Vehicle stability control method based on four-wheel independent steering, vehicle, storage medium and program product

Abstract

The invention discloses a whole vehicle stability control method based on four-wheel independent steering, a vehicle, a storage medium and a program product. The method comprises the steps that a vehicle state model is established based on the relation between tire tangential force and the vehicle speed; wherein the tire tangential force comprises a wheel longitudinal force and a wheel lateral force of each tire; a control target model is established based on the relation between the wheel lateral force and the whole vehicle mass center balance; in response to the expected vehicle state, a target wheel longitudinal force and a target wheel lateral force are solved based on the vehicle state model and the control target model; target tire tangential parameters are obtained according to conversion of the target wheel longitudinal force and the target wheel lateral force; and in response to the target tire tangential parameter of each tire, performing steering braking control on the corresponding tire. The stability and safety of the four-wheel independent drive vehicle can be guaranteed, and the method can be widely applied to the technical field of vehicle control.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a whole vehicle stability control method based on four-wheel independent steering, a vehicle, a storage medium and a program product. Background Art

[0002] With the development of the automobile industry, the structure of automobiles has gradually evolved from the initial front-wheel steering to coordinated steering of the front and rear wheels and four-wheel independent steering. At the same time, steering control has also evolved from traditional mechanical control to wire-controlled steering.

[0003] The chassis electronic control system is the first barrier to ensure vehicle stability and safe driving. As the vehicle structure changes, the control strategy also needs to change with the structure. Traditional vehicle stability control strategies are all implemented through differential braking. However, with the introduction of four-wheel independent steering vehicle structure, traditional differential braking control strategies can no longer fully meet the vehicle stability requirements under this structure. Summary of the Invention

[0004] The main purpose of the embodiments of the present invention is to propose a vehicle stability control method, vehicle, storage medium and program product based on four-wheel independent steering, in order to solve at least one problem of the prior art. The present invention can effectively realize vehicle stability control with four-wheel independent steering.

[0005] To achieve the above objectives, one aspect of an embodiment of the present invention provides a vehicle stability control method based on four-wheel independent steering, the control method comprising: A vehicle state model is established based on the relationship between tire tangential force and vehicle speed; wherein the tire tangential force includes the wheel longitudinal force and wheel lateral force of each tire; Establish a control target model based on the relationship between wheel lateral force and vehicle center of mass balance; In response to a desired vehicle state, a target wheel longitudinal force and a target wheel lateral force are obtained based on a vehicle state model and a control target model; The target tire tangential parameters are obtained according to the conversion of the target wheel longitudinal force and the target wheel lateral force; In response to the target tire tangential parameter of each tire, steering braking control is performed on the corresponding tire.

[0006] In some embodiments, the vehicle state model includes a longitudinal force balance model, a lateral force balance model, and a yaw return model; and establishing the vehicle state model based on the relationship between tire tangential force and vehicle speed includes: A longitudinal force balance model is established based on the relationship between the longitudinal wheel force and the longitudinal vehicle speed of all tires. The expression of the longitudinal force balance model is:

[0007] Where, represents the derivative of the longitudinal vehicle speed; Indicates the The longitudinal force of the wheel of each tire; Indicates the vehicle mass; Indicates the lateral moving speed of the vehicle; represents the vehicle's yaw angular velocity; A lateral force balance model is established based on the relationship between the wheel lateral force of all tires and the lateral vehicle speed. The expression of the lateral force balance model is:

[0008] Where, represents the derivative of the lateral vehicle speed; Indicates the The wheel lateral force of each tire; Indicates the longitudinal moving speed of the vehicle; A yaw-righting model is established based on the relationship between the tire tangential force and the yaw angular velocity of all tires. The expression of the yaw-righting model is:

[0009] Where, represents the derivative of the yaw rate; Represents the moment of inertia of the vehicle around the z-axis; Indicates the The longitudinal force of the wheel of each tire, ; Indicates the The lateral force of the wheel of each tire, ; Indicates the vehicle wheelbase; , Indicates the distance of the center of mass from the front axle and the distance from the rear axle.

[0010] In some embodiments, the control target model includes a yaw balance model and a lateral balance model. The control target model is established based on the relationship between the wheel lateral force and the balance of the center of mass of the vehicle, including: The cornering balance model is established based on the relationship between the wheel lateral force and the vehicle's center of mass slip angle. The expression of the cornering balance model is:

[0011] Where, represents the derivative of the vehicle's center of mass sideslip angle; Indicates the vehicle mass; Indicates longitudinal vehicle speed; Indicates the total lateral force on the front axle; Represents the total lateral force on the rear axle; the total lateral force on the front axle is obtained by summing the wheel lateral forces of all tires on the front axle, and the total lateral force on the rear axle is obtained by summing the wheel lateral forces of all tires on the rear axle; The yaw balance model is established based on the relationship between the wheel lateral force and the yaw angle of the vehicle's center of mass. The expression of the yaw balance model is:

[0012] Where, represents the derivative of the vehicle's center of mass yaw angle; Represents the moment of inertia of the vehicle around the z-axis; Indicates the distance between the center of mass and the front axle; Indicates the distance from the center of mass to the rear axle.

[0013] In some embodiments, in response to a desired vehicle state, obtaining a target wheel longitudinal force and a target wheel lateral force based on a vehicle state model and a control target model includes: The desired vehicle state is converted into input parameters, and the preset multi-input and multi-output control algorithm is adopted. The vehicle state model and the control target model are used to solve the target wheel longitudinal force and target wheel lateral force of each tire.

[0014] In some embodiments, obtaining a target tire tangential parameter based on the target wheel longitudinal force and the target wheel lateral force includes: According to the target wheel longitudinal force and target wheel lateral force of each tire, the target tire tangential parameters of the corresponding tire are obtained by using the preset tangential force formula.

[0015] In some embodiments, the target tire tangential parameters include a target tire tangential force and a target tire tangential force direction. The target tire tangential parameters of the corresponding tire are obtained by solving a preset tangential force formula based on the target wheel longitudinal force and target wheel lateral force of each tire, including: Calculate the square root of the sum of the target wheel longitudinal force and the target wheel lateral force of each tire to obtain the target tire tangential force of the corresponding tire; Performing an inverse tangent on the ratio of the target wheel lateral force to the target wheel longitudinal force of each tire to obtain the target tire tangential force direction of the corresponding tire; Among them, the expression of the tangential force formula is:

[0016] Where, Indicates the Target tire tangential force for each tire; Indicates the The longitudinal force of the wheel of each tire; Indicates the The wheel lateral force of each tire; Indicates the Target tire tangential force direction for each tire; is the inverse tangent function.

[0017] In some embodiments, the target tire tangential parameter includes a target tire tangential force and a target tire tangential force direction; and in response to the target tire tangential parameter of each tire, performing steering and braking control on the corresponding tire includes: controlling the brake pressure of the corresponding tire in response to a target tire tangential force of each tire; In response to the target tire tangential force direction of each tire, the steering angle of the corresponding tire is controlled.

[0018] To achieve the above-mentioned purpose, another aspect of an embodiment of the present invention proposes a vehicle, which includes a memory, a processor, and a program stored in the memory and executable on the processor. When the program is executed by the processor, the above-mentioned vehicle stability control method based on four-wheel independent steering is implemented.

[0019] To achieve the above-mentioned purpose, another aspect of an embodiment of the present invention provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are executed by a processor, the above-mentioned vehicle stability control method based on four-wheel independent steering is implemented.

[0020] To achieve the above objectives, another aspect of an embodiment of the present invention provides a computer program product, including a computer program, which implements the above-mentioned vehicle stability control method based on four-wheel independent steering when executed by a processor.

[0021] The embodiment of the present invention establishes a vehicle state model based on the relationship between tire tangential force and vehicle speed; wherein the tire tangential force includes the wheel longitudinal force and wheel lateral force of each tire; a control target model is established based on the relationship between the wheel lateral force and the balance of the center of mass of the entire vehicle; in response to the desired vehicle state, the target wheel longitudinal force and target wheel lateral force are solved based on the vehicle state model and the control target model; the target tire tangential parameters are converted according to the target wheel longitudinal force and the target wheel lateral force; and steering and braking control is performed on the corresponding tire in response to the target tire tangential parameters of each tire. The present invention solves the target tire tangential parameters that ensure vehicle stability by solving the relevant parameter models simultaneously, and then can distribute the steering angle and braking torque of each wheel in a targeted manner according to the relevant tangential force information. The present invention can ensure the stability and safety of four-wheel independent drive vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1This is a schematic diagram of an implementation environment for vehicle stability control based on four-wheel independent steering provided by an embodiment of the present invention; Figure 2 This is a flow chart of a vehicle stability control method based on four-wheel independent steering provided by an embodiment of the present invention; Figure 3 A schematic diagram of the principle flow of a vehicle stability control method based on four-wheel independent steering provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] It should be noted that although the system diagrams illustrate functional module divisions and the flowcharts illustrate a logical sequence, in certain circumstances, the steps shown or described may be performed in a sequence that differs from the module divisions in the system or the sequence in the flowcharts. The terms "first / S100," "second / S200," and the like in the specification, claims, and drawings are used to distinguish similar objects and are not necessarily intended to describe a specific sequence or precedence.

[0025] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0026] It is understandable that the vehicle stability control method based on four-wheel independent steering provided in the embodiment of the present invention can be applied to any computer device with data processing and computing capabilities (such as an on-board terminal device or a related control system of the vehicle), and this computer device can be various terminals or servers. When the computer device in the embodiment is a server, the server is an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms. In some embodiments, the terminal is a smart phone, tablet computer, laptop computer, desktop computer, etc., but is not limited to this.

[0027] like Figure 1 FIG. 1 is a schematic diagram of an implementation environment provided by an embodiment of the invention. Figure 1 , the implementation environment includes at least one terminal 102 and a server 101. The terminal 102 and the server 101 can be connected to the network in a wireless or wired manner to complete data transmission and exchange.

[0028] Server 101 can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers. It can also be a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN (Content Delivery Network), as well as big data and artificial intelligence platforms.

[0029] In addition, server 101 can also be a node server in a blockchain network. Blockchain is a new application model of computer technologies such as distributed data storage, peer-to-peer transmission, consensus mechanism, and encryption algorithm.

[0030] Terminal 102 may be a smartphone, tablet computer, laptop computer, desktop computer, smart speaker, smartwatch, etc. Terminal 102 may also be a vehicle-mounted terminal of the various device types described above, but is not limited thereto. Terminal 102 and server 101 may be connected directly or indirectly via wired or wireless communication, which is not limited in this embodiment of the present invention.

[0031] Based on the example Figure 1 In the implementation environment shown, an embodiment of the present invention provides a vehicle stability control method based on four-wheel independent steering. The following is explained using the example of the vehicle stability control method based on four-wheel independent steering being applied to the server 101. It can be understood that the vehicle stability control method based on four-wheel independent steering can also be applied to the terminal 102.

[0032] Reference Figure 2 , Figure 2 This is a flowchart of a vehicle stability control method based on four-wheel independent steering applied to a server according to an embodiment of the present invention. The execution subject of the vehicle stability control method based on four-wheel independent steering can be any of the aforementioned computer devices (including servers or terminals). Figure 2 The method is applied to a vehicle with an automatic parking system, and the method may include the following steps: S100, establishing a vehicle state model based on the relationship between tire tangential force and vehicle speed; Among them, the tire tangential force includes the wheel longitudinal force and wheel lateral force of each tire; It should be noted that the vehicle state model includes a longitudinal force balance model, a lateral force balance model, and a yaw return model; in some embodiments, step S100 may include the following steps: A longitudinal force balance model is established based on the relationship between the longitudinal wheel force and the longitudinal vehicle speed of all tires. The expression of the longitudinal force balance model is:

[0033] Where, represents the derivative of the longitudinal vehicle speed; Indicates the The longitudinal force of the wheel of each tire; Indicates the vehicle mass; Indicates the lateral moving speed of the vehicle; represents the vehicle's yaw angular velocity; A lateral force balance model is established based on the relationship between the wheel lateral force of all tires and the lateral vehicle speed. The expression of the lateral force balance model is:

[0034] Where, represents the derivative of the lateral vehicle speed; Indicates the The wheel lateral force of each tire; Indicates the longitudinal moving speed of the vehicle; A yaw-righting model is established based on the relationship between the tire tangential force and the yaw angular velocity of all tires. The expression of the yaw-righting model is:

[0035] Where, represents the derivative of the yaw rate; Represents the moment of inertia of the vehicle around the z-axis; Indicates the The longitudinal force of the wheel of each tire, ; Indicates the The lateral force of the wheel of each tire, ; Indicates the vehicle wheelbase; , Represents the distance from the center of mass to the front axle and the distance from the rear axle. They correspond to the left front, right front, left rear, and right rear tires respectively.

[0036] For example, in some specific implementations, a vehicle state model considering tire tangential force is first established, and the model expression is as follows:

[0037] in, represents the longitudinal vehicle speed derivative; represents the longitudinal force of the i-th wheel; Represents the quality of the vehicle; Represents the lateral moving speed of the vehicle, Represents the yaw rate of the vehicle.

[0038] S200, establishing a control target model based on the relationship between the wheel lateral force and the center of mass balance of the entire vehicle; It should be noted that the control target model includes a yaw balance model and a lateral balance model; in some embodiments, step S200 may include the following steps: The cornering balance model is established based on the relationship between the wheel lateral force and the vehicle's center of mass slip angle. The expression of the cornering balance model is:

[0039] Where, represents the derivative of the vehicle's center of mass sideslip angle; Indicates the vehicle mass; Indicates longitudinal vehicle speed; Indicates the total lateral force on the front axle; Represents the total lateral force on the rear axle; the total lateral force on the front axle is obtained by summing the wheel lateral forces of all tires on the front axle, and the total lateral force on the rear axle is obtained by summing the wheel lateral forces of all tires on the rear axle; A yaw balance model is established based on the relationship between the wheel lateral force and the yaw angle of the vehicle's center of mass;

[0040] Where, represents the derivative of the vehicle's center of mass yaw angle; Represents the moment of inertia of the vehicle around the z-axis; Indicates the distance between the center of mass and the front axle; Indicates the distance from the center of mass to the rear axle.

[0041] For example, in some specific implementations, a control target model is further established, which is a standard two-degree-of-freedom model, and its expression is as follows:

[0042] in, Represents the side slip angle derivative of the vehicle's center of mass; is the total lateral force on the front axle, is the total lateral force on the rear axle, represents the yaw angle derivative of the vehicle's center of mass, is the distance from the center of mass to the front axle; is the distance from the center of mass to the rear axle; is the moment of inertia of the vehicle around the z-axis.

[0043] S300, in response to a desired vehicle state, obtaining a target wheel longitudinal force and a target wheel lateral force based on a vehicle state model and a control target model; It should be noted that, in some embodiments, step S300 may include the following steps: converting the desired vehicle state into input parameters, adopting a preset multi-input and multi-output control algorithm, and using the vehicle state model and the control target model to solve and obtain the target wheel longitudinal force and target wheel lateral force of each tire.

[0044] For example, in some specific implementations, a multi-input multi-output control algorithm is used to achieve multi-objective integrated optimization control, improve vehicle stability through the desired vehicle state, and solve the optimal tire tangential force. It should be noted that by determining other parameters besides the tire tangential force based on the desired vehicle state, and further performing a joint solution based on the vehicle state model and the control target model established in the aforementioned steps of the embodiment of the present invention, the tire tangential force (including longitudinal force and lateral force) of each tire can be obtained. Specifically, when the logical relationship between the parameters in the model is clear, the specific computer language used to implement the multi-input and multi-output control algorithm can be set according to actual needs, and the embodiment of the present invention does not impose any restrictions.

[0045] S400, obtaining a target tire tangential parameter according to the target wheel longitudinal force and the target wheel lateral force; It should be noted that, in some embodiments, step S400 may include the following steps: according to the target wheel longitudinal force and target wheel lateral force of each tire, using a preset tangential force formula to solve the target tire tangential parameters of the corresponding tire.

[0046] Furthermore, in some embodiments, the target tire tangential parameters include a target tire tangential force and a target tire tangential force direction; based on the target wheel longitudinal force and target wheel lateral force of each tire, a preset tangential force formula is used to solve the target tire tangential parameters of the corresponding tire, including: taking the square root of the sum of the target wheel longitudinal force and the target wheel lateral force of each tire to obtain the target tire tangential force of the corresponding tire; taking the inverse tangent of the ratio of the target wheel lateral force to the target wheel longitudinal force of each tire to obtain the target tire tangential force direction of the corresponding tire.

[0047] For example, in some specific implementations, the tangential forces of the four wheels are solved as shown in the following equation:

[0048] Where, Indicates the Target tire tangential force for each tire; Indicates the The longitudinal force of the wheel of each tire; Indicates the The wheel lateral force of each tire; Indicates the Target tire tangential force direction for each tire; is the inverse tangent function.

[0049] S500, performing steering braking control on the corresponding tire in response to the target tire tangential parameter of each tire; It should be noted that the target tire tangential parameters include the target tire tangential force and the target tire tangential force direction; in some embodiments, step S500 may include the following steps: in response to the target tire tangential force of each tire, controlling the braking pressure of the corresponding tire; in response to the target tire tangential force direction of each tire, controlling the steering angle of the corresponding tire.

[0050] For example, in some specific implementations, according to the solution obtained and Each wheel applies a corresponding steering angle and brake pressure.

[0051] In order to explain the principle of the technical solution of the present invention in detail, the overall process of the present invention is described below in combination with some specific embodiments. It is easy to understand that the following is an explanation of the technical principle of the present invention and cannot be regarded as a limitation of the present invention.

[0052] First of all, it should be noted that traditional vehicle stability control strategies are all differential braking control strategies, which only use longitudinal force for tire performance and do not fully utilize the performance of the tire.

[0053] In view of this, in order to give full play to the stability of the four-wheel independent steering vehicle and fully ensure the vehicle driving stability and safety, the embodiment of the present invention provides a vehicle stability control method based on four-wheel independent steering, such as Figure 3 As shown, the present invention can be implemented through the following process: 1. Establish a vehicle state model that takes into account tire tangential force. The model expression is as follows:

[0054] in, represents the longitudinal vehicle speed derivative; represents the longitudinal force of the i-th wheel; Represents the quality of the vehicle; Represents the lateral moving speed of the vehicle, Represents the yaw rate of the vehicle; 2. The control target model is a standard two-degree-of-freedom model, and its expression is as follows:

[0055] in, Represents the side slip angle derivative of the vehicle's center of mass; is the total lateral force on the front axle, is the total lateral force on the rear axle, represents the yaw angle derivative of the vehicle's center of mass, is the distance from the center of mass to the front axle; is the distance from the center of mass to the rear axle; is the moment of inertia of the vehicle around the z-axis; 3. Use a multi-input and multi-output control algorithm to achieve multi-objective integrated optimization control, improve vehicle stability through the desired vehicle state, and solve the optimal tire tangential force. .

[0056] 4. The tangential forces of the four wheels are solved as follows:

[0057] in, is the tire tangential force; is the direction of the tire tangential force; 5. According to the solution and Each wheel applies a corresponding steering angle and brake pressure.

[0058] In summary, the present invention belongs to the field of stability control for four-wheel independent steering vehicles. Embodiments of the present invention can effectively address the technical problem of insufficient performance. Specifically, it relates to a whole-vehicle stability control method based on four-wheel independent steering. By rationally designing a reference model, the optimal tangential force to ensure vehicle stability is determined. Based on this tangential force information and combined with the tire friction ellipse boundary, the steering angle and braking torque distribution results for each wheel are optimized. The vehicle stability control method proposed in the present invention maximizes the performance of each wheel by integrating the steering and braking performance of the four wheels, thereby ensuring the stability and safety of the four-wheel independent drive vehicle to the greatest extent possible.

[0059] An embodiment of the present invention further provides a vehicle control device, comprising a memory, a processor, and a program stored in the memory and executable on the processor, wherein the program implements the control method of the above embodiment when executed by the processor.

[0060] For example, the processor and memory in a vehicle controller can be connected via a bus. Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer executable programs. Furthermore, the memory can include high-speed random access memory and non-transitory memory, such as at least one disk drive, flash memory device, or other non-transitory solid-state memory device. In some embodiments, the memory can optionally include memory remotely located relative to the control processor, and these remote memories can be connected to the control device via a network.

[0061] The non-transitory software program and instructions required to implement the control method of the above embodiment are stored in the memory, and when executed by the processor, the control method of the above embodiment is executed.

[0062] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0063] An embodiment of the present invention further provides a vehicle, comprising the vehicle control device of the above embodiment.

[0064] The vehicle can be a private car, such as a sedan, SUV, MPV, or pickup truck. It can also be a commercial vehicle, such as a van, bus, small truck, or large trailer. The vehicle must have an electric motor that can output power or store mechanical energy as a generator. If the vehicle is a new energy vehicle, it can be a hybrid or a pure electric vehicle.

[0065] Since the vehicle applies all the technical solutions of the above-mentioned control device or vehicle controller, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here.

[0066] In addition, an embodiment of the present invention further provides a computer-readable storage medium, which stores computer-executable instructions for executing the above-mentioned vehicle stability control method based on four-wheel independent steering.

[0067] It is worth noting that since the computer-readable storage medium of an embodiment of the present invention is capable of executing the vehicle stability control method based on four-wheel independent steering of any of the above-mentioned embodiments, the specific implementation methods and technical effects of the computer-readable storage medium of an embodiment of the present invention can refer to the specific implementation methods and technical effects of the vehicle stability control method based on four-wheel independent steering of any of the above-mentioned embodiments.

[0068] In addition, an embodiment of the present invention also provides a computer program product, including a computer program or computer instructions, which are stored in a computer-readable storage medium. The processor of the computer device reads the computer program or computer instructions from the computer-readable storage medium, and the processor executes the computer program or computer instructions, so that the computer device executes the above-mentioned vehicle stability control method based on four-wheel independent steering.

[0069] It is worth noting that since the computer program product of the embodiment of the present invention is capable of executing the vehicle stability control method based on four-wheel independent steering of any of the above-mentioned embodiments, the specific implementation methods and technical effects of the computer program product of the embodiment of the present invention can refer to the specific implementation methods and technical effects of the vehicle stability control method based on four-wheel independent steering of any of the above-mentioned embodiments.

[0070] Those skilled in the art will appreciate that all or some of the steps and systems disclosed above can be implemented as software, firmware, hardware, or any suitable combination thereof. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on computer-readable media, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is well known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVDs) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. Furthermore, as is well known to those skilled in the art, communication media typically includes computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0071] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

Claims

1. A vehicle stability control method based on four-wheel independent steering, characterized in that: The control method comprises: Establishing a vehicle state model based on the relationship between tire tangential force and vehicle speed; wherein the tire tangential force includes the wheel longitudinal force and wheel lateral force of each tire; Establishing a control target model based on the relationship between the wheel lateral force and the center of mass balance of the vehicle; In response to a desired vehicle state, obtaining a target wheel longitudinal force and a target wheel lateral force based on the vehicle state model and the control target model; Obtaining a target tire tangential parameter according to the target wheel longitudinal force and the target wheel lateral force; In response to the target tire tangential parameter of each tire, steering braking control is performed on the corresponding tire.

2. The vehicle stability control method based on four-wheel independent steering according to claim 1, characterized in that: The vehicle state model includes a longitudinal force balance model, a lateral force balance model, and a yaw return model; the vehicle state model is established based on the relationship between the tire tangential force and the vehicle speed, including: The longitudinal force balance model is established based on the relationship between the wheel longitudinal force and the longitudinal vehicle speed of all tires; wherein the expression of the longitudinal force balance model is: Where, represents the derivative of the longitudinal vehicle speed; Indicates the The longitudinal force of the wheel of each tire; Indicates the vehicle mass; Indicates the lateral moving speed of the vehicle; represents the vehicle's yaw angular velocity; The lateral force balance model is established based on the relationship between the wheel lateral force and the lateral vehicle speed of all tires; wherein the expression of the lateral force balance model is: Where, represents the derivative of the lateral vehicle speed; Indicates the The wheel lateral force of each tire; Indicates the longitudinal moving speed of the vehicle; The yaw righting model is established based on the relationship between the tire tangential force and the yaw angular velocity of all tires; wherein the expression of the yaw righting model is: Where, represents the derivative of the yaw rate; Represents the moment of inertia of the vehicle around the z-axis; Indicates the The longitudinal force of the wheel of each tire, ; Indicates the The lateral force of the wheel of each tire, ; Indicates the vehicle wheelbase; , Indicates the distance of the center of mass from the front axle and the distance from the rear axle.

3. The vehicle stability control method based on four-wheel independent steering according to claim 1, characterized in that: The control target model includes a yaw balance model and a lateral balance model; the control target model is established based on the relationship between the wheel lateral force and the center of mass balance of the vehicle, including: The cornering balance model is established based on the relationship between the wheel lateral force and the vehicle center of mass slip angle; wherein the expression of the cornering balance model is: Where, represents the derivative of the vehicle's center of mass sideslip angle; Indicates the vehicle mass; Indicates longitudinal vehicle speed; Indicates the total lateral force on the front axle; represents the total lateral force of the rear axle; wherein the total lateral force of the front axle is obtained by summing the wheel lateral forces of all tires on the front axle, and the total lateral force of the rear axle is obtained by summing the wheel lateral forces of all tires on the rear axle; Establishing the yaw balance model based on the relationship between the wheel lateral force and the yaw angle of the vehicle center of mass; Where, represents the derivative of the vehicle's center of mass yaw angle; Represents the moment of inertia of the vehicle around the z-axis; Indicates the distance between the center of mass and the front axle; Indicates the distance from the center of mass to the rear axle.

4. The vehicle stability control method based on four-wheel independent steering according to claim 1, characterized in that: The step of obtaining a target wheel longitudinal force and a target wheel lateral force based on the vehicle state model and the control target model in response to the desired vehicle state includes: The desired vehicle state is converted into input parameters, and a preset multi-input multi-output control algorithm is adopted to solve the target wheel longitudinal force and target wheel lateral force of each tire using the vehicle state model and the control target model.

5. The vehicle stability control method based on four-wheel independent steering according to claim 1, characterized in that: The step of converting the target wheel longitudinal force and the target wheel lateral force to obtain the target tire tangential parameter includes: According to the target wheel longitudinal force and the target wheel lateral force of each tire, the target tire tangential parameter of the corresponding tire is obtained by solving a preset tangential force formula.

6. The vehicle stability control method based on four-wheel independent steering according to claim 5, characterized in that: The target tire tangential parameters include a target tire tangential force and a target tire tangential force direction; and the target tire tangential parameters of the corresponding tire are obtained by solving a preset tangential force formula based on the target wheel longitudinal force and the target wheel lateral force of each tire, including: Taking the square root of the sum of the target wheel longitudinal force and the target wheel lateral force of each tire to obtain the target tire tangential force of the corresponding tire; Performing an inverse tangent on the ratio of the target wheel lateral force to the target wheel longitudinal force of each tire to obtain the target tire tangential force direction of the corresponding tire; Wherein, the expression of the tangential force formula is: Where, Indicates the Target tire tangential force for each tire; Indicates the The longitudinal force of the wheel of each tire; Indicates the The wheel lateral force of each tire; Indicates the Target tire tangential force direction for each tire; is the inverse tangent function.

7. The vehicle stability control method based on four-wheel independent steering according to claim 1, characterized in that: The target tire tangential parameters include a target tire tangential force and a target tire tangential force direction; The step of performing steering braking control on the corresponding tire in response to the target tire tangential parameter of each tire comprises: performing brake pressure control on the corresponding tire in response to the target tire tangential force of each tire; In response to the target tire tangential force direction of each tire, the steering angle of the corresponding tire is controlled.

8. A vehicle, characterized in that: The invention comprises a memory, a processor and a program stored in the memory and executable on the processor, wherein when the program is executed by the processor, the vehicle stability control method based on four-wheel independent steering as claimed in any one of claims 1 to 7 is implemented.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the vehicle stability control method based on four-wheel independent steering according to any one of claims 1 to 7.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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