Vehicle steering control methods and devices, storage media and electronic devices

Abstract

This application discloses a control method, apparatus, storage medium, and electronic device for vehicle in-situ steering. The method includes: activating the in-situ steering function when a driver issues a control command containing an in-situ steering requirement, and monitoring the torque data output by the driver through controlling the target vehicle; determining the current driving force of the target vehicle based on the torque data; acquiring the yaw rate of the target vehicle when the current driving force is greater than or equal to the yaw resistance torque of the target vehicle; determining the target wheel speed of each wheel during the in-situ steering process based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle; and performing closed-loop steering control of the target vehicle based on the target wheel speed and the real-time wheel speed during the steering process. This solves the problem of poor stability during in-situ steering in current multi-motor vehicles.

Description

Technical Field

[0001] This application relates to the field of new energy vehicle control, and more specifically, to a control method and device for vehicle in-situ steering, a storage medium, and an electronic device. Background Technology

[0002] With the rapid development of electric vehicle technology, multi-motor vehicles have attracted widespread attention due to their superior power performance and handling flexibility. In the design of multi-motor vehicles, the ability to turn on the spot is an important technical challenge. Traditional steering systems rely on mechanical connections, such as steering column and gear systems. These systems have limitations in achieving on-the-spot turning because they require the vehicle to have a certain forward or reverse speed to assist in steering. Existing multi-motor vehicles usually use differential control methods for on-the-spot turning, but the above methods often have the following problems in actual practice: (1) Differential control is difficult to accurately control the vehicle's steering angle and speed, resulting in less smooth steering. (2) High energy consumption: In order to achieve a larger steering angle, the motor needs to output a large torque, which increases energy consumption. (3) Slow response speed: In emergency situations, the response speed of differential control may not be sufficient to quickly adjust the vehicle's driving direction. Therefore, the above scheme cannot control the whole vehicle to complete stable steering with a certain yaw rate according to the actual steering situation, and the stability of the on-the-spot turning process is poor.

[0003] There is currently no effective solution to the problem of poor stability during the turning process of multi-motor vehicles in place.

[0004] Therefore, it is necessary to improve the relevant technology to overcome the aforementioned defects. Summary of the Invention

[0005] This application provides a control method and apparatus for vehicle in-situ steering, a storage medium and an electronic device, which at least solves the problem of poor stability during in-situ steering of current multi-motor vehicles.

[0006] According to one aspect of the embodiments of this application, a control method for vehicle stationary steering is provided, comprising: activating the stationary steering function when a driver issues a control command including a stationary steering requirement, and monitoring torque data output by the driver through controlling the target vehicle; wherein the torque data includes at least: a first torque corresponding to the front wheel on the steering side of the target vehicle, a second torque corresponding to the rear wheel on the steering side of the target vehicle, a third torque corresponding to the front wheel on the non-steering side of the target vehicle, and a fourth torque corresponding to the rear wheel on the non-steering side of the target vehicle; determining the current driving force of the target vehicle based on the torque data; obtaining the yaw rate of the target vehicle when the current driving force is greater than or equal to the yaw resistance torque of the target vehicle; determining the target wheel speed of each wheel during the stationary steering process based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle, and performing closed-loop steering control on the target vehicle based on the target wheel speed and the real-time wheel speed during the steering process.

[0007] In an exemplary embodiment, before obtaining the yaw rate of the target vehicle when the current driving force is greater than or equal to the yaw resistance torque of the target vehicle, the method further includes: calculating a first sub-yaw resistance torque that the target vehicle needs to overcome during the static friction phase, wherein the first sub-yaw resistance torque is the total resistance value against the longitudinal static friction force of each wheel in the target vehicle; calculating a second sub-yaw resistance torque that the target vehicle needs to overcome during the static friction phase, wherein the second sub-yaw resistance torque is the total resistance value against the lateral static friction force of each wheel in the target vehicle; and determining the yaw resistance torque of the target vehicle based on the first sub-yaw resistance torque and the second sub-yaw resistance torque.

[0008] In an exemplary embodiment, after obtaining the yaw rate of the target vehicle, the method further includes: comparing the yaw rate with a preset yaw rate; if the yaw rate is less than the preset yaw rate, determining that the target vehicle is in a state of preparing to enter a steering state, and sending a prompt message to the driver, wherein the prompt message is used to instruct the driver to increase the control force of the accelerator pedal; if the yaw rate is greater than or equal to the preset yaw rate, determining that the target vehicle has entered a steering state, and initiating closed-loop steering control of the target vehicle.

[0009] In an exemplary embodiment, determining the target wheel speed of each wheel during a stationary turn based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle includes: determining the target slip ratio corresponding to each wheel of the target vehicle by using the slip ratio and a preset slip error; determining the target basic parameters corresponding to each wheel by using the factory information of the target vehicle, wherein the target basic parameters include at least: the track width of the target vehicle and the tire radius corresponding to each wheel of the target vehicle; substituting the target slip ratio, the target basic parameters corresponding to each wheel, and the yaw rate into a preset first formula to obtain the target wheel speed to be achieved by each wheel, wherein the preset first formula is: S d =1-ω / Ω dss *(B / 2) / r d S d Let B be the slip ratio of the target vehicle when turning in place, and r be the wheelbase of the target vehicle. d Let Ω be the tire radius corresponding to each wheel, ω be the yaw rate of the target vehicle, and Ω be the yaw rate of the target vehicle. dss Target wheel speed.

[0010] In an exemplary embodiment, before determining the target wheel speed of each wheel during the vehicle's stationary turning process based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle, the method further includes: determining the steering parameters of the current turning area where the target vehicle is located, wherein the steering parameters include at least: the ground type corresponding to the current turning area, the wheel type of the target vehicle, and the contact area between each wheel and the current turning area; searching for a reference slip ratio that matches the steering parameters in a preset database; and determining the slip ratio of the target vehicle based on the reference slip ratio and a preset slip error.

[0011] In an exemplary embodiment, closed-loop steering control of the target vehicle is performed based on the target wheel speed and the real-time wheel speed during the steering process, including: substituting the real-time wheel speed and the target wheel speed into a preset second formula to obtain the adjustment driving force of the target vehicle to be dynamically adjusted; wherein, the preset second formula is: △Ftx=Kp(Ω dss -Ω)+Kd(Ω dss -Ω) / dt+Ki*∫(Ω dss -Ω)dt, △Ftx is the adjustment driving force of the multi-motor closed-loop control on the target vehicle, Kp is the proportional feedback gain, Kd is the derivative gain, Ki is the integral gain, Ω dss Ω represents the target wheel speed and Ω represents the real-time wheel speed. The target torque output from the multiple motors on the target vehicle to each wheel is determined based on the adjusted driving force and the current driving force. The target torque is used to coordinate the driving object to control the torque data output by the target vehicle in order to perform closed-loop steering control on the target vehicle.

[0012] In an exemplary embodiment, after the driver issues a control command containing a stationary turning requirement, and the stationary turning function is activated, the method further includes: determining the steering angle and steering direction to be executed by the target vehicle in the stationary turning requirement; determining the current turning area of ​​the target vehicle based on the steering angle to be executed, the steering direction to be executed, and the vehicle size of the target vehicle; if the current turning area does not meet the standard turning requirements of the target vehicle, not triggering the operation of locking the target vehicle, and sending an alarm message to the driver, wherein the alarm message is used to indicate that the target vehicle cannot complete the stationary turning function and needs to be adjusted and reactivated; the standard turning requirements include at least: the maximum turning area that the target vehicle is allowed to complete stationary turning; if the current turning area meets the standard turning requirements of the target vehicle, triggering the operation of locking the target vehicle, prohibiting the driver from operating the target vehicle.

[0013] According to another aspect of the embodiments of this application, a vehicle stationary steering control device is also provided, comprising: a monitoring module, configured to activate the stationary steering function when a driver issues a control command including a stationary steering requirement, and monitor torque data output by the driver through controlling the target vehicle; wherein the torque data includes at least: a first torque corresponding to the front wheel on the steering side of the target vehicle, a second torque corresponding to the rear wheel on the steering side of the target vehicle, a third torque corresponding to the front wheel on the non-steering side of the target vehicle, and a fourth torque corresponding to the rear wheel on the non-steering side of the target vehicle; a determining module, configured to determine the current driving force of the target vehicle based on the torque data; an acquiring module, configured to acquire the yaw rate of the target vehicle when the current driving force is greater than or equal to the yaw resistance torque of the target vehicle; and a control module, configured to determine the target wheel speed of each wheel during the stationary steering process based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle, and perform closed-loop steering control on the target vehicle based on the target wheel speed and the real-time wheel speed during the steering process.

[0014] According to another aspect of the embodiments of this application, a computer-readable storage medium is also provided, wherein a computer program is stored in the computer program, and the computer program is configured to execute the above-described vehicle stationary steering control method when it is run.

[0015] According to another aspect of the embodiments of this application, an electronic device is also provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the vehicle in-situ steering control method through the computer program.

[0016] According to another aspect of the embodiments of this application, a computer program product is also provided, including a computer program, wherein the above-mentioned vehicle in-situ steering control method is executed by a processor.

[0017] This application, after determining the driving target and issuing the control command for stationary steering, determines the vehicle's current driving force based on the torque data output by the target vehicle. This allows for the determination that after the stationary steering begins, the target motor's torque increases from 0 Nm in absolute value until the vehicle's yaw rate exceeds a certain value. It also determines the situation where the target vehicle overcomes static friction and then enters dynamic friction. The target wheel speed for stable rotation under dynamic friction is then calculated. Based on the target wheel speed and the real-time wheel speed during rotation, closed-loop PID control of the target vehicle's steering is implemented. This achieves stable stationary steering while conserving vehicle energy, solving the problem of poor stability during stationary steering in current multi-motor vehicles. By determining the difference between the target wheel speed and the real-time wheel speed, the driving force output by multiple motors under closed-loop control is dynamically adjusted, precisely controlling the speed and torque of each motor on the target vehicle, resulting in more precise, energy-efficient, and faster-responding stationary steering. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a hardware structure block diagram of a mobile terminal for a vehicle stationary steering control method according to an embodiment of this application.

[0021] Figure 2 This is a flowchart of a vehicle in-situ steering control method according to an embodiment of this application;

[0022] Figure 3 This is a schematic diagram of the force analysis of the target vehicle during in-situ turning according to an embodiment of this application;

[0023] Figure 4 This is a flowchart illustrating a turning maneuver in place according to an embodiment of this application;

[0024] Figure 5 This is a structural block diagram of a vehicle in-situ steering control device according to an embodiment of this application. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a vehicle stationary steering control method according to an embodiment of this application. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor (MCU) or a field-programmable gate array (FPGA)) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0028] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the vehicle stationary steering control method in this embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0029] The transmission device 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0030] This embodiment provides a method for controlling vehicle turning in place. Figure 2 This is a flowchart of a vehicle in-situ steering control method according to an embodiment of this application, such as... Figure 2 As shown, the process includes the following steps S202-S208:

[0031] Step S202: When the driver issues a control command that includes a need for stationary turning, the stationary turning function is activated, and the torque data output by the driver through controlling the target vehicle is monitored; wherein the torque data includes at least: a first torque corresponding to the front wheel on the turning side of the target vehicle, a second torque corresponding to the rear wheel on the turning side of the target vehicle, a third torque corresponding to the front wheel on the non-turning side of the target vehicle, and a fourth torque corresponding to the rear wheel on the non-turning side of the target vehicle.

[0032] It should be noted that the aforementioned steering direction can be the direction of rotation of the vehicle's centerline with the front of the target vehicle in front and the rear of the vehicle behind after the target vehicle has been fixed in place. When the front of the vehicle shifts to the left of the centerline, it indicates that the target vehicle is turning counterclockwise; when the front of the vehicle shifts to the right of the centerline, it indicates that the target vehicle is turning clockwise. In this counterclockwise steering scenario, the aforementioned steering-side front wheel corresponds to the left front wheel when the front of the vehicle is in front, and the steering-side rear wheel corresponds to the left rear wheel when the front of the vehicle is in front; the aforementioned non-steering-side front wheel corresponds to the vehicle's... When the vehicle is facing forward, the right front wheel corresponds to the right rear wheel on the non-steering side. When the vehicle is turning clockwise, the aforementioned steering side front wheel corresponds to the right front wheel when the vehicle is facing forward, and the steering side rear wheel corresponds to the right rear wheel on the same side. Similarly, the aforementioned non-steering side front wheel corresponds to the left front wheel when the vehicle is facing forward, and the non-steering side rear wheel corresponds to the left rear wheel on the same side. During the rotation of the target vehicle, each wheel is in a rotating state, and each wheel is controlled by a motor.

[0033] Step S204: Determine the current driving force of the target vehicle based on the torque data;

[0034] Step S206: If the current driving force is greater than or equal to the yaw resistance torque of the target vehicle, obtain the yaw rate of the target vehicle;

[0035] It should be noted that when the current driving force is less than the yaw resistance torque of the target vehicle, the target vehicle is in the stage of overcoming the static friction of the ground, and the vehicle will not start to rotate significantly during the entire process; when the current driving force is greater than the yaw resistance torque of the target vehicle, the vehicle will start to rotate only after the yaw rate of the vehicle exceeds a certain value; the whole process is a transformation from overcoming the static friction of the ground to overcoming the dynamic friction of the ground.

[0036] Step S208: Based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle, determine the target wheel speed of each wheel during the vehicle's stationary turning process, and perform closed-loop steering control on the target vehicle according to the target wheel speed and the real-time wheel speed during the turning process.

[0037] Understandably, during a vehicle's stationary turn, the control system first determines the target wheel speed for each wheel based on the vehicle's yaw rate, slip ratio, and fundamental parameters (such as mass and wheelbase). This target wheel speed is the ideal speed each wheel should achieve to achieve optimal steering performance and vehicle stability; it is essentially the single-wheel traction speed. Then, the control system monitors the actual wheel speed of each wheel in real time. By comparing the target wheel speed with the real-time wheel speed, the control system can identify any deviations and adjust the driving or braking force of the wheels accordingly. This adjustment is achieved through closed-loop control, meaning the system continuously monitors the results and adjusts the input based on them to ensure the actual wheel speed is as close as possible to the target speed. This closed-loop steering control improves vehicle handling and stability, especially at high speeds or on complex road surfaces. By precisely controlling the speed of each wheel, the vehicle can better respond to the driver's steering commands, reducing understeer or oversteer, thereby improving driving safety and ride comfort.

[0038] Optional, yaw rate: Yaw rate refers to the speed at which the vehicle rotates about an axis perpendicular to the ground (i.e., the vehicle's Z-axis). This parameter is crucial for understanding the vehicle's steering dynamics, as it directly affects the vehicle's stability and handling.

[0039] Optional, slip ratio: Slip ratio refers to the ratio between the actual distance a wheel travels and the distance it should theoretically travel. This parameter helps to understand the friction between the wheel and the road surface, thus affecting steering control strategies.

[0040] Optional, basic parameters: Basic parameters may include vehicle mass, wheelbase, track width, etc., which are crucial for calculating the target wheel speed.

[0041] Optional, target wheel speed: Based on the above parameters, the system can calculate the ideal speed that each wheel should reach when the vehicle is turning in place. This speed helps the vehicle maintain stability during turns, reduces slippage, and provides better handling.

[0042] Optional, real-time wheel speed: This is the current speed of each wheel during actual steering. This data changes dynamically and needs to be monitored in real time.

[0043] Optional, closed-loop steering control: This is a feedback control strategy where the system adjusts the driving or braking force of the wheels based on the difference between the target wheel speed and the real-time wheel speed to ensure that the actual wheel speed is as close as possible to the target speed. This control can be electronic or mechanical.

[0044] Through the above steps, after determining the driving target and issuing the control command for stationary steering, the current driving force of the vehicle is determined based on the torque data output by the target vehicle. This determines that after the stationary steering begins, the absolute value of the target motor's torque increases from 0 Nm until the vehicle's yaw rate exceeds a certain value. It also determines the situation where the target vehicle overcomes static friction and then enters dynamic friction. The target wheel speed for stable rotation under dynamic friction is then calculated. Based on the target wheel speed and the real-time wheel speed during rotation, closed-loop PID control of the target vehicle's steering is implemented. This achieves stable stationary steering while conserving vehicle energy, solving the problem of poor stability during stationary steering in current multi-motor vehicles. By determining the difference between the target wheel speed and the real-time wheel speed, the driving force output by multiple motors under closed-loop control is dynamically adjusted, precisely controlling the speed and torque of each motor on the target vehicle, resulting in more precise, energy-efficient, and faster-responding stationary steering.

[0045] In an exemplary embodiment, before obtaining the yaw rate of the target vehicle when the current driving force is greater than or equal to the yaw resistance torque of the target vehicle, the method further includes: calculating a first sub-yaw resistance torque that the target vehicle needs to overcome during the static friction phase, wherein the first sub-yaw resistance torque is the total resistance value against the longitudinal static friction force of each wheel in the target vehicle; calculating a second sub-yaw resistance torque that the target vehicle needs to overcome during the static friction phase, wherein the second sub-yaw resistance torque is the total resistance value against the lateral static friction force of each wheel in the target vehicle; and determining the yaw resistance torque of the target vehicle based on the first sub-yaw resistance torque and the second sub-yaw resistance torque.

[0046] In one alternative embodiment, assume a new energy multi-motor vehicle equipped with four motors, one for each wheel. The vehicle is preparing to perform a stationary turn. When the driver activates the stationary turn mode through the vehicle's human-machine interface and sets the target rotation angle to 90 degrees, clockwise, the first sub-yaw resistance torque is calculated: The system first calculates the yaw resistance torque generated by the longitudinal static friction of the wheels. If the longitudinal static friction force F of each wheel... fs Approximately 1000N, with a wheelbase B of 1.5 meters, the first sub-yaw resistance torque ΣMz fs = 4 * 1000 N * 1.5 m / 2 = 3000 Nm. Calculate the second yaw resistance torque: Next, the system calculates the yaw resistance torque generated by the lateral static friction of the wheels. Assume the lateral static friction force F of each wheel is... μs The torque is approximately 500 N, and the vehicle's wheelbase L is 2.5 meters. Therefore, the second yaw resistance torque ΣMz is... μs= 4 * 500 N * 2.5 m / 2 = 2500 Nm. Determine the yaw resistance torque and control the torque: Add the first sub-yaw resistance torque and the second sub-yaw resistance torque to obtain the total yaw resistance torque Mz of the vehicle during the static friction stage. StaticFriction =3000Nm + 2500Nm = 5500Nm. Afterwards, the system will gradually increase the motor torque until it reaches a level sufficient to overcome the 5500Nm yaw resistance torque. During this process, the system will continuously monitor the vehicle's yaw rate. Once it reaches a preset threshold (e.g., 0.1 rad / s), it enters the dynamic friction stage. At this point, PID closed-loop control is performed based on the difference between the target wheel speed and the actual wheel speed to adjust the motor torque and ensure stable on-the-spot steering of the vehicle.

[0047] Through the above embodiments, it is clear how this application overcomes the resistance in the static friction stage in actual operation, thereby ensuring that the vehicle smoothly enters the dynamic friction stage and achieves precise, smooth and safe on-the-spot steering based on the above solution.

[0048] In an exemplary embodiment, after obtaining the yaw rate of the target vehicle, the method further includes: comparing the yaw rate with a preset yaw rate; if the yaw rate is less than the preset yaw rate, determining that the target vehicle is in a state of preparing to enter a steering state, and sending a prompt message to the driver, wherein the prompt message is used to instruct the driver to increase the control force of the accelerator pedal; if the yaw rate is greater than or equal to the preset yaw rate, determining that the target vehicle has entered a steering state, and initiating closed-loop steering control of the target vehicle.

[0049] Understandably, the vehicle's sensor system continuously monitors the vehicle's yaw rate, which is used to determine whether the vehicle has entered a turning state. The system compares the monitored yaw rate with a preset yaw rate threshold. This preset threshold is set based on vehicle characteristics and ground conditions, for example, it can be set to 0.1 rad / s. If the monitored yaw rate is less than the preset threshold (i.e., yaw rate < 0.1 rad / s), the system determines that the target vehicle is still in a state awaiting turning, meaning that the current acceleration has not yet enabled the vehicle to overcome static friction and enter the dynamic friction turning stage. At this time, the system sends a prompt to the driver through the vehicle's driving information display system (such as the instrument panel or central display screen), instructing them to appropriately increase the pressure on the accelerator pedal to increase driving torque and help the vehicle overcome static friction. Conversely, if the monitored yaw rate is greater than or equal to the preset threshold (i.e., yaw rate ≥ 0.1 rad / s), the system determines that the target vehicle has entered a turning state, meaning the vehicle has begun to overcome static friction and successfully perform a stationary turn. At this point, the system will automatically switch to closed-loop control mode and use the PID control algorithm to adjust the motor torque according to the difference between the target and the actual wheel speeds of the four wheels, ensuring that each wheel rotates at the target speed, thereby achieving smooth steering of the vehicle.

[0050] For example, a new energy multi-motor vehicle is preparing to turn 90 degrees clockwise while stationary. The driver has already activated the stationary turning mode through the vehicle's control interface and set the rotation angle and direction. The vehicle's intelligent driving system has calculated the total yaw resistance torque required to overcome static friction to be 5500 Nm and begins to gradually increase the motor torque to overcome this resistance torque. The driver lightly presses the accelerator, and the vehicle begins to generate driving force. However, due to the relatively small accelerator pressure, the vehicle's yaw rate is only 0.05 rad / s, which is less than the preset threshold of 0.1 rad / s for entering the turning state. After detecting this situation, the system immediately sends a prompt message to the driver through the vehicle information display system (e.g., the central display screen or instrument panel), instructing them to increase the accelerator pressure to increase driving force and overcome static friction. Following the prompt, the driver moderately increases the pressure on the accelerator pedal, and the vehicle's motor torque increases accordingly. When the motor torque increases sufficiently to make the vehicle's yaw rate reach or exceed the preset 0.1 rad / s, the system detects that the vehicle has entered the turning state, at which point the system automatically activates the steering closed-loop control mode. The closed-loop control system uses a PID algorithm to adjust the motor torque based on the difference between the target wheel speed and the actual wheel speed, ensuring that all four wheels rotate at a preset speed, achieving stable and precise turning in place until the target rotation of 90 degrees is reached.

[0051] In summary, through real-time monitoring and comparison of yaw rate, as well as precise driving object prompts and automatic control switching, the vehicle can smoothly and steadily transition from the static friction stage to the dynamic friction steering stage. This not only improves steering efficiency and comfort but also enhances the driver's sense of participation and control during the steering process, ensuring the safety and reliability of turning on the spot.

[0052] In an exemplary embodiment, determining the target wheel speed of each wheel during a stationary turn based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle includes: determining the target slip ratio corresponding to each wheel of the target vehicle by using the slip ratio and a preset slip error; determining the target basic parameters corresponding to each wheel by using the factory information of the target vehicle, wherein the target basic parameters include at least: the track width of the target vehicle and the tire radius corresponding to each wheel of the target vehicle; substituting the target slip ratio, the target basic parameters corresponding to each wheel, and the yaw rate into a preset first formula to obtain the target wheel speed to be achieved by each wheel, wherein the preset first formula is: S d =1-ω / Ω dss *(B / 2) / r d S d Let B be the slip ratio of the target vehicle when turning in place, and r be the wheelbase of the target vehicle. d Let Ω be the tire radius corresponding to each wheel, ω be the yaw rate of the target vehicle, and Ω be the yaw rate of the target vehicle. dss Target wheel speed.

[0053] Understandably, during stationary turning, the system needs to set a reasonable target slip ratio Sd to ensure stability and efficiency. The slip ratio measures the ratio between the degree of wheel slippage and the degree of wheel roll; setting the target slip ratio is crucial for stationary turning. In this embodiment, the system determines the target slip ratio for each wheel using the slip ratio and a preset slip error. The preset slip error is set during vehicle design based on ground type, wheel type, and vehicle characteristics to ensure that the wheels neither slip excessively nor remain completely stationary during turning, maintaining good ground adhesion. Once the yaw rate ω is detected, the system calculates the target slip ratio Sd based on the current yaw rate and the preset slip error. To further calculate the target wheel speed, the system also needs to obtain the target basic parameters for each wheel, including but not limited to single-wheel traction speed and tire radius r. d The vehicle's factory information provides detailed parameters for each wheel, including tire model, size, etc., where the tire radius r... d This is one of the key parameters for calculating the target wheel speed. In addition, the system also utilizes the vehicle's yaw rate ω and the target slip ratio S. d Combined with the preset first formula S d =1-ω / Ωdss *(B / 2) / r d To calculate the target wheel speed Ω for each wheel. dss B / 2 is half of the vehicle's track width, a fixed basic parameter representing the vertical distance between the wheel and the center point of the vehicle body.

[0054] Assuming the target vehicle is a new energy vehicle equipped with four motors, its target slip ratio is S. d =0.2 (i.e., 20%), tire radius r d The yaw rate is 0.3 meters. When the vehicle begins to prepare for a stationary turn, the system monitors and obtains the vehicle's yaw rate ω as 0.1 rad / s. At this point, the system will first determine the target slip ratio S. d Then, based on the vehicle's factory information, the target basic parameters corresponding to each wheel are obtained, such as the tire radius r. d =0.3 meters. Next, the system will set the target slip ratio S d Tire radius r d And the yaw rate ω is substituted into the preset first formula S d =1-ω / Ω dss *(B / 2) / r d In the process, the target wheel speed Ω of each wheel is calculated. dss Assuming the vehicle's track width B is 2 meters, substituting this into the formula yields Ω. dss The calculation process is as follows: S d =1-ω / Ω dss *(B / 2) / r d Specifically: 0.2 = 1 - 0.1 / Ω dss *(2 / 2) / 0.3; Solving this equation yields the target wheel speed Ω. dss To simplify the calculation, the result is given directly: the target wheel speed is approximately 0.417 rad / s (approximately 4 revolutions per minute). In practical applications, the system will calculate the above target wheel speed for each wheel of the vehicle separately, and then adjust the motor torque through PID closed-loop control to ensure that each wheel reaches its respective target wheel speed. In this way, the vehicle can smoothly turn on the spot while maintaining traction until the predetermined rotation angle is achieved.

[0055] In summary, accurately calculating the target wheel speed is key to achieving on-the-spot steering control. It ensures that each wheel can rotate at the optimal speed under different slip ratios and vehicle parameters, thereby achieving efficient and stable on-the-spot steering of the entire vehicle.

[0056] In an exemplary embodiment, before determining the target wheel speed of each wheel during the vehicle's stationary turning process based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle, the method further includes: determining the steering parameters of the current turning area where the target vehicle is located, wherein the steering parameters include at least: the ground type corresponding to the current turning area, the wheel type of the target vehicle, and the contact area between each wheel and the current turning area; searching for a reference slip ratio that matches the steering parameters in a preset database; and determining the slip ratio of the target vehicle based on the reference slip ratio and a preset slip error.

[0057] Optionally, before steering begins, the vehicle's intelligent driving system collects steering parameter information for the target vehicle's current steering area using sensors (such as cameras, radar, and pressure sensors). This information includes ground type (such as wet / slippery surfaces, dry / hard surfaces, sand, etc.), wheel type (tire size, tread pattern, material, etc.), and the contact area between each wheel and the ground. The contact area may be affected by factors such as vehicle load and tire pressure, directly impacting the friction between the wheel and the ground. After collecting the steering parameters, the system queries a preset database for reference slip ratios that match these parameters. The preset database stores optimal slip ratio data under different ground types, wheel types, and contact area conditions. This data is derived from laboratory conditions or through extensive real-world testing and is used to guide the setting of the most suitable slip ratio during actual steering. Based on the found reference slip ratio and a preset slip error, the system further determines the target vehicle's slip ratio. The preset slip error is a safety redundancy used to ensure that the vehicle can still perform stable on-the-spot steering even when actual road conditions differ from those in the database. The determination of slip ratio takes into account the vehicle's dynamic response and ground adhesion to balance steering efficiency and vehicle stability.

[0058] Assume the target vehicle is a new energy four-motor drive vehicle, preparing to perform a 90-degree clockwise in-situ turn in a slippery parking lot. The system collects steering parameters via sensors, including: slippery surface type, standard-sized tires with high-grip tread patterns, and each wheel's contact area with the ground approximately 0.05 square meters. Based on these parameters, the system queries a preset database to find a reference slip ratio of 0.15 that matches the slippery surface, high-grip tires, and contact area. The preset slip error is ±0.05, meaning the target slip ratio will be set between 0.10 and 0.20 to accommodate potential differences in road conditions and ensure steering stability and efficiency. Assume the final determined target slip ratio is S. d =0.18, tire radius r d The yaw rate is 0.45 meters, and the vehicle's track width (B) is 2 meters. When the vehicle's yaw rate (ω) is detected to be 0.3 rad / s, the system will set the target slip ratio (S) to 0.3 rad / s.d Tire radius r d Substituting the yaw rate ω and half the wheelbase B (i.e., 1 meter) into the preset first formula, we calculate: Ω dss = (0.3*(2 / 2) / 0.45) / (1-0.18); Solving this equation, we obtain the target wheel speed Ω for each wheel. dss It is approximately 0.813 rad / s (approximately 7.76 revolutions per minute).

[0059] In practical applications, the system calculates the target wheel speed for each wheel separately and adjusts the motor torque through PID closed-loop control to ensure that the wheel reaches its target wheel speed, thereby enabling the vehicle to turn in place efficiently and stably on wet and slippery roads until the predetermined rotation angle is achieved.

[0060] Through the process described in the above embodiments, the vehicle can automatically adjust the slip ratio according to the actual road conditions and wheel characteristics, ensuring smooth and safe on-the-spot steering in various environments, demonstrating the intelligence and adaptability of the vehicle control strategy.

[0061] In an exemplary embodiment, closed-loop steering control of the target vehicle is performed based on the target wheel speed and the real-time wheel speed during the steering process, including: substituting the real-time wheel speed and the target wheel speed into a preset second formula to obtain the adjustment driving force of the target vehicle to be dynamically adjusted; wherein, the preset second formula is: △Ftx=Kp(Ω dss -Ω)+Kd(Ω dss -Ω) / dt+Ki*∫(Ω dss -Ω)dt, △Ftx is the adjustment driving force of the multi-motor closed-loop control on the target vehicle, Kp is the proportional feedback gain, Kd is the derivative gain, Ki is the integral gain, Ω dss Ω represents the target wheel speed and Ω represents the real-time wheel speed. The target torque output from the multiple motors on the target vehicle to each wheel is determined based on the adjusted driving force and the current driving force. The target torque is used to coordinate the driving object to control the torque data output by the target vehicle in order to perform closed-loop steering control on the target vehicle.

[0062] In an exemplary embodiment, after the driver issues a control command containing a stationary turning requirement, and the stationary turning function is activated, the method further includes: determining the steering angle and steering direction to be executed by the target vehicle in the stationary turning requirement; determining the current turning area of ​​the target vehicle based on the steering angle to be executed, the steering direction to be executed, and the vehicle size of the target vehicle; if the current turning area does not meet the standard turning requirements of the target vehicle, not triggering the operation of locking the target vehicle, and sending an alarm message to the driver, wherein the alarm message is used to indicate that the target vehicle cannot complete the stationary turning function and needs to be adjusted and reactivated; the standard turning requirements include at least: the maximum turning area that the target vehicle is allowed to complete stationary turning; if the current turning area meets the standard turning requirements of the target vehicle, triggering the operation of locking the target vehicle, prohibiting the driver from operating the target vehicle.

[0063] When a driver issues a control command requiring a stationary turn, the system first parses the specific requirements, including the desired steering angle and direction. For example, the command might instruct the vehicle to rotate 90 degrees clockwise to the left. Based on this parsed steering angle and direction, the system uses vehicle sensors (such as cameras, radar, and GPS) to determine the target vehicle's current turning area. This step considers the vehicle's actual size and the surrounding space constraints. For instance, the system assesses whether the clearance around the vehicle is sufficient to allow it to complete the specified 90-degree clockwise rotation without colliding with obstacles. The system then checks if the current turning area meets the target vehicle's standard steering requirements. A key aspect of these standard requirements is the maximum turning area the target vehicle is allowed to complete a stationary turn; this parameter is pre-set based on the vehicle's size and maximum turning radius. If the current turning area is too small to allow the vehicle to complete a stationary turn, the system will not lock the target vehicle but will instead send a warning message to the driver, explicitly indicating that the target vehicle cannot currently perform a stationary turn and needs to be repositioned before reactivation. This mechanism effectively avoids safety accidents that may be caused by insufficient space. The system will only trigger the locking operation of the target vehicle when the current steering area meets the standard steering requirements. This involves locking the steering wheel and wheel steering angles to ensure that the wheel steering action is parallel to the direction of the vehicle's front during steering, creating conditions for the vehicle to perform a stationary turn. Once locked, the driver will be unable to manually operate the wheels, thus ensuring the consistency and safety of steering actions.

[0064] Obviously, the embodiments described above are only some embodiments of this application, and not all embodiments. To better understand the above method, the following description, in conjunction with embodiments, illustrates the process, but is not intended to limit the technical solutions of the embodiments of this application. Specifically:

[0065] Optionally, this application provides a multi-motor vehicle stationary steering control method, including: a vehicle equipped with four motors (equivalent to the target vehicle in the above embodiment), and torque vector control to achieve stationary steering with a zero rotation radius. When the driver (equivalent to the driving object in the above embodiment) wants the vehicle to implement stationary steering mode, the stationary steering mode is activated by clicking on the large screen, and the target rotation angle and direction are set. The intelligent driving system identifies that the distance of surrounding obstacles meets the stationary steering requirements and triggers the steering wheel lock, locking the four wheel rotation angles parallel to the direction of the vehicle's front. After the driver depresses the accelerator, forward torque is provided to the outer front wheel and the outer rear wheel of the vehicle in the direction of rotation of the target vehicle, and backward torque is provided to the inner front wheel and the inner rear wheel of the vehicle. During the process from the start of vehicle rotation to the stop of rotation, the target slip ratio of the four wheels is determined according to the ground type, wheel type, and wheel-ground contact condition, and the target wheel speed is calculated based on the target slip ratio and target rotation speed. By controlling the multiple motors according to the target wheel speed to ensure that the four wheels of the vehicle rotate at the target speed, the entire vehicle can be stably rotated at a certain yaw rate.

[0066] As an optional implementation method, Figure 3 This is a schematic diagram of the force analysis of the target vehicle when it is turned in place according to an embodiment of this application. Figure 3 The main scenario involves vehicles turning counter-clockwise.

[0067] Specifically, during the static friction stage, it is necessary to overcome the longitudinal static friction force F of the four wheels. fs The resulting yaw resistance torque, and the total longitudinal static friction force of the target vehicle are: ΣMz fs =(F fs1 +F fs2 +F fs3 +F fs4 )*B / 2, F fs1 F is the longitudinal static friction force of the vehicle's left front wheel. fs2 F is the longitudinal static friction force of the vehicle's left rear wheel. fs3 F represents the longitudinal static friction force of the vehicle's right rear wheel. fs4 Let B be the longitudinal static friction force of the vehicle's right front wheel, and B be the vehicle's track width. Simultaneously, when the vehicle turns, it must also overcome the lateral static friction force F of all four wheels. μs The resulting yaw resistance torque, and the total lateral static friction force of the target vehicle are: ΣMz μs =(F μs1 +F μs2 +F μs3 +F μs4 )*L / 2, where F μs1 F is the lateral static friction force of the vehicle's left front wheel. μs2 F is the lateral static friction force of the vehicle's left rear wheel.μs3 F represents the lateral static friction force on the right rear wheel of the vehicle. μs4 Let L be the lateral static friction force of the vehicle's right front wheel, and L be the vehicle's wheelbase.

[0068] Furthermore, the yaw driving torque generated by the longitudinal driving force of the four wheels is: ΣMz t =(F t1 +F t2 +F t3 +F t4 )*B / 2;F t1 F is the longitudinal driving force of the vehicle's left front wheel. t2 F is the longitudinal driving force of the vehicle's left rear wheel. t3 F is the longitudinal driving force of the vehicle's right rear wheel. t4 This refers to the longitudinal driving force of the vehicle's right front wheel;

[0069] It should be noted that at the moment the vehicle starts to rotate from a standstill, the sum of the driving torque and the static friction torque is equal: Mz = ΣMz t =ΣMz fs +ΣMz μs During the static friction phase, Mz utilizes its ability to drive yaw moment. Capacity The target is to increase the torque until the static friction resistance torque can be overcome. That is, Mz = 0 Nm -> Mz Capacity (Mz StaticFriction ).

[0070] Optionally, when the yaw rate of the target vehicle exceeds a certain value, the vehicle begins to rotate and enters the dynamic friction stage. At this time, based on the torque at the end of the static friction stage, and taking into account the torque deviation, feedforward processing is performed on the target vehicle to achieve closed-loop control of the vehicle's in-situ steering in this stage.

[0071] As an optional implementation method, Figure 4 This is a flowchart illustrating a turning maneuver in place according to an embodiment of this application, specifically including the following steps:

[0072] Step 1: Activate stationary steering. This includes: determining the rotation direction (counterclockwise / clockwise), the target turning angle (Deg degrees), and determining the torque of each of the four wheels (Ft1 (0 Nm), Ft2 (0 Nm), Ft3 (0 Nm), and Ft4 (0 Nm). Optional steps include: vehicle stationary condition: speed V = 0, turning angle r = 0; flat ground condition: slope = 0, bank = 0; steering wheel angle = 0; all four wheel angles locked at 0 degrees, brake pedal = 0, accelerator pedal greater than the threshold, and off state greater than the threshold. After confirming the above, the vehicle meets the initial conditions for activating stationary steering and is allowed to perform stationary steering.

[0073] Step 2: The vehicle enters the static friction stage. At this time, the driving force Ftx output by the throttle control increases from 0 Nm to the static friction resistance torque MzCapacity.

[0074] Step 3: Once the yaw rate is determined to be greater than the yaw rate threshold, the target vehicle enters the Dynamic Friction control stage. At this point, closed-loop control is achieved through the four-wheel speeds and slip ratios. Specifically: ω is the target yaw rate of the entire vehicle, the vehicle's track width is B, and the target wheel speed is Ω. dss r d Let S be the tire radius, and assume the slip ratio during stationary steering is S. d Then the wheel traction speed and the target wheel speed satisfy: Assuming the vehicle rotates clockwise, the target wheel speeds for the four wheels are as follows: Assuming the vehicle rotates counterclockwise, the target wheel speeds for the four wheels are as follows:

[0075]

[0076] At this point, the four-wheel angular acceleration closed-loop slip ratio control => ΔFx, where the closed-loop control uses the difference between the target and the actual four-wheel speed as the PID control target: ΔFtx = Kp(Ω dss -Ω)+Kd(Ω dss -Ω) / dt+Ki*∫(Ω dss -Ω)dt;△Ftx is the driving force of multi-motor closed-loop control, Kp is the proportional feedback gain, and Kd is the derivative gain.

[0077] Ftx = FtxFF + ΔFtx; It should be noted that the above feedforward quantity FtxFF is the driving torque at the moment when the target vehicle starts to rotate as the vehicle overcomes friction and changes from static friction to dynamic friction. This feedforward quantity can be determined by the driving force information recorded when the target vehicle moves.

[0078] As an optional implementation method, the relationship between the feedforward process and dynamic friction and static friction in practical applications is as follows:

[0079] When the driver presses the accelerator, forward torque is provided to the outer front wheel and the outer rear wheel in the direction of rotation of the target vehicle, and backward torque is provided to the inner front wheel and the inner rear wheel. The driving force varies with the accelerator pedal. Alternatively, after the acceleration pedal exceeds a certain value, the absolute value of the driving torque can be increased at a certain slope. It should be noted that the above slope can be obtained by experimentally controlling the force of pressing the pedal to obtain test data on the relationship between the driving torque and the pedal, and then linearly fitting the test data. When the vehicle enters a lateral movement state, the system will collect the driving force of the wheel at the end of the vehicle's stationary state. Then, this driving force is compared with a preset friction deviation value. Based on the comparison result, the difference between the wheel driving force at the end of the vehicle's stationary state and the preset friction deviation value of that wheel is determined as the feedforward signal of that wheel during the lateral movement process. That is, in the static friction stage, the feedforward FtxFF is mainly based on the wheel driving force and the preset friction deviation value of that wheel, until the wheel driving force increases to overcome the static friction, so that open-loop control of stationary steering can be performed before entering the dynamic friction stage.

[0080] Furthermore, when the vehicle's yaw rate exceeds a certain value, the vehicle begins to rotate and enters the dynamic friction stage. After that, the torque deviation is considered based on the torque at the end of the static friction stage to perform feedforward FtxFF, and in this stage, stationary steering closed-loop control is performed.

[0081] Step 4: Through the above steps, achieve stable on-the-spot steering of the vehicle. When the vehicle reaches the target rotation angle, the on-the-spot steering ends. At this point, the yaw rate is less than or equal to the yaw rate threshold, and the vehicle returns to a stationary state.

[0082] In summary, the above-described implementation method can precisely control the wheel speed during on-the-spot turning, ensuring smooth and efficient steering, improving vehicle maneuverability and agility, while enhancing driving safety and user experience. In practical applications, this solution is executed through the vehicle's electronic control system. The system receives signals from the accelerator pedal, monitors wheel torque and vehicle status, and through calculation and analysis, ultimately adjusts the wheel speed to achieve on-the-spot turning. The entire process involves the transmission and processing of electronic signals, such as torque data monitoring signals, yaw rate acquisition signals, and control signals for adjusting driving force and torque. These signals constitute information exchange between the vehicle and the driver, and between the vehicle and the control system, working together to achieve precise vehicle control.

[0083] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods of the various embodiments of this application.

[0084] This embodiment also provides a vehicle in-situ steering control device, which is used to implement the above embodiments and preferred embodiments, and will not be repeated as already described. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0085] Figure 5 This is a structural block diagram of a vehicle stationary steering control device according to an embodiment of this application. The device includes:

[0086] The monitoring module 52 is used to activate the stationary steering function when the driver issues a control command that includes a stationary steering requirement, and to monitor the torque data output by the driver through controlling the target vehicle; wherein the torque data includes at least: a first torque corresponding to the front wheel on the steering side of the target vehicle, a second torque corresponding to the rear wheel on the steering side of the target vehicle, a third torque corresponding to the front wheel on the non-steering side of the target vehicle, and a fourth torque corresponding to the rear wheel on the non-steering side of the target vehicle.

[0087] It should be noted that the aforementioned steering direction can be the direction of rotation of the vehicle's centerline with the front of the target vehicle in front and the rear of the vehicle behind after the target vehicle has been fixed in place. When the front of the vehicle shifts to the left of the centerline, it indicates that the target vehicle is turning counterclockwise; when the front of the vehicle shifts to the right of the centerline, it indicates that the target vehicle is turning clockwise. In this counterclockwise steering scenario, the aforementioned steering-side front wheel corresponds to the left front wheel when the front of the vehicle is in front, and the steering-side rear wheel corresponds to the left rear wheel when the front of the vehicle is in front; the aforementioned non-steering-side front wheel corresponds to the vehicle's... When the vehicle is facing forward, the right front wheel corresponds to the right rear wheel on the non-steering side. When the vehicle is turning clockwise, the aforementioned steering side front wheel corresponds to the right front wheel when the vehicle is facing forward, and the steering side rear wheel corresponds to the right rear wheel on the same side. Similarly, the aforementioned non-steering side front wheel corresponds to the left front wheel when the vehicle is facing forward, and the non-steering side rear wheel corresponds to the left rear wheel on the same side. During the rotation of the target vehicle, each wheel is in a rotating state, and each wheel is controlled by a motor.

[0088] The determination module 54 is used to determine the current driving force of the target vehicle based on the torque data;

[0089] The acquisition module 56 is used to acquire the yaw rate of the target vehicle when the current driving force is greater than or equal to the yaw resistance torque of the target vehicle.

[0090] The control module 58 is used to determine the target wheel speed of each wheel during the vehicle's stationary turning process based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle, and to perform closed-loop steering control on the target vehicle based on the target wheel speed and the real-time wheel speed during the turning process.

[0091] The aforementioned device, after determining that the driver has issued a control command for stationary steering, determines the vehicle's current driving force based on the torque data output by the target vehicle. This determines that after the stationary steering begins, the target motor's torque increases from 0 Nm in absolute value until the vehicle's yaw rate exceeds a certain value. It then determines the situation where the target vehicle overcomes static friction and enters dynamic friction, calculating the target wheel speed at which the vehicle rotates stably under dynamic friction. Based on the target wheel speed and the real-time wheel speed during rotation, it performs closed-loop PID control for the target vehicle's steering. This achieves stable stationary steering while conserving vehicle energy, solving the problem of poor stability during stationary steering in current multi-motor vehicles. By determining the difference between the target wheel speed and the real-time wheel speed, it dynamically adjusts the driving force output by multiple motors under closed-loop control, precisely controlling the speed and torque of each motor on the target vehicle, achieving more precise, energy-efficient, and faster-responding stationary steering.

[0092] In an exemplary embodiment, before obtaining the yaw rate of the target vehicle when the current driving force is greater than or equal to the yaw resistance torque of the target vehicle, the method further includes: calculating a first sub-yaw resistance torque that the target vehicle needs to overcome during the static friction phase, wherein the first sub-yaw resistance torque is the total resistance value against the longitudinal static friction force of each wheel in the target vehicle; calculating a second sub-yaw resistance torque that the target vehicle needs to overcome during the static friction phase, wherein the second sub-yaw resistance torque is the total resistance value against the lateral static friction force of each wheel in the target vehicle; and determining the yaw resistance torque of the target vehicle based on the first sub-yaw resistance torque and the second sub-yaw resistance torque.

[0093] In an exemplary embodiment, after obtaining the yaw rate of the target vehicle, the method further includes: comparing the yaw rate with a preset yaw rate; if the yaw rate is less than the preset yaw rate, determining that the target vehicle is in a state of preparing to enter a steering state, and sending a prompt message to the driver, wherein the prompt message is used to instruct the driver to increase the control force of the accelerator pedal; if the yaw rate is greater than or equal to the preset yaw rate, determining that the target vehicle has entered a steering state, and initiating closed-loop steering control of the target vehicle.

[0094] In an exemplary embodiment, determining the target wheel speed of each wheel during a stationary turn based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle includes: determining the target slip ratio corresponding to each wheel of the target vehicle by using the slip ratio and a preset slip error; determining the target basic parameters corresponding to each wheel by using the factory information of the target vehicle, wherein the target basic parameters include at least: the track width of the target vehicle and the tire radius corresponding to each wheel of the target vehicle; substituting the target slip ratio, the target basic parameters corresponding to each wheel, and the yaw rate into a preset first formula to obtain the target wheel speed to be achieved by each wheel, wherein the preset first formula is: S d =1-ω / Ω dss *(B / 2) / r d S d Let B be the slip ratio of the target vehicle when turning in place, and r be the wheelbase of the target vehicle. d Let Ω be the tire radius corresponding to each wheel, ω be the yaw rate of the target vehicle, and Ω be the yaw rate of the target vehicle. dss Target wheel speed.

[0095] In an exemplary embodiment, before determining the target wheel speed of each wheel during the vehicle's stationary turning process based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle, the method further includes: determining the steering parameters of the current turning area where the target vehicle is located, wherein the steering parameters include at least: the ground type corresponding to the current turning area, the wheel type of the target vehicle, and the contact area between each wheel and the current turning area; searching for a reference slip ratio that matches the steering parameters in a preset database; and determining the slip ratio of the target vehicle based on the reference slip ratio and a preset slip error.

[0096] In an exemplary embodiment, closed-loop steering control of the target vehicle is performed based on the target wheel speed and the real-time wheel speed during the steering process, including: substituting the real-time wheel speed and the target wheel speed into a preset second formula to obtain the adjustment driving force of the target vehicle to be dynamically adjusted; wherein, the preset second formula is: △Ftx=Kp(Ω dss -Ω)+Kd(Ω dss -Ω) / dt+Ki*∫(Ω dss -Ω)dt, △Ftx is the adjustment driving force of the multi-motor closed-loop control on the target vehicle, Kp is the proportional feedback gain, Kd is the derivative gain, Ki is the integral gain, Ω dss Ω represents the target wheel speed and Ω represents the real-time wheel speed. The target torque output from the multiple motors on the target vehicle to each wheel is determined based on the adjusted driving force and the current driving force. The target torque is used to coordinate the driving object to control the torque data output by the target vehicle in order to perform closed-loop steering control on the target vehicle.

[0097] In an exemplary embodiment, after the driver issues a control command containing a stationary turning requirement, and the stationary turning function is activated, the method further includes: determining the steering angle and steering direction to be executed by the target vehicle in the stationary turning requirement; determining the current turning area of ​​the target vehicle based on the steering angle to be executed, the steering direction to be executed, and the vehicle size of the target vehicle; if the current turning area does not meet the standard turning requirements of the target vehicle, not triggering the operation of locking the target vehicle, and sending an alarm message to the driver, wherein the alarm message is used to indicate that the target vehicle cannot complete the stationary turning function and needs to be adjusted and reactivated; the standard turning requirements include at least: the maximum turning area that the target vehicle is allowed to complete stationary turning; if the current turning area meets the standard turning requirements of the target vehicle, triggering the operation of locking the target vehicle, prohibiting the driver from operating the target vehicle.

[0098] Embodiments of this application also provide a computer-readable storage medium storing a computer program, wherein the computer program is configured to execute the steps in any of the above method embodiments when run.

[0099] Optionally, in this embodiment, the storage medium may be configured to store a computer program for performing the following steps:

[0100] S1, when the driver issues a control command that includes a need for stationary turning, the stationary turning function is activated, and the torque data output by the driver through controlling the target vehicle is monitored; wherein, the torque data includes at least: a first torque corresponding to the front wheel on the turning side of the target vehicle, a second torque corresponding to the rear wheel on the turning side of the target vehicle, a third torque corresponding to the front wheel on the non-turning side of the target vehicle, and a fourth torque corresponding to the rear wheel on the non-turning side of the target vehicle.

[0101] S2, determine the current driving force of the target vehicle based on the torque data;

[0102] S3, if the current driving force is greater than or equal to the yaw resistance torque of the target vehicle, obtain the yaw rate of the target vehicle;

[0103] S4. Based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle, determine the target wheel speed of each wheel during the vehicle's stationary turning process, and perform closed-loop steering control on the target vehicle according to the target wheel speed and the real-time wheel speed during the turning process.

[0104] In one exemplary embodiment, the aforementioned computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard disk, magnetic disk, or optical disk.

[0105] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0106] Embodiments of this application also provide a computer program product, including a computer program, wherein the computer program, when executed by a processor, performs the steps in any of the above method embodiments.

[0107] Embodiments of this application also provide an electronic device including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0108] Optionally, in this embodiment, the processor can be configured to perform the following steps via a computer program:

[0109] S1, when the driver issues a control command that includes a need for stationary turning, the stationary turning function is activated, and the torque data output by the driver through controlling the target vehicle is monitored; wherein, the torque data includes at least: a first torque corresponding to the front wheel on the turning side of the target vehicle, a second torque corresponding to the rear wheel on the turning side of the target vehicle, a third torque corresponding to the front wheel on the non-turning side of the target vehicle, and a fourth torque corresponding to the rear wheel on the non-turning side of the target vehicle.

[0110] S2, determine the current driving force of the target vehicle based on the torque data;

[0111] S3, if the current driving force is greater than or equal to the yaw resistance torque of the target vehicle, obtain the yaw rate of the target vehicle;

[0112] S4. Based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle, determine the target wheel speed of each wheel during the vehicle's stationary turning process, and perform closed-loop steering control on the target vehicle according to the target wheel speed and the real-time wheel speed during the turning process.

[0113] In one exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0114] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0115] Obviously, those skilled in the art should understand that the modules or steps of this application described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented here, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.

[0116] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for controlling vehicle steering in place, characterized in that, include: When the driver issues a control command that includes a need for stationary turning, the stationary turning function is activated, and the torque data output by the driver through controlling the target vehicle is monitored; wherein, the torque data includes at least: a first torque corresponding to the front wheel on the turning side of the target vehicle, a second torque corresponding to the rear wheel on the turning side of the target vehicle, a third torque corresponding to the front wheel on the non-turning side of the target vehicle, and a fourth torque corresponding to the rear wheel on the non-turning side of the target vehicle. The current driving force of the target vehicle is determined based on the torque data; If the current driving force is greater than or equal to the yaw resistance torque of the target vehicle, the yaw rate of the target vehicle is obtained. Based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle, the target wheel speed of each wheel is determined during the vehicle's stationary turning process, and closed-loop steering control of the target vehicle is performed based on the target wheel speed and the real-time wheel speed during the turning process.

2. The vehicle in-situ steering control method according to claim 1, characterized in that, Before obtaining the yaw rate of the target vehicle when the current driving force is greater than or equal to the yaw drag torque of the target vehicle, the method further includes: Calculate the first sub-yaw resistance torque that the target vehicle needs to overcome in the static friction stage, wherein the first sub-yaw resistance torque is the total resistance value to overcome the longitudinal static friction force of each wheel in the target vehicle. Calculate the second sub-yaw resistance torque that the target vehicle needs to overcome during the static friction stage, wherein the second sub-yaw resistance torque is the total resistance value to overcome the lateral static friction force of each wheel in the target vehicle; The yaw resistance moment of the target vehicle is determined based on the first sub-yaw resistance moment and the second sub-yaw resistance moment.

3. The vehicle in-situ steering control method according to claim 1, characterized in that, After obtaining the yaw rate of the target vehicle, the method further includes: Compare the magnitude of the yaw rate with the preset angular velocity; When the yaw rate is less than a preset yaw rate, it is determined that the target vehicle is in a state of preparing to enter a turn, and a prompt message is sent to the driver, wherein the prompt message is used to instruct the driver to increase the pressure of the accelerator pedal. If the yaw rate is greater than or equal to a preset yaw rate, the target vehicle is determined to be in a steering state, and closed-loop steering control of the target vehicle is initiated.

4. The vehicle in-situ steering control method according to claim 1, characterized in that, Based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle, the target wheel speed of each wheel during the vehicle's stationary turning process is determined, including: The target slip ratio for each wheel in the target vehicle is determined by the slip ratio and the preset slip error. The target basic parameters corresponding to each wheel are determined by the factory information of the target vehicle, wherein the target basic parameters include at least: the wheelbase of the target vehicle and the tire radius corresponding to each wheel of the target vehicle; Substituting the target slip ratio, the target basic parameters corresponding to each wheel, and the yaw rate into a preset first formula, the target wheel speed to be achieved for each wheel is obtained, wherein the preset first formula is: S d =1-ω / Ω dss *(B / 2) / r d S d Let B be the slip ratio of the target vehicle when turning in place, and r be the wheelbase of the target vehicle. d Let ω be the tire radius corresponding to each wheel, ω be the yaw rate of the target vehicle, and Ω be the yaw rate. dss Target wheel speed.

5. The vehicle in-situ steering control method according to claim 1, characterized in that, Before determining the target wheel speed of each wheel during the vehicle's stationary turning process based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle, the method further includes: Determine the steering parameters of the current steering area where the target vehicle is located, wherein the steering parameters include at least: the ground type corresponding to the current steering area, the wheel type of the target vehicle, and the contact area between each wheel and the current steering area; Search the preset database for a reference slip ratio that matches the steering parameters; The slip ratio of the target vehicle is determined based on the reference slip ratio and the preset slip error.

6. The vehicle in-situ steering control method according to claim 1, characterized in that, Closed-loop steering control of the target vehicle is performed based on the target wheel speed and the real-time wheel speed during the steering process, including: Substituting the real-time wheel speed and the target wheel speed into the preset second formula, the adjustment driving force to be dynamically adjusted for the target vehicle is obtained; wherein, the preset second formula is: △Ftx=Kp(Ω dss -Ω)+Kd(Ω dss -Ω) / dt+Ki*∫(Ω dss -Ω)dt, △Ftx is the adjustment driving force of the multi-motor closed-loop control on the target vehicle, Kp is the proportional feedback gain, Kd is the derivative gain, Ki is the integral gain, Ω dss Ω represents the target wheel speed, and Ω represents the real-time wheel speed. The target torque output from the multiple motors on the target vehicle to each wheel is determined based on the adjusted driving force and the current driving force. The target torque is coordinated by the driving object to control the torque data output by the target vehicle in order to perform closed-loop steering control on the target vehicle.

7. The method according to claim 1, characterized in that, When the driver issues a control command that includes a need for stationary turning, after activating the stationary turning function, the method further includes: Determine the steering angle and steering direction to be executed for the target vehicle in the in-situ steering requirement; The current steering area of ​​the target vehicle is determined based on the steering angle to be executed, the steering direction to be executed, and the vehicle size of the target vehicle; If the current turning area does not meet the standard turning requirements of the target vehicle, the operation of locking the target vehicle will not be triggered, and an alarm message will be sent to the driver. The alarm message indicates that the target vehicle cannot complete the stationary turning function and needs to be adjusted before restarting. The standard turning requirements include at least the maximum turning area that the target vehicle is allowed to complete stationary turning. If the current steering area meets the standard steering requirements of the target vehicle, the operation of locking the target vehicle is triggered, prohibiting the driver from operating the target vehicle.

8. A control device for vehicle in-situ steering, characterized in that, include: The monitoring module is used to activate the stationary steering function when the driver issues a control command that includes a stationary steering requirement, and to monitor the torque data output by the driver through controlling the target vehicle; wherein the torque data includes at least: a first torque corresponding to the front wheel on the steering side of the target vehicle, a second torque corresponding to the rear wheel on the steering side of the target vehicle, a third torque corresponding to the front wheel on the non-steering side of the target vehicle, and a fourth torque corresponding to the rear wheel on the non-steering side of the target vehicle. A determination module is used to determine the current driving force of the target vehicle based on the torque data; The acquisition module is used to acquire the yaw rate of the target vehicle when the current driving force is greater than or equal to the yaw resistance torque of the target vehicle. The control module is used to determine the target wheel speed of each wheel during the vehicle's stationary turning process based on the yaw rate, the slip ratio of the target vehicle, and the basic parameters of the target vehicle, and to perform closed-loop steering control on the target vehicle based on the target wheel speed and the real-time wheel speed during the turning process.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein the program, when executed, performs the method of any one of claims 1 to 7.

10. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to execute the method of any one of claims 1 to 7 through the computer program.

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