Vehicle steering control method and apparatus

Abstract

A vehicle steering control method and apparatus. The method comprises: in response to a steering control request, determining a target steering direction; and during a vehicle steering control process, controlling front wheels of a vehicle to turn towards the target steering direction to a maximum steering angle, and performing wheel speed control on each wheel of the vehicle, so as to reach a target rotation speed.

Description

A method and apparatus for vehicle steering control

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to Chinese Patent Application No. 202410807254.8, filed on June 20, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of automotive technology, specifically, it relates to a method and apparatus for vehicle steering control. Background Technology

[0004] With the development of automotive technology, users have increasingly higher demands for vehicle functions. One important function requirement is vehicle turning on the spot. However, existing turning-on-the-spot solutions are too complex and difficult to implement, and they cannot significantly reduce the turning radius, thus not improving the passability. On the other hand, solutions that can reduce the turning radius have problems such as greater tire wear.

[0005] Public content

[0006] One objective of this application is to provide a method and apparatus for vehicle steering control.

[0007] This application provides a method for vehicle steering control, the method comprising:

[0008] In response to a steering control request, determine the target's direction of rotation; and

[0009] During vehicle steering control, the front wheels of the vehicle are controlled to rotate toward the target direction of rotation to the maximum turning angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

[0010] In some embodiments, during vehicle steering control, controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target rotation direction and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed includes:

[0011] During vehicle steering control, the front wheels of the vehicle are controlled to rotate to the maximum angle in the target rotation direction, the rear wheels on the first side of the vehicle corresponding to the target rotation direction are controlled to remain stationary relative to the vehicle, and the wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

[0012] In some embodiments, during vehicle steering control, controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target rotation direction and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed includes:

[0013] During vehicle steering control, the front wheels of the vehicle are controlled to rotate to the maximum angle in the target rotation direction. The rear wheels on the first side of the vehicle corresponding to the target rotation direction are braked to lock up. The wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

[0014] In some embodiments, controlling the wheel speed of the other wheels of the vehicle to achieve a target rotational speed includes:

[0015] Based on the target rotational speed, the wheel speed of the other wheels of the vehicle is controlled; and

[0016] During the process of controlling the wheel speed of the other wheels of the vehicle, the front wheel on the first side is controlled so that the wheel speed of the front wheel on the first side is less than the wheel speed of the front wheel on the second side.

[0017] In some embodiments, controlling the wheel speed of other wheels of the vehicle based on the target rotational speed includes:

[0018] Based on the target rotational speed, determine the target wheel speeds of the other wheels of the vehicle; and

[0019] The wheel speeds of the other wheels of the vehicle are controlled according to the target wheel speed.

[0020] In some embodiments, during vehicle steering control, controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target rotation direction and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed includes:

[0021] When the vehicle steering control system is currently active, the following steps are performed during vehicle steering control: controlling the front wheels of the vehicle to rotate to the maximum angle in the target direction of rotation, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed.

[0022] In some embodiments, the method further includes providing feedback to the user when the current state of the vehicle steering control system is inactive.

[0023] In some embodiments, the current state of the vehicle steering control system is active if one or more of the following conditions are met:

[0024] A steering control request has been detected. The indicator light is on. The target gear is forward. The steering wheel angle is valid. The left front wheel speed is valid. The right front wheel speed is valid. The left rear wheel speed and the right rear wheel speed are valid.

[0025] In some embodiments, during vehicle steering control, controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target rotation direction and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed includes:

[0026] When the vehicle enters the first state, the following steps are performed during the vehicle steering control process: controlling the front wheels of the vehicle to rotate to the maximum angle in the target rotation direction, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed.

[0027] The first state is the state of entering steering control.

[0028] In some embodiments, the vehicle enters a first state when one or more of the following conditions are met: the vehicle steering control system is activated, the vehicle speed is less than a first threshold, and the braking depth is less than a second threshold.

[0029] In some embodiments, it also includes:

[0030] When the vehicle enters the second state, the vehicle is controlled to perform a specified operation to exit steering control; wherein, the second state is the state of exiting steering control.

[0031] In some embodiments, the specified operation includes one or more of the following operations: returning the vehicle steering wheel to center, unloading the drive motor torque, and restoring the braking system to basic braking.

[0032] In some embodiments, the vehicle enters the second state if any of the following conditions are met:

[0033] The vehicle steering control system is inactive, the vehicle speed is greater than or equal to the first threshold, the braking depth is greater than or equal to the second threshold, and the steering wheel angle is less than the third threshold.

[0034] In some embodiments, prior to determining the target rotation direction in response to a steering control request, the method further includes:

[0035] Get the steering control request based on the user input.

[0036] This application provides a vehicle steering control device, the device being used for:

[0037] In response to a steering control request, determine the target's direction of rotation; and

[0038] During vehicle steering control, the front wheels of the vehicle are controlled to rotate toward the target direction of rotation to the maximum turning angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

[0039] This application provides an electronic device, including a processor, a memory, and computer instructions stored in the memory and capable of running on the processor. When the computer instructions are executed by the processor, they implement the method described above.

[0040] This application provides a vehicle including the device described above, or the electronic device described above. A computer-readable storage medium stores computer instructions that, when executed by a processor, implement the method described above.

[0041] This application provides a computer program product, including computer instructions that, when executed by a processor, implement the method described above.

[0042] In this embodiment, by responding to a steering control request, the target rotation direction is determined, and during the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to the maximum angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed. This optimizes the vehicle's stationary steering function, reduces the complexity of the stationary steering scheme, and makes it easier to implement. Attached Figure Description

[0043] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.

[0044] Figure 1 is a schematic diagram of a vehicle system provided in some embodiments of this application;

[0045] Figure 2 is a schematic diagram of another vehicle system provided by some embodiments of this application;

[0046] Figure 3 is a schematic diagram of vehicle steering provided in some embodiments of this application;

[0047] Figure 4 is a flowchart of the steps of a vehicle steering control method provided in some embodiments of this application;

[0048] Figure 5 is a schematic diagram of a display interface provided in some embodiments of this application;

[0049] Figure 6 is a flowchart of the steps of another vehicle steering control method provided in some embodiments of this application. Detailed Implementation

[0050] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0051] In some embodiments, by equipping the vehicle with front and rear dual motors and controlling the two motors to drive independently, the electric vehicle with front and rear dual motors can independently control the direction and torque of the front and rear power outputs. When turning, the inner front wheel and the outer rear wheel are locked, and a positive torque is applied to the outer front wheel and a negative torque is applied to the inner rear wheel, thereby enabling the vehicle to rotate approximately around the center of gravity in place, reducing the turning radius to 1 / 2 of the cross axle, and thus enabling the vehicle to turn in place.

[0052] While this approach only requires the vehicle to be equipped with dual front and rear motors, the method of locking the inner front wheel and the outer rear wheel, applying a positive torque to the outer front wheel and a negative torque to the inner rear wheel, presents several challenges. First, the wheels applying the applied torque may lack sufficient traction to turn the vehicle on the spot. Second, turning on the spot inevitably leads to the locked wheels slipping, while the drive wheels experience significant spin. This results in severe tire wear, making it impractical for real-world applications.

[0053] In some embodiments, by equipping the vehicle with a single front motor and dual rear motors, the electric vehicle can independently control the power output direction and output torque of the front axle and the left and right rear wheels; or by equipping the vehicle with four distributed drive motors, controlling the four motors to drive independently, enabling the vehicle to turn on the spot. The target yaw rate is obtained by the accelerator pedal opening, and then the target yaw torque of each wheel motor is determined based on the actual yaw rate, the road adhesion coefficient, and the target yaw rate. Based on the target yaw torque of each wheel motor, the inner front wheel and inner rear wheel are controlled to rotate in reverse, and the outer front wheel and outer rear wheel are controlled to rotate in forward, thereby enabling the vehicle to turn on the spot.

[0054] The most basic requirement for this approach is that the vehicle needs to have three or four motors, and the four wheels should be able to drive independently as much as possible. Currently, only a few OEMs use this type of distributed drive vehicle in their top-of-the-line cars, and it is not as common as dual-motor models.

[0055] In some embodiments, the vehicle is turned in place around the inner rear wheel by braking or locking the inner rear wheel during a turn. The target wheel is determined according to the turning direction, and braking force is applied to the target wheel or the target wheel is locked to turn the vehicle in place around the inner rear wheel.

[0056] With this approach, all wheels are driven except for the inner rear wheel when it is braked or locked. This causes the inner rear wheel to be dragged and slide, resulting in a turning radius that is generally larger than the cross axle. It cannot reliably achieve the effect of significantly reducing the turning radius when turning in place.

[0057] In this embodiment, the system components only need to meet the requirements of having one motor at the front and one at the rear to drive the front and rear wheels respectively through the inter-wheel differential and having an electronic parking system. Other aspects such as braking, steering, and suspension are similar to those of existing common vehicles and have no other special requirements.

[0058] Moreover, the control strategy in this application embodiment is mainly that after pressing the stationary turn button or receiving the stationary turn signal, the steering motor turns the wheel angle to the maximum in the steering direction, and then locks the inner rear wheel through the hydraulic braking system or electronic parking system, and brakes the inner front wheel to control its wheel speed.

[0059] In addition, the positive torque output of the front and rear motors is controlled simultaneously, and the wheel speed of the outer front and rear wheels is controlled by the differential. Under the action of the hydraulic braking system and the front and rear motor drive, the inner wheels are subjected to a rearward longitudinal force, while the outer wheels are subjected to a forward longitudinal force. While suppressing the forward movement of the vehicle, a yaw moment is generated, thereby achieving on-the-spot steering.

[0060] In this process, the front and rear wheels of the vehicle using this application may require driving force close to the ground adhesion. Therefore, there are certain requirements for the torque of the front and rear motors or the deceleration and torque amplification mechanism on high-speed roads. In addition, the steering motor is also required when the front wheels are turning, which may require a certain increase in the torque of the existing steering motor. However, most existing vehicles with motors at both the front and rear can meet the requirements. If they cannot meet the requirements, the modifications are relatively small. Compared with the existing technical solutions, the requirements for the vehicle are relatively low and it is easier to implement.

[0061] Furthermore, in the execution of the control strategy of this application embodiment, the steering motor first turns the wheel angle to the maximum in the steering direction, and then the hydraulic braking system locks the inner rear wheel and brakes the inner front wheel to control its wheel speed. In addition, the front and rear motors are controlled to output positive torque, and the wheel speed of the outer front and rear wheels is controlled under the action of the differential. Under the action of the hydraulic braking system and the front and rear motors, the inner wheel is subjected to a rearward longitudinal force, while the outer wheel is subjected to a forward longitudinal force. While suppressing the forward movement of the vehicle, a yaw moment is generated. Since the inner rear wheel is locked, the outer wheel slightly slips and the inner front wheel slightly slips under the control of the wheel speed of the inner front wheel and the outer wheel, so that the vehicle rotates around the inner rear wheel as the center, thereby greatly reducing the turning radius, improving the vehicle's passability in narrow environments, and increasing the convenience of steering for the driver. During this process, except for the inner rear wheel rotating at a fixed point, all other wheels are in a rolling state, which helps to reduce tire wear.

[0062] The following description, in conjunction with the accompanying drawings, illustrates this application:

[0063] As shown in Figure 1, the vehicle includes an auxiliary steering request input device, an auxiliary steering controller, a steering motor controller, a front drive motor controller, a rear drive motor controller, a steering motor, a front drive motor, a rear drive motor, an electro-hydraulic brake controller, and an electro-hydraulic brake system.

[0064] The steering request input device can be activated directly by voice, or it can be a physical button located in a position accessible to the driver, such as on the dashboard, center console, or steering wheel. Alternatively, it can be a virtual button, allowing the driver to select the stationary steering function via the vehicle's display screen.

[0065] The auxiliary steering controller is the core component for enabling vehicles to turn on the spot. This part is responsible for receiving the function activation signal input from the steering request input device, then judging whether the entry conditions are met, and calculating the required steering, drive and braking signals through the control algorithm to the steering and drive motor controller and the electro-hydraulic brake. When the function exit conditions are met, it controls the unloading of driving force and braking force and the steering to return to center, thus exiting the function.

[0066] The motor controller receives the torque signal from the stationary steering controller and controls the motor to output the corresponding torque to drive the wheels to rotate.

[0067] The electro-hydraulic brake controller receives braking requests from the stationary steering controller and controls the locking of the inner rear wheel and the braking of the inner front wheel.

[0068] In the embodiments of this application, the vehicle with one drive motor at the front and one at the rear and the electronic power steering includes the above-mentioned structure. This application can achieve the purpose of greatly reducing the turning radius simply by controlling the driving force and braking force of the above-mentioned structure.

[0069] As shown in Figure 2, an electronic parking brake controller has been added to the vehicle's stationary steering control system. The rest of the structure remains the same and will not be described in detail here. The difference from the previous solution is that the braking force source for the inner rear wheel is different. The previous solution uses the braking force generated by the electro-hydraulic braking system to lock the inner rear wheel, while this solution uses the braking force generated by the parking brake control system to lock the inner rear wheel. Both solutions can achieve the goal of locking the inner rear wheel.

[0070] As shown in Figure 3, the scheme of this application embodiment is implemented by turning the front wheels to the maximum turning angle through the steering system. Then, the braking system locks the inner rear wheel and applies braking to the inner front wheel. The rear motor is controlled to output positive torque, and under the action of the differential, the outer rear wheel is turned forward. The front motor is controlled to output positive torque, driving the front wheel to turn forward. Under the action of the differential and braking, the inner front wheel turns forward by a certain proportion lower than the outer front wheel, so that the inner front wheel obtains a rearward braking force, thereby suppressing the forward tendency of the vehicle and achieving better yaw rotation. Finally, the resultant force of the ground on the other three wheels except the inner rear wheel is less than the adhesion force of the inner rear wheel. With the inner rear wheel locked, the vehicle can achieve a stationary turn with the inner rear wheel as the center and the distance between the inner rear wheel and the outer front wheel as the maximum radius, thereby drastically reducing the turning radius of the vehicle.

[0071] For example, when the vehicle turns left, by locking the left rear wheel, the control motor 2 outputs positive torque to drive the right rear wheel to turn forward, and the control motor 1 outputs positive torque to drive the front wheel to turn forward, braking the left front wheel, so that the longitudinal force on the left side is negative and the longitudinal force on the right side is positive, which greatly increases the yaw moment of the vehicle and reduces the forward tendency, achieving the effect of turning on the spot.

[0072] Referring to Figure 4, a flowchart of the steps of a vehicle steering control method according to some embodiments of this application is shown. The vehicle has a first drive motor for driving the front wheels and a second drive motor for driving the rear wheels. Specifically, the method may include the following steps:

[0073] Step 401: In response to the steering control request, determine the target rotation direction.

[0074] In practical applications, a steering control request can be a request to control the vehicle to turn in place, such as turning around a rear wheel of the vehicle. The steering control request can carry the target rotation direction, which can be the direction of the requested turn, such as left turn or right turn.

[0075] In some examples, the steering control request can also carry a target rotation speed, which is the speed to be maintained when steering. The target rotation speed can be set to a specific speed value or a speed level, such as slow, normal speed, or fast.

[0076] In some embodiments of this application, before determining the target rotation direction in response to a steering control request, the method further includes: obtaining a steering control request based on user input.

[0077] As shown in Figure 5, the vehicle is equipped with a central control display interface. Users can select automatic, manual, or turn off the stationary steering function through the vehicle's infotainment display screen. They can also select the target rotation speed, which can be set to a specific speed value or a speed level, such as slow, normal, or fast. They can also select the target rotation direction, such as left or right turn.

[0078] In some examples, the target rotation speed can be related to the environment in which the vehicle is located. When the environment is more complex, such as when there is less turning space and more nearby vehicles, pedestrians and obstacles, a lower target rotation speed can be used. When there is more turning space and fewer nearby vehicles, pedestrians and obstacles, a higher target rotation speed can be used.

[0079] After the user completes their selection, the vehicle's infotainment display sends the relevant information to the stationary steering controller and instrument cluster. The stationary steering controller then controls the vehicle to perform a U-turn at the target rotation speed and direction. In some examples, the instrument cluster displays corresponding animations, torque, braking pressure, wheel speed, and other information.

[0080] Step 402: During the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to the maximum turning angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

[0081] After determining the target rotation direction, in order to achieve on-the-spot turning, the front wheels of the vehicle can be controlled to rotate to the maximum angle in the target rotation direction. Furthermore, by controlling the wheel speed of each wheel, the vehicle can achieve the target rotation speed while rotating, thus adapting to the on-site environment.

[0082] In some embodiments of this application, the step of controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target rotation direction during vehicle steering control, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0083] During vehicle steering control, the front wheels of the vehicle are controlled to rotate to the maximum angle in the target rotation direction, the rear wheels on the first side of the vehicle corresponding to the target rotation direction are controlled to remain stationary relative to the vehicle, and the wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

[0084] The first side is the inner side of the stationary turning, that is, the side closest to the rotation axis.

[0085] In practical applications, on the one hand, the front wheels of the vehicle can be controlled to rotate to the maximum angle in the target rotation direction. On the other hand, the rear wheels on the first side of the vehicle corresponding to the target rotation direction can be controlled to remain stationary relative to the vehicle. Thus, the stationary rear wheels can be used as the axis of rotation to perform on-the-spot turning. Furthermore, the wheel speed of the other wheels of the vehicle can be controlled to achieve the target rotation speed when turning on the spot.

[0086] In some embodiments of this application, the step of controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target rotation direction during vehicle steering control, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0087] During vehicle steering control, the front wheels of the vehicle are controlled to rotate to the maximum angle in the target rotation direction. The rear wheels on the first side of the vehicle corresponding to the target rotation direction are braked to lock up. The wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

[0088] In practical applications, on the one hand, the front wheels of the vehicle can be controlled to rotate to the maximum angle in the target rotation direction. On the other hand, the rear wheels on the first side of the vehicle corresponding to the target rotation direction can be braked to lock up. Then, the locked rear wheels can be used as the axis of rotation to turn in place. Furthermore, the wheel speed of the other wheels of the vehicle can be controlled to achieve the target rotation speed when turning in place.

[0089] In some examples, the vehicle can be braked by an electro-hydraulic braking system or a parking brake control system. As shown in Figure 1, the braking force generated by the electro-hydraulic braking system locks the inner rear wheel. As shown in Figure 2, the braking force generated by the parking brake control system locks the inner rear wheel.

[0090] In practical applications, the steering motor output torque is controlled to turn the front wheel angle to the maximum. Then, the rear motor torque is used to control the wheel speed of the outer rear wheel, and the front motor torque is used to control the wheel speed of the outer front wheel. At the same time, the left rear wheel is locked and the left front wheel is braked through braking control.

[0091] In the electro-hydraulic braking system, the master cylinder outputs maximum pressure, which controls the opening of the inner rear wheel boost valve and the closing of the pressure relief valve. After reaching the maximum pressure, the pressure is maintained. The inner front wheel boost valve opens and the pressure relief valve closes. After reaching the target wheel speed, the boost valve closes and the pressure is maintained. The outer wheel boost and pressure relief valves close.

[0092] In some embodiments of this application, the step of controlling the wheel speed of other wheels of the vehicle to achieve a target rotational speed includes: controlling the wheel speed of other wheels of the vehicle according to the target rotational speed; and during the wheel speed control of other wheels of the vehicle, controlling the front wheel on the first side so that the wheel speed of the front wheel on the first side is less than the wheel speed of the front wheel on the second side.

[0093] The second side is the side opposite to the first side, that is, the outer side when turning in place.

[0094] In some embodiments of this application, the step of controlling the wheel speed of other wheels of the vehicle according to the target rotation speed includes: determining the target wheel speed of other wheels of the vehicle according to the target rotation speed; and controlling the wheel speed of other wheels of the vehicle according to the target wheel speed.

[0095] In practical applications, there is a correlation between the target rotation speed for turning in place and the wheel speed of the vehicle's wheels. Therefore, the target turning speed can be mapped to the target wheel speed of the other wheels of the vehicle, and then the corresponding target wheel speed can be used to control the wheel speed of the other wheels of the vehicle.

[0096] Furthermore, during the process of controlling the wheel speed of the other wheels of the vehicle, differential control can be applied to the wheel speed of the two front wheels, so that the wheel speed of the front wheel on the first side is less than that of the front wheel on the second side, thereby enabling the vehicle to achieve the effect of turning in place towards the first side.

[0097] For example, when the vehicle turns left, as shown in Figure 3, the steering motor is first controlled to output torque to turn the front wheel angle to the left to its maximum. At this time, according to the selected mode, the target wheel speed of the right front wheel is ω4. Based on the geometric relationship, the target wheel speeds of each wheel are controlled to satisfy the following relationship: ω2=0

[0098] Where L is the wheelbase, d is the track width, ω1, ω2, ω 3 ω4 represents the target wheel speeds for the left front, left rear, right rear, and right front wheels, respectively, and δ is half the sum of the steering angles of the left and right front wheels.

[0099] In practical applications, by controlling the maximum output pressure of the master cylinder, the pressure boosting valve of the left rear wheel is opened, and the pressure relief valve is closed. Once the maximum pressure is reached, it is maintained. The pressure boosting and relief valves of the outer wheel are closed, and the front and rear motors simultaneously increase torque. This controls the wheel speed of the right front wheel to ω4 and the wheel speed of the right rear wheel to ω. 3 At the same time, the boost valve on the left front wheel opens and the pressure relief valve closes. When the target wheel speed ω1 is reached, the boost valve is closed to maintain pressure.

[0100] The torque distribution between the front and rear motors and the braking pressure control of the left front wheel must meet the requirements that the tire force of the left rear wheel is less than the adhesion force and the total longitudinal force F of the vehicle. x The total longitudinal force F is 0, which suppresses the vehicle's forward tendency. xIt can be represented as: F x =-F1cosδ-F2+F3+F4cosδ=0

[0101] Among them, F1, F2, F3, and F4 represent the tangential forces exerted on the ground by the left front, left rear, right rear, and right front wheels, respectively. The left front wheel speed, the torque distribution between the front and rear motors, and the left front wheel braking pressure control all require adjustment, calibration, and confirmation based on actual conditions.

[0102] In this embodiment of the application, when turning, the inner rear wheel locks up, the front wheel brakes, and the outer front and rear wheels rotate clockwise to achieve rotation around the inner rear wheel, which greatly reduces the turning radius, improves the vehicle's passability, reduces the driver's burden and tire wear, and can stably achieve an effect similar to turning on the spot.

[0103] In some embodiments of this application, the step of controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target rotation direction during vehicle steering control, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0104] When the vehicle steering control system is currently active, the following steps are performed during vehicle steering control: controlling the front wheels of the vehicle to rotate to the maximum angle in the target direction of rotation, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed.

[0105] In some embodiments of this application, the vehicle steering control system is in an active state when one or more of the following conditions are met:

[0106] A steering control request has been detected. The indicator light is on. The target gear is forward. The steering wheel angle is valid. The left front wheel speed is valid. The right front wheel speed is valid. The left rear wheel speed and the right rear wheel speed are valid.

[0107] In some embodiments of this application, the method further includes providing feedback to the user when the current state of the vehicle steering control system is inactive.

[0108] In practical applications, a conditional judgment can be used to determine whether the vehicle's stationary steering control system can be activated. When all of the following conditions are met, the activation permission flag for the stationary steering system is set to 1 (activation permitted); otherwise, the activation permission flag is set to 0 (activation not permitted), and the vehicle's display screen will show the reason for disallowed activation. The conditions include: 1. The stationary steering request flag is 1 (driver has issued a request); 2. The OK light is illuminated; 3. The target gear is D; 4. The steering wheel angle is valid; 5. The left front wheel speed is valid; 6. The right front wheel speed is valid; 7. The left rear wheel speed is valid; 8. The right rear wheel speed is valid.

[0109] In some embodiments of this application, the step of controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target rotation direction during vehicle steering control, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0110] When the vehicle enters the first state, the process of controlling the vehicle steering involves controlling the front wheels of the vehicle to rotate to the maximum angle in the target rotation direction and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed.

[0111] The first state is the state of entering steering control.

[0112] In some embodiments of this application, the vehicle enters a first state when one or more of the following conditions are met: the vehicle steering control system is activated, the vehicle speed is less than a first threshold, and the braking depth is less than a second threshold.

[0113] In some embodiments of this application, it also includes:

[0114] When the vehicle enters the second state, the vehicle is controlled to perform a specified operation to exit steering control; wherein, the second state is the state of exiting steering control.

[0115] In some embodiments of this application, the vehicle enters a second state when any of the following conditions are met: the vehicle steering control system is inactive, the vehicle speed is greater than or equal to a first threshold, the braking depth is greater than or equal to a second threshold, and the steering wheel angle is less than a third threshold.

[0116] In some embodiments of this application, the specified operation includes one or more of the following operations: the vehicle steering wheel is returned to center, the drive motor torque is unloaded, and the braking system is restored to basic braking.

[0117] When the vehicle's stationary steering system activation indicator is 1, the vehicle control status is determined. The vehicle control status is divided into three states: state 0 (no control state), state 1 (entering control, i.e., the first state), and state 2 (steering return, torque and hydraulic unloading, i.e., the second state).

[0118] In practical applications, the default initial control state of vehicle control is 0. The vehicle enters control state 1 when the following conditions are met: 1. The vehicle's stationary steering system activation flag is set to 1; 2. The vehicle speed is less than threshold 1; 3. The braking depth is less than threshold 2.

[0119] When any of the above conditions are not met, the vehicle control state enters state 2: 1. The vehicle's stationary steering system activation permission flag is 0; 2. The vehicle speed is greater than or equal to threshold 1; 3. The braking depth is greater than or equal to threshold 2; 4. The steering wheel angle is less than threshold 3.

[0120] When the vehicle enters state 1, the steering, drive, and braking systems are controlled to enable in-situ steering. When the vehicle enters state 2, the steering motor controls the steering wheel to return to center, the torque of the front and rear motors is unloaded, and the braking pressure of the master cylinder and wheel cylinders responds to the basic braking pressure. When the torque unloading is complete and the hydraulic braking response is at the basic braking level, the vehicle enters state 0, exiting the in-situ steering function.

[0121] In this embodiment, by responding to a steering control request, the target rotation direction is determined, and during the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to the maximum angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed. This optimizes the vehicle's stationary steering function, reduces the complexity of the stationary steering scheme, and makes it easier to implement.

[0122] Moreover, without making significant changes to the vehicle structure, it achieves the goal of greatly reducing the turning radius and tire wear.

[0123] The following is an illustrative description of this application with reference to Figure 6: 1. The driver selects to enter the stationary steering function; 2. The driver selects the corresponding mode and direction; 3. The vehicle stationary steering control system determines whether the function entry conditions are met. If met, proceed to step 4; if not, exit the function and generate a prompt on the vehicle's display screen; 4. Calculate the target pressure of the master cylinder or the electronic parking brake pressure, determine the braking commands for each wheel and the control commands for the solenoid valves, and calculate the target torque of the steering motor, front motor, and rear motor based on the target speed; 5. Output the steering motor control commands, etc., to the actuators for execution. After execution, proceed to step 6; 6. Output the target torque of the front motor and rear motor, the master cylinder pressure, the valve body, the electronic parking brake motor control commands, etc., to the actuators for execution. After execution, proceed to step 7; 7. Determine whether the exit conditions are met. If yes, proceed to step 8; if no, return to step 4; 8. The torque is unloaded to 0, and the pressure response returns to the basic braking pressure; 9. Exit the function.

[0124] It should be noted that, for the sake of simplicity, the method embodiments are all described as a series of actions. However, those skilled in the art should understand that the embodiments of this application are not limited to the described order of actions, because according to the embodiments of this application, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of this application.

[0125] Some embodiments of this application also provide a vehicle steering control device for:

[0126] In response to a steering control request, determine the target's direction of rotation; and

[0127] During vehicle steering control, the front wheels of the vehicle are controlled to rotate toward the target direction of rotation to the maximum turning angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

[0128] In some embodiments of this application, the step of controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target rotation direction during vehicle steering control, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0129] During vehicle steering control, the front wheels of the vehicle are controlled to rotate to the maximum angle in the target rotation direction, the rear wheels on the first side of the vehicle corresponding to the target rotation direction are controlled to remain stationary relative to the vehicle, and the wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

[0130] In some embodiments of this application, the step of controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target rotation direction during vehicle steering control, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0131] During vehicle steering control, the front wheels of the vehicle are controlled to rotate to the maximum angle in the target rotation direction. The rear wheels on the first side of the vehicle corresponding to the target rotation direction are braked to lock up. The wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

[0132] In some embodiments of this application, controlling the wheel speed of other wheels of the vehicle to achieve a target rotational speed includes:

[0133] Based on the target rotational speed, the wheel speed of the other wheels of the vehicle is controlled; and

[0134] During the process of controlling the wheel speed of the other wheels of the vehicle, the front wheel on the first side is controlled so that the wheel speed of the front wheel on the first side is less than the wheel speed of the front wheel on the second side.

[0135] In some embodiments of this application, the step of controlling the wheel speed of other wheels of the vehicle based on the target rotational speed includes:

[0136] Based on the target rotational speed, determine the target wheel speeds of the other wheels of the vehicle; and

[0137] The wheel speeds of the other wheels of the vehicle are controlled according to the target wheel speed.

[0138] In some embodiments of this application, the step of controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target rotation direction during vehicle steering control, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0139] When the vehicle steering control system is currently active, the following steps are performed during vehicle steering control: controlling the front wheels of the vehicle to rotate to the maximum angle in the target direction of rotation, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed.

[0140] In some embodiments of this application, it is also used to: provide feedback to the user when the current state of the vehicle steering control system is inactive.

[0141] In some embodiments of this application, the vehicle steering control system is in an active state when one or more of the following conditions are met:

[0142] A steering control request has been detected. The indicator light is on. The target gear is forward. The steering wheel angle is valid. The left front wheel speed is valid. The right front wheel speed is valid. The left rear wheel speed and the right rear wheel speed are valid.

[0143] In some embodiments of this application, the step of controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target rotation direction during vehicle steering control, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0144] When the vehicle enters the first state, the following steps are performed during the vehicle steering control process: controlling the front wheels of the vehicle to rotate to the maximum angle in the target rotation direction, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed.

[0145] The first state is the state of entering steering control.

[0146] In some embodiments of this application, the vehicle enters a first state when one or more of the following conditions are met: the vehicle steering control system is activated, the vehicle speed is less than a first threshold, and the braking depth is less than a second threshold.

[0147] In some embodiments of this application, it is also used for:

[0148] When the vehicle enters the second state, the vehicle is controlled to perform a specified operation to exit steering control; wherein, the second state is the state of exiting steering control.

[0149] In some embodiments of this application, the specified operation includes one or more of the following operations: returning the vehicle steering wheel to center, unloading the drive motor torque, and restoring the braking system to basic braking.

[0150] In some embodiments of this application, the vehicle enters a second state when any of the following conditions are met: the vehicle steering control system is inactive, the vehicle speed is greater than or equal to a first threshold, the braking depth is greater than or equal to a second threshold, and the steering wheel angle is less than a third threshold.

[0151] In some embodiments of this application, before determining the target rotation direction in response to a steering control request, the method is further configured to:

[0152] Get the steering control request based on the user input.

[0153] Some embodiments of this application also provide an electronic device, including a processor, a memory, and computer instructions stored in the memory and capable of running on the processor, wherein the computer instructions, when executed by the processor, implement the method described above.

[0154] Some embodiments of this application also provide a vehicle including the device described above, or the electronic device described above.

[0155] Some embodiments of this application also provide a computer-readable storage medium storing computer instructions that, when executed by a processor, implement the method described above.

[0156] Some embodiments of this application also provide a computer program product, including computer instructions that, when executed by a processor, implement the method described above.

[0157] As the device embodiment is basically similar to the method embodiment, the description is relatively simple, and relevant parts can be found in the description of the method embodiment.

[0158] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of the relevant data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and corresponding operation portals are provided for users to choose to authorize or refuse.

[0159] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0160] Those skilled in the art will understand that embodiments of this application can be provided as methods, apparatus, or computer program products. Therefore, embodiments of this application can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of this application can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0161] This application describes embodiments with reference to flowchart illustrations and / or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer instructions. These computer instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0162] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more flowcharts and / or one or more block diagrams.

[0163] These computer program instructions may also be loaded onto a computer or other programmable data processing terminal equipment to cause a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable terminal equipment, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0164] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0165] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes the aforementioned element.

[0166] The above provides a detailed description of a vehicle steering control method and apparatus. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this application. At the same time, those skilled in the art will recognize that there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for vehicle steering control, comprising: In response to a steering control request, determine the target's rotation direction; and During vehicle steering control, the front wheels of the vehicle are controlled to rotate toward the target direction of rotation to the maximum turning angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

2. The method according to claim 1, wherein, During vehicle steering control, controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target direction and controlling the wheel speed of each wheel to achieve the target rotation speed includes: During vehicle steering control, the front wheels of the vehicle are controlled to rotate to the maximum angle in the target rotation direction, the rear wheels on the first side of the vehicle corresponding to the target rotation direction are controlled to remain stationary relative to the vehicle, and the wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

3. The method according to claim 1, wherein, During vehicle steering control, controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target direction and controlling the wheel speed of each wheel to achieve the target rotation speed includes: During vehicle steering control, the front wheels of the vehicle are controlled to rotate to the maximum angle in the target rotation direction. The rear wheels on the first side of the vehicle corresponding to the target rotation direction are braked to lock up. The wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

4. The method according to claim 2 or 3, wherein, The method of controlling the wheel speed of the other wheels of the vehicle to achieve the target rotational speed includes: Based on the target rotational speed, the wheel speed of the other wheels of the vehicle is controlled; and During the process of controlling the wheel speed of the other wheels of the vehicle, the front wheel on the first side is controlled so that the wheel speed of the front wheel on the first side is less than the wheel speed of the front wheel on the second side.

5. The method according to claim 4, wherein, The method of controlling the wheel speed of other wheels of the vehicle based on the target rotational speed includes: Based on the target rotational speed, determine the target wheel speeds of the other wheels of the vehicle; and The wheel speeds of the other wheels of the vehicle are controlled according to the target wheel speed.

6. The method according to claim 1, wherein, During vehicle steering control, controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target direction and controlling the wheel speed of each wheel to achieve the target rotation speed includes: When the vehicle steering control system is currently active, the following steps are performed during vehicle steering control: controlling the front wheels of the vehicle to rotate to the maximum angle in the target direction of rotation, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed.

7. The method according to claim 6, further comprising: If the vehicle steering control system is currently inactive, feedback will be provided to the user.

8. The method according to claim 6, wherein, The vehicle steering control system is currently in an active state if one or more of the following conditions are met: A steering control request has been detected. The indicator light is on. The target gear is forward. The steering wheel angle is valid. The left front wheel speed is valid. The right front wheel speed is valid. The left rear wheel speed and the right rear wheel speed are valid.

9. The method according to claim 1, wherein, During vehicle steering control, controlling the front wheels of the vehicle to rotate to the maximum turning angle in the target direction and controlling the wheel speed of each wheel to achieve the target rotation speed includes: When the vehicle enters the first state, the following steps are performed during the vehicle steering control process: controlling the front wheels of the vehicle to rotate to the maximum angle in the target rotation direction, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed. The first state is the state of entering steering control.

10. The method according to claim 9, wherein, The vehicle enters a first state when one or more of the following conditions are met: the vehicle steering control system is activated, the vehicle speed is less than a first threshold, and the braking depth is less than a second threshold.

11. The method according to claim 9 or 10, further comprising: When the vehicle enters the second state, the vehicle is controlled to perform a specified operation to exit steering control; wherein, the second state is the state of exiting steering control.

12. The method according to claim 11, wherein, The specified operation includes one or more of the following operations: returning the vehicle steering wheel to center, unloading the drive motor torque, and restoring the braking system to basic braking.

13. The method according to claim 11, wherein, The vehicle enters the second state if any of the following conditions are met: The vehicle steering control system is inactive, the vehicle speed is greater than or equal to the first threshold, the braking depth is greater than or equal to the second threshold, and the steering wheel angle is less than the third threshold.

14. The method according to any one of claims 1-13, wherein, Prior to determining the target rotation direction in response to a steering control request, the method further includes: Get the steering control request based on the user input.

15. A vehicle steering control device, wherein, The device is used for: In response to a steering control request, determine the target's direction of rotation; and During vehicle steering control, the front wheels of the vehicle are controlled to rotate toward the target direction of rotation to the maximum turning angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

16. An electronic device comprising a processor, a memory, and computer instructions stored in the memory and executable on the processor, wherein the computer instructions, when executed by the processor, implement the method as described in any one of claims 1 to 14.

17. A vehicle comprising the device of claim 15, or the electronic device of claim 16.

18. A computer-readable storage medium storing computer instructions that, when executed by a processor, implement the method as described in any one of claims 1 to 14.

19. A computer program product comprising computer instructions that, when executed by a processor, implement the method as described in any one of claims 1 to 14.

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