A dual-motor vehicle spin-on-the-spot control method and system

Abstract

This invention provides a method and system for controlling on-the-spot steering in a dual-motor vehicle, relating to the field of chassis dynamics control technology for new energy vehicles. The method includes: when the front wheel steering angle reaches its maximum value, firstly, physically anchoring the vehicle, then performing reverse driving to generate a rotational torque around the outer rear wheel, which is the wheel pointing away from the steering wheel; utilizing the nonlinear characteristics of tire dynamics to eliminate lateral damping of the front wheels; using the limit steering angle to convert the front axle driving force into an active rotational torque; and performing braking balancing and torque transfer on the inner side of the front axle to achieve on-the-spot steering. This invention solves the technical problems of high lateral resistance, rotation center offset, poor adaptability to unpaved roads, and high hardware cost in existing dual-motor vehicles, and is suitable for off-road and multi-condition new energy vehicles.

Description

Technical Field

[0001] This invention relates to the field of chassis dynamics control technology for new energy vehicles, and in particular to a method and system for controlling in-situ steering of a dual-motor vehicle. Background Technology

[0002] With the development of new energy vehicle technology, the dual-motor drive architecture (single motor on the front axle and single motor on the rear axle) has been widely used in off-road and multi-condition vehicles. To improve vehicle passability and maneuverability, it is urgent to realize small-radius steering and even stationary turning functions.

[0003] Existing stationary steering technologies are mainly divided into two categories:

[0004] 1) Traditional fuel-powered off-road vehicles employ a tank turn strategy, steer by braking the inner rear wheel and driving the outer rear wheel. Its drawbacks include: uncontrollable turning radius, significant susceptibility to road conditions, low steering efficiency, and poor adaptability to unpaved surfaces.

[0005] 2) Dual-motor electric vehicles employ a geometric speed matching strategy, controlling the front motor output based on the theoretical linear velocity of the rotation center. Its drawbacks include: incomplete elimination of lateral damping in the front wheels, high rotational resistance, susceptibility to "plowing effect," easy forward shift of the rotation center, severe trajectory deviation, and low success rate of turning in place.

[0006] In summary, existing technologies cannot simultaneously solve core problems such as lateral resistance elimination, rotation center stability, unpaved road surface adaptation, and low-cost implementation. There is an urgent need for a dual-motor vehicle in-situ steering control method and system to solve the problems of existing technologies. Summary of the Invention

[0007] The present invention aims to solve at least one of the technical problems existing in the prior art, and proposes a method and system for controlling the in-situ steering of a dual-motor vehicle.

[0008] In a first aspect, embodiments of the present invention provide a method for controlling the in-situ steering of a dual-motor vehicle, comprising:

[0009] When the front wheel steering angle reaches its maximum value, the vehicle is first physically anchored, and then reverse drive is performed to generate a rotational torque around the outer rear wheel, which is the wheel pointing to the side opposite to the steering wheel.

[0010] The lateral damping of the front wheels is eliminated by utilizing the nonlinear characteristics of tire dynamics;

[0011] The front axle driving force is converted into active rotational torque by utilizing the extreme steering angle;

[0012] Braking balance and torque transfer are performed on the inner side of the front axle to achieve stationary steering of the vehicle.

[0013] Furthermore, the vehicle is physically anchored and then reverse-driven. The specific method includes: first, braking and locking the outer rear wheel as a fixed fulcrum for the vehicle's rotation; then controlling the rear axle motor to output reverse torque, calculating and matching the target speed of the inner rear wheel according to the differential speed law and a set standard yaw rate; relying on the characteristics of the open rear axle differential, all the reverse power of the motor is transmitted to the inner rear wheel to form a driving torque, ultimately generating a rotational torque around the outer rear wheel, providing stable initial rotational power to the vehicle; the inner rear wheel is the wheel on the side the steering wheel is pointing towards.

[0014] Furthermore, the target speed of the rear wheel is calculated based on the desired target yaw rate centered on the outer locked rear wheel. The specific calculation formula is as follows:

[0015]

[0016] in, The target speed for the rear wheels. Let d be the desired target yaw rate with the outermost locked rear wheel as the center, and d be the wheelbase of the vehicle.

[0017] Furthermore, the lateral damping of the front wheels is eliminated by utilizing the nonlinear characteristics of tire dynamics. Specific methods include:

[0018] By outputting positive torque through the front axle motor, the theoretical linear velocity of the left and right front wheels around the instantaneous center of rotation is first calculated based on the vehicle's fixed-point rotational geometry. With the target slip ratio as the control target, the wheel speed constraint conditions are derived by combining the motion direction projection. The characteristics of the front axle differential are used to control the sum of the wheel speeds of the two wheels, so that both the left and right front wheels enter the high slip ratio range.

[0019] Increasing the slip ratio of the front wheels causes the longitudinal driving force to approach the road surface adhesion limit, significantly reducing the lateral force margin and making the lateral resistance of the front wheels almost disappear.

[0020] Furthermore, the theoretical linear velocities of the left and right front wheels around the instantaneous center of rotation are calculated using the following formula:

[0021]

[0022]

[0023] in, Let the linear velocity of the left front wheel around the instantaneous center be denoted as . Let the linear velocity of the right front wheel around the instantaneous center be denoted as . Let d be the desired target yaw rate with the outermost locked rear wheel as the center, and l be the vehicle's left and right wheel track width and front and rear wheel track width.

[0024] Furthermore, both front wheels are brought into a high slip ratio range. The slip ratio of the left front wheel is calculated using the following formula:

[0025]

[0026] in, The speed of the left front wheel. This represents the maximum front wheel steering angle. , The linear velocity of the left front wheel around the instantaneous center;

[0027] The formula for calculating the slip ratio of the right front wheel is:

[0028]

[0029] in, The speed of the left front wheel. This represents the maximum front wheel steering angle. , The linear velocity of the right front wheel around the instantaneous center is given.

[0030] Furthermore, the front axle driving force is converted into an active rotational torque, which is decomposed into longitudinal and lateral components. Horizontal component ;in, Front-wheel drive This represents the maximum front wheel steering angle.

[0031] Furthermore, by applying braking torque only to the inner wheels of the front axle and not braking the outer front wheels, braking balance and torque transfer can be achieved on the inner side of the front axle.

[0032] Furthermore, specific methods for applying braking torque to the inner front wheels while not braking the outer front wheels include:

[0033] By consuming the longitudinal component of the driving force decomposition through the braking torque of the inner front wheel, the longitudinal forward movement of the vehicle body is suppressed, and the instantaneous center of rotation is fixed.

[0034] By maintaining a high slip ratio with the outer front wheel, a continuous lateral rotational torque is provided, achieving steady-state stationary steering with zero longitudinal displacement and maximized yaw torque.

[0035] Secondly, the present invention also discloses a dual-motor vehicle stationary steering control system, comprising: a rear axle locking and anchoring and reverse torque construction unit, a front axle geometric vector active swivel unit, and a front axle inner side braking longitudinal balance and torque transfer unit; wherein:

[0036] The rear axle locking anchoring and reverse torque construction unit is used to first physically anchor the vehicle when the front wheel steering angle reaches its maximum value, and then reverse drive to generate a rotational torque around the outer rear wheel, which is the wheel pointing away from the steering wheel.

[0037] The front axle high slip ratio drag reduction control unit utilizes the nonlinear characteristics of tire dynamics to eliminate lateral damping of the front wheels;

[0038] The front axle geometric vector active rotation unit converts the front axle driving force into active rotational torque by utilizing the extreme steering angle;

[0039] The front axle inner side braking longitudinal balance and torque transfer unit is used to perform braking balance and torque transfer on the inner side of the front axle, so as to realize vehicle stationary turning.

[0040] Thirdly, the present invention also discloses an electronic device, comprising:

[0041] One or more processors;

[0042] Memory, used to store one or more programs;

[0043] When the one or more programs are executed by the one or more processors, the one or more processors implement the control method.

[0044] A computer-readable medium storing a computer program, characterized in that the computer program, when executed by a processor, implements the steps in the control method.

[0045] This invention provides a method and system for controlling stationary steering in a dual-motor vehicle. The method includes: when the front wheel steering angle reaches its maximum value, firstly, physically anchoring the vehicle, then performing reverse driving to generate a rotational torque around the outer rear wheel, where the outer rear wheel is the wheel pointing away from the steering wheel; eliminating lateral damping of the front wheels using the nonlinear characteristics of tire dynamics; converting the front axle driving force into an active rotational torque using the limit steering angle; and performing braking balancing and torque transfer on the inner side of the front axle to achieve stationary steering. This invention solves the technical problems of high lateral resistance, rotation center offset, poor adaptability to unpaved roads, and high hardware cost in existing dual-motor vehicles, and is suitable for off-road and multi-condition new energy vehicles.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] 1. Complete elimination of lateral resistance: The high slip ratio of this invention makes the lateral force of the front wheel approach zero, and there is no soil accumulation or plowing effect on unpaved roads, making it highly adaptable.

[0048] 2. Fixed-point steering and zero trajectory deviation: The inner braking of this invention cancels the longitudinal component, and the instantaneous center of rotation is fixed to the outer rear wheel, realizing true on-the-spot steering.

[0049] 3. Low-cost torque vectoring: This invention eliminates the need for four independent motors and utilizes an open differential and brake control to simulate high-end torque vectoring effects with low hardware costs. Attached Figure Description

[0050] Figure 1 This is a flowchart illustrating a method for controlling the in-situ steering of a dual-motor vehicle according to an embodiment of the present invention.

[0051] Figure 2 This is a schematic diagram showing the decomposition of the linear velocities of the left and right front wheels provided in an embodiment of the present invention;

[0052] Figure 3 This is a structural block diagram of a dual-motor vehicle in-situ steering control system provided in an embodiment of the present invention;

[0053] Figure 4 This is a structural block diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0054] To enable those skilled in the art to better understand the technical solutions of the present invention, exemplary embodiments of the present invention are described below in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0055] Where there is no conflict, the various embodiments of the present invention and the features thereof may be combined with each other.

[0056] As used herein, the term “and / or” includes any and all combinations of one or more related enumerated entries.

[0057] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when the terms “comprising” and / or “made of” are used in this specification, the presence of the stated feature, integral, step, operation, element, and / or component is specified, but the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof is not excluded. Terms such as “connected” or “linked” are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect.

[0058] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art and the invention, and will not be interpreted as having an idealized or overly formal meaning unless expressly so defined herein.

[0059] In the technical solution of this invention, the collection, storage, use, processing, transmission, provision, and disclosure of user personal information all comply with relevant laws and regulations and do not violate public order and good morals. The use of user data in this technical solution follows relevant national laws and regulations (e.g., the "Information Security Technology - Personal Information Security Specification"). For example: appropriate measures are taken for personal information access control; restrictions are imposed on the display of personal information; the purpose of using personal information does not exceed the scope of direct or reasonable association; and explicit identity targeting is eliminated when using personal information to avoid precisely locating a specific individual.

[0060] To address at least one of the technical problems existing in the aforementioned related technologies, the present invention provides a method and system for controlling the in-situ steering of a dual-motor vehicle.

[0061] This embodiment discloses a method for controlling the in-situ steering of a dual-motor vehicle, such as... Figure 1 ,include:

[0062] S100. When the steering angle of the front wheel reaches its maximum value, the vehicle is first physically anchored, and then reverse drive is performed to generate a rotational torque around the outer rear wheel, wherein the outer rear wheel is the wheel pointing to the side opposite to the steering wheel.

[0063] In this embodiment, the vehicle is physically anchored and then reverse-driven. The specific method includes: first, braking and locking the outer rear wheel as a fixed fulcrum for the rotation of the entire vehicle; then controlling the rear axle motor to output reverse torque, and calculating and matching the target speed of the inner rear wheel according to the differential speed law and the set standard yaw rate through feedback control; relying on the characteristics of the open differential of the rear axle, all the reverse power of the motor is transmitted to the inner rear wheel to form a driving torque, and finally generating a rotational torque around the outer rear wheel, providing stable initial rotational power to the vehicle; the inner rear wheel is the wheel on the side to which the steering wheel is pointing.

[0064] Specifically, before implementing this control method, preconditions are set. Specifically, the steering wheel is turned to the mechanical limit so that the front wheel steering angle reaches its maximum value. (Usually greater than 35°). The inner wheel is defined as the wheel pointing to the side where the steering wheel is turned; the outer wheel is defined as the wheel pointing away from the side where the steering wheel is turned.

[0065] In this embodiment, the vehicle is first physically anchored: the vehicle's integrated braking system is controlled to apply high-intensity hydraulic braking pressure (locking) to the outer rear wheel, thus establishing a physical fulcrum for the vehicle's rotation.

[0066] Then reverse drive is implemented: the rear axle motor is controlled to output torque for backward travel. This driving force propels the vehicle to rotate around the outer rear wheel, while simultaneously causing the inner rear wheel to reach the target speed. According to the differential's kinematic equation: ω1 + ω2 = 2ω, this indicates that the sum of the rotational speeds of the left and right half-shaft gears is equal to twice the rotational speed of the differential housing. When the outer wheel is locked, the relationship between the rotational speed of the inner rear wheel and the motor's rotational speed is fixed, making it completely controllable. The target speed of the rear wheel is based on the desired yaw rate centered on the locked outer rear wheel. Calculated. In this embodiment, a velocity trending towards the front of the vehicle is defined as positive, and a velocity trending towards the rear of the vehicle is defined as negative. To ensure that the vehicle's rotational speed simultaneously meets the requirements of good comfort, easily controllable rotational efficiency, and prevents the instantaneous center of gravity from shifting during rotation, the target yaw rate is typically... Set as Excessive yaw rate generates excessive centrifugal force, and the ultimate adhesion provided by the ground may not be sufficient to generate enough centripetal force to overcome such centrifugal force. A better method is to calibrate different target yaw rates based on different ground types. However, the focus of this method is not on how to determine the target yaw rate, so it will not be discussed further. The target yaw rate... Set as It can basically meet the requirements of most scenarios.

[0067] Next, the torque is transmitted: since the outer rear wheel is locked, according to the principle of the open differential on the rear axle, all the reverse power will be transmitted to the inner rear wheel, causing it to generate a reverse driving torque. The fundamental rotational torque about the outer rear wheel pivot point is generated by the reverse driving torque. This provides the vehicle with an initial rotational trend.

[0068] S200. Eliminating lateral damping of the front wheels using the nonlinear characteristics of tire dynamics; In this embodiment, the lateral damping of the front wheels is eliminated using the nonlinear characteristics of tire dynamics, specifically including:

[0069] S201. By outputting positive torque through the front axle motor, the theoretical linear velocity of the left and right front wheels around the instantaneous center of rotation is first calculated based on the vehicle's fixed-point rotational geometry. The target slip ratio is used as the control target. The wheel speed constraint condition is derived by combining the motion direction projection. The characteristics of the front axle differential are used to control the sum of the wheel speeds of the two wheels, so that both the left and right front wheels enter the high slip ratio range.

[0070] S202. Increase the slip ratio of the front wheels. When the slip ratio of the front wheels is increased, the longitudinal driving force approaches the road adhesion limit, which greatly reduces the lateral force margin, making the lateral resistance of the front wheels almost disappear.

[0071] Specifically, the core of step S200 in this implementation lies in utilizing the nonlinear characteristics of tire dynamics to eliminate the lateral damping of the front wheels. The control logic is as follows: control the front axle motor to output positive torque. Ideally, the yaw rate of the vehicle body with the outer rear wheel as the center is... The wheels rotate at a constant speed. The linear velocities of the left and right front wheels around the instantaneous center can be determined, such as... Figure 2 As shown, the theoretical linear velocities of the left and right front wheels around the instantaneous center of rotation are calculated using the following formula:

[0072]

[0073]

[0074] in, Let the linear velocity of the left front wheel around the instantaneous center be denoted as . Let the linear velocity of the right front wheel around the instantaneous center be denoted as . Let d be the desired target yaw rate with the outermost locked rear wheel as the center, and l be the vehicle's left and right wheel track width and front and rear wheel track width.

[0075] In this embodiment, the controllable objective is to make the actual wheel speeds of the two front wheels exceed the high slip ratio. Since the vehicle is not moving in a straight line at this time, the slip ratio needs to be calculated by projecting the wheel speed onto the front wheel in the direction of the linear velocity.

[0076] Left front wheel slip ratio: ;

[0077] slip ratio of the right front wheel: ;

[0078] in, The speed of the left front wheel. This represents the maximum front wheel steering angle. , The linear velocity of the left front wheel around the instantaneous center; The speed of the left front wheel. This represents the maximum front wheel steering angle. , The linear velocity of the right front wheel around the instantaneous center is given.

[0079] In this embodiment, to make and If all are greater than 0.2, then , Because of the differential, the wheel speeds of the left and right wheels cannot be precisely controlled. However, the sum of the wheel speeds of the left and right wheels can be controlled, making... The goal is to keep both wheels in a high slip ratio state as much as possible.

[0080] In this embodiment, according to the tire friction circle theory, the resultant force that the tire can provide at the contact surface is limited by the road adhesion coefficient μ and the vertical load Fz, that is:

[0081]

[0082] Where Fx is the longitudinal driving force and Fy is the lateral friction force (i.e., the lateral resistance that hinders rotation). This invention forces the front wheels into a high slip ratio saturation state by significantly increasing the front wheel speed. At this point, the tire's longitudinal force Fx approaches the adhesion limit Fy. According to the formula, when Fx approaches... At this point, the available lateral force space is compressed to its limit, that is:

[0083]

[0084] At this point, the physical characteristics of the front tire undergo a qualitative change, transforming from a "rolling body with high lateral damping" into a "sliding body with extremely low lateral damping." The front tire seems to "float" on the road surface and is easily pushed sideways by the torque generated by the rear axle.

[0085] S300. The front axle driving force is converted into active rotational torque using the extreme steering angle; in this embodiment, the front axle driving force is converted into active rotational torque, and the driving force is decomposed into a longitudinal component and a lateral component, the longitudinal component... Horizontal component ;in, Front-wheel drive This represents the maximum front wheel steering angle.

[0086] This implementation, step S300, utilizes the extreme steering angle to convert the front axle driving force into active rotational torque. Through dynamic analysis, at the extreme steering angle... Below, the direction of the front-wheel drive force Fdrive is perpendicular to the longitudinal axis of the vehicle body. Angle. At this point, the driving force is decomposed into two components: a longitudinal component and a lateral component.

[0087] Longitudinal component: The longitudinal component causes the vehicle body to move forward, which needs to be eliminated in step S400.

[0088] Lateral component: The line connecting the outer rear wheel and the drive wheel perpendicular to the wheel directly causes the front of the vehicle to sway sideways.

[0089] As can be seen from the above decomposition of driving force, the front wheels can not only actively reduce lateral resistance, but also actively push the front of the car to rotate around the rear axle, which greatly improves the steering power.

[0090] S400. Braking balance and torque transfer are performed on the inner side of the front axle to achieve stationary steering of the vehicle. In this embodiment, braking balance and torque transfer on the inner side of the front axle are achieved by applying braking torque only to the inner wheels of the front axle and not braking the outer front wheels.

[0091] The specific methods for applying braking torque to the inner front wheel while not braking the outer front wheel include:

[0092] By consuming the longitudinal component of the driving force decomposition through the braking torque of the inner front wheel, the longitudinal forward movement of the vehicle body is suppressed, and the instantaneous center of rotation is fixed.

[0093] By maintaining a high slip ratio with the outer front wheel, a continuous lateral rotational torque is provided, achieving steady-state stationary steering with zero longitudinal displacement and maximized yaw torque.

[0094] Specifically, while embodiments S200-S300 eliminate drag and provide cyclonic force, they also generate a side effect: a longitudinal component Flong. Embodiment S400 addresses this issue by using independent braking of the inner front wheel.

[0095] This implementation of the S400 step-controlled braking system applies active braking torque (Tbrake_Finne) only to the inner front wheels to suppress forward movement, strictly prohibiting braking the outer front wheels. Through mechanical calculations and analysis, it is known that a larger proportion of the driving force on the inner front wheels is used to propel the vehicle forward, while a very small proportion is used to assist the vehicle's rotation around the outer rear wheels. Therefore, braking the inner front wheels can significantly and effectively improve the problem of the vehicle's instantaneous center of gravity not being fixed, without significantly negatively impacting the vehicle's rotation around the outer rear wheels. This method only describes the qualitative implementation strategy and does not specifically describe the quantitative control methods.

[0096] This embodiment provides a method for controlling on-the-spot steering of a dual-motor vehicle, comprising: firstly, physically anchoring the vehicle when the front wheel steering angle reaches its maximum value, and then performing reverse driving to generate a rotational torque around the outer rear wheel, wherein the outer rear wheel is the wheel pointing away from the steering wheel; eliminating the lateral damping of the front wheels using the nonlinear characteristics of tire dynamics; converting the front axle driving force into an active rotational torque using the limit steering angle; and performing braking balancing and torque transfer on the inner side of the front axle to achieve on-the-spot steering. This invention solves the technical problems of existing dual-motor vehicles, such as high lateral resistance during on-the-spot steering, rotation center offset, poor adaptability to unpaved roads, and high hardware costs, and is suitable for off-road and multi-condition new energy vehicles.

[0097] Based on the same inventive concept, embodiments of the present invention also provide a dual-motor vehicle in-situ steering control system, such as... Figure 3 It includes: a rear axle locking anchoring and reverse torque construction unit, a front axle geometric vector active rotation unit, and a front axle inner braking longitudinal balance and torque transfer unit; wherein:

[0098] The rear axle locking anchoring and reverse torque construction unit is used to first physically anchor the vehicle when the front wheel steering angle reaches its maximum value, and then reverse drive to generate a rotational torque around the outer rear wheel, which is the wheel pointing away from the steering wheel.

[0099] The front axle high slip ratio drag reduction control unit utilizes the nonlinear characteristics of tire dynamics to eliminate lateral damping of the front wheels;

[0100] The front axle geometric vector active rotation unit converts the front axle driving force into active rotational torque by utilizing the extreme steering angle;

[0101] The front axle inner side braking longitudinal balance and torque transfer unit is used to perform braking balance and torque transfer on the inner side of the front axle, so as to realize vehicle stationary turning.

[0102] The specific working methods of the rear axle locking anchoring and reverse torque construction unit, the front axle geometric vector active rotation unit, and the front axle inner braking longitudinal balance and torque transfer unit have been described in detail in the above control methods, and will not be repeated here.

[0103] Based on the same inventive concept, embodiments of the present invention also provide an electronic device. Figure 4 This is a structural block diagram of an electronic device provided in an embodiment of the present invention. Figure 4 As shown, an embodiment of the present invention provides an electronic device including: one or more processors 101, a memory 102, and one or more I / O interfaces 103. The memory 102 stores one or more programs, which, when executed by the one or more processors, cause the one or more processors to implement any of the control methods described in the above embodiments; the one or more I / O interfaces 103 are connected between the processor and the memory, configured to enable information interaction between the processor and the memory.

[0104] The processor 101 is a device with data processing capabilities, including but not limited to a central processing unit (CPU); the memory 102 is a device with data storage capabilities, including but not limited to random access memory (RAM, more specifically SDRAM, DDR, etc.), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and flash memory (FLASH); the I / O interface (read / write interface) 103 is connected between the processor 101 and the memory 102, and can realize information interaction between the processor 101 and the memory 102, including but not limited to a data bus (Bus).

[0105] In some embodiments, the processor 101, memory 102, and I / O interface 103 are interconnected via bus 104, and thus connected to other components of the computing device.

[0106] In some embodiments, the one or more processors 101 include a field-programmable gate array.

[0107] This invention also provides a computer-readable medium. The computer-readable medium stores a computer program, which, when executed by a processor, implements the steps of any of the control methods described in the above embodiments. The computer-readable storage medium may be volatile or non-volatile.

[0108] This invention also provides a computer program product, including computer-readable code, or a non-volatile computer-readable storage medium carrying computer-readable code. When the computer-readable code is run in the processor of an electronic device, the processor in the electronic device executes the above-described control method.

[0109] Those skilled in the art will understand that all or some of the steps, systems, and apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all 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 (ASIC). Such software can be distributed on a computer-readable storage medium, which may include computer storage media (or non-transitory media) and communication media (or transient media).

[0110] As is known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable program instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), static random access memory (SRAM), flash memory or other memory technologies, portable compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, it is known to those skilled in the art that communication media typically contain computer-readable program instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0111] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0112] The computer program instructions used to perform the operations of this invention may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing state information from the computer-readable program instructions. This electronic circuitry can execute the computer-readable program instructions to implement various aspects of the invention.

[0113] The computer program product described herein can be implemented specifically through hardware, software, or a combination thereof. In one alternative embodiment, the computer program product is specifically embodied in a computer storage medium; in another alternative embodiment, the computer program product is specifically embodied in a software product, such as a software development kit (SDK), etc.

[0114] Various aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should 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-readable program instructions.

[0115] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when executed by the processor of the computer or other programmable data processing apparatus, they create means for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, programmable data processing apparatus, and / or other device to operate in a particular manner; thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0116] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0117] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction, which contains one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0118] Example embodiments have been disclosed herein, and while specific terminology has been used, it is for illustrative purposes only and should be construed as such, and is not intended to be limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in conjunction with particular embodiments may be used alone, or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of the invention as set forth in the appended claims.

Claims

1. A method for controlling in-situ steering of a dual-motor vehicle, characterized in that, include: When the steering angle of the front wheel reaches its maximum value, the vehicle is physically anchored and reverse-driven to generate a rotational torque around the outer rear wheel, which is the wheel pointing to the side opposite to the steering wheel. The lateral damping of the front wheels is eliminated by utilizing the nonlinear characteristics of tire dynamics; The front axle driving force is converted into active rotational torque by utilizing the extreme steering angle; Braking balance and torque transfer are performed on the inner side of the front axle to achieve stationary steering of the vehicle.

2. The control method according to claim 1, characterized in that, The vehicle is physically anchored and then reverse-driven. The specific method includes: first, braking and locking the outer rear wheel as a fixed fulcrum for the vehicle's rotation; then controlling the rear axle motor to output reverse torque, and calculating and matching the target speed of the inner rear wheel according to the differential speed law and the set standard yaw rate; relying on the characteristics of the open differential of the rear axle, all the reverse power of the motor is transmitted to the inner rear wheel to form a driving torque, which ultimately generates a rotational torque around the outer rear wheel, providing the vehicle with stable initial rotational power; the inner rear wheel is the wheel on the side the steering wheel is pointing.

3. The control method according to claim 1, characterized in that, The target speed of the rear wheel is calculated based on the desired yaw rate centered on the outermost locked rear wheel. The specific calculation formula is as follows: in, The target speed for the rear wheels. Let d be the desired target yaw rate with the outermost locked rear wheel as the center, and d be the wheelbase of the vehicle.

4. The control method according to claim 1, characterized in that, The lateral damping of the front wheels can be eliminated by utilizing the nonlinear characteristics of tire dynamics. Specific methods include: By outputting positive torque through the front axle motor, the theoretical linear velocity of the left and right front wheels around the instantaneous center of rotation is first calculated based on the vehicle's fixed-point rotational geometry. With the target slip ratio as the control target, the wheel speed constraint conditions are derived by combining the motion direction projection. The characteristics of the front axle differential are used to control the sum of the wheel speeds of the two wheels, so that both the left and right front wheels enter the high slip ratio range. Increasing the slip ratio of the front wheels causes the longitudinal driving force to approach the road surface adhesion limit, significantly reducing the lateral force margin and making the lateral resistance of the front wheels almost disappear.

5. The control method according to claim 1, characterized in that, The theoretical linear velocities of the left and right front wheels around the instantaneous center of rotation are calculated using the following formula: in, Let the linear velocity of the left front wheel around the instantaneous center be denoted as . Let the linear velocity of the right front wheel around the instantaneous center be denoted as . Let d be the desired target yaw rate with the outermost locked rear wheel as the center, and l be the vehicle's left and right wheel track width and front and rear wheel track width.

6. The control method according to claim 5, characterized in that, This allows both front wheels to enter a high slip ratio range. The slip ratio of the left front wheel is calculated using the following formula: in, The speed of the left front wheel. This is the maximum front wheel steering angle. , The linear velocity of the left front wheel around the instantaneous center; The formula for calculating the slip ratio of the right front wheel is: in, The speed of the left front wheel. This is the maximum front wheel steering angle. , The linear velocity of the right front wheel around the instantaneous center is given.

7. The control method according to claim 1, characterized in that, The front axle driving force is converted into active rotational torque, which is decomposed into longitudinal and lateral components. Horizontal component ;in, Front-wheel drive This represents the maximum front wheel steering angle.

8. The control method according to claim 1, characterized in that, By applying braking torque only to the inner wheels of the front axle and not braking the outer front wheels, braking balance and torque transfer are achieved on the inner side of the front axle.

9. The control method according to claim 8, characterized in that, Specific methods for applying braking torque to the inner front wheels while not braking the outer front wheels include: By consuming the longitudinal component of the driving force decomposition through the braking torque of the inner front wheel, the longitudinal forward movement of the vehicle body is suppressed, and the instantaneous center of rotation is fixed. By maintaining a high slip ratio with the outer front wheel, a continuous lateral rotational torque is provided, achieving steady-state stationary steering with zero longitudinal displacement and maximized yaw torque.

10. A dual-motor vehicle in-situ steering control system, characterized in that, include: Rear axle locking and anchoring and reverse torque construction unit, front axle high slip ratio drag reduction control unit, front axle geometric vector active rotation unit, and front axle inner braking longitudinal balance and torque transfer unit; wherein: The rear axle locking anchoring and reverse torque construction unit is used to first physically anchor the vehicle when the front wheel steering angle reaches its maximum value, and then reverse drive to generate a rotational torque around the outer rear wheel, which is the wheel pointing away from the steering wheel. The front axle high slip ratio drag reduction control unit utilizes the nonlinear characteristics of tire dynamics to eliminate lateral damping of the front wheels; The front axle geometric vector active rotation unit converts the front axle driving force into active rotational torque by utilizing the extreme steering angle; The front axle inner side braking longitudinal balance and torque transfer unit is used to perform braking balance and torque transfer on the inner side of the front axle, so as to realize vehicle stationary turning.

11. An electronic device, characterized in that, include: One or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the control method as described in any one of claims 1 to 9.

12. A computer-readable medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the control method as described in any one of claims 1 to 9.

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