Vehicle braking method, device, controller and vehicle

Abstract

The application discloses a vehicle braking method, device, controller and vehicle, and belongs to the technical field of vehicles. In the case that a braking system of a vehicle fails, the steering angle of at least one group of wheels of the vehicle is adjusted based on the braking pedal stroke and the steering wheel corner of the vehicle, so as to perform redundant braking on the vehicle. In the case that the steering wheel corner is a target corner, the adjusted steering angle of a first wheel and the adjusted steering angle of a second wheel in the at least one group of wheels are opposite numbers. Or, in the case that the steering wheel corner is not a target corner, the adjusted steering angle of the first wheel and the adjusted steering angle of the second wheel in the at least one group of wheels are opposite and different in absolute value. The flexibility, safety and practicability of the redundant braking of the independent steering system are improved, so that the effect of intelligent driving is improved.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, specifically to vehicle braking methods, devices, controllers, and vehicles. Background Technology

[0002] A vehicle's braking system is a device that applies resistance to slow down and stop the vehicle. When the braking system fails, redundant braking can be achieved through an independent steering system. The principle of redundant braking with an independent steering system is as follows: when the vehicle's braking system fails, the wheels actively steer. The wheels on the same axle rotate in opposite directions, so that during vehicle movement, the steering wheels experience lateral friction from the ground. Furthermore, the lateral friction forces of the coaxial wheels rotating in opposite directions are superimposed in the vehicle's direction of travel and weakened in the lateral direction, allowing the vehicle to achieve redundant braking while maintaining its direction of travel, ideally.

[0003] However, the redundant braking of current independent steering systems suffers from low flexibility, safety, and practicality. Summary of the Invention

[0004] This application provides a vehicle braking method, device, controller, and vehicle, aiming to improve the flexibility, safety, and practicality of redundant braking in an independent steering system.

[0005] In a first aspect, embodiments of this application provide a vehicle braking method, including: In the event of a failure of the vehicle's braking system, the steering angle of at least one set of wheels of the vehicle is adjusted based on the brake pedal travel and steering wheel angle of the vehicle to perform redundant braking on the vehicle. Wherein, when the steering wheel angle is the target angle, the adjusted steering angle of the first wheel and the adjusted steering angle of the second wheel in the at least one set of wheels are opposite numbers. Alternatively, if the steering wheel angle is not the target angle, the adjusted steering angle of the first wheel and the adjusted steering angle of the second wheel in at least one set of wheels are opposite and have different absolute values.

[0006] Optionally, adjusting the steering angle of at least one set of wheels of the vehicle based on the brake pedal travel and steering wheel angle includes: Based on the brake pedal travel of the vehicle, the target deceleration is determined, and based on the steering wheel angle, the target yaw rate is determined. Based on the rotational range of at least one set of wheels, multiple candidate steering angle combinations are determined, and each candidate steering angle combination includes the candidate steering angles of at least one set of wheels. Determine the expected deceleration and expected yaw rate for each of the above candidate steering angle combinations; Based on the target deceleration, the expected deceleration, the target yaw rate, and the expected yaw rate, an adjusted steering angle is determined from a plurality of candidate steering angle combinations, and the steering angle of at least one set of wheels of the vehicle is adjusted based on the adjusted steering angle.

[0007] Optionally, based on the rotational range of at least one set of wheels, the above-mentioned determination of multiple candidate steering angle combinations includes: Based on the brake pedal travel of the vehicle, an initial steering angle combination is determined, wherein the initial steering angle of the first wheel and the initial steering angle of the second wheel in at least one set of wheels in the initial steering angle combination are opposite numbers. Based on the aforementioned steering wheel angle, the rotational range of at least one set of wheels, and the aforementioned initial steering angle combination, multiple candidate steering angle combinations are determined.

[0008] Optionally, based on the steering wheel angle, the rotational range of at least one set of wheels, and the initial steering angle combination, multiple candidate steering angle combinations are determined, including: Based on the rotational range of at least one set of wheels, the initial steering angle in the above initial steering angle combination is adjusted to obtain the first candidate steering angle combination. Based on the above first candidate steering angle combination, the first candidate lateral friction force of the above at least one set of wheels is determined; If the direction of the resultant torque of the first candidate lateral friction force acting on the center of mass of the vehicle is consistent with the rotation direction indicated by the steering wheel angle, the first candidate steering angle combination is determined as the candidate steering angle combination.

[0009] Optionally, based on the rotational range of at least one set of wheels, the above-mentioned determination of multiple candidate steering angle combinations includes: From the rotatable range of the at least one set of wheels, multiple candidate steering angle combinations are selected, wherein in each candidate steering angle combination, the candidate steering angle of the first wheel and the candidate steering angle of the second wheel in the at least one set of wheels are opposite numbers, and / or, in each candidate steering angle combination, the candidate steering angle of the first wheel and the candidate steering angle of the second wheel are opposite and have different absolute values.

[0010] Optionally, the determination of the adjusted steering angle from multiple candidate steering angle combinations based on the target deceleration, the expected deceleration, the target yaw rate, and the expected yaw rate includes: Based on the target deceleration and the expected deceleration mentioned above, the velocity difference is determined; Based on the target yaw rate and the expected yaw rate, the yaw rate difference is determined; Based on the aforementioned speed differences and yaw angle differences, the total difference is determined; Based on the above total differences, the adjusted steering angle is determined from multiple candidate steering angle combinations.

[0011] Optionally, if the aforementioned brake pedal travel is not collected, the aforementioned brake pedal travel is the maximum pedal travel of the aforementioned vehicle.

[0012] Optionally, adjusting the steering angle of at least one set of wheels of the vehicle based on the brake pedal travel and steering wheel angle includes: Obtain the vehicle dynamics equations corresponding to the above vehicles; Based on the brake pedal travel, steering wheel angle, and vehicle dynamics equations of the aforementioned vehicle, the steering angle of at least one set of wheels of the aforementioned vehicle is adjusted.

[0013] Optionally, adjusting the steering angle of at least one set of wheels of the vehicle based on the brake pedal travel and steering wheel angle includes: When the vehicle's condition meets the preset redundant braking conditions, the steering angle of at least one set of wheels of the vehicle is adjusted based on the vehicle's brake pedal travel and steering wheel angle.

[0014] Optionally, the aforementioned preset redundant braking conditions include at least one of the following: the vehicle's attitude information does not exceed an attitude threshold, the vehicle's speed information does not exceed a first speed threshold, the vehicle's accelerator pedal travel is less than or equal to a travel threshold, and the difference between the vehicle's target yaw rate and the vehicle's expected yaw rate is less than or equal to a difference threshold.

[0015] Optionally, the aforementioned at least one set of wheels includes a set of independently controllable wheels symmetrically arranged on the aforementioned vehicle.

[0016] Secondly, embodiments of this application provide a vehicle braking device, comprising: Braking system, used to brake the aforementioned vehicle; An independent steering system is used to execute the vehicle braking method provided in the embodiments of this application in the event of failure of the aforementioned braking system.

[0017] Thirdly, embodiments of this application also provide a controller, including: a memory storing a computer program thereon; and a processor for executing the computer program in the memory to implement the vehicle braking method provided in embodiments of this application.

[0018] Fourthly, embodiments of this application also provide a vehicle, including a braking device for the vehicle provided in embodiments of this application, or a controller provided in embodiments of this application, or braking is achieved through a braking method provided in embodiments of this application.

[0019] Fifthly, this application also provides a computer-readable storage medium having a computer program stored thereon, the computer program being loaded by a processor to perform the steps of the vehicle braking method provided in this embodiment.

[0020] Sixthly, this application also provides a computer program product, including a computer program or instructions, which, when executed by a processor, implement the steps of the vehicle braking method provided in this embodiment.

[0021] Beneficial Effects: In the event of a vehicle's braking system failure, this embodiment adjusts the steering angle of at least one set of wheels based on the vehicle's brake pedal travel and steering wheel angle to perform redundant braking. Specifically, when the steering wheel angle is the target angle, the adjusted steering angles of the first wheel and the second wheel in the at least one set of wheels are opposite; or, when the steering wheel angle is not the target angle, the adjusted steering angles of the first wheel and the second wheel in the at least one set of wheels are opposite and have different absolute values. This ensures that the resultant force information of the lateral friction force of the at least one set of wheels at the adjusted steering angle matches the braking intensity indicated by the brake pedal travel and the steering requirement indicated by the steering wheel angle. This allows the driver to control the braking intensity and direction of the redundant braking, improving braking flexibility and practicality, and preventing vehicle slippage and instability, thus enhancing braking safety. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of redundant braking performed by an independent steering system provided in an exemplary embodiment of this disclosure; Figure 2 This is a schematic flowchart of a vehicle braking method provided by an exemplary embodiment of this disclosure; Figure 3 This is a schematic diagram of the lateral friction force, the resultant force of the lateral friction force, and the resultant torque of the lateral friction force in a four-wheel independent steering system provided by an exemplary embodiment of this disclosure; Figure 4This is a schematic diagram of the lateral friction force, the resultant force of the lateral friction force, and the resultant torque of the lateral friction force in the front wheel independent steering system provided by an exemplary embodiment of this disclosure; Figure 5 This is a schematic diagram of the lateral friction force, the resultant force of the lateral friction force, and the resultant torque of the lateral friction force in the rear wheel independent steering system provided by an exemplary embodiment of this disclosure; Figure 6 This is a schematic diagram illustrating the process of determining whether a preset redundant braking condition is met, provided by an exemplary embodiment of this disclosure. Figure 7 This is another schematic flowchart of a vehicle braking method provided by an exemplary embodiment of this disclosure; Figure 8 This is a schematic diagram of the vehicle architecture provided by an exemplary embodiment of this disclosure; Figure 9 This is a schematic diagram of a vehicle provided by an exemplary embodiment of this disclosure. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0027] The use of "applies to" or "configured to" in this application implies open and inclusive language, which does not exclude the applicability to or configuration to devices performing additional tasks or steps. Additionally, the use of "based on" implies openness and inclusivity, because processes, steps, calculations, or other actions "based on" one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0028] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0029] The following reference Figure 1 The principle of redundant braking for independent steering systems will be explained.

[0030] The vehicle's direction of travel is x-axis. The left front wheel 101 turns left with a steering angle of a1, the right front wheel 102 turns right with a steering angle of a1, the left rear wheel 103 turns right with a steering angle of a2, and the right rear wheel 104 turns left with a steering angle of a2. The steering angle is the angle between the wheel's velocity Vx in the x-axis (the vehicle's forward direction) and its velocity Vr after turning at the same time. The steering angle of the left front wheel 101 is the same as that of the right front wheel 102, both a1, but in different directions. Under the control of their respective independent motors, the left front wheel 101 and the right front wheel 102 turn outwards from the vehicle, as shown below. Figure 1As shown, the left front wheel 101 turns left, and the right front wheel 102 turns right. For the left front wheel 101, its speed along the x-direction is Vx1, its speed in the direction after turning is Vr1, and its speed in the direction perpendicular to the direction after turning is Vy1. For the right front wheel 102, its speed along the x-direction is also Vx1, its speed in the direction after turning is Vr1, and its speed in the direction perpendicular to the direction after turning is Vy1. The speeds of the left front wheel 101 and the right front wheel 102 are indicated by the same symbol only for simplicity, but it should be understood that the directions of Vr1 and Vy1 differ due to the different turns of the left and right front wheels 101 and 102. The steering angle of the left rear wheel 103 is the same as that of the right rear wheel 104, a2, but in different directions. Under the control of their respective independent motors, the left rear wheel 103 and the right rear wheel 104 turn towards the inside of the vehicle, as shown... Figure 1 As shown, the left rear wheel 103 turns right, and the right rear wheel 104 turns left. For the left rear wheel 103, its speed along the x-direction is Vx2, its speed in the direction after turning is Vr2, and its speed in the direction perpendicular to the direction after turning is Vy2. For the right rear wheel 104, its speed along the x-direction is also Vx2, its speed in the direction after turning is Vr2, and its speed in the direction perpendicular to the direction after turning is Vy2. The speeds of the left rear wheel 103 and the right rear wheel 104 are indicated by the same symbol only for simplicity, to illustrate that they are equal in magnitude. However, it should be understood that the directions of Vr2 and Vy2 differ because the left rear wheel 103 and the right rear wheel 104 are turning differently.

[0031] The lateral friction force of the wheel is Fs. For the left front wheel 101, its lateral friction force is Fs1. L, the lateral friction force Fs1 L points outward from the vehicle and is perpendicular to the direction in which the left front wheel 101 turns backward; for the right front wheel 102, its lateral friction force is Fs1. R, the lateral friction force Fs1 R points outward from the vehicle and is perpendicular to the direction in which the right front wheel 102 turns backward; for the left rear wheel 103, its lateral friction force is Fs2. L, the frictional force Fs2 L is oriented towards the vehicle and perpendicular to the direction in which the left rear wheel 103 turns; for the right rear wheel 104, its lateral friction force is Fs2. R, the lateral friction force Fs2 R is directed towards the vehicle and perpendicular to the direction the right rear wheel 104 is turning. Lateral friction force Fs1 The component of force L along the y-axis, Fy1, and the lateral friction force, Fs1 The component of force R along the y-axis, Fy1, is equal in magnitude and opposite in direction, thus canceling each other out. Therefore, the lateral friction force is Fs1. L and frictional force Fs1 The resultant force of R is the sum of their resultant forces Fb1 and Fb1 along the x-axis, that is, the lateral friction force is Fs1. L and frictional force Fs1 The resultant force R is along the negative x-axis and has a magnitude of 2. The force is Fb1. The lateral frictional force is Fs2. The component of force L along the y-axis, Fy2, and the lateral friction force, Fs2 The component of force R along the y-axis, Fy2, is equal in magnitude and opposite in direction, thus canceling each other out. Therefore, the lateral friction force is Fs2. L and lateral friction force Fs2 The resultant force of R is the sum of their resultant forces along the x-axis, Fb2 and Fb2, that is, the lateral friction force is Fs2. L and lateral friction force Fs2 The resultant force R is along the negative x-axis and has a magnitude of 2. The force Fb2. Ultimately, the braking force used to brake the vehicle is along the negative x-axis and has a magnitude of "2". Fb1+2 The force of "Fb2". It is understandable that... Figure 1 The same symbols are used to indicate the velocities and forces in all directions of the left front wheel 101 and the right front wheel 102, simply to show that they are equal in magnitude. However, it should be understood that their respective directions differ due to the different steering of the left front wheel 101 and the right front wheel 102. A similar approach is applied to the left rear wheel 103 and the right rear wheel 104.

[0032] Based on the above, although the independent steering system can perform redundant braking, it lacks steering operation function, which may cause the vehicle to veer off course, skid, and become unstable, reducing the flexibility, practicality, and safety of the independent steering system in performing redundant braking.

[0033] To address this technical problem, in this embodiment, in the event of a vehicle's braking system failure, the steering angle of at least one set of wheels is adjusted based on the vehicle's brake pedal travel and steering wheel angle to provide redundant braking. This ensures that the resultant force information of the lateral friction of at least one set of wheels at the adjusted steering angle matches the braking intensity indicated by the brake pedal travel and the steering requirements indicated by the steering wheel angle. This allows the driver to control the braking intensity and direction of the redundant braking, improving braking flexibility and practicality, and preventing vehicle swerving and instability, thus enhancing braking safety. Specific embodiments will be described below.

[0034] On the one hand, this embodiment provides a vehicle braking method, such as Figure 2 As shown, it includes: S201: In the event of a failure of the vehicle's braking system, adjust the steering angle of at least one set of the vehicle's wheels based on the vehicle's brake pedal travel and steering wheel angle to provide redundant braking to the vehicle.

[0035] Wherein, vehicle braking system failure refers to a malfunction in the vehicle's braking system that prevents the system from decelerating or stopping based on the driver's commands. The vehicle's braking system may include at least one of the following: friction braking, which converts kinetic energy into heat energy via friction brakes, and regenerative braking, which recovers kinetic energy and converts it into electrical energy. Optionally, vehicle braking system failure may be determined when the braking systems of at least one front wheel and at least one rear wheel fail.

[0036] Of the four wheels of a vehicle, some can be independently controlled for steering. For example, the steering of the left front wheel and the right front wheel can be independently controlled, and / or the steering of the left rear wheel and the right rear wheel can be independently controlled. This application does not limit the scope of this embodiment. When the steering of the left front wheel and the right front wheel can be independently controlled, the vehicle can be called a front-wheel independent steering system. When the steering of the left rear wheel and the right rear wheel can be independently controlled, the vehicle can be called a rear-wheel independent steering system. When the steering of the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel can be independently controlled, the vehicle can be called a four-wheel independent steering vehicle. Optionally, one set of wheels may include the left front wheel and the right front wheel, or one set of wheels may include the left rear wheel and the right rear wheel. Two sets of wheels may include the left front wheel and the right front wheel, and the left rear wheel and the right rear wheel, wherein the left front wheel and the right front wheel form one set of wheels, and the left rear wheel and the right rear wheel form another set of wheels. This application does not limit the scope of this embodiment.

[0037] The resultant force information of the lateral friction forces of at least one set of wheels at the adjusted steering angle is matched with the braking intensity indicated by the brake pedal travel and the steering requirements indicated by the steering wheel angle. Specifically, after the steering angle is adjusted, at least one set of wheels will experience lateral friction forces from the ground. The resultant force information of the lateral friction forces experienced by at least one set of wheels can refer to the resultant force information of the combined lateral friction forces acting on the vehicle's center of mass, which may include the resultant force and resultant torque acting on the vehicle's center of mass after the lateral friction forces are combined. The direction of the resultant force is opposite to the vehicle's direction of travel, and the magnitude of the resultant force matches the braking intensity indicated by the brake pedal travel. The direction and magnitude of the resultant torque match the steering requirements indicated by the steering wheel angle. Matching the magnitude of the resultant force with the braking intensity indicated by the pedal travel can be understood as ensuring that the vehicle's speed is as close as possible to the speed indicated by the pedal travel when controlling the vehicle based on the resultant force. Matching the direction of the resultant torque to the steering wheel angle indicator can be understood as the direction of the resultant torque being consistent with the steering wheel angle indicator. When controlling the vehicle based on the resultant torque, the vehicle's steering angle should be as close as possible to the steering wheel angle. For example, if the direction of the resultant torque is to the right, the steering wheel angle indicator should also be to the right, and the magnitude of the resultant torque is N, which can make the vehicle rotate n°. The steering wheel angle indicator can also make the vehicle rotate n°.

[0038] Optionally, in at least one set of wheels, the adjusted steering angles of the first wheel and the second wheel are opposite numbers; or, in at least one set of wheels, the adjusted steering angles of the first wheel and the second wheel are opposite and have different absolute values. Here, "the adjusted steering angles of the first wheel and the second wheel are opposite numbers" can be understood as the rotation direction of one wheel being opposite to the rotation direction of the second wheel while the rotation amplitude is the same. "The adjusted steering angles of the first wheel and the second wheel are opposite and have different absolute values" can be understood as the rotation direction of one wheel being opposite to the rotation direction of the second wheel while the rotation amplitude is different. For example, if the first wheel is the left front wheel and the second wheel is the right front wheel, the adjusted steering angle of the left front wheel is n°, and the adjusted steering angle of the right front wheel is -n°, which are opposite numbers. Or, for example, if the adjusted steering angle of the left front wheel is n°, and the adjusted steering angle of the right front wheel is -(n+10°), which are opposite in rotation direction and have different rotation amplitudes.

[0039] In this embodiment, in the event of a brake system failure, the steering angle of at least one set of wheels is adjusted based on the brake pedal travel and steering wheel angle to perform redundant braking. This ensures that the resultant force information of the lateral friction of at least one set of wheels at the adjusted steering angle matches the braking intensity indicated by the brake pedal travel and the steering requirements indicated by the steering wheel angle. This allows for dynamic adjustment of braking intensity based on the brake pedal travel, enabling the driver to adjust the braking intensity more autonomously and smoothly, ensuring braking safety. Furthermore, the redundant braking process allows the vehicle to generate a yaw response, which is positively correlated with the steering wheel angle. This prevents the vehicle from veering off course during redundant braking, improving braking safety and enhancing the effectiveness of intelligent driving.

[0040] In some embodiments, at least one set of wheels includes a set of independently steerable wheels symmetrically arranged on the vehicle. For example, one set of wheels may include the left front wheel and the right front wheel, or one set of wheels may include the left rear wheel and the right rear wheel. Two sets of wheels may include the left front wheel and the right front wheel, and the left rear wheel and the right rear wheel, wherein the left front wheel and the right front wheel constitute one set of wheels, and the left rear wheel and the right rear wheel constitute another set of wheels. This application embodiment does not limit the scope of the invention.

[0041] It is understood that when at least one set of wheels includes a set of wheels, the other wheels in the vehicle can be wheels that cannot be controlled independently or wheels whose independent steering system has failed. For example, if a set of wheels includes the left front wheel and the right front wheel, the vehicle can be a front-wheel independent steering vehicle, or the vehicle can be a four-wheel independent steering vehicle but its rear-wheel independent steering system has failed. This application does not limit this.

[0042] In the embodiments of this application, at least one set of wheels includes a set of independently controllable steering wheels symmetrically arranged on the vehicle, so that even if it is not a four-wheel independent steering wheel, braking can be performed by the vehicle braking method provided in the embodiments of this application, further improving the flexibility and practicality of the vehicle braking method provided in the embodiments of this application.

[0043] In some embodiments, when the steering wheel angle is the target angle, the adjusted steering angle of the first wheel and the adjusted steering angle of the second wheel in at least one set of wheels are opposite numbers; or, when the steering wheel angle is not the target angle, the adjusted steering angle of the first wheel and the adjusted steering angle of the second wheel in at least one set of wheels are opposite and have different absolute values.

[0044] The target steering angle is used to indicate that the steering wheel is not turning; for example, the target steering angle is 0°. This embodiment of the application does not limit this. The fact that the adjusted steering angles of the first wheel and the second wheel are opposite can be understood as the rotation direction of one wheel being opposite to that of the second wheel, while the rotation amplitude is the same. For example, if the first wheel is the left front wheel and the second wheel is the right front wheel, the adjusted steering angle of the left front wheel is n°, and the adjusted steering angle of the right front wheel is -n°, which are opposites.

[0045] The fact that the adjusted steering angles of the first and second wheels are opposite in direction and have different absolute values ​​can be understood as the first and second wheels rotating in opposite directions and with different amplitudes. For example, if the first wheel is the left front wheel and the second wheel is the right front wheel, the adjusted steering angle of the left front wheel is n°, and the adjusted steering angle of the right front wheel is -(n+10°). Their rotation directions are opposite, and their amplitudes are different.

[0046] It is understandable that when the steering wheel angle is not the target angle, it means that the driver has turned the steering wheel. If the vehicle decelerates along the direction of travel at this time, the braking direction will not match the driver's steering operation requirements. Therefore, the steering angles of the first wheel after adjustment and the second wheel after adjustment are opposite and have different absolute values, so that the resultant torque is not zero, thereby causing the vehicle to change direction during braking.

[0047] For example, when a vehicle is a four-wheel independent steering vehicle, the four wheels can... Figure 3 As shown, Figure 3 In the diagram, 301, 302, 303, and 304 represent the lateral friction forces acting on the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel, respectively. Figure 3 In the figure 305, the resultant torque of the lateral friction torque of the four wheels acting on the center of mass after vector synthesis is expressed. Figure 3 The 306 in the figure represents the resultant force acting on the center of mass after the lateral friction torques of the four wheels are vectored together. Figure 3 As can be seen, the direction of the resultant force is opposite to the direction of travel, so the vehicle can be braked. The direction of the resultant torque to the right indicates that the vehicle turns to the right when braking.

[0048] For example, when a vehicle is a front-wheel independent steering vehicle, all four wheels can... Figure 4 As shown, Figure 4 In the diagram, 401 and 402 represent the lateral friction forces acting on the left front wheel and the right front wheel, respectively. Figure 4 In the figure 403, the resultant torque acting on the center of mass after the lateral friction torques of the two wheels are vectored together is represented. Figure 4The 404 in the figure represents the resultant force acting on the center of mass after the lateral frictional torques of the two wheels are vectored together. Figure 4 As can be seen, the direction of the resultant force is opposite to the direction of travel, so the vehicle can be braked. The direction of the resultant torque to the left indicates that the vehicle turns to the left when braking.

[0049] For example, when a vehicle is a rear-wheel independent steering vehicle, all four wheels can... Figure 5 As shown, Figure 5 In the diagram, 501 and 502 represent the lateral friction forces acting on the left and right rear wheels, respectively. Figure 5 In the equation 503, the resultant torque acting on the center of mass after the lateral frictional torques of the two wheels are vectored together. Figure 5 The 504 in the figure represents the resultant force acting on the center of mass after the lateral frictional torques of the two wheels are vectored together. Figure 5 As can be seen, the direction of the resultant force is opposite to the direction of travel, so the vehicle can be braked. The direction of the resultant torque to the right indicates that the vehicle turns to the right when braking.

[0050] In this embodiment, when the steering wheel angle is the target angle, it means the driver is not turning the steering wheel. In this case, the vehicle can decelerate along the driving direction. Therefore, the adjusted steering angles of the first wheel and the second wheel in at least one set of wheels are opposite, so that the resultant torque of at least one set of wheels is 0. This allows the vehicle to decelerate along the driving direction, further improving the vehicle's braking flexibility. Alternatively, when the steering wheel angle is not the target angle, the adjusted steering angles of the first wheel and the second wheel in at least one set of wheels are opposite and have different absolute values, so that the resultant torque of at least one set of wheels is not 0. This makes the braking direction match the driver's directional operation requirements, thereby allowing the vehicle to decelerate in other directions, further improving the vehicle's braking flexibility.

[0051] In some embodiments, adjusting the steering angle of at least one set of wheels of a vehicle based on the vehicle's brake pedal travel and steering wheel angle includes: The target deceleration is determined based on the vehicle's brake pedal travel, and the target yaw rate is determined based on the steering wheel angle. Based on the rotational range of at least one set of wheels, multiple candidate steering angle combinations are determined, each candidate steering angle combination including candidate steering angles of at least one set of wheels; Determine the expected deceleration and expected yaw rate for each candidate combination of steering angles; Based on the target deceleration, expected deceleration, target yaw rate, and expected yaw rate, the adjusted steering angle is determined from multiple candidate steering angle combinations, and the steering angle of at least one set of wheels of the vehicle is adjusted based on the adjusted steering angle.

[0052] The target deceleration can be the vehicle's deceleration. A travel speed mapping table can be preset, which includes the deceleration corresponding to a preset brake pedal travel. The preset brake pedal travel corresponding to the preset brake pedal travel that matches the brake pedal travel in the travel speed mapping table can be determined as the target deceleration. The preset brake pedal travel that matches the brake pedal travel can be understood as the preset brake pedal travel in the travel speed mapping table that is closest to the brake pedal travel, or a preset brake pedal travel whose difference from the brake pedal travel is within a preset difference range.

[0053] An angle mapping table can be preset, including yaw rates corresponding to preset steering wheel angles. The yaw rate corresponding to the preset steering wheel angle that matches the steering wheel angle in the angle mapping table is determined as the target yaw rate. The preset steering wheel angle that matches the steering wheel angle can be understood as the preset steering wheel angle closest to the original steering wheel angle, or a preset steering wheel angle whose difference from the original steering wheel angle is within a preset angle difference range. Optionally, the yaw rate corresponding to the preset steering wheel angle can be different for different speeds. In this case, the target yaw rate can be determined from the angle mapping table based on the vehicle's current speed and steering wheel angle.

[0054] Optionally, at least one set of wheels includes a first wheel and a second wheel, and the candidate steering angles of the first wheel and the second wheel included in a candidate steering angle combination are opposite numbers, and / or the candidate steering angles of the first wheel and the second wheel included in a candidate steering angle combination are opposite and have different absolute values.

[0055] Optionally, the vehicle dynamics equations may include the vehicle's longitudinal dynamics equations, lateral dynamics equations, and yaw dynamics equations. Candidate lateral friction forces for each wheel can be determined based on the candidate steering angles and tire models in each candidate steering angle combination. These candidate lateral friction forces are then substituted into the longitudinal dynamics equations and integrated to obtain the expected longitudinal deceleration. Similarly, the candidate lateral friction forces are substituted into the lateral dynamics equations and integrated to obtain the expected lateral deceleration. Finally, the candidate lateral friction forces are substituted into the yaw dynamics equations and integrated to obtain the expected yaw rate. Based on the expected longitudinal and lateral decelerations, the expected vehicle deceleration is obtained. The expected deceleration and expected yaw rate corresponding to each candidate steering angle combination refer to the expected deceleration and expected yaw rate of the vehicle obtained through the candidate steering angles in each candidate steering angle combination.

[0056] Alternatively, the tire model can be derived based on the vehicle's mass, yaw moment of inertia, wheelbase, front track, rear track, wheel rolling radius, the feasible range of the four wheels, tire vertical force, slip angle, and road adhesion coefficient.

[0057] Optionally, the vehicle can be configured to not generate driving and braking torque, relying solely on lateral friction for braking. Optionally, the longitudinal dynamics equation can be determined based on road information and the vehicle's longitudinal load. The road information may include the road's coefficient of adhesion and / or slope information. Optionally, the lateral dynamics equation can be determined based on the road information and the vehicle's lateral load. Optionally, the yaw dynamics equation can be determined based on road information, the vehicle's lateral load, and the longitudinal load.

[0058] In this embodiment, a target deceleration is determined based on the vehicle's brake pedal travel, and a target yaw rate is determined based on the steering wheel angle. Multiple candidate steering angle combinations are determined based on the rotational range of at least one set of wheels, each candidate steering angle combination including candidate steering angles for at least one set of wheels. The expected deceleration and expected yaw rate corresponding to each candidate steering angle combination are determined. Based on the target deceleration, expected deceleration, target yaw rate, and expected yaw rate, an adjusted steering angle is determined from the multiple candidate steering angle combinations. The steering angle of at least one set of wheels is adjusted based on the adjusted steering angle. This achieves optimization processing based on the target deceleration, expected deceleration, target yaw rate, and expected yaw rate to obtain the adjusted steering angle, further improving the accuracy of the obtained adjusted steering angle. This ensures that when the wheel steering angle is adjusted based on the adjusted steering angle, the vehicle's braking intensity is as close as possible to the braking intensity indicated by the brake pedal travel, and the vehicle's rotation direction is as close as possible to the rotation direction indicated by the steering wheel angle.

[0059] In some embodiments, determining multiple candidate steering angle combinations based on the rotational range of at least one set of wheels includes: Based on the vehicle's brake pedal travel, an initial steering angle combination is determined, wherein in at least one set of wheels, the initial steering angle of the first wheel and the initial steering angle of the second wheel are opposite numbers. Based on the steering wheel angle, the rotation range of at least one set of wheels, and the initial steering angle combination, multiple candidate steering angle combinations are determined.

[0060] This process involves selecting multiple second candidate steering angle combinations from the rotatable range of each wheel. Each second candidate steering angle combination includes the second candidate steering angles of at least one set of wheels, including a first wheel and a second wheel. The second candidate steering angles of the first wheel and the second wheel in a given combination are opposites. Multiple second candidate lateral friction forces are determined for at least one set of wheels using the second candidate steering angles in each combination and the tire model. Each second candidate lateral friction force is then substituted into the longitudinal dynamics equation and integrated to obtain the candidate expected longitudinal deceleration. The second candidate lateral friction force is then substituted into the lateral dynamics equation and integrated to obtain the candidate expected lateral deceleration. Based on the candidate expected longitudinal and lateral decelerations, the candidate expected deceleration is obtained. The second candidate steering angle corresponding to the candidate expected deceleration that matches the target deceleration is determined as the initial steering angle, and the combination containing the initial steering angle is the initial steering angle combination. The candidate expected deceleration that matches the target deceleration can be the candidate expected deceleration closest to the target deceleration or a candidate expected deceleration whose difference from the target deceleration is within a preset difference speed range.

[0061] Optionally, when there is a wheel among the four wheels that cannot rotate independently, the second candidate steering angle of the wheel that cannot rotate independently can be 0.

[0062] Optionally, after obtaining the initial steering angle combination, the initial steering angle in the initial steering angle combination is adjusted based on the steering wheel angle and the rotation range of at least one set of wheels to obtain the adjusted steering angle, so that the resultant force information of the lateral friction force of at least one set of wheels under the adjusted steering angle matches the braking intensity indicated by the brake pedal travel and the steering requirements indicated by the steering wheel angle.

[0063] Optionally, when the steering wheel angle is the target angle, the candidate steering angle of the first wheel and the candidate steering angle of the second wheel in at least one group of wheels in a candidate steering angle combination are opposite numbers; when the steering wheel angle is not the target angle, the candidate steering angle of the first wheel and the candidate steering angle of the second wheel in at least one group of wheels in a candidate steering angle combination are opposite and have different absolute values.

[0064] Optionally, when the vehicle is turned based on a candidate steering angle, the direction of rotation is the same as the direction indicated by the steering wheel angle. For example, if the steering wheel angle indicates a rightward direction, the vehicle will also turn to the right when turned based on the candidate steering angle. Optionally, when there is a wheel among the four wheels that cannot rotate independently, the candidate steering angle of that wheel can be 0.

[0065] In this embodiment, it is first assumed that the vehicle's steering wheel is not turned. Based on the vehicle's brake pedal travel, an initial steering angle combination is determined. In the initial steering angle combination, the initial steering angles of the first wheel and the second wheel in at least one group of wheels are opposite numbers to obtain a rough solution. Then, based on the steering wheel angle, the rotatable range of at least one group of wheels, and the initial steering angle combination, multiple candidate steering angle combinations are determined to obtain an accurate solution. This achieves the goal of obtaining the adjusted steering angle step by step. Compared to the method of "selecting multiple candidate steering angle combinations from the rotatable range of at least one group of wheels", this method can reduce the amount of computation and improve computational efficiency.

[0066] In some embodiments, multiple candidate steering angle combinations are determined based on the steering wheel angle, the rotatable range of at least one set of wheels, and an initial steering angle combination, including: The initial steering angle in the initial steering angle combination is adjusted based on the rotation range of at least one set of wheels to obtain the first candidate steering angle combination. Based on the first candidate steering angle combination, determine at least one set of first candidate lateral friction forces for the wheels; If the direction of the resultant torque of the first candidate lateral friction force acting on the center of mass of the vehicle is consistent with the rotation direction indicated by the steering wheel angle, the first candidate steering angle combination is determined as the candidate steering angle combination.

[0067] Specifically, when the steering wheel angle is the target angle, the first candidate steering angle of the first wheel and the first candidate steering angle of the second wheel in at least one group of wheels in a first candidate steering angle combination are opposite numbers. When the steering wheel angle is not the target angle, the first candidate steering angle of the first wheel and the first candidate steering angle of the second wheel in at least one group of wheels in a first candidate steering angle combination are opposite and have different absolute values.

[0068] After obtaining the first candidate steering angle combination, at least one set of first candidate lateral friction forces for the wheels can be determined using the first candidate steering angle and the tire model. Finally, the resultant torque of the first candidate lateral friction forces acting on the vehicle's center of gravity is calculated. The direction of the resultant torque of the first candidate lateral friction forces acting on the vehicle's center of gravity is consistent with the rotation direction indicated by the steering wheel angle. The first candidate steering angle combination is determined as the candidate steering angle combination, ensuring that if the vehicle is rotated based on the candidate steering angles, the vehicle's rotation direction is consistent with the rotation direction indicated by the steering wheel angle.

[0069] In this embodiment, the initial steering angle in the initial steering angle combination is adjusted based on the rotatable range of at least one set of wheels to obtain a first candidate steering angle combination; based on the first candidate steering angle combination, a first candidate lateral friction force of at least one set of wheels is determined; when the direction of the resultant torque of the first candidate lateral friction force acting on the center of mass of the vehicle is consistent with the rotation direction indicated by the steering wheel angle, the first candidate steering angle combination is determined as a candidate steering angle combination, thereby ensuring that when the vehicle is rotated based on the candidate steering angle in the candidate steering angle combination, the rotation direction of the vehicle is consistent with the rotation direction indicated by the steering wheel angle.

[0070] In some embodiments, determining multiple candidate steering angle combinations based on the rotational range of at least one set of wheels includes: From the rotatable range of at least one set of wheels, multiple candidate steering angle combinations are selected, wherein in each candidate steering angle combination, the candidate steering angle of the first wheel and the candidate steering angle of the second wheel in at least one set of wheels are opposite numbers, and / or, in each candidate steering angle combination, the candidate steering angle of the first wheel and the candidate steering angle of the second wheel are opposite and have different absolute values.

[0071] When selecting multiple candidate steering angle combinations from the rotatable range of at least one set of wheels, since it is not assumed that the vehicle's steering wheel is not rotating, in each selected candidate steering angle combination, the candidate steering angle of the first wheel and the candidate steering angle of the second wheel may be opposite numbers, and / or the candidate steering angle of the first wheel and the candidate steering angle of the second wheel may be opposite and have different absolute values.

[0072] In this embodiment of the application, multiple candidate steering angle combinations are selected from the rotatable range of at least one set of wheels. In each candidate steering angle combination, the candidate steering angle of the first wheel and the candidate steering angle of the second wheel in at least one set of wheels are opposite numbers, and / or, the candidate steering angle of the first wheel and the candidate steering angle of the second wheel in each candidate steering angle combination are opposite and have different absolute values, so as to ensure that the candidate steering angle is within the rotatable range of the wheels, thereby ensuring the accuracy of the adjusted steering angle.

[0073] In some embodiments, determining the adjusted steering angle from a plurality of candidate steering angle combinations based on the target deceleration, the expected deceleration, the target yaw rate, and the expected yaw rate includes: Determine the velocity difference based on the target deceleration and the expected deceleration; Determine the difference in yaw rate based on the target yaw rate and the expected yaw rate; The total difference is determined based on the speed difference and the yaw angle difference; Based on the total difference, the adjusted steering angle is determined from multiple candidate steering angle combinations.

[0074] In this process, when determining the initial steering angle combination and the candidate steering angle combination based on the initial steering angle combination and the steering wheel angle, if the vehicle is rotated based on the candidate steering angle, although the direction of vehicle rotation is consistent with the direction of rotation indicated by the steering wheel angle, it is still necessary to make the steering amplitude of the vehicle as consistent as possible with the steering amplitude indicated by the steering wheel angle, and to make the braking intensity of the vehicle as consistent as possible with the braking intensity indicated by the brake pedal travel. Therefore, the speed difference between the target deceleration and the expected deceleration corresponding to each candidate steering angle combination is determined, the yaw rate difference between the target yaw rate and the expected yaw rate corresponding to each candidate steering angle combination is determined, the total difference of each candidate steering angle combination is determined based on the speed difference and the yaw rate difference corresponding to each candidate steering angle combination, and the adjusted steering angle is determined from multiple candidate steering angle combinations based on the total difference.

[0075] Alternatively, when selecting multiple candidate steering angle combinations from the rotatable range of at least one set of wheels, if the vehicle's rotation direction may or may not be consistent with the steering wheel angle indication when the vehicle is rotated based on the candidate steering angles, the vehicle's steering amplitude may or may not be consistent with the steering wheel angle indication, and the braking intensity of the vehicle needs to be as consistent as possible with the braking intensity indicated by the brake pedal travel, therefore, the speed difference between the target deceleration and the expected deceleration corresponding to each candidate steering angle combination is determined, the yaw rate difference between the target yaw rate and the expected yaw rate corresponding to each candidate steering angle combination is determined, the total difference of each candidate steering angle combination is determined based on the speed difference and the yaw rate difference corresponding to each candidate steering angle combination, and the adjusted steering angle is determined from the multiple candidate steering angle combinations based on the total difference.

[0076] The process of determining the total difference based on the speed difference and the yaw angle difference can be as follows: add the absolute value of the speed difference and the absolute value of the yaw angle difference to obtain the total difference; or, the process of determining the total difference based on the speed difference and the yaw angle difference can also be as follows: multiply the first optimization weight by the absolute value of the speed difference to obtain the first optimization objective; multiply the second optimization weight by the absolute value of the yaw angle difference to obtain the second optimization objective; and add the first optimization objective and the second optimization objective to obtain the total difference.

[0077] Optionally, after obtaining the total difference for each candidate steering angle combination, the candidate steering angle in the candidate steering angle combination with the smallest total difference is determined as the adjusted steering angle.

[0078] In this embodiment, the speed difference is determined based on the target deceleration and the expected deceleration; the yaw angle difference is determined based on the target yaw rate and the expected yaw rate; the total difference is determined based on the speed difference and the yaw angle difference; and the adjusted steering angle is determined from multiple candidate steering angle combinations based on the total difference. This achieves optimization processing based on the total difference to obtain the adjusted steering angle, further improving the accuracy of the obtained adjusted steering angle. This ensures that when the steering angle of the wheels is adjusted based on the adjusted steering angle, the braking intensity of the vehicle is as close as possible to the braking intensity indicated by the brake pedal travel, and the rotation direction of the vehicle is as close as possible to the rotation direction indicated by the steering wheel angle.

[0079] In some embodiments, when the brake pedal travel is not collected, the brake pedal travel is the vehicle's maximum pedal travel. When the brake pedal travel is not collected, the steering angle of at least one set of the vehicle's wheels can be adjusted based on the vehicle's maximum pedal travel and steering wheel angle to further improve the vehicle's braking flexibility.

[0080] In some embodiments, adjusting the steering angle of at least one set of wheels of a vehicle based on the vehicle's brake pedal travel and steering wheel angle includes: Obtain the vehicle dynamics equations corresponding to the vehicle; Based on the vehicle's brake pedal travel, steering wheel angle, and vehicle dynamics equations, adjust the steering angle of at least one set of the vehicle's wheels.

[0081] The vehicle dynamics equations can be created based on vehicle parameters. These parameters can include real-time information collected by the vehicle or fixed information about the vehicle itself. For example, real-time information can include data from a microcontroller unit (IMU) and wheel speed sensors, while fixed information includes vehicle dimensions, weight, and wheel type. This embodiment does not limit the specific parameters. Optionally, the road information where the vehicle is located can be determined based on the real-time information collected by the vehicle, and the vehicle dynamics equations can be created based on this road information. Road information can include the road's adhesion coefficient and / or gradient information, which is not limited in this embodiment.

[0082] Optionally, the vehicle dynamics equations may include longitudinal dynamics equations, lateral dynamics equations, and yaw dynamics equations. The longitudinal dynamics equations can be determined based on road information and the vehicle's longitudinal loads; the lateral dynamics equations can be determined based on road information and the vehicle's lateral loads; and the yaw dynamics equations can be determined based on road information, the vehicle's lateral loads, and the longitudinal loads.

[0083] Alternatively, the process of adjusting the steering angle of at least one set of wheels of a vehicle based on the vehicle's brake pedal travel, steering wheel angle, and vehicle dynamics equations can be as follows: The target deceleration is determined based on the vehicle's brake pedal travel, and the target yaw rate is determined based on the steering wheel angle. Based on the rotational range of at least one set of wheels, multiple candidate steering angle combinations are determined, each steering angle combination including candidate steering angles of at least one set of wheels; The candidate lateral friction force of each wheel is determined by the candidate steering angle and tire model. The candidate lateral friction force is then substituted into the longitudinal dynamic equation and integrated to obtain the expected longitudinal deceleration. The candidate lateral friction force is then substituted into the lateral dynamic equation and integrated to obtain the expected lateral deceleration. The expected deceleration is obtained based on the expected longitudinal deceleration and the expected lateral deceleration. Based on the target deceleration, expected deceleration, target yaw rate, and expected yaw rate, the adjusted steering angle is determined from multiple candidate steering angle combinations, and the steering angle of at least one set of wheels of the vehicle is adjusted based on the adjusted steering angle.

[0084] In this embodiment, the vehicle dynamics equation corresponding to the vehicle is obtained; based on the vehicle's brake pedal travel, steering wheel angle, and vehicle dynamics equation, the steering angle of at least one set of wheels of the vehicle is adjusted, thereby adjusting the steering angle of at least one set of wheels through the vehicle dynamics equation. This ensures that the vehicle dynamics equation is different when the vehicle parameters are different, further improving the accuracy of the adjusted steering angle and increasing the applicability of the vehicle braking method in this embodiment.

[0085] In some embodiments, adjusting the steering angle of at least one set of wheels of a vehicle based on the vehicle's brake pedal travel and steering wheel angle includes: When the vehicle's condition meets preset redundant braking conditions, the steering angle of at least one set of wheels is adjusted based on the vehicle's brake pedal travel and steering wheel angle. Meeting the preset redundant braking conditions means that when braking, the vehicle is stable and / or meets the driver's needs without risk of instability. Therefore, adjusting the steering angle of at least one set of wheels based on the brake pedal travel and steering wheel angle further improves braking safety.

[0086] In some embodiments, the preset redundant braking conditions include at least one of the following: the vehicle's attitude information does not exceed an attitude threshold, the vehicle's speed information does not exceed a first speed threshold, the vehicle's accelerator pedal travel is less than or equal to a travel threshold, and the difference between the vehicle's target yaw rate and the vehicle's expected yaw rate is less than or equal to a difference threshold.

[0087] The vehicle's attitude information can refer to its current attitude, and its speed information can refer to angular velocity or angular acceleration, which can be the time derivative of the current attitude. When the vehicle's attitude information does not exceed an attitude threshold and its speed information does not exceed a first speed threshold, it means the vehicle has no risk of instability, indicating that the vehicle's state meets the preset redundant braking conditions. Optionally, the vehicle's state may be determined not to meet the preset redundant braking conditions only if the duration for which the vehicle's attitude information exceeds the attitude threshold or the duration for which the vehicle's speed information exceeds the first speed threshold is greater than the first threshold time.

[0088] If the accelerator pedal travel is less than or equal to the travel threshold, it means the vehicle has no acceleration requirement, indicating that the vehicle's state meets the preset redundant braking conditions. Optionally, the vehicle's state may be determined not to meet the preset redundant braking conditions only when the duration of the accelerator pedal travel exceeding the travel threshold is greater than a second threshold time.

[0089] If the difference between the target yaw rate and the vehicle's expected yaw rate is less than or equal to a difference threshold, it means that the adjusted steering angle after redundant braking can meet the driver's directional control needs, indicating that the vehicle's state meets the preset redundant braking conditions. Optionally, it can be determined that the vehicle's state does not meet the preset redundant braking conditions only when the duration for which the difference between the vehicle's target yaw rate and the vehicle's expected yaw rate is greater than the difference threshold is greater than a third threshold time.

[0090] Optionally, it can be first determined whether the vehicle's attitude information exceeds an attitude threshold and whether the vehicle's speed information exceeds a first speed threshold. If the vehicle's speed information does not exceed the first speed threshold and the vehicle's attitude information does not exceed the attitude threshold, then it can be determined whether the vehicle's accelerator pedal travel is less than or equal to a travel threshold. If the vehicle's accelerator pedal travel is less than or equal to the travel threshold, then it can be determined whether the difference between the vehicle's target yaw rate and the vehicle's expected yaw rate is less than or equal to a difference threshold. If the difference between the target yaw rate and the vehicle's expected yaw rate is less than or equal to the difference threshold, then it is determined that the vehicle's state meets the preset redundant braking conditions; otherwise, it is determined that the vehicle's state does not meet the preset redundant braking conditions. For example, such as... Figure 6 As shown, the vehicle's attitude and speed information are obtained to determine whether the vehicle is at risk of instability. If the vehicle is not at risk of instability, the accelerator pedal travel is obtained to determine whether the driver has an acceleration need. If the driver does not have an acceleration need, the difference between the target yaw rate and the vehicle's expected yaw rate is determined to be greater than the difference threshold. If so, the preset redundant braking condition is not met; otherwise, the preset redundant braking condition is met. If the vehicle is at risk of instability and / or the driver has an acceleration need, the preset redundant braking condition is not met.

[0091] In this embodiment, the preset redundant braking conditions include at least one of the following: the vehicle's attitude information does not exceed the attitude threshold, the vehicle's speed information does not exceed the first speed threshold, the vehicle's accelerator pedal travel is less than or equal to the travel threshold, and the difference between the vehicle's target yaw rate and the vehicle's expected yaw rate is less than or equal to the difference threshold. This enables the determination of whether the vehicle's state meets the preset redundant braking conditions through multiple dimensions, improving the comprehensiveness of the judgment on whether the vehicle is safe during braking, thereby further improving the safety of the vehicle during braking.

[0092] In some embodiments, during redundant braking of the vehicle, the vehicle can also be controlled by the suspension system and / or conventional steering system to improve the attitude stability of the vehicle body during redundant braking.

[0093] In some embodiments, after redundant braking of the vehicle, the vehicle speed can be determined. If the vehicle speed is lower than a preset speed threshold for a duration longer than a fourth threshold time, the steering angle of the vehicle wheels is controlled to 0 to straighten the wheels and exit the redundant braking process.

[0094] The following is based on Figure 7 The vehicle braking method provided in this application embodiment is further described below. It is determined whether the vehicle's braking system (including a friction braking system and a regenerative braking system) has failed. If the vehicle's braking system has failed, the brake pedal travel and steering wheel angle are obtained. A target deceleration is determined based on the brake pedal travel, and a target yaw rate is determined based on the steering wheel angle. An initial steering angle combination is determined based on the brake pedal travel and the vehicle dynamics equations. The initial steering angle in the initial steering angle combination is adjusted based on the steering wheel angle to obtain multiple candidate steering angle combinations. The expected deceleration and expected yaw rate corresponding to each candidate steering angle combination are determined. Based on the target deceleration, expected deceleration, target yaw rate, and expected yaw rate, the adjusted steering angle is determined from the multiple candidate steering angle combinations. Determine whether the vehicle's state meets the preset redundant braking conditions. If the vehicle's state meets the preset redundant braking conditions, adjust the steering angle of at least one set of wheels of the vehicle based on the adjusted steering angle. If the vehicle does not stop, return to the step of determining whether the vehicle's braking system (including friction braking system and regenerative braking system) has failed. If the vehicle's state does not meet the preset redundant braking conditions, enter the normal vehicle control mode.

[0095] The following is based on Figure 8This application describes the vehicle braking architecture provided in its embodiments. The vehicle braking architecture includes a command input module, a data processing module, an information acquisition module, and an action execution module. The command input module may include a brake pedal travel sensor, a steering wheel angle sensor, and an accelerator pedal travel sensor. The information acquisition module can acquire road information, vehicle speed, vehicle fixation information, and vehicle attitude information. The data processing module includes an MCU, used to obtain an adjusted steering angle based on the brake pedal travel and steering wheel angle. The action execution module includes steering motors for the four wheels, used to receive the adjusted steering angle output by the data processing module and control wheel rotation based on the adjusted steering angle.

[0096] As can be seen from the above, in the event of a failure in the vehicle's braking system, the present application's embodiments adjust the steering angle of at least one set of wheels based on the vehicle's brake pedal travel and steering wheel angle to perform redundant braking. Specifically, when the steering wheel angle is the target angle, the adjusted steering angles of the first wheel and the second wheel in the at least one set of wheels are opposite numbers; or, when the steering wheel angle is not the target angle, the adjusted steering angles of the first wheel and the second wheel in the at least one set of wheels are opposite and have different absolute values. This ensures that the resultant force information of the lateral friction force of the at least one set of wheels at the adjusted steering angle matches the braking intensity indicated by the brake pedal travel and the steering requirement indicated by the steering wheel angle. This allows the driver to control the braking intensity and direction of the redundant braking, improving braking flexibility and practicality, and preventing vehicle slippage and instability, thus enhancing braking safety.

[0097] This application also provides a computer-readable storage medium storing instructions that, when executed by a processor, configure the processor to perform the vehicle braking method described above.

[0098] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0099] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0100] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0101] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0102] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0103] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0104] Computer-readable media include both permanent and non-permanent, removable and non-removable media, which can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient media, such as modulated communication signals and carrier waves.

[0105] This application also provides a computer program product, including a computer program or instructions, which, when executed by a processor, implement the vehicle braking method provided in this application.

[0106] This application also provides a controller that stores a computer program or instructions, which, when executed by a processor, implements the vehicle braking method provided in this application.

[0107] This application also provides a vehicle braking device, including a braking system for braking the vehicle; and an independent steering system for executing the vehicle braking method provided in this application in the event of brake system failure.

[0108] This application also provides a vehicle 900, including the controller or vehicle braking device provided in this embodiment, or executing the vehicle braking method provided in this application embodiment, such as... Figure 9 The diagram shown is a schematic representation of the architecture of a vehicle 900 provided in an embodiment of this application. In this embodiment, the vehicle 900 can be a gasoline-powered vehicle, a plug-in hybrid electric vehicle, or a new energy vehicle, etc., and this application does not specifically limit it in this regard.

[0109] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0110] It should be noted that, in the data processing stage, the technical solution of this application has strictly limited the scope of data collection to the minimum necessary to achieve the technical objectives, preventing the acquisition of irrelevant information. For any user information to be collected, the data subject will be clearly informed and their consent obtained. Furthermore, technologies such as encrypted storage and access control are employed to strengthen data security and ensure the security and compliance of the entire data processing process. The technical model and decision-making mechanism are based on objective technical parameters and do not introduce unnecessary parameters such as gender or age that may lead to discrimination, resolutely eliminating algorithmic discrimination and upholding public order and good morals. In addition, the specification fully describes the technical implementation methods, application scenarios, and compliance protection details. The claims are consistent with the content of the specification, key compliance designs are clear and verifiable, and the overall technical design is guided by the protection of public interests and adherence to social ethics, without any circumstances that harm public interests or violate public order and good morals.

[0111] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0112] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0113] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A vehicle braking method, characterized in that, include: In the event of a failure of the vehicle's braking system, the steering angle of at least one set of the vehicle's wheels is adjusted based on the vehicle's brake pedal travel and steering wheel angle to provide redundant braking for the vehicle. Wherein, when the steering wheel angle is the target angle, the adjusted steering angle of the first wheel and the adjusted steering angle of the second wheel in the at least one set of wheels are opposite numbers; Alternatively, if the steering wheel angle is not the target angle, the adjusted steering angle of the first wheel and the adjusted steering angle of the second wheel in the at least one set of wheels are opposite and have different absolute values.

2. The method according to claim 1, characterized in that, Adjusting the steering angle of at least one set of wheels of the vehicle based on the brake pedal travel and steering wheel angle includes: Based on the vehicle's brake pedal travel, the target deceleration is determined, and based on the steering wheel angle, the target yaw rate is determined. Based on the rotational range of the at least one set of wheels, a plurality of candidate steering angle combinations are determined, each candidate steering angle combination including candidate steering angles of the at least one set of wheels; Determine the expected deceleration and expected yaw rate for each of the candidate steering angle combinations; Based on the target deceleration, the expected deceleration, the target yaw rate, and the expected yaw rate, an adjusted steering angle is determined from a plurality of candidate steering angle combinations, and the steering angle of at least one set of wheels of the vehicle is adjusted based on the adjusted steering angle.

3. The method according to claim 2, characterized in that, The determination of multiple candidate steering angle combinations based on the rotational range of the at least one set of wheels includes: Based on the brake pedal travel of the vehicle, an initial steering angle combination is determined, wherein the initial steering angle of the first wheel and the initial steering angle of the second wheel in the at least one set of wheels in the initial steering angle combination are opposite numbers; Based on the steering wheel angle, the rotatable range of the at least one set of wheels, and the initial steering angle combination, multiple candidate steering angle combinations are determined.

4. The method according to claim 3, characterized in that, The determination of multiple candidate steering angle combinations based on the steering wheel angle, the rotatable range of at least one set of wheels, and the initial steering angle combination includes: The initial steering angle in the initial steering angle combination is adjusted based on the rotation range of the at least one set of wheels to obtain a first candidate steering angle combination; Based on the first candidate steering angle combination, determine the first candidate lateral friction force of the at least one set of wheels; When the direction of the resultant torque of the first candidate lateral friction force acting on the center of mass of the vehicle is consistent with the rotation direction indicated by the steering wheel angle, the first candidate steering angle combination is determined as the candidate steering angle combination.

5. The method according to claim 2, characterized in that, The determination of multiple candidate steering angle combinations based on the rotational range of the at least one set of wheels includes: From the rotatable range of the at least one set of wheels, multiple candidate steering angle combinations are selected, wherein in each candidate steering angle combination, the candidate steering angle of the first wheel and the candidate steering angle of the second wheel in the at least one set of wheels are opposite numbers, and / or, in each candidate steering angle combination, the candidate steering angle of the first wheel and the candidate steering angle of the second wheel are opposite and have different absolute values.

6. The method according to claim 2, characterized in that, The step of determining the adjusted steering angle from multiple candidate steering angle combinations based on the target deceleration, the expected deceleration, the target yaw rate, and the expected yaw rate includes: The velocity difference is determined based on the target deceleration and the expected deceleration; The yaw rate difference is determined based on the target yaw rate and the expected yaw rate; The total difference is determined based on the speed difference and the yaw angle difference; Based on the total difference, the adjusted steering angle is determined from the multiple candidate steering angle combinations.

7. The method according to claim 1, characterized in that, If the brake pedal travel is not collected, the brake pedal travel is the maximum pedal travel of the vehicle.

8. The method according to claim 1, characterized in that, Adjusting the steering angle of at least one set of wheels of the vehicle based on the brake pedal travel and steering wheel angle includes: Obtain the vehicle dynamics equations corresponding to the vehicle; Based on the vehicle's brake pedal travel, steering wheel angle, and vehicle dynamics equations, the steering angle of at least one set of wheels of the vehicle is adjusted.

9. The method according to claim 1, characterized in that, Adjusting the steering angle of at least one set of wheels of the vehicle based on the brake pedal travel and steering wheel angle includes: When the vehicle's condition meets the preset redundant braking conditions, the steering angle of at least one set of the vehicle's wheels is adjusted based on the vehicle's brake pedal travel and steering wheel angle.

10. The method according to claim 9, characterized in that, The preset redundant braking conditions include at least one of the following: the vehicle's attitude information does not exceed an attitude threshold, the vehicle's speed information does not exceed a first speed threshold, the vehicle's accelerator pedal travel is less than or equal to a travel threshold, and the difference between the vehicle's target yaw rate and the vehicle's expected yaw rate is less than or equal to a difference threshold.

11. The method according to any one of claims 1-10, characterized in that, The at least one set of wheels includes a set of independently controllable wheels symmetrically arranged on the vehicle.

12. A braking device for a vehicle, characterized in that, include: A braking system for braking the vehicle; An independent steering system for performing the vehicle braking method as described in any one of claims 1 to 11 in the event of failure of the braking system.

13. A controller, characterized in that, include: A memory on which computer programs are stored; A processor for executing the computer program in the memory to implement the vehicle braking method as described in any one of claims 1 to 11.

14. A vehicle, characterized in that, The braking device of the vehicle as described in claim 12, or the controller as described in claim 13, or braking is achieved by the vehicle braking method as described in any one of claims 1 to 11.

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