the tracking expected deceleration, the braking torque change amount, and the energy recovery rate.

[0103] In step 208, a braking torque of the tire is determined based on the minimum tracking expected deceleration, the minimum braking torque change amount, the maximum energy recovery rate, and the target tire slope.

[0104] In implementation, a braking torque algorithm is preset in the central controller. The central controller performs data processing on the minimum tracking expected deceleration, the minimum braking torque change amount, the maximum energy recovery rate, and the target tire slope according to the braking torque algorithm to obtain the braking torque of the tire.

[0105] In particular, the desired deceleration is the difference between the desired longitudinal deceleration and the actual longitudinal deceleration.

[0106] The total braking torque of the tires is converted into a ground perceptible longitudinal braking by the effective radius of the tires. As shown in the following equation (1):

[0107] (1)

[0108] wherein, in the above equation (1), denotes the ground perceptible longitudinal braking force of the i-th tire, denotes braking, denotes longitudinal, is the effective radius of the tire. denotes the total braking torque of the i-th tire. denotes the demand. denotes the requirement.

[0109] The actual deceleration of the vehicle is determined by the resultant of the vehicle longitudinal forces according to the vehicle longitudinal dynamics balance, thus reflecting the indirect mapping of the braking torque to the vehicle deceleration. The indirect mapping of the braking torque and the vehicle deceleration is shown in the following equation (2):

[0110] (2)

[0111] wherein, in the above equation (2), denotes the ground perceptible longitudinal braking force of the i-th tire, is the total longitudinal braking force of the four tires, denotes braking, denotes longitudinal. denotes the mass of the vehicle, denotes the actual longitudinal deceleration of the vehicle. denotes the gravitational acceleration. is the average of the effective slopes of the four tires. The effective slopes can be determined according to the target tire slopes of the four tires. The relationship between the regenerative braking torque and the regenerative power is shown in the following equation (3):

[0112] (3)

[0113] wherein, in the above equation (3), is the regenerative braking torque of the i-th tire,

[0114] is the regenerative power of the i-th tire. is the regenerative braking torque of the i-th tire, is the regenerative power of the i-th tire. is the regenerative braking torque of the i-th tire, is the regenerative power of the i-th tire. is the regenerative braking torque of the i-th tire, ​the rotational speed of the tire.

[0115] The relationship between the regenerative braking torque and the braking torque of the tire is shown in the following equation (4):

[0116] (4)

[0117] In the above equation (4), the total braking torque of the i-th tire is represented by represents the demand.

[0118] The relationship between the braking torque and the braking torque change amount is shown in the following equation (5):

[0119] (5)

[0120] In the above equation (5), the braking torque change amount is represented by

[0121] The central controller determines the braking torque algorithm according to the above equations (1) to (5). The central controller processes the minimum tracking expected deceleration, the minimum braking torque change amount, the maximum energy recovery rate, and the target tire slope according to the braking torque algorithm to obtain the braking torque of the tire.

[0122] In an optional embodiment, the central controller sends the braking torque of the tire to the angular module controller corresponding to the tire. The angular module controller distributes the braking torque into the regenerative braking torque and the friction braking torque according to the coordinated distribution strategy, and feeds back the regenerative braking torque and the friction braking torque to the central controller. The central controller constructs the control instruction according to the regenerative braking torque and the braking torque, and sends the control instruction to the angular module controller, so that the angular module controller controls the vehicle to move forward according to the control instruction.

[0123] ​​​​​​​​​​​​​In the above brake control method, the unified slope value of the vehicle is decomposed according to the attribute and state of the vehicle, and compared with the unified slope value, the two factors of the attribute and state of the vehicle are added to improve the accuracy of the target tire slope. Furthermore, the brake torque of the tire is determined by comprehensively tracking the expected deceleration, energy recovery rate, brake torque conversion amount and target tire slope of the tire in units of tires, the factors of tracking the expected deceleration, energy recovery rate and target tire slope of each tire are added to improve the accuracy of the brake torque, and the accuracy of the brake control method is improved.

[0124] In one exemplary embodiment, according to the attribute data set and the state data set, as shown in Figure 3 The specific processing process of step 202 includes steps 302 to 304. Among them:

[0125] Step 302, according to the attribute data set, decompose the unified slope value to get the tire environment slope of each tire in the vehicle.

[0126] Among them, the attribute data set contains the wheelbase, track and mass of the vehicle.

[0127] In implementation, the central controller decomposes the unified slope value, and according to the wheelbase, track and mass of the vehicle, the decomposed unified slope value is coordinate transformed and geometrically projected to get the tire environment slope of each tire in the vehicle.

[0128] Specifically, the central controller directly decomposes the unified slope value to get the environment longitudinal slope pitch angle and the environment transverse slope roll angle. Then, the central controller performs coordinate transformation and geometric projection on the environment longitudinal slope pitch angle and the environment transverse slope roll angle according to the wheelbase and track of the vehicle to get the elevation difference of each tire in the vehicle, and determines the tire environment slope of the vehicle according to the elevation difference and the unified slope value.

[0129] Step 304, according to the attribute data set and the state data set, update the tire environment slope to get the target tire slope of the tire.

[0130] In implementation, the central controller determines the tire state slope of each tire according to the attribute data set and the state data set, and updates the tire environment slope according to the tire state slope to get the target tire slope of the tire.

[0131] Specifically, the central controller determines the tire state slope of each tire according to the state data set and the attribute data set. Then, the central controller fuses the tire state slope and the tire environment slope of the tire based on an extended Kalman filter to get the target tire slope of the tire and the confidence of the target tire slope.

[0132] In this embodiment, the uniform slope value of the vehicle is decomposed according to the vehicle's attributes and status. Compared with the uniform slope value, the vehicle attributes and status are taken into consideration, which improves the accuracy of the target tire slope.

[0133] In one exemplary embodiment, the attribute dataset contains the vehicle's wheelbase and track width, such as... Figure 4 As shown, the specific processing procedure of step 302 includes steps 402 to 404. Wherein:

[0134] Step 402: Decompose the uniform slope value to obtain the environmental longitudinal slope pitch angle and the environmental transverse slope tilt angle.

[0135] The uniform slope value is a two-dimensional vector.

[0136] In implementation, the central controller decomposes the uniform slope value to obtain the environmental longitudinal slope pitch angle and the environmental lateral slope tilt angle.

[0137] Step 404: Determine the tire environmental slope of each tire in the vehicle based on the environmental longitudinal slope pitch angle, environmental lateral slope roll angle, vehicle wheelbase, and track width.

[0138] In implementation, an environmental slope algorithm is pre-set in the central controller. The central controller processes data on the longitudinal slope pitch angle, the lateral slope roll angle, the wheelbase, and the track width of the vehicle according to the environmental slope algorithm to obtain the tire environmental slope of each tire in the vehicle. The environmental slope algorithm is shown in the following formula (6):

[0139] (6)

[0140] In the above formula (6), Indicates the first Tire slope of each tire environment This represents a uniform slope value. Vehicle geometry parameters include the vehicle's environmental longitudinal slope pitch angle, environmental lateral slope roll angle, wheelbase, and track width. Represented as the first Calculate the environmental slope of each tire. ={1,2,3,4} represents the four tires of the vehicle.

[0141] Specifically, the central controller performs coordinate transformation and geometric projection on the longitudinal slope pitch angle and the lateral slope roll angle of the environment based on the vehicle's wheelbase and track width to obtain the elevation difference of each tire in the vehicle. Then, based on the elevation difference and a uniform slope value, it determines the vehicle's tire environmental slope. The tire environmental slope is a priori estimate of the slope of the target tire.

[0142] In an example embodiment, the central controller calculates the elevation difference of the four tire contact points due to the change of the vehicle posture by coordinate transformation and geometric projection according to the wheelbase, the track, the environmental longitudinal slope pitch angle and the environmental lateral slope roll angle of the vehicle. Then, the central controller determines the local longitudinal and lateral slopes of each tire according to the elevation difference of each tire and the uniform slope value, and obtains the tire environmental slope of each tire.

[0143] In the embodiment, the uniform slope value is decomposed by the attribute information of the vehicle to obtain the tire environmental slope of each tire from the aspect of the environment where the vehicle is located, so that the slope is determined in the granularity of the tire, the processing granularity is refined, and the accuracy of the braking torque is improved.

[0144] In an example embodiment, as shown in FIG. 5, the specific processing procedure of step 304 includes steps 502 to 504. In which: Figure 5

[0145] Step 502, determining the tire state slope of each tire according to the state data set and the attribute data set.

[0146] In which, the state data set includes the longitudinal acceleration of the vehicle, the wheel speed of each tire and the driving force. The tire state slope is the slope where the tire is located according to the state of the vehicle, which is a dynamic observation value.

[0147] In implementation, the central controller determines the total longitudinal force of the vehicle according to the state data set and the attribute data set. Then, the central controller determines the state slope of each tire according to the attribute data set, the state data set and the total longitudinal force.

[0148] Specifically, the central controller determines the equivalent slope angle of the vehicle according to the driving force of each tire, the mass and the longitudinal acceleration of the vehicle, and determines the total longitudinal force of the vehicle on the slope according to the equivalent slope angle, the mass and the longitudinal acceleration. Then, the central controller determines the initial tire state slope of each tire according to the pitch angle and the suspension displacement where the tire is located, and determines the tire state slope of the tire according to the initial tire state slope, the mass and the total longitudinal force.

[0149] Step 504, fusing the tire state slope and the tire environmental slope of each tire based on the extended Kalman filter to obtain the target tire slope of each tire and the confidence of the target tire slope.

[0150] ​In implementation, the central controller uses an extended Kalman filter to fuse the tire state slope and tire environment slope of each tire, obtaining the target tire slope and its estimated error covariance. The central controller then determines the estimated error covariance as the confidence level of the target tire slope. The higher the confidence level, the higher the probability that the tire is at the target tire slope.

[0151] Specifically, due to the limitations of a single sensing method, the central controller employs an Extended Kalman Filter (EKF) to fuse tire state slope and tire environment slope, obtaining the target tire slope and estimation error covariance. This target tire slope is the optimal posterior estimate of the tire environment slope. The central controller determines the estimation error covariance as the confidence level of the target tire slope. The Kalman filter is shown in equations (7) and (8) below:

[0152] State vector: (7)

[0153] Observation equation: (8)

[0154] Among them, in the above formulas (7) and (8), For the first The target tire slope for each tire. Indicates the first Tire slope of each tire environment Indicates the first Tire condition slope of each tire This indicates transpose. For the observation matrix, To observe noise. This is the calculated intermediate value.

[0155] In this embodiment, the tire condition slope of each tire is determined by the vehicle's operating status, and the tire environment slope is updated by the tire condition slope. This enables the determination of the target tire slope from different angles, which improves the accuracy of the target tire slope compared to a single uniform slope value.

[0156] In one exemplary embodiment, the state dataset includes the vehicle's longitudinal acceleration, wheel speeds of each tire, and driving force, such as... Figure 6 As shown, the specific processing procedure of step 502 includes steps 602 to 606. Wherein:

[0157] Step 602: Determine the equivalent slope angle of the vehicle based on the driving force of each tire, the mass of the vehicle, and the longitudinal acceleration.

[0158] In implementation, the central controller is equipped with an equivalent slope angle algorithm. The central controller processes data on the driving force of each tire, the mass of the vehicle, and the longitudinal acceleration according to the equivalent slope angle algorithm to obtain the vehicle's equivalent slope angle. The equivalent slope angle algorithm is shown in the following formula (9):

[0159] (9)

[0160] In the above formula (9), For the equivalent slope angle, Indicates the first The longitudinal braking force of a tire can also be the driving force. Indicates the mass of the vehicle. This indicates the longitudinal deceleration of the vehicle. It represents the acceleration due to gravity.

[0161] Specifically, the central controller estimates the braking force or driving force of each tire based on the motor torque or braking pressure. Then, the central controller processes the driving force of each tire, the vehicle's mass, and longitudinal acceleration using an equivalent slope angle algorithm to obtain the vehicle's equivalent slope angle. The equivalent slope angle is the slope angle corresponding to the equivalent force of the resultant force of non-slope resistances (such as rolling resistance, air resistance, acceleration resistance, etc.) experienced by the vehicle during driving, converted into a single slope resistance.

[0162] Optionally, the central controller can process data on the braking force of each tire, the mass of the vehicle, and the longitudinal acceleration according to the equivalent slope angle algorithm to obtain the vehicle's equivalent slope angle.

[0163] Step 604: Determine the total longitudinal force of the vehicle on the slope based on the equivalent slope angle, mass, and longitudinal acceleration.

[0164] The attribute dataset includes the vehicle's mass.

[0165] In implementation, the central controller is equipped with a total longitudinal force algorithm. The central controller processes the equivalent slope angle, mass, and longitudinal acceleration data according to the total longitudinal force algorithm to obtain the total longitudinal force of the vehicle on the slope. The total longitudinal force algorithm is shown in the following formula (10):

[0166] (10)

[0167] In the above formula (10), Indicates the mass of the vehicle. This indicates the longitudinal deceleration of the vehicle. It represents the acceleration due to gravity. For the equivalent slope angle, This represents the total longitudinal force of the vehicle. These are trigonometric functions.

[0168] Step 606: For each tire, determine the initial tire state slope based on the tire's pitch angle and suspension displacement, and further determine the tire state slope based on the initial tire state slope, mass, and total longitudinal force.

[0169] The state dataset contains the pitch angle and suspension displacement of each tire. Suspension displacement refers to the relative displacement in the vertical direction between the vehicle body (or frame) and the wheels (or axles). The attribute dataset contains the vehicle's mass.

[0170] In practice, the principle of tire state slope is as follows: based on the vehicle's longitudinal dynamics equation, the longitudinal force on each wheel can be inferred by using the longitudinal acceleration measured by the sensing system and the rotational speed of each tire measured by the wheel speed sensor, thereby estimating the influence of the slope. For each tire, the central controller decouples the initial local slope angle observation value of the tire based on the pitch angle and suspension displacement of the tire. This initial local slope angle observation value is the initial tire state slope of the vehicle. Then, the central controller iterates the initial tire state slope using the tire state slope iteration algorithm, mass, and total longitudinal force to obtain the tire state slope. The tire state slope iteration algorithm is shown in the following formula (11):

[0171] (11)

[0172] In the above formula (11), For observer gain, For time steps. Indicates the mass of the vehicle. Indicates in The longitudinal deceleration of the vehicle at any given moment. It represents the acceleration due to gravity. In order to be in The total longitudinal force of the vehicle at any given moment. In order to be in The initial tire condition and slope of the vehicle at any given time. In order to be in The vehicle's tire condition and slope at all times.

[0173] In this embodiment, the tire state slope of each tire in the vehicle is determined by the vehicle state dataset, which realizes the determination of the slope of each tire from the vehicle state, and facilitates the subsequent updating of the tire environment slope based on the tire state slope.

[0174] In one exemplary embodiment, such as Figure 7 As shown, the specific processing steps for constructing the tire braking torque model based on the target tire slope in step 206 include steps 702 to 706. Wherein:

[0175] Step 702, for each tire, a target function is constructed according to the target tire slope of the tire, aiming to minimize the tracking expected deceleration, minimize the brake torque variation amount, and maximize the energy recovery rate.

[0176] In implementation, the central controller constructs a target function based on the target tire slope of the tire, the state data set and the attribute data set of the vehicle, aiming to minimize the expected deceleration, minimize the brake torque variation amount, and maximize the energy recovery rate for each tire.

[0177] Specifically, the brake torque model is a discretized vehicle longitudinal dynamics prediction model (prediction time domain N, sampling time Δt). The state variables are selected as the vehicle longitudinal speed and the wheel speed of each wheel . The state variables are shown in the following formula (12):

[0178] x (k)=[ v x (k), ω 1 (k), ω 2 (k), ω 3 (k), ω 4 (k) ] T (12)

[0179] In the above formula (12), denotes the state variable at time , and denotes the vehicle longitudinal speed at time . denotes the wheel speed of the first tire, the second tire, the third tire, and the fourth tire at time , respectively. denotes the transpose.

[0180] The control variable is the brake torque of each tire (the brake torque includes the regenerative brake torque and the friction brake torque). The control variable is shown in the following formula (13):

[0181] u (k)=[ T b,req,1 (k), T b,req,2 (k), T b,req,3 (k), T b,req,4 (k) ] T (13)

[0182] wherein in the above equation (13), denote the braking torque of the 1st, 2nd, 3rd, 4th tire at time denote the control variable. denote the transpose.

[0183] The MPC in the central controller solves the following optimization problem at each control period, which is to trade-off among the three objectives of “tracking the desired deceleration, maximizing energy recovery, and ensuring control smoothness”. Therefore, the central controller constructs an objective function for each tire based on the target tire slope of the tire, the state dataset and the property dataset of the vehicle, with the goal of minimizing the tracking error of the desired deceleration, minimizing the variation of the braking torque, and maximizing the energy recovery rate. The objective function is shown in the following equation (14):

[0184] (14)

[0185] wherein in the above equation (14), denote the control variable, denote the trade-off objective, is to minimize the value of the trade-off objective (objective function). The first term is , which denotes the sum of the square of the tracking error of the desired deceleration, and is also the tracking error of the desired deceleration. The smaller the sum of the square of the tracking error of the desired deceleration, the more accurately the vehicle brakes according to the driver's intention, which is the core safety objective of the braking system. denote the actual longitudinal deceleration at time in the future at time denote the desired longitudinal deceleration (the desired deceleration is determined by the factory calibration test of the vehicle, but will be dynamically corrected according to the current speed, load, road adhesion coefficient, etc. of the vehicle), is a weight matrix.

[0186] The second term is , which is the energy recovery rate, and also denotes the maximum total regenerative energy recovery power of the four wheels (the negative sign is because the maximum recovery in the minimization problem is equivalent to the minimum negative recovery). Wherein is the regenerative braking power of a single wheel at time in the future at time is the weight coefficient of energy recovery.

[0187] The third term is ​​​is the increment of the control variable (the change of the braking torque), and is the increment of the control variable (the change of the braking torque), and is the weight matrix, and the smaller this part is, the more gentle the change of the braking torque is, and the better the comfort is.

[0188] Then, the central controller establishes the attribute data set, the state data set, and the correlation between the target tire slope and the braking torque change amount energy recovery rate and the minimum tracking expected deceleration.

[0189] In step 704, each constraint condition of the target function is constructed according to the attribute information of the actuators in the vehicle, the available adhesion of the tires, and the charging power threshold of the battery.

[0190] In implementation, the central controller determines the attribute information of the actuators and the charging power threshold of the battery in the attribute data set, and constructs each constraint condition of the target function according to the attribute information of the actuators in the vehicle, the available adhesion of the tires, and the charging power threshold of the battery.

[0191] Specifically, the central controller determines the attribute information of the actuators and the charging power threshold of the battery in the attribute data set. Then, the central controller constructs the anti-skid constraint condition with the goal of the braking force of the tires not exceeding the available adhesion, and constructs the attribute constraint condition with the goal of the braking torque of the tires not exceeding the regenerative braking torque threshold and the total regenerative braking power of each tire not exceeding the charging power threshold of the battery. At the same time, the central controller constructs the demand constraint condition with the goal of the braking torque of each tire meeting the driving demand.

[0192] In step 706, the braking torque model of the tires is obtained by combining the target function and each constraint condition.

[0193] In implementation, the central controller combines the target function and each constraint condition together to obtain the braking torque model of the tires.

[0194] In this embodiment, by constructing the target function with the goals of maximizing the energy recovery rate, minimizing the tracking expected deceleration, and minimizing the braking torque change amount, and constructing the braking torque model according to the target function and the required constraint conditions of the vehicle, the braking torque corresponding to the braking torque model can reduce energy loss and improve the energy utilization rate of the vehicle while maintaining the stability of the vehicle.

[0195] In an exemplary embodiment, the attribute information of the actuators includes the regenerative braking torque threshold and the friction braking torque threshold, as shown in Figure 8 The specific processing process of step 704 includes steps 802 to 806. Among them:

[0196] Step 802: Construct anti-skid constraint conditions with the goal of ensuring that the braking force of the tires does not exceed the available adhesion.

[0197] In implementation, the central controller establishes anti-skid constraints with the goal of ensuring that the tire braking force does not exceed the available traction. These anti-skid constraints also serve as anti-lock braking constraints. Then, the central controller establishes a correlation between tracking the desired deceleration, changes in braking torque, and the energy recovery rate, and the anti-skid constraints.

[0198] Specifically, during vehicle operation, the braking force of each tire must not exceed the available adhesion, leaving a margin. Therefore, the central controller constructs anti-skid constraints with the goal of ensuring that the tire braking force does not exceed the available adhesion. The anti-skid constraints are shown in the following formula (15):

[0199] (15)

[0200] In the above formula (15), In the first The controller cycle, the future... At the moment, the first The longitudinal force prediction values ​​(braking force or driving force, here it is braking force) of each wheel (i=1,2,3,4, corresponding to the left front wheel, right front wheel, left rear wheel and right rear wheel of the vehicle, respectively). The safety factor is less than 1. For the first The coefficient of friction of each wheel (tire) (derived from the vehicle's attribute dataset). This represents the vertical load at the corresponding moment (which can be determined based on the vehicle's attribute dataset and state dataset). For the first The effective slope angle of a tire is derived from the following formula (16):

[0201] (16)

[0202] In the above formula (16), For the first The target tire slope for each tire. This is the conservative adjustment factor, which corresponds to the confidence level. No. Confidence level of each wheel (tire). For the first The effective slope angle of each tire.

[0203] Then, the central controller establishes the correlation between the target of tracking the desired deceleration, the change in braking torque, and the energy recovery rate and anti-skid constraints. Specifically, the braking force of each tire is the direct source of longitudinal acceleration, which is correlated through the vehicle's longitudinal dynamics equation, thus reflecting the direct mapping between braking force and longitudinal acceleration. The vehicle's longitudinal dynamics equation is shown in the following formula (17):

[0204] (17)

[0205] In the above formula (17), Indicates the first The braking force that can be felt on the ground from each tire. Indicates vertical direction. Indicates the mass of the vehicle. This indicates the vehicle's actual longitudinal deceleration. It represents the acceleration due to gravity. for This represents the average effective gradient of the four tires. The effective gradient can be determined based on the target tire gradient of the four tires.

[0206] Braking force is divided into regenerative braking force and frictional braking force. The relationship between braking force, regenerative braking force and frictional braking force is shown in the following formula (18):

[0207] (18)

[0208] In the above formula (18), Indicates the first Total braking force of each tire. This indicates a need. For the first Regenerative braking force of each tire For the first The frictional braking force of each tire.

[0209] The regenerative braking power is determined by the regenerative braking force and the wheel speed, as shown in the following formula (19):

[0210] (19)

[0211] In the above formula (19), For the first Regenerative braking power of each tire For the first Regenerative braking force of each tire For the first The wheel speed of each tire. The above formula (19) reflects the indirect mapping between braking force and regenerative braking power.

[0212] It represents the change in torque at different times. As shown in the following formula (20):

[0213] (20)

[0214] In the above formula (20), This represents the change in braking torque. For the future Braking torque at any given moment No. -1 braking torque at moment 1. Indicates the first One control cycle. The torque can be obtained by relating the braking force and the wheel radius, thus reflecting the indirect mapping between torque and braking force.

[0215] Step 804: With the objectives of ensuring that the braking torque of the tires does not exceed the regenerative braking torque threshold and that the total regenerative braking power of each tire does not exceed the battery charging power threshold, construct attribute constraints.

[0216] The attribute constraints include actuator constraints and battery constraints. The charging power threshold is the maximum charging power of the battery.

[0217] In implementation, the central controller constructs actuator constraints with the objective that the braking torque of the tires does not exceed the regenerative braking torque threshold, and constructs battery constraints with the objective that the total regenerative braking power of all tires does not exceed the battery charging power threshold. Then, the central controller establishes the correlation between tracking the desired deceleration, the change in braking torque, and the energy recovery rate and the actuator constraints.

[0218] Specifically, during vehicle braking, the total braking torque of each wheel must be within the range of the motor's regenerative braking capacity and the friction brake's capacity. Therefore, the central controller constructs actuator constraints with the goal of ensuring that the tire braking torque does not exceed the regenerative braking torque threshold. The actuator constraints are shown in the following set of formulas (21):

[0219] (twenty one)

[0220] In the above formula group (21), Indicates in The controller cycle, the future... At the moment, the first The regenerative braking torque of each tire. This indicates the maximum regenerative braking torque of the vehicle at the current wheel speed. Indicates the first The total braking torque of each tire. Indicates the first friction braking torque of the i-th tire. represents the maximum friction braking force of the i-th tire. Then, the central controller establishes the association between the tracking desired deceleration, the braking torque variation and the energy recovery rate and the actuator constraint condition. The association between the tracking desired deceleration, the braking torque variation and the energy recovery rate and the actuator constraint condition is shown in the above formula (1) to formula (5). Moreover, since the total regenerative braking power of the four tires during the driving of the vehicle cannot exceed the maximum charging power allowed by the BMS, the central controller targets the charging power threshold of the battery, and builds the battery constraint. The battery constraint is shown in the following formula (22):

[0221] (22)

[0222] In the above formula (22), the sum of the regenerative braking power of the four tires at the i-th time in the future in the controller cycle is represented by is the charging power threshold of the BMS, which is also the maximum charging power.

[0223] Step 806, building a demand constraint condition with the braking torque of each tire meeting the driving demand as the target.

[0224] In the implementation, during the driving of the vehicle, the braking torque of the four tires should meet the driving demand of the driver. Therefore, the central controller builds a demand constraint condition with the braking torque of each tire meeting the driving demand as the target. The demand constraint condition is shown in the following formula (23):

[0225] (23)

[0226] In the above formula (23), the sum of the braking force of the four tires at the i-th time in the future in the controller cycle is represented by is the mass of the vehicle, is the desired longitudinal deceleration. is the acceleration of gravity. is the average value of the effective slope of the four tires.

[0227] In this embodiment, by building the demand constraint condition, the attribute constraint condition and the anti-skid constraint condition of the vehicle, the braking torque model of the tire is built subsequently, so that the braking torque model can output the braking torque under the condition of meeting each constraint condition, and the safety of the vehicle is ensured.​​​​​​

[0228] In one exemplary embodiment, as shown in FIG. 9, the specific processing procedure of outputting the minimum tracking desired deceleration, the minimum brake torque variation and the maximum energy recovery rate in the case that the brake torque model meets the preset constraint condition in step 206 includes steps 902 to 904. Wherein: Figure 9

[0229] Step 902, determining the effective slope average value according to each target tire slope.

[0230] In implementation, the central controller determines the effective slope of each tire according to each target tire slope and confidence. Then, the central controller determines the effective slope average value according to the effective slopes of each tire.

[0231] Specifically, the central controller determines the conservative adjustment coefficient according to the confidence of each target tire slope of each tire, and determines the effective slope angle of each tire based on the target tire slope, the confidence and the conservative adjustment coefficient. Then, the effective slope angles of each tire are processed by mean value to obtain the effective slope average value.

[0232] Step 904, analyzing the brake torque model according to the linear solver, the effective slope average value, the attribute data set and the state data set to obtain the values of the tracking desired deceleration, the brake torque variation and the energy recovery rate.

[0233] In implementation, the central controller inputs the attribute data set, the state data set, the effective slope average value and the brake model into the linear solver, and analyzes the brake torque model by the linear solver to obtain the values of the tracking desired deceleration, the brake torque variation and the energy recovery rate.

[0234] Specifically, the linear solver linearizes the nonlinear MPC problem in the brake torque model at each working point into a quadratic programming (QP) problem, which contains an objective function and a constraint matrix, so as to realize the dynamic optimization distribution of the brake force. The principle of the dynamic optimization distribution is shown in the following formula (24):

[0235] (24)

[0236] Wherein, the formula (24) is the objective function in the quadratic programming solving task, is the control increment sequence, i.e. the adjustment amount of the brake torque of each tire (such as the regenerative torque increment, the friction torque increment); is the Hessian matrix, which is composed of the quadratic term coefficients of the objective function, and reflects the curvature relationship between the control increment and the objective function; ​The gradient vector, composed of the coefficients of the first-order terms of the objective function, reflects the linear effect of the control increment on the objective function. This linear solver also includes a set of constraint formulas, as shown in the following formula set (25):

[0237] (25)

[0238] In the above formula group (25), It consists of constraint matrices and vectors. To control the increment sequence, the linear solver transforms the aforementioned constraints into mathematical boundaries, ensuring that the optimal braking torque increment is obtained. It satisfies all physical constraints and minimizes the objective function, thus achieving the core objective of "cooperative braking control".

[0239] Optionally, the linear solver is an efficient QP (quadratic programming) solver (such as ASM (Effective Set Method) or ADMM (Alternating Direction Multiplier Method)) for online solving, with the control frequency set to 100 Hz (10 ms). If the solution times out, a degradation strategy is enabled.

[0240] In this embodiment, taking the tire as a unit, the braking torque model of the tire is solved to obtain the comprehensive tracking expected deceleration, energy recovery rate and braking torque transformation amount. This facilitates the subsequent determination of the braking torque based on the comprehensive tracking expected deceleration, energy recovery rate and braking torque transformation amount. The addition of tracking expected deceleration and energy recovery rate as considerations improves the accuracy of the braking torque, thereby improving the accuracy of the braking control method.

[0241] In one exemplary embodiment, such as Figure 10 As shown, the specific processing procedure of step 902 includes steps 1002 to 1006. Wherein:

[0242] Step 1002: Determine the conservative adjustment coefficient based on the confidence level of the target tire slope for each tire.

[0243] In implementation, the central controller establishes a correlation between confidence level and conservative adjustment coefficient. For each tire's target tire slope, the central controller determines the conservative adjustment coefficient corresponding to the confidence level of the target tire slope, based on the correlation between the confidence level and the conservative adjustment coefficient.

[0244] Step 1004: Determine the effective slope angle of the tire based on the target tire slope, confidence level, and conservative adjustment factor.

[0245] In implementation, the central controller is provided with an effective slope angle algorithm. The central controller processes the target tire slope, the confidence level and the conservatism adjustment factor according to the effective slope angle algorithm to obtain the effective slope angle of the tire. The effective slope angle is determined to deal with the perception uncertainty. The effective slope angle algorithm is shown in the following formula (26):

[0246] (26)

[0247] In the above formula (26), the effective slope angle of the i-th tire is denoted as the confidence level of the i-th tire is denoted as the conservatism adjustment factor is denoted as

[0248] Step 1006, the effective slope angles of the tires are processed by mean value to obtain the effective slope average value.

[0249] In implementation, the central controller processes the effective slope angles of the tires by mean value to obtain the effective slope angle average value of the vehicle.

[0250] In an optional embodiment, after obtaining the effective slope angle, the central controller determines the tire adhesion according to the effective slope angle of each tire. Specifically, the slope directly affects the vertical load of the wheel and the available adhesion of the tire. The vertical load calculation after the slope is more complex, and the weight transfer needs to be considered. The central controller processes the mass, the longitudinal acceleration, the height of the center of mass and the wheelbase of the vehicle according to the longitudinal acceleration load transfer amount algorithm to obtain the longitudinal acceleration load transfer amount. The longitudinal acceleration load transfer amount algorithm is shown in the following formula (27):

[0251] (27)

[0252] In the above formula (27), the longitudinal acceleration load transfer amount of the i-th tire is denoted as the mass of the vehicle is denoted as the actual longitudinal deceleration of the vehicle is denoted as the gravitational acceleration is denoted as the wheelbase is denoted as the height of the center of mass is denoted as

[0253] ​​​​​The central controller calculates the load transfer amount based on the vehicle's mass, lateral acceleration, center of gravity height, and torque according to the load transfer amount algorithm. The load transfer amount algorithm is shown in formula (28) below:

[0254] (28)

[0255] In the above formula (28), Indicates the first Load transfer amount per tire. Indicates the mass of the vehicle. This indicates the lateral deceleration of the vehicle. It represents the acceleration due to gravity. For torque, The height of the center of mass.

[0256] The central controller processes the effective slope angle, wheelbase, mass, and distance from the front and rear axles to the centroid parameters according to the slope load variation algorithm to obtain the slope load variation value. The slope load variation algorithm is shown in the following formula (29):

[0257] (29)

[0258] In the above formula (29), Indicates the first The slope load variation value of each tire. Indicates the mass of the vehicle. This indicates the lateral deceleration of the vehicle. It represents the acceleration due to gravity. Wheelbase For the first The effective slope angle of each tire. These are the distance parameters from the front and rear axles to the center of mass.

[0259] Then, the central controller processes the static load longitudinal acceleration load transfer, load transfer, and slope load change value according to the vertical load algorithm to obtain the vertical load of the tire. The vertical load algorithm is shown in formula (30) below:

[0260] (30)

[0261] In the above formula (30), For the first The static load of each tire can be determined based on vehicle attribute data such as vehicle mass and axle load distribution ratio. Indicates the first The slope load variation value of each tire. Indicates the first The load transfer amount of the tire. The longitudinal acceleration load transfer amount of the tire is represented as The vertical load of the tire is represented as

[0262] The central controller performs data operation on the effective slope angle, the vertical load and the tire-road adhesion coefficient of the tire according to the friction upper limit algorithm to obtain the maximum longitudinal force of the tire, which is also the friction upper limit value. The friction upper limit algorithm is shown in the following formula (31):

[0263] (31)

[0264] In the above formula (31), the tire-road adhesion coefficient (which can be estimated by a traditional method or set as a conservative constant value) is represented as The vertical load of the tire is represented as The effective slope angle of the tire is represented as

[0265] In this embodiment, by determining the effective slope angle of each tire, it is convenient to subsequently solve the brake torque model according to the effective slope angle, thereby improving the solving speed of the brake torque model.

[0266] In an exemplary embodiment, after determining the brake torque, it is necessary to generate a control instruction according to the brake torque to control the operation of the vehicle. As shown in FIG. 8, after step 208 is executed, the specific processing process of the brake control method includes steps 1102 to 1106. Among them: Figure 11

[0267] Step 1102, the brake torque of the tire is sent to the angle module controller of the tire.

[0268] The angle module controller is used to distribute the brake torque into regenerative brake torque and friction brake torque based on the coordinated distribution strategy.

[0269] In implementation, the central controller directly sends the brake torque of each tire to the angle module controller corresponding to the tire. The angle module controller will distribute the brake torque into regenerative brake torque and friction brake torque according to the coordinated distribution strategy.

[0270] Specifically, the central controller directly sends the brake torque of each tire to the angle module controller corresponding to the tire. After the LMC receives the instruction, it performs execution layer distribution:

[0271] ​​​​​​​(1) Preferential use of regenerative braking: If the wheel is a drive wheel and the motor can provide regenerative braking, it is preferentially allocated. The strategy for preferential use of regenerative braking is shown in the following equation (32):

[0272] (32)

[0273] In the above equation (32), represents the total braking torque of the i-th tire. represents the demand. is the regenerative braking torque of the i-th tire. represents the maximum regenerative braking torque threshold that can be achieved when the wheel speed of the i-th tire is

[0274] (2) Friction braking compensation: The part not covered by regenerative braking is supplemented by friction braking, i.e., the following equation (33):

[0275] (33)

[0276] In the above equation (33), represents the total braking torque of the i-th tire. represents the demand. is the regenerative braking torque of the i-th tire, is the friction braking torque of the i-th tire.

[0277] (3) Smooth switching: To ensure smooth mode switching and eliminate torque jumps when switching between regenerative braking and friction braking modes, S-shaped functions are used for transition. The S-shaped function is shown in the following equation (34):

[0278] (34)

[0279] In the above equation (34), and are smoothing parameters that are adjusted according to factors such as battery SOC and wheel speed. Actual tests have shown that it can achieve a non-inductive switch within 50 ms with a deceleration fluctuation of less than 0.05g (g is the acceleration of gravity). represents the total braking torque of the i-th tire. represents the demand. is the regenerative braking torque of the i-th tire.

[0280] ​​​​​​​​​Step 1104: Receive the regenerative braking torque and friction braking torque returned by the corner module controller, and determine the target slip ratio.

[0281] In implementation, the central controller receives the regenerative braking torque and friction braking torque returned by the corner module controller. Then, the central controller determines the initial slip ratio based on the tire-road adhesion coefficient, and continuously corrects the initial slip ratio based on the vertical load caused by slope changes and the load transfer caused by longitudinal and lateral accelerations, ultimately determining the target slip ratio. .

[0282] Step 1106: Based on the target slip ratio, braking torque, regenerative braking torque and target tire slope, construct control commands and send the control commands to the corner module controller.

[0283] Among them, the control commands are used to instruct the corner module controller to control the vehicle's operation.

[0284] In implementation, the central controller generates control commands based on the target slip ratio, braking torque, regenerative braking torque, and target tire inclination. The central controller then sends these commands to the corresponding corner module controller for that tire. The corner module controller executes the control commands and feeds back the execution status (such as actual braking pressure, motor torque, and wheel speed) and ABS (anti-lock braking system) trigger events to the central controller for status updates and MPC optimization in the next control cycle.

[0285] In an optional embodiment, the central controller performs data calculations on the vehicle's state dataset, attribute dataset, and tire braking torque according to a speed iteration algorithm to obtain the vehicle's speed. The speed iteration algorithm is shown in the following formula (35):

[0286] (35)

[0287] In the above formula (35), for The longitudinal speed of the vehicle at any given moment. for The longitudinal speed of the vehicle at any given moment. Indicates vertical direction. Indicates the mass of the vehicle. It represents the acceleration due to gravity. This represents the average effective gradient of the four tires. The effective gradient can be determined based on the target tire gradient of the four tires. , This indicates the longitudinal braking force of each tire. Indicates the time of change. This indicates the total driving resistance.

[0288] The central controller performs data calculations on the vehicle's state dataset, attribute dataset, and tire braking torque based on the rotational speed (wheel speed) iterative algorithm to obtain the rotational speed of each tire. The rotational speed iterative algorithm is shown in the following formula (36):

[0289] (36)

[0290] In the above formula (36), express Time of the first The rotational speed of each tire, express Time of the first The rotational speed of each tire, express Time of the first Braking torque of each tire for Time of the first The longitudinal braking force of each tire, This is the effective radius of the vehicle. express Time of the first The driving torque of each tire Indicates the time of change. This refers to the wheel's rotational inertia. The central controller generates control commands based on vehicle speed, tire speed, target slip ratio, braking torque, regenerative braking torque, and target tire gradient.

[0291] In one exemplary embodiment, the central controller, when controlling the vehicle, also needs to consider low confidence levels and the setting of vehicle safety policies. Specifically:

[0292] (1) Low confidence handling: If the confidence of the slope estimate for a certain wheel is lower than the confidence threshold, then the adhesion constraint can be tightened for that wheel (reducing the confidence level). In addition, the regenerative braking weight in the MPC is reduced, and more braking force is allocated to the high-confidence wheels.

[0293] (2) MPC solution failure or communication error: Switch to a rule-based braking force distribution strategy based on a fixed ratio (such as static load distribution) and limit the total regenerative braking ratio (such as ≤30%).

[0294] (3) ABS / ESP (ABS is Anti-lock Braking System, ESP is Electronic Stability Program) intervention: When a wheel slips excessively, the ABS system is activated. After receiving this signal, the VCU immediately stops the regenerative braking of that wheel and coordinates the braking force of other wheels to compensate.

[0295] (4) BMS Limitation: If the battery temperature is too high or the SOC is full, the BMS will send a warning. If this is the case, the VCU will set all regenerative braking commands to zero, and the required braking force will be provided entirely by friction braking.

[0296] In this embodiment, the braking torque model determined based on real-time slope information is sent to the corner module controller to facilitate the corner module controller in allocating braking torque and optimizing the coordinated allocation of regenerative braking and friction braking.

[0297] In one exemplary embodiment, Figure 12 This is an architectural diagram of a braking system in an exemplary embodiment. Figure 12 As shown, the braking system includes a central controller, four corner module controllers (LMC1, LMC2, LMC3, and LMC4), a sensing system, and a force battery management system. The central controller interacts with the sensing system, each corner module controller, and the force battery management system. The central controller is used for total braking force calculation, slope dynamic sensing and fusion, MPC optimization solution (QP), and coordinated allocation decision-making, as well as for confidence-driven safety and degradation strategies.

[0298] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0299] Based on the same inventive concept, this application also provides a braking control device for implementing the braking control method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more braking control device embodiments provided below can be found in the limitations of the braking control method described above, and will not be repeated here.

[0300] In one exemplary embodiment, such as Figure 13As shown, a brake control device 1300 is provided, comprising an acquisition module 1301, a decomposition module 1302, a construction module 1303 and a determination module 1304, wherein:

[0301] The acquisition module 1301 is configured to acquire a unified slope value of the vehicle, an attribute data set and a state data set.

[0302] The decomposition module 1302 is configured to decompose the unified slope value according to the attribute data set and the state data set to obtain a target tire slope corresponding to each tire in the vehicle.

[0303] The construction module 1303 is configured to construct a tire braking torque model according to the target tire slope, and output a minimum tracking expected deceleration, a minimum braking torque change amount and a maximum energy recovery rate in a case where the braking torque model meets a preset constraint condition.

[0304] The determination module 1304 is configured to determine a braking torque of the tire based on the minimum tracking expected deceleration, the minimum braking torque change amount, the maximum energy recovery rate and the target tire slope.

[0305] In an example embodiment, the decomposition module 1302 comprises:

[0306] A first decomposition submodule is configured to decompose the unified slope value according to the attribute data set to obtain a tire environment slope of each tire in the vehicle.

[0307] A first update submodule is configured to update the tire environment slope according to the attribute data set and the state data set to obtain the target tire slope of the tire.

[0308] In an example embodiment, the attribute data set comprises a wheelbase and a track of the vehicle, and the first decomposition submodule is specifically configured to decompose the unified slope value to obtain an environment longitudinal slope pitch angle and an environment transverse slope roll angle; and determine the tire environment slope of each tire in the vehicle according to the environment longitudinal slope pitch angle, the environment transverse slope roll angle, the wheelbase and the track of the vehicle.

[0309] In an example embodiment, the first update submodule comprises:

[0310] A first determination submodule is configured to determine a tire state slope of each tire according to the state data set and the attribute data set.

[0311] A first fusion submodule is configured to fuse the tire state slope and the tire environment slope of the tire based on an extended Kalman filter to obtain the target tire slope of the tire and a confidence degree of the target tire slope.

[0312] In an example embodiment, the state data set comprises longitudinal acceleration of the vehicle, wheel speed of each tire, and driving force, the first determining submodule is specifically configured to determine an equivalent slope angle of the vehicle according to the driving force of each tire, the mass of the vehicle, and the longitudinal acceleration; determine a total longitudinal force of the vehicle on the slope according to the equivalent slope angle, the mass, and the longitudinal acceleration; for each tire, determine an initial tire state slope of the tire according to the pitch angle and the suspension displacement of the tire, and determine a tire state slope of the tire according to the initial tire state slope, the mass, and the total longitudinal force.

[0313] In an example embodiment, the constructing module 1303 comprises a first constructing submodule and a first output submodule. The first constructing submodule comprises:

[0314] The second constructing submodule is configured to, for each tire, construct a target function according to the target tire slope of the tire, with the target of minimizing the tracking expected deceleration, the target of minimizing the brake torque variation, and the target of maximizing the energy recovery rate.

[0315] The third constructing submodule is configured to construct each constraint condition of the target function according to attribute information of an actuator in the vehicle, available adhesion of the tire, and a charging power threshold of a battery.

[0316] The first combining submodule is configured to combine the target function and each constraint condition to obtain a brake torque model of the tire.

[0317] In an example embodiment, the attribute information of the actuator comprises a regenerative brake torque threshold and a friction brake torque threshold, and the third constructing submodule is specifically configured to construct a skid prevention constraint condition with the target of the brake force of the tire not exceeding the available adhesion; construct an attribute constraint condition with the target of the brake torque of the tire not exceeding the regenerative brake torque threshold and the target of the total regenerative brake power of each tire not exceeding the charging power threshold of the battery; and construct a demand constraint condition with the target of the brake torque of each tire satisfying a driving demand.

[0318] In an example embodiment, the constructing module 1303 comprises a first constructing submodule and a first output submodule. The first output submodule comprises:

[0319] The second determining submodule is configured to determine an effective slope average value according to each target tire slope.

[0320] The first analyzing submodule is configured to analyze the brake torque model according to the linear solver, the effective slope average value, the attribute data set, and the state data set to obtain values of the tracking expected deceleration, the brake torque variation, and the energy recovery rate.

[0321] In an example embodiment, the second determining sub-module is specifically configured to determine a conservative adjustment coefficient according to the confidence of the target tire slope of each tire; determine the effective slope angle of the tire based on the target tire slope, the confidence and the conservative adjustment coefficient; and perform mean processing on the effective slope angles of the tires to obtain an effective slope average value.

[0322] In an example embodiment, the brake control device further comprises:

[0323] The first sending module is configured to send the tire braking torque to the corner module controller of the tire; and the corner module controller is configured to distribute the braking torque into the regenerative braking torque and the friction braking torque based on the coordination distribution strategy.

[0324] The receiving module is configured to receive the regenerative braking torque and the friction braking torque returned by the corner module controller and determine the target slip ratio.

[0325] The second sending module is configured to construct a control instruction according to the target slip ratio, the braking torque, the regenerative braking torque and the target tire slope, and send the control instruction to the corner module controller; and the control instruction is configured to instruct the corner module controller to control the vehicle to operate.

[0326] The above-mentioned modules in the brake control device can be realized by software, hardware and combinations thereof in whole or in part. The above-mentioned modules can be embedded in or independent of the processor in the computer device in hardware form, or can be stored in the memory in the computer device in software form, so as to be called and executed by the processor to perform the operations corresponding to the above-mentioned modules.

[0327] In an example embodiment, a computer device is provided, which can be a server, and an internal structure diagram thereof can be as shown in Figure 14 The computer device includes a processor, a memory, an input / output interface (I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The database of the computer device is configured to store data used by the brake control method. The input / output interface of the computer device is configured to exchange information between the processor and external devices. The communication interface of the computer device is configured to communicate with external terminals through network connection. The computer program is executed by the processor to implement a brake control method.

[0328] Those skilled in the art can understand that,Figure 14 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0329] In an embodiment, a computer device is also provided, including a memory and a processor, the memory storing a computer program, and the processor implementing the steps in the above method embodiments when executing the computer program.

[0330] In an embodiment, a computer readable storage medium is provided, storing a computer program, and the computer program implementing the steps in the above method embodiments when executed by a processor.

[0331] In an embodiment, a computer program product is provided, including a computer program, and the computer program implementing the steps in the above method embodiments when executed by a processor.

[0332] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiment methods. Any reference to memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. The non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. The volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, the RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central controller, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., without being limited thereto.

[0333] The technical features of the above embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application.

[0334] The above-described embodiments are merely illustrative of several embodiments of the present application, and the description is relatively specific and detailed, but should not be understood as a limitation on the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A braking control method, characterized in that, The method includes: Obtain the vehicle's uniform slope value, attribute dataset, and status dataset; Based on the attribute dataset and the state dataset, the uniform slope value is decomposed to obtain the target tire slope corresponding to each tire in the vehicle. Based on the target tire slope, a braking torque model of the tire is constructed, and under the condition that the braking torque model meets the preset constraints, the minimum expected tracking deceleration, the minimum braking torque change, and the maximum energy recovery rate are output. The braking torque of the tire is determined based on the minimum expected tracking deceleration, the minimum change in braking torque, the maximum energy recovery rate, and the target tire slope.

2. The method according to claim 1, characterized in that, The step of decomposing the uniform slope value based on the attribute dataset and the state dataset to obtain the target tire slope corresponding to each tire in the vehicle includes: Based on the attribute dataset, the uniform slope value is decomposed to obtain the tire environmental slope of each tire in the vehicle. Based on the attribute dataset and the state dataset, the tire environmental slope is updated to obtain the target tire slope.

3. The method according to claim 2, characterized in that, The attribute dataset contains the vehicle's wheelbase and track width. The step of decomposing the uniform slope value based on the attribute dataset to obtain the tire environmental slope of each tire in the vehicle includes: By decomposing the uniform slope value, the longitudinal slope pitch angle and the transverse slope tilt angle of the environment are obtained; The tire environmental slope of each tire in the vehicle is determined based on the longitudinal slope pitch angle, the lateral slope roll angle, the wheelbase, and the track width.

4. The method according to claim 2, characterized in that, The step of updating the tire environmental slope based on the attribute dataset and the state dataset to obtain the target tire slope includes: Based on the state dataset and the attribute dataset, determine the tire state slope of each tire; Based on the extended Kalman filter, the tire state slope and the tire environment slope of the tire are fused to obtain the target tire slope and the confidence level of the target tire slope.

5. The method according to claim 4, characterized in that, The state dataset includes the vehicle's longitudinal acceleration, the wheel speed of each tire, and the driving force. Determining the tire state slope of each tire based on the state dataset and the attribute dataset includes: The equivalent slope angle of the vehicle is determined based on the driving force of each tire, the mass of the vehicle, and the longitudinal acceleration. The total longitudinal force of the vehicle on the slope is determined based on the equivalent slope angle, the mass, and the longitudinal acceleration. For each tire, the initial tire state slope is determined based on the tire's pitch angle and suspension displacement, and the tire state slope is further determined based on the initial tire state slope, the mass, and the total longitudinal force.

6. The method according to claim 1, characterized in that, The step of constructing the braking torque model of the tire based on the target tire slope includes: For each tire, with the objectives of minimizing the desired tracking deceleration, minimizing the change in braking torque, and maximizing the energy recovery rate, an objective function is constructed based on the target tire slope of the tire. Based on the attribute information of the actuators in the vehicle, the available adhesion of the tires, and the charging power threshold of the battery, the constraints of the objective function are constructed. By combining the objective function and each of the constraints, the braking torque model of the tire is obtained.

7. The method according to claim 6, characterized in that, The actuator's attribute information includes a regenerative braking torque threshold and a frictional braking torque threshold. The constraints for constructing the objective function based on the actuator's attribute information, the tire's available adhesion, and the battery's charging power threshold include: Anti-skid constraint conditions are constructed with the goal of ensuring that the braking force of the tire does not exceed the available adhesion. With the objectives of ensuring that the braking torque of the tires does not exceed the regenerative braking torque threshold and that the total regenerative braking power of each tire does not exceed the charging power threshold of the battery, attribute constraints are constructed. With the goal of ensuring that the braking torque of each tire meets driving requirements, demand constraints are constructed.

8. The method according to claim 1, characterized in that, When the braking torque model satisfies preset constraints, the output includes the minimum expected tracking deceleration, the minimum braking torque change, and the maximum energy recovery rate, including: Determine the average effective slope based on the target tire slope described above; Based on the linear solver, the effective slope average value, the attribute dataset, and the state dataset, the braking torque model is analyzed to obtain the values ​​of the tracking desired deceleration, the change in braking torque, and the energy recovery rate.

9. The method according to claim 8, characterized in that, The step of determining the effective slope average value based on the slope of each target tire includes: Based on the confidence level of the target tire slope for each tire, a conservative adjustment factor is determined; The effective slope angle of the tire is determined based on the target tire slope, the confidence level, and the conservative adjustment coefficient. The effective slope angles of each tire are averaged to obtain the average effective slope.

10. The method according to claim 1, characterized in that, After determining the braking torque of the tire based on the minimum expected tracking deceleration, the minimum change in braking torque, the maximum energy recovery rate, and the target tire slope, the method further includes: The braking torque of the tire is sent to the corner module controller of the tire; the corner module controller is used to allocate the braking torque into regenerative braking torque and friction braking torque based on a coordinated allocation strategy; Receive the regenerative braking torque and the friction braking torque returned by the corner module controller, and determine the target slip ratio; Based on the target slip ratio, the braking torque, the regenerative braking torque, and the target tire slope, a control command is constructed and sent to the corner module controller; the control command is used to instruct the corner module controller to control the operation of the vehicle.

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