Turn-around method and device of electric automobile, electric automobile and electronic equipment

Abstract

The invention relates to the technical field of electric vehicle control, in particular to a turning-around method and device of an electric vehicle, the electric vehicle and a storage medium, and the method comprises the steps that in response to an in-situ turning-around request, the electric vehicle is controlled to enter an in-situ turning-around mode, and the target driving torque of each wheel is distributed based on the vertical load of the electric vehicle; based on the target driving torque, the electric vehicle is controlled to rotate according to the target yaw velocity, and the vehicle mass center offset of the electric vehicle is obtained; and generating a torque adjustment value of at least one wheel according to the mass center offset so as to adjust the driving torque of the at least one wheel until turning around is completed. Therefore, the technical problems that in the related technology, a special steering mechanism is complex in structure, low in reliability and high in cost, a distributed driving system is poor in flexibility, the needed ground area is large, and other structural spaces are compressed are solved.

Description

Technical Field

[0001] This application relates to the field of electric vehicle control technology, and in particular to a method, apparatus, electric vehicle, and storage medium for turning around an electric vehicle. Background Technology

[0002] When driving, cars inevitably need to turn on the spot in narrow spaces (especially U-turns), particularly in alleys or residential areas with heavy traffic. This not only makes turning and U-turns inconvenient but also causes congestion for electric vehicles.

[0003] To address the aforementioned issues, in-situ turning technology has emerged. Among related technologies, a special steering mechanism can reduce the turning radius, but this is not only structurally complex and unreliable, but also yields less than ideal in-situ turning results. Another approach involves a distributed drive system, such as a four-wheel hub motor distributed drive system. However, this is less flexible and requires a larger ground area, compressing the space available for other structural components, and therefore urgently needs improvement. Summary of the Invention

[0004] This application provides a method, apparatus, electric vehicle, and storage medium for turning around an electric vehicle, in order to solve the technical problems in related technologies, such as the complex structure, low reliability, and high cost of special steering mechanisms, the poor flexibility of distributed drive systems, and the large ground area required, which compresses the space of other structures.

[0005] The first aspect of this application provides a method for turning around an electric vehicle, applied to a distributed electric vehicle driven by four motors. The method includes the following steps: in response to a request to turn around in place, controlling the electric vehicle to enter a turn-around mode to distribute a target driving torque to each wheel based on the vertical load of the electric vehicle; based on the target driving torque, controlling the electric vehicle to rotate at a target yaw rate, and obtaining the vehicle center of gravity offset of the electric vehicle; generating a torque adjustment value for at least one wheel based on the center of gravity offset to adjust the driving torque of the at least one wheel until the turn-around is completed.

[0006] Optionally, in one embodiment of this application, before completing the U-turn, the method further includes: detecting whether the electric vehicle has rotated to a target turning angle; and if the target turning angle is detected, controlling the electric vehicle to exit the U-turn mode.

[0007] Optionally, in one embodiment of this application, the step of allocating the target driving torque of each wheel based on the vertical load of the electric vehicle includes: obtaining the road surface adhesion coefficient of the current road; and determining the target driving torque of each wheel according to the vertical load and the road surface adhesion coefficient.

[0008] Optionally, in one embodiment of this application, before determining the target drive torque for each wheel, the method further includes: acquiring the vehicle body state of the electric vehicle; matching the vehicle body state with an allocation strategy for the electric vehicle to determine the target drive torque using the allocation strategy.

[0009] Optionally, in one embodiment of this application, generating the torque adjustment value of at least one wheel based on the center of gravity offset includes: determining the target yaw rate of the electric vehicle based on the target turning speed; and generating the torque adjustment value of the at least one wheel based on the target yaw rate when the center of gravity offset is within a preset range.

[0010] A second aspect of this application provides a U-turn device for an electric vehicle, applied to a distributed electric vehicle with four motors. The device includes: a response module, configured to control the electric vehicle to enter a U-turn mode in response to a U-turn request, and to distribute a target driving torque to each wheel based on the vertical load of the electric vehicle; a first control module, configured to control the electric vehicle to rotate at a target yaw rate based on the target driving torque, and to acquire the vehicle center of gravity offset of the electric vehicle; and an adjustment module, configured to generate a torque adjustment value for at least one wheel based on the center of gravity offset, to adjust the driving torque of the at least one wheel until the U-turn is completed.

[0011] Optionally, in one embodiment of this application, it further includes: a detection module for detecting whether the electric vehicle has rotated to the target turning angle; and a second control module for controlling the electric vehicle to exit the U-turn mode when the target turning angle is detected.

[0012] Optionally, in one embodiment of this application, the response module includes: a first acquisition unit, configured to acquire the road surface adhesion coefficient of the current road; and a determination unit, configured to determine the target driving torque of each wheel based on the vertical load and the road surface adhesion coefficient.

[0013] Optionally, in one embodiment of this application, the acquisition module further includes: a second acquisition unit, configured to acquire the vehicle body state of the electric vehicle; and a matching unit, configured to match the allocation strategy of the electric vehicle according to the vehicle body state, so as to determine the target driving torque using the allocation strategy.

[0014] Optionally, in one embodiment of this application, the adjustment module includes: a calculation unit, configured to determine the target yaw rate of the electric vehicle based on the target turning speed; and a generation unit, configured to generate torque adjustment values ​​for at least one wheel based on the target yaw rate when the center of gravity offset is within a preset range.

[0015] A third aspect of this application provides an electric vehicle, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the turning method of the electric vehicle as described in the above embodiments.

[0016] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for turning around an electric vehicle.

[0017] A fourth aspect of this application provides a computer program product, including a computer program that is executed to implement the above-described method for turning around an electric vehicle.

[0018] This application embodiment can respond to a U-turn request. After the electric vehicle enters the U-turn mode, it distributes the target drive torque to each wheel according to the vertical load of each wheel to control the electric vehicle to rotate at the target yaw rate. Furthermore, it generates a torque adjustment value for at least one wheel based on the center of gravity offset to adjust the drive torque of at least one wheel until the U-turn is completed. This enables the electric vehicle to perform a U-turn without steering wheels, rotating to any angle on the spot. Moreover, the ground area required for the electric vehicle during the entire turning process is much smaller than that required for conventional front-wheel steering, eliminating the need for a complex four-wheel steering mechanism, resulting in greater flexibility and easier application. Therefore, it solves the technical problems in related technologies where special steering mechanisms are complex, have low reliability and high cost, and distributed drive systems have poor flexibility and require a large ground area, compressing the space of other structures.

[0019] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0020] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0021] Figure 1 This is a flowchart illustrating a method for turning around an electric vehicle according to an embodiment of this application;

[0022] Figure 2 This is a simplified diagram illustrating the force analysis of a single tire during a U-turn according to an embodiment of this application.

[0023] Figure 3 This is a block diagram of the force analysis of four wheels when making a U-turn in place according to an embodiment of this application;

[0024] Figure 4 This is a schematic diagram illustrating the principle of a U-turn method for an electric vehicle according to an embodiment of this application;

[0025] Figure 5 This is a schematic diagram of the control logic for a U-turn method for an electric vehicle according to an embodiment of this application;

[0026] Figure 6 This is a schematic diagram of the yaw rate control principle according to an embodiment of this application;

[0027] Figure 7 This is a schematic diagram of the wheel speed difference control principle according to an embodiment of this application;

[0028] Figure 8 This is a schematic diagram of the target corner control logic provided according to an embodiment of this application;

[0029] Figure 9 This is a schematic diagram of the structure of a U-turn device for an electric vehicle according to an embodiment of this application;

[0030] Figure 10 This is a schematic diagram of the structure of an electric vehicle provided according to an embodiment of this application. Detailed Implementation

[0031] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0032] The following description, with reference to the accompanying drawings, describes a method, apparatus, electric vehicle, and storage medium for turning around an electric vehicle according to embodiments of this application. Addressing the technical problems mentioned in the background section of the related technologies, such as complex structures, low reliability, high costs, poor flexibility of distributed drive systems, and large required ground area, which compresses the space of other structures, this application provides a method for turning around an electric vehicle. In this method, in response to a request for turning around in place, after the electric vehicle enters the turning-around mode, a target drive torque is allocated to each wheel based on the vertical load of each wheel to control the electric vehicle to rotate at a target yaw rate. Furthermore, a torque adjustment value is generated for at least one wheel based on the center of gravity offset to adjust the drive torque of at least one wheel until the turn is completed. This enables the electric vehicle to turn around in place without steering wheels, rotating to any angle. Moreover, the ground area required by the electric vehicle during the entire turning process is much smaller than that required for conventional front-wheel steering, eliminating the need for a complex four-wheel steering mechanism, resulting in higher flexibility and easier application. Therefore, this solves the technical problems of complex structures, low reliability, high costs, poor flexibility of distributed drive systems, and large required ground area, which compress the space of other structures, in the related technologies.

[0033] Specifically, Figure 1 This is a flowchart illustrating a method for turning around an electric vehicle, as provided in an embodiment of this application.

[0034] like Figure 1 As shown, this method for turning around an electric vehicle is applied to a four-motor driven distributed electric vehicle, and the method includes the following steps:

[0035] In step S101, in response to a U-turn request, the electric vehicle is controlled to enter a U-turn mode to distribute the target drive torque to each wheel based on the vertical load of the electric vehicle.

[0036] In actual implementation, the electric vehicle in this application embodiment can receive a U-turn request. The U-turn request can be issued through voice commands, button triggering, or can also be triggered based on the current driving status of the electric vehicle, the surrounding road environment, or navigation information.

[0037] Upon receiving a request to turn around on the spot, this embodiment of the application can control the electric vehicle to enter the turn-around mode and obtain the relevant parameters of the electric vehicle required for the turn-around. Based on different adhesion coefficients and the magnitude of the vertical load on the four wheels, the drive torque of the four wheels is initially distributed to determine the target drive torque of each wheel, i.e., the initial drive torque.

[0038] Optionally, in one embodiment of this application, the target driving torque of each wheel is allocated based on the vertical load of the electric vehicle, including: obtaining the road surface adhesion coefficient of the current road; and determining the target driving torque of each wheel according to the vertical load and the road surface adhesion coefficient respectively.

[0039] Understandably, the coefficient of friction is a key parameter for measuring the maximum friction potential between a tire and the road surface, and is defined as the ratio of the adhesion force to the vertical load on the wheel.

[0040] The vertical load on a wheel refers to the vertical pressure exerted on the ground by an electric vehicle through its tires. Essentially, it is the normal support reaction force generated at the tire contact point by the electric vehicle's gravity and dynamic inertial force.

[0041] When an electric vehicle is stationary, the vertical load can be distributed to each wheel by gravity; during dynamic driving, the dynamic load transfer is determined based on longitudinal acceleration / braking and lateral turning. In the embodiments of this application, the dynamic vertical load can be monitored in real time using wheel-mounted finite element sensors.

[0042] When calculating the target driving torque, the embodiments of this application can obtain the road surface adhesion coefficient of the current road where the electric vehicle is located, and then dynamically allocate the target driving torque.

[0043] For example, embodiments of this application can calculate the vertical load of each wheel, identify the road surface adhesion coefficient, determine the torque limit of a single wheel, and distribute the load in combination with the efficiency or stability requirements of in-place steering to obtain the target driving torque.

[0044] Optionally, in one embodiment of this application, before determining the target drive torque for each wheel, the method further includes: obtaining the vehicle body state of the electric vehicle; matching the electric vehicle's allocation strategy according to the vehicle body state to determine the target drive torque using the allocation strategy.

[0045] Furthermore, in this embodiment, the electric vehicle's state parameters, primarily the four-wheel speed and yaw rate, can be used for state determination, as shown in Table 1. When the vehicle body state one is satisfied, torque distribution strategy one is implemented; when the vehicle body state two is satisfied, torque distribution strategy two is implemented; and when the vehicle body state three is satisfied, torque distribution strategy three is implemented. This ensures that the electric vehicle rotates around its center of mass during rotation, achieving a U-turn effect with minimal displacement of the electric vehicle's center of mass. Table 1 is the state description table for the collaborative control layer.

[0046] Table 1

[0047]

[0048] In step S102, based on the target driving torque, the electric vehicle is controlled to rotate at the target yaw rate, and the vehicle center of gravity offset of the electric vehicle is obtained.

[0049] As one possible approach, after obtaining the target driving torque, embodiments of this application can control the electric vehicle to perform in-situ steering with the target driving torque and obtain the vehicle's center of gravity offset to perform coordinated calculations on the target driving torque.

[0050] For example, in this embodiment of the application, the yaw rate and longitudinal vehicle speed can be obtained in real time, and the center of gravity lateral speed can be estimated to obtain the target yaw rate. The vehicle center of gravity offset can be obtained in real time by combining the parameter estimator.

[0051] In step S103, a torque adjustment value for at least one wheel is generated based on the centroid offset to adjust the drive torque of at least one wheel until the turn is completed.

[0052] To achieve the goal of adjusting wheel torque based on the center of gravity offset to complete a U-turn, the core is to calculate the center of gravity offset (usually referring to the lateral deviation between the center of gravity of the electric vehicle and the desired path) in real time, generate wheel torque adjustment values, and use differential drive torque to generate yaw torque to gradually correct the vehicle's orientation.

[0053] Optionally, in one embodiment of this application, generating torque adjustment values ​​for at least one wheel based on the center of gravity offset includes: determining the target yaw rate of the electric vehicle based on the target turning speed; and generating torque adjustment values ​​for at least one wheel based on the target yaw rate when the center of gravity offset is within a preset range.

[0054] As one possible approach, embodiments of this application can coordinate the distribution of driving torque among the four wheels by designing a four-wheel wheel speed difference control system, thereby keeping the center of gravity offset of the electric vehicle within a certain range.

[0055] For example, in this embodiment of the application, the target yaw rate of the four wheels can be determined by the steering speed and the road adhesion coefficient. A PID algorithm is designed based on the difference between the target yaw rate of each wheel and the actual vehicle speed to generate the torque adjustment value of at least one wheel.

[0056] Optionally, in one embodiment of this application, before completing the U-turn, the method further includes: detecting whether the electric vehicle has rotated to the target turning angle; and if the target turning angle is detected, controlling the electric vehicle to exit the U-turn mode.

[0057] In this embodiment of the application, the in-place turn exit strategy can be that the in-place turn exits when any of the following conditions are not met:

[0058] 1) Electric vehicles are ready;

[0059] 2) Electric vehicles are in Drive (D) mode;

[0060] 3) The difference between the speeds of any two wheels or the speeds of the two motors is less than a certain value;

[0061] 4) The angle turned is within the set target steering angle range;

[0062] 5) The absolute value of the steering wheel angle is less than a certain value (calibrated value, initially set to 30°);

[0063] 6) The brakes were not applied.

[0064] The control logic of item 4) is shown in the figure below: The IMU sensor collects the actual yaw rate, which is integrated to obtain the angle turned by the electric vehicle. When the target turning angle is reached, the steering control state is cleared to 0, and the torque and hydraulic control are coordinated. The torque smoothly exits according to a certain gradient, and the hydraulic system performs parking according to a certain gradient.

[0065] Combination Figures 2 to 8 As shown, the working principle of the electric vehicle turning method of this application embodiment is explained in detail with reference to one embodiment.

[0066] The solution in this application embodiment is to calculate the four-wheel drive torque in real time through yaw rate tracking control and four-wheel wheel speed difference control algorithm, so as to realize smooth stationary steering of electric vehicles in different scenarios.

[0067] First, such as Figure 2 As shown, this is a simplified diagram of the force analysis of a single tire when making a U-turn in place. The lateral force Fy' acting on the center of the wheel increases, the tire undergoes elastic deformation, and the elastic deformation and slip angle reach their limits, resulting in lateral slip Δv. Figure 3 This is a block diagram analyzing the forces acting on the four wheels during a U-turn. Driven by the drive shaft, opposing driving torques are applied to the left and right wheels, causing the electric vehicle to generate yaw moment and yaw rate. The longitudinal velocity and lateral slip of the electric vehicle combine to form the yaw rate, causing the wheels to travel along the tangent of the vehicle's circumference. When the applied driving torque equals the resistance torque, the electric vehicle rotates stably and at a constant speed.

[0068] Therefore, the control scheme of this application embodiment distributes the driving torque of the four wheels according to the magnitude of the vertical load on each wheel, so that the drive wheels generate driving force to overcome the resistance torque of the ground that hinders the rotation of the electric vehicle, causing the electric vehicle to rotate at a certain yaw rate. At the same time, through the design of the four-wheel speed difference control, the driving torque of the four wheels is coordinated and distributed, so that the center of gravity deviation of the electric vehicle is controlled within a certain range.

[0069] Specifically, the block diagram of the on-the-spot U-turn control system involved in the embodiments of this application can be as follows: Figure 4As shown, the IMU (Inertial Measurement Unit) sensor collects yaw rate information, the PBM (Parking Brake Module) outputs information such as lateral acceleration, longitudinal acceleration, four-wheel wheel speed, and four-wheel wheel cylinder pressure, and the EPS (Electric Power Steering) system outputs information such as steering wheel angle. The HMI (Human Machine Interface) (or the APP via BLE (Bluetooth module)) outputs the U-turn request, the target U-turn angle, the U-turn speed, and the U-turn direction. Based on the electric vehicle's status information, the PDCU (Power Distribution Unit) calculates the four-wheel drive torque in real time through yaw rate tracking control and four-wheel wheel speed difference algorithms, converting it into motor torque and outputting it to the MCU (Motor Control Unit). The MCU controls the four motors to achieve the target torque. When the electric vehicle rotates to the target angle, it exits the U-turn control and simultaneously sends a hydraulic request to the PBM to park.

[0070] By coordinating and controlling the pressure of four motors and four wheel cylinders, differential torque is applied to the left and right wheels to achieve differential steering or even turning on the spot, improving the passability of electric vehicles on narrow roads such as congested sections, bridges, and mountain roads, as well as the convenience of parallel parking.

[0071] The in-place U-turn function control can be divided into demand torque calculation and torque collaborative distribution.

[0072] I. Calculation of required torque:

[0073] The required torque is calculated using a yaw rate PID control algorithm. The yaw rate PID control algorithm is as follows: Figure 6As shown, after the U-turn function is activated, the U-turn speed is set via HMI (or via BLE (Bluetooth module) in the APP) to obtain the target yaw rate. A PID control algorithm is designed based on the deviation between the target yaw rate and the actual yaw rate. To ensure that the integral torque of term I (the torque calculated by integrating the difference between the target yaw rate and the actual yaw rate) is normal each time the U-turn is activated, a clearing module needs to be added (to add clearing logic for the integral torque, i.e., it is calculated when the function is activated and cleared to zero after the function is deactivated to avoid a large value causing problems in the next calculation). That is, there is no torque integral in term I when the function is not activated. The steering status flag is issued by the center console, which determines whether the stationary steering function is activated; the steering speed is sent to the stationary steering module via CAN, and the target yaw rate is determined based on the steering speed; the actual yaw rate is measured by the IMU sensor, and after signal processing (first-order filtering) in the stationary steering module, it is used by the torque controller; the road adhesion coefficient is calculated by the longitudinal estimation module, which determines the controller's initial learning rate, i.e., kp, ki, and kd.

[0074] II. Calculating the required torque using the wheel speed difference PID control algorithm:

[0075] Wheel speed difference PID control algorithm such as Figure 7 As shown, after the U-turn is activated, the target speed of the four wheels is determined by the steering speed and the road adhesion coefficient. A PID algorithm is designed based on the difference between the target speed and the actual speed of each wheel. To ensure that the wheel speed difference is within the designed control range, the algorithm is activated only after the wheel speed difference reaches a certain value (calibration value).

[0076] Furthermore, such as Figure 8 As shown, after the function is activated (steering status indicator position), the vehicle rotates stably; the angle through which the rotation speed passes is calculated by integrating the actual yaw rate; the function exits when the angle reached the target angle. To ensure smoothness and safety when the function exits, the torque is released at a certain slope, and the pressure is applied at the same slope to smoothly park the vehicle.

[0077] Torque Coordination Distribution:

[0078] When the U-turn function is activated, the electric vehicle's state parameters, mainly the four-wheel speed and yaw rate, are used to determine the state, as shown in Table 1. When the vehicle body state one is met, torque distribution strategy one is implemented; when the vehicle body state two is met, torque distribution strategy two is implemented; when the vehicle body state three is met, torque distribution strategy three is implemented. This ensures that the electric vehicle rotates around its center of gravity during the rotation process, achieving the effect of a U-turn with minimal displacement of the electric vehicle's center of gravity.

[0079] In summary, the embodiments of this application can initially distribute the driving torque of the four wheels according to different adhesion coefficients and the magnitude of the vertical load on the four wheels, causing the electric vehicle to rotate. Based on the set target rotational speed, wheel speed differential torque is coordinated and controlled to ensure the electric vehicle rotates smoothly at a certain yaw rate, keeping the center of gravity offset of the electric vehicle within a certain range. This avoids complex transmission and steering mechanisms, increasing reliability; simultaneously, it enables smooth steering on surfaces with varying adhesion, enhancing the driving experience and enjoyment.

[0080] The electric vehicle turning method proposed in this application can respond to a turning-in-place request. After the electric vehicle enters the turning-in-place mode, it distributes the target drive torque of each wheel according to the vertical load of each wheel to control the electric vehicle to rotate at the target yaw rate. Furthermore, it generates a torque adjustment value for at least one wheel based on the center of gravity offset to adjust the drive torque of at least one wheel until the turning-in is completed. This enables the electric vehicle to turn in place without steering wheels, rotating to any angle. Moreover, the ground area required for the electric vehicle during the entire turning process is much smaller than that required for conventional front-wheel steering, eliminating the need for a complex four-wheel steering mechanism, thus offering greater flexibility and facilitating widespread application. This solves the technical problems in related technologies where special steering mechanisms are complex, have low reliability and high cost, and distributed drive systems have poor flexibility and require a large ground area, compressing the space of other structures.

[0081] Next, referring to the accompanying drawings, a turning device for an electric vehicle according to an embodiment of this application is described.

[0082] Figure 9 This is a block diagram of a U-turn device for an electric vehicle according to an embodiment of this application.

[0083] like Figure 9 As shown, the electric vehicle turning device 10 is applied to a four-motor driven distributed electric vehicle. The device 10 includes: a response module 100, a first control module 200, and an adjustment module 300.

[0084] Specifically, the response module 100 is used to control the electric vehicle to enter the U-turn mode in response to a U-turn request, so as to distribute the target drive torque of each wheel based on the vertical load of the electric vehicle.

[0085] The first control module 200 is used to control the electric vehicle to rotate at a target yaw rate based on the target driving torque, and to obtain the vehicle's center of gravity offset.

[0086] The adjustment module 300 is used to generate torque adjustment values ​​for at least one wheel based on the center of gravity offset, so as to adjust the drive torque of at least one wheel until the turn is completed.

[0087] Optionally, in one embodiment of this application, the electric vehicle turning device 10 further includes a detection module and a second control module.

[0088] The detection module is used to detect whether the electric vehicle has rotated to the target turning angle.

[0089] The second control module is used to control the electric vehicle to exit the U-turn mode when it detects that the vehicle has rotated to the target turning angle.

[0090] Optionally, in one embodiment of this application, the response module 100 includes a first acquisition unit and a determination unit.

[0091] The first acquisition unit is used to acquire the road surface adhesion coefficient of the current road.

[0092] A determination unit is used to determine the target driving torque for each wheel based on the vertical load and the road adhesion coefficient.

[0093] Optionally, in one embodiment of this application, the acquisition module 100 further includes a second acquisition unit and a matching unit.

[0094] The second acquisition unit is used to acquire the vehicle body status of the electric vehicle.

[0095] The matching unit is used to match the electric vehicle's distribution strategy according to the vehicle body status, so as to determine the target drive torque using the distribution strategy.

[0096] Optionally, in one embodiment of this application, the adjustment module 300 includes a calculation unit and a generation unit.

[0097] The calculation unit is used to determine the target yaw rate of the electric vehicle based on the target turning speed.

[0098] The generation unit is used to generate torque adjustment values ​​for at least one wheel based on the target yaw rate when the center of mass offset is within a preset range.

[0099] It should be noted that the foregoing explanation of the method embodiment for turning around an electric vehicle also applies to the turning device for the electric vehicle in this embodiment, and will not be repeated here.

[0100] The electric vehicle turning device proposed in this application can respond to a turning-in-place request. After the electric vehicle enters the turning-in-place mode, it distributes the target driving torque of each wheel according to the vertical load of each wheel to control the electric vehicle to rotate at the target yaw rate. Furthermore, it generates a torque adjustment value for at least one wheel based on the center of gravity offset to adjust the driving torque of at least one wheel until the turning-in is completed. This enables the electric vehicle to turn in place without steering wheels, rotating to any angle. Moreover, the ground area required for the electric vehicle during the entire turning process is much smaller than that required for conventional front-wheel steering, eliminating the need for a complex four-wheel steering mechanism, thus offering greater flexibility and facilitating widespread application. This solves the technical problems in related technologies where special steering mechanisms are complex, have low reliability and high cost, and distributed drive systems have poor flexibility and require a large ground area, compressing the space of other structures.

[0101] Figure 10 A schematic diagram of the structure of an electric vehicle provided in an embodiment of this application. The electric vehicle may include:

[0102] The memory 1001, the processor 1002, and the computer program stored on the memory 1001 and capable of running on the processor 1002.

[0103] When the processor 1002 executes the program, it implements the electric vehicle turning method provided in the above embodiments.

[0104] Furthermore, electric vehicles also include:

[0105] Communication interface 1003 is used for communication between memory 1001 and processor 1002.

[0106] The memory 1001 is used to store computer programs that can run on the processor 1002.

[0107] The memory 1001 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0108] If the memory 1001, processor 1002, and communication interface 1003 are implemented independently, then the communication interface 1003, memory 1001, and processor 1002 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be divided into address buses, data buses, control buses, etc. For ease of representation, Figure 10 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0109] Optionally, in a specific implementation, if the memory 1001, processor 1002, and communication interface 1003 are integrated on a single chip, then the memory 1001, processor 1002, and communication interface 1003 can communicate with each other through an internal interface.

[0110] The processor 1002 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0111] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the above-described method for turning around an electric vehicle.

[0112] This application also provides a computer program product, including a computer program that is executed to implement the above-described method for turning around an electric vehicle.

[0113] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0114] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0115] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0116] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0117] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or more of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0118] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0119] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0120] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A method for turning around an electric vehicle, characterized in that, The method, applied to a distributed electric vehicle with four motors, includes the following steps: In response to a U-turn request, the electric vehicle is controlled to enter a U-turn mode to distribute the target drive torque to each wheel based on the vertical load of the electric vehicle. Based on the target driving torque, the electric vehicle is controlled to rotate at the target yaw rate, and the vehicle center of gravity offset of the electric vehicle is obtained; Based on the centroid offset, a torque adjustment value is generated for at least one wheel to adjust the drive torque of the at least one wheel until the turn is completed.

2. The method according to claim 1, characterized in that, Before completing the U-turn, it also includes: Detect whether the electric vehicle has rotated to the target turning angle; If the target turning angle is detected, the electric vehicle is controlled to exit the U-turn mode.

3. The method according to claim 1, characterized in that, The allocation of the target drive torque to each wheel based on the vertical load of the electric vehicle includes: Obtain the road surface adhesion coefficient of the current road; The target driving torque of each wheel is determined based on the vertical load and the road surface adhesion coefficient.

4. The method according to claim 3, characterized in that, Before determining the target drive torque for each wheel, the process also includes: Obtain the vehicle body status; The electric vehicle's allocation strategy is matched according to the vehicle body state to determine the target drive torque using the allocation strategy.

5. The method according to claim 1, characterized in that, The step of generating torque adjustment values ​​for at least one wheel based on the centroid offset includes: The target yaw rate of the electric vehicle is determined based on the target turning speed in place. When the center of gravity offset is within a preset range, the torque adjustment value of the at least one wheel is generated based on the target yaw rate.

6. A U-turn device for an electric vehicle, characterized in that, The device is applied to a distributed electric vehicle with a four-motor drive system, and includes: A response module is used to control the electric vehicle to enter a U-turn mode in response to a U-turn request, so as to distribute the target drive torque of each wheel based on the vertical load of the electric vehicle. The first control module is used to control the electric vehicle to rotate at a target yaw rate based on the target driving torque, and to obtain the vehicle center of gravity offset of the electric vehicle. An adjustment module is used to generate torque adjustment values ​​for at least one wheel based on the centroid offset, so as to adjust the driving torque of the at least one wheel until the turn is completed.

7. The apparatus according to claim 6, characterized in that, Also includes: The detection module is used to detect whether the electric vehicle has rotated to the target turning angle; The second control module is used to control the electric vehicle to exit the U-turn mode when it detects that the vehicle has rotated to the target turning angle.

8. An electric vehicle, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the method for turning around an electric vehicle as described in any one of claims 1-5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the method for turning around an electric vehicle as described in any one of claims 1-5.

10. A computer program product, comprising a computer program, characterized in that, The computer program is executed to implement the method for turning around an electric vehicle as described in any one of claims 1-5.

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