CN-118665423-B - Vehicle turning braking force distribution method and device, electronic equipment and storage medium

CN118665423BCN 118665423 BCN118665423 BCN 118665423BCN-118665423-B

Abstract

The application provides a vehicle turning braking force distribution method and device, electronic equipment and a storage medium, and can be applied to the technical field of vehicle brake-by-wire. According to the application, when the turning braking demand information is detected, the real-time state information of the vehicle is obtained, then the initial braking force distribution is carried out on the vehicle according to the longitudinal lateral acceleration and the first braking pedal displacement in the real-time state information, then the first longitudinal vehicle speed and the first steering wheel corner in the real-time state information are input into the linear two-degree-of-freedom automobile model, the second yaw rate and the second centroid lateral angle of the vehicle are obtained, and then the additional yaw moment of the vehicle is calculated according to the first yaw rate, the first centroid lateral angle, the second yaw rate and the second centroid lateral angle, and then the secondary braking force distribution is carried out on the vehicle according to the additional yaw moment.

Inventors

ZHANG PEI
Cheng Binwei
HU JIE
YAN FUWU
ZHANG KEFAN
You Zhanpeng
Rong Feiyue

Assignees

武汉理工大学

Dates

Publication Date: 20260505
Application Date: 20240724

Claims (8)

1. A vehicle turning brake force distribution method, characterized in that the method comprises the steps of: When turning braking demand information is detected, acquiring real-time state information of a vehicle, wherein the real-time state information comprises a first yaw rate, a first centroid lateral angle, a first longitudinal vehicle speed, a first steering wheel corner, a first brake pedal displacement and a longitudinal lateral acceleration; Performing an initial braking force distribution on the vehicle based on the longitudinal lateral acceleration and the first brake pedal displacement; inputting the first longitudinal speed and the first steering wheel corner into a linear two-degree-of-freedom automobile model to obtain a second yaw rate and a second centroid lateral angle of the vehicle; calculating an additional yaw moment of the vehicle from the first yaw rate, the first centroid offset angle, the second yaw rate, and the second centroid offset angle; Performing a secondary braking force distribution to the vehicle according to the additional yaw moment, the secondary braking force distribution comprising: The secondary distribution amount of each wheel braking force is calculated by the following formula: M, wherein, the total number of the components is equal to the total number of the components, Representing an additional yaw moment of the vehicle, The rotation angle of the front wheel is represented, B represents the track of the automobile; The following constraints are satisfied: when the additional yaw moment is positive, the longitudinal forces of the left wheels satisfy: Wherein i=f, r; Assigning a value to an initial braking force of the left wheel; A value is assigned to the secondary braking force of the left wheel, Represents the road adhesion coefficient of the left front and rear wheels, Representing left wheel vertical load; When the additional yaw moment is positive, the longitudinal force of the right wheel satisfies: Wherein i=f, r; Assigning a value to an initial braking force of the right wheel; A value is distributed to the secondary braking force of the right wheel; when the additional yaw moment is negative, the longitudinal force of the left wheel satisfies: Wherein i=f, r; Assigning a value to an initial braking force of the left wheel; assigning a value to the secondary braking force of the left wheel; when the additional yaw moment is negative, the longitudinal force of the right wheel satisfies: Wherein i=f, r; A value is assigned to the initial braking force of the right wheel, A value is assigned to the secondary braking force of the right wheel, For the vertical load of the right-hand wheel, The road adhesion coefficient of the front and rear wheels on the right side; meanwhile, the secondary braking force distribution also meets the relation between the longitudinal force and the lateral force of the constraint tire based on the tire attachment elliptical model, the longitudinal force equal to the secondary distribution of the left and right wheels of the whole vehicle is taken as an optimization target, and the secondary braking force distribution is solved through a sequential quadratic programming method; in the secondary braking force distribution process, the flow of the initial braking force distribution-the additional yaw moment calculation-the secondary braking force distribution is continuously and circularly performed until the braking release requirement is detected.
2. The method of claim 1, wherein said initially braking force distribution of the vehicle as a function of said longitudinal lateral acceleration and said first brake pedal displacement comprises: Calculating the vertical load of each wheel according to the longitudinal lateral acceleration; calculating the proportion of the vertical load of each wheel; calculating a desired braking deceleration from the first brake pedal displacement; calculating a desired braking force according to the desired braking deceleration; And performing initial braking force distribution on the vehicle according to the proportion of the vertical load of each wheel and the expected braking force.
3. The method of claim 2, wherein the vertical load of each wheel is calculated as: ; wherein a represents the front wheelbase, b represents the rear wheelbase, Representing the height of the centroid, The wheel track of the front wheel is indicated, The wheel track of the rear wheel is indicated, Indicating the longitudinal acceleration of the vehicle, Indicating the lateral acceleration of the vehicle, Representing the vertical load of the left front wheel, Representing the vertical load of the right front wheel, Representing the vertical load of the left rear wheel, The vertical load of the right rear wheel is represented, m represents the mass of the whole vehicle, and g represents the gravitational acceleration.
4. A method according to claim 3, characterized in that the calculation formula of the desired braking force is as follows: ; Wherein, the Is a desired braking deceleration; is the desired braking force; the initial braking force calculation formula for each wheel is as follows: ; Wherein, the A left front wheel braking force initially allocated; a right front wheel braking force initially allocated; left rear wheel braking force for initial distribution; For the initially assigned left rear wheel brake force.
5. The method of claim 4, wherein said inputting the first longitudinal vehicle speed and the first steering wheel angle into a linear two-degree-of-freedom automobile model results in a second yaw rate and a second centroid yaw angle of the vehicle, comprising: the second yaw rate is calculated by the following formula: ; Calculating the second centroid offset angle by the formula: ; Wherein, the Representing the second yaw rate, Representing the second centroid offset angle, Represents the road adhesion coefficient and, The rotation angle of the front wheel is represented, For the longitudinal speed of the car, Indicating the cornering stiffness of the front axle, Represents the cornering stiffness of the rear axle, K represents a stability factor, L represents the wheelbase of the car, l=a+b, g represents the gravitational acceleration.
6. A vehicle turning brake force distribution device, characterized in that the device comprises: the first module is used for acquiring real-time state information of the vehicle when the turning braking demand information is detected, wherein the real-time state information comprises a first yaw rate, a first centroid lateral angle, a first longitudinal vehicle speed, a first steering wheel angle, a first brake pedal displacement and a longitudinal lateral acceleration; a second module for initial braking force distribution of the vehicle as a function of said longitudinal lateral acceleration and said first brake pedal displacement; The third module is used for inputting the first longitudinal speed and the first steering wheel angle into a linear two-degree-of-freedom automobile model to obtain a second yaw rate and a second centroid lateral angle of the automobile; a fourth module for calculating an additional yaw moment of the vehicle based on the first yaw rate, the first centroid offset angle, the second yaw rate, and the second centroid offset angle; a fifth module for performing a secondary braking force distribution to the vehicle according to the additional yaw moment, the secondary braking force distribution including calculating a secondary distribution amount of braking force of each wheel by the following formula: M, wherein, the total number of the components is equal to the total number of the components, Representing an additional yaw moment of the vehicle, The rotation angle of the front wheel is represented, Respectively representing the secondary distribution value of the braking force of each wheel, B representing the track of the automobile, and meeting the following constraint conditions: when the additional yaw moment is positive, the longitudinal forces of the left wheels satisfy: Wherein i=f, r; Assigning a value to an initial braking force of the left wheel; A value is assigned to the secondary braking force of the left wheel, Represents the road adhesion coefficient of the left front and rear wheels, Representing left wheel vertical load; When the additional yaw moment is positive, the longitudinal force of the right wheel satisfies: Wherein i=f, r; Assigning a value to an initial braking force of the right wheel; A value is distributed to the secondary braking force of the right wheel; when the additional yaw moment is negative, the longitudinal force of the left wheel satisfies: Wherein i=f, r; Assigning a value to an initial braking force of the left wheel; assigning a value to the secondary braking force of the left wheel; when the additional yaw moment is negative, the longitudinal force of the right wheel satisfies: Wherein i=f, r; A value is assigned to the initial braking force of the right wheel, A value is assigned to the secondary braking force of the right wheel, For the vertical load of the right-hand wheel, The road adhesion coefficient of the front and rear wheels on the right side; Meanwhile, the secondary braking force distribution further meets the relation of restraining the longitudinal force and the lateral force of the tire based on the tire attachment elliptical model, the longitudinal force equal to the longitudinal force distributed secondarily by the left and right wheels of the whole vehicle is used as an optimization target, the secondary braking force distribution is solved through a sequential quadratic programming method, and in the secondary braking force distribution process, the flow of initial braking force distribution, additional yaw moment calculation and secondary braking force distribution is continuously and circularly executed until the braking release requirement is detected.
7. An electronic device, comprising: At least one processor; At least one memory for storing at least one program; The at least one program, when executed by the at least one processor, causes the at least one processor to implement the method of any one of claims 1 to 5.
8. A computer readable storage medium storing a computer program, characterized in that the computer program, when executed by a processor, implements the method of any one of claims 1 to 5.

Description

Vehicle turning braking force distribution method and device, electronic equipment and storage medium Technical Field The present application relates to the field of brake-by-wire technology of vehicles, and in particular, to a method and an apparatus for distributing a turning braking force of a vehicle, an electronic device, and a storage medium. Background In the related art, the braking force distribution method for the brake-by-wire vehicle during turning braking mainly comprises two types, namely a vertical load-based distribution method, namely, distributing braking force according to the proportion of the vertical load of each wheel, and a multi-objective optimization-based distribution method, namely, distributing the braking force of four wheels by setting an optimization objective function and constraint conditions. The first type of distribution method distributes initial braking force according to the vertical load proportion of each wheel, and then adds braking force required for generating additional yaw moment, in this case, locking of one wheel due to excessive braking may occur, and the second type of distribution method may not meet the requirements of braking force and yaw moment at the same time, so that no solution may occur in the process of solving the optimization target type. It is known that both the distribution methods have low stability and safety during running of the vehicle. In summary, the technical problems in the related art are to be improved. Disclosure of Invention The embodiment of the application mainly aims to provide a vehicle turning braking force distribution method and device, electronic equipment and a storage medium, which can effectively improve the stability and safety of a vehicle in the running process. To achieve the above object, an aspect of an embodiment of the present application provides a vehicle turning braking force distribution method, including the steps of: When turning braking demand information is detected, acquiring real-time state information of a vehicle, wherein the real-time state information comprises a first yaw rate, a first centroid lateral angle, a first longitudinal vehicle speed, a first steering wheel corner, a first brake pedal displacement and a longitudinal lateral acceleration; Performing an initial braking force distribution on the vehicle based on the longitudinal lateral acceleration and the first brake pedal displacement; inputting the first longitudinal speed and the first steering wheel corner into a linear two-degree-of-freedom automobile model to obtain a second yaw rate and a second centroid lateral angle of the vehicle; calculating an additional yaw moment of the vehicle from the first yaw rate, the first centroid offset angle, the second yaw rate, and the second centroid offset angle; And performing secondary braking force distribution on the vehicle according to the additional yaw moment. In some embodiments, said initially braking force distribution of the vehicle as a function of said longitudinal lateral acceleration and said first brake pedal displacement comprises: Calculating the vertical load of each wheel according to the longitudinal lateral acceleration; calculating the proportion of the vertical load of each wheel; calculating a desired braking deceleration from the first brake pedal displacement; calculating a desired braking force according to the desired braking deceleration; And performing initial braking force distribution on the vehicle according to the proportion of the vertical load of each wheel and the expected braking force. In some embodiments, the vertical load of each wheel is calculated as follows: Wherein a represents a front wheel base, B represents a rear wheel base, h represents a mass center height, B f represents a front wheel track, B r represents a rear wheel track, a x represents a longitudinal acceleration, a y represents a lateral acceleration, F z_fl represents a left front wheel vertical load, F z_fr represents a right front wheel vertical load, F z_rl represents a left rear wheel vertical load, F z_rr represents a right rear wheel vertical load, m represents a vehicle mass, and g represents a gravitational acceleration. In some embodiments, the calculation formula of the desired braking force is as follows: Fd＝m·ad; Wherein a d is a desired braking deceleration, F d is a desired braking force; the initial braking force calculation formula for each wheel is as follows: wherein F 'x_fl is the initial distribution left front wheel braking force, F' x_fr is the initial distribution right front wheel braking force, F 'x_rl is the initial distribution left rear wheel braking force, and F' x_rr is the initial distribution left rear wheel braking force. In some embodiments, the inputting the first longitudinal vehicle speed and the first steering wheel angle into a linear two-degree-of-freedom automobile model to obtain a second yaw rate and a second centroid yaw angle of the vehicl