Vehicle and method and system for controlling steering thereof

Abstract

The application discloses a vehicle and a steering control method and system thereof, the vehicle comprising a plurality of axles, each of which is connected with a plurality of steering wheels, the plurality of steering wheels being synchronously steered or independently steered, wherein the method comprises: receiving a steering control mode instruction; when the steering control mode instruction is an automatic control mode instruction, acquiring position information of the vehicle; when it is determined according to the position information that the vehicle is about to reach a turning road section, acquiring a vehicle speed of the vehicle, and according to the vehicle speed, acquiring a minimum allowable turning radius of the vehicle, and controlling each steering wheel according to the minimum allowable turning radius to control the steering of the vehicle. Thus, not only the accurate control of the steering wheels in the automatic control mode can be realized, but also the slip can be reduced, the tire wear can be reduced, and the rollover or spin during turning can be effectively prevented, and the safety of driving is improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and in particular to a vehicle and its steering control method and steering control system. Background Technology

[0002] Currently, for multi-axle steering control vehicles, the combination of linkage steering axle and electronic steering axle is one of the common steering control modes. However, due to the limitations of the response frequency of the electro-hydraulic proportional solenoid valve and mechanical transmission, this mode will produce errors when steering, especially large dynamic errors. This will cause slippage when driving on turning sections, wear down the tires, and affect steering performance and tire life. Moreover, the level of intelligence is low, and it cannot achieve precise control of the steering wheels. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in the related art. Therefore, the first objective of this invention is to propose a vehicle steering control method that not only achieves precise control of the steering wheels in automatic control mode, but also reduces slippage, reduces tire wear, and effectively prevents rollovers or fishtailing during cornering, thereby improving driving safety.

[0004] The second objective of this invention is to provide a vehicle steering control system.

[0005] The third objective of this invention is to provide a vehicle.

[0006] To achieve the above objectives, a first aspect of the present invention provides a vehicle steering control method. The vehicle includes multiple axles, each axle is connected to multiple steering wheels, and the multiple steering wheels steer synchronously or independently. The vehicle steering control method includes: receiving a steering control mode command; when the steering control mode command is an automatic control mode command, acquiring the vehicle's position information; when it is determined from the position information that the vehicle is about to reach a turning section, acquiring the vehicle's speed, acquiring the vehicle's minimum permissible turning radius based on the speed, and controlling each steering wheel based on the minimum permissible turning radius to control the vehicle's steering.

[0007] The vehicle steering control method according to embodiments of the present invention receives a steering control mode command, and when the steering control mode command is an automatic control mode command, acquires the vehicle's position information, and when it is determined from the position information that the vehicle is about to reach a turning section, acquires the vehicle's speed, and acquires the vehicle's minimum permissible turning radius based on the speed, and controls each steering wheel according to the minimum permissible turning radius to control the vehicle's steering. Therefore, it not only achieves precise control of the steering wheels in automatic control mode, but also reduces slippage, reduces tire wear, and effectively prevents rollovers or fishtailing during cornering, thus improving driving safety.

[0008] According to one embodiment of the present invention, controlling each steering wheel according to the minimum permissible turning radius to control vehicle steering includes: if the minimum permissible turning radius is greater than the maximum permissible turning radius corresponding to the turning segment, controlling the vehicle to reduce its speed so that the minimum permissible turning radius corresponding to the reduced speed is less than the maximum permissible turning radius; obtaining target steering information for each steering wheel according to the reduced speed; and controlling the steering of each steering wheel according to the target steering information to control vehicle steering.

[0009] According to one embodiment of the present invention, the method further includes: when it is determined from the location information that the vehicle has not reached the turning section, determining whether the vehicle has deviated from the lane; if the vehicle deviates from the lane, obtaining deviation information of the vehicle deviating from the lane, and obtaining target steering information for each steering wheel based on the deviation information; controlling the steering of each steering wheel based on the target steering information to control the vehicle steering so that the vehicle remains in the lane.

[0010] According to one embodiment of the present invention, the method further includes: when the steering control mode command is a manual control mode command or an override control mode command, acquiring the vehicle's steering mode and steering wheel steering information; acquiring target steering information for each steering wheel based on the steering mode and steering wheel steering information; and controlling the steering of each steering wheel based on the target steering information to control the vehicle's steering.

[0011] According to one embodiment of the present invention, when controlling the steering of each steering wheel according to the target steering information to control the vehicle steering, the method further includes: acquiring the actual steering information of each steering wheel; acquiring the steering adjustment amount of each steering wheel according to the actual steering information and the target steering information; and adjusting the target steering information according to the steering adjustment amount.

[0012] According to an embodiment of the present invention, when the steering control mode command is the override control mode command, the method further includes: obtaining the actual steering information of each steering wheel, obtaining the actual turning radius based on the actual steering information, and obtaining the maximum allowable vehicle speed corresponding to the actual turning radius; if the vehicle speed is greater than the maximum allowable vehicle speed, controlling the vehicle to reduce its speed so that the reduced vehicle speed is less than or equal to the maximum allowable vehicle speed.

[0013] According to an embodiment of the present invention, when the steering control mode command is an override control mode command, the method further includes: when the vehicle speed is greater than a preset vehicle speed threshold or the road surface adhesion coefficient is less than a coefficient threshold, prohibiting the use of the first type of steering mode in the preset steering modes to control the vehicle steering, and using the second type of steering mode in the preset steering modes to control the vehicle steering, wherein the first type of steering mode includes a small turning driving mode and a crab driving mode, and the second type of steering mode is a steering mode other than the first type of steering mode in the preset steering modes.

[0014] According to one embodiment of the present invention, when the steering control mode command is the override control mode command, the method further includes: acquiring obstacle information around the vehicle; when it is determined that there is a safety risk to the vehicle based on the obstacle information, controlling the vehicle to reduce speed, and controlling each steering wheel based on the obstacle information to control the vehicle steering.

[0015] To achieve the above objectives, a second aspect of the present invention provides a vehicle steering control system. The vehicle includes multiple axles, each axle is connected to multiple steering wheels, and the multiple steering wheels steer synchronously or independently. The vehicle steering control system includes: an input module for receiving steering control mode commands; a communication and positioning module for acquiring vehicle position information when the steering control mode command is an automatic control mode command; and a main control module for acquiring vehicle speed when the vehicle is about to reach a turning section based on the position information, acquiring the minimum permissible turning radius of the vehicle based on the vehicle speed, and controlling each steering wheel based on the minimum permissible turning radius to control vehicle steering.

[0016] According to an embodiment of the present invention, the vehicle steering control system receives steering control mode commands through an input module, and acquires vehicle position information through a communication and positioning module when the steering control mode command is an automatic control mode command. Furthermore, when the main control module determines that the vehicle is about to reach a turning section based on the position information, it acquires the vehicle speed and, based on the vehicle speed, obtains the minimum permissible turning radius. Then, it controls each steering wheel according to the minimum permissible turning radius to control the vehicle's steering. Therefore, it not only achieves precise control of the steering wheels in automatic control mode, but also reduces slippage, reduces tire wear, and effectively prevents rollovers or fishtailing during turns, thus improving driving safety.

[0017] To achieve the above objectives, a third aspect of the present invention provides a vehicle comprising: a memory, a processor, and a vehicle steering control program stored in the memory and executable on the processor, wherein when the processor executes the program, it implements the above-described vehicle steering control method.

[0018] According to embodiments of the present invention, a vehicle receives a steering control mode command, and when the steering control mode command is an automatic control mode command, acquires the vehicle's position information, and when it is determined from the position information that the vehicle is about to reach a turning section, acquires the vehicle's speed, and acquires the vehicle's minimum permissible turning radius based on the speed. Then, it controls each steering wheel according to the minimum permissible turning radius to control the vehicle's steering. Therefore, it not only achieves precise control of the steering wheels in automatic control mode, but also reduces slippage, reduces tire wear, and effectively prevents rollovers or fishtailing during turns, thus improving driving safety.

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

[0020] Figure 1 This is a schematic diagram of the vehicle steering control system for a pure rod-type steering device in a large-tonnage crane, as described in related technologies.

[0021] Figure 2 for Figure 1 A schematic diagram of the steering trapezoidal mechanism in a vehicle steering control system;

[0022] Figure 3 This is a schematic diagram of the vehicle steering control system of a steering device that combines a crane's linkage steering axle with an electro-hydraulic control steering axle in related technologies.

[0023] Figure 4 for Figure 3 A schematic diagram of the steering trapezoidal mechanism in a vehicle steering control system;

[0024] Figure 5 A flowchart of a vehicle steering control method according to an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram illustrating the ideal steering angle relationship between the inner and outer steering wheels according to an embodiment of the present invention;

[0026] Figure 7 This is a schematic diagram of a vehicle steering control system according to an embodiment of the present invention;

[0027] Figure 8 A flowchart of a vehicle steering control method according to another embodiment of the present invention;

[0028] Figure 9 This is a structural block diagram of a vehicle steering control system according to an embodiment of the present invention;

[0029] Figure 10 This is a structural block diagram of a vehicle according to an embodiment of the present invention. Detailed Implementation

[0030] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0031] The vehicle steering control method, vehicle steering control system, and vehicle provided in the embodiments of the present invention are described below with reference to the accompanying drawings.

[0032] It should be noted that the ideal steering state of a vehicle is pure rolling of the steering wheels. However, the relationship between the turning angles of the left and right wheels on the same axle is determined by its steering trapezoidal mechanism, and the vehicle's instantaneous steering center is determined by the steering mode and the steering mechanism. Steering control is constrained by the rigid structure of the steering trapezoidal mechanism, making it impossible to simultaneously ensure that the vehicle's instantaneous steering center matches the theoretical steering center during multi-wheel steering. This can lead to slippage during steering, resulting in tire wear. The steering maneuverability of a vehicle is not entirely dependent on the steering system but is also related to the running gear. For example, inappropriate vehicle speed can cause fishtailing or rollover.

[0033] For two- or three-axle wheeled vehicles, steering is achieved by the driver turning the steering wheel, which drives the front wheels to turn, thus steering the entire vehicle. However, for multi-axle engineering vehicles, their longer wheelbase, heavier weight, and higher center of gravity result in poor steering flexibility and stability. When making U-turns or turns in limited working spaces, the driver must repeatedly turn the steering wheel left and right, simultaneously engaging and disengaging the clutch and shifting gears, requiring repeated forward and backward movements. This leads to driver fatigue, low work efficiency, environmental pollution, and energy waste. To address these issues and enhance the vehicle's adaptability to various road conditions, large-tonnage cranes have developed multi-axle steering technology using a mechanical structure and hydraulic power assist.

[0034] For multi-axle steering vehicles, there are currently two different steering control modes: one is a pure linkage steering control mode with power assist, and the other is a steering control mode that combines linkage steering axle with electronic steering axle.

[0035] Figure 1 This is a schematic diagram of the vehicle steering control system for a pure linkage steering device in a large-tonnage crane, as described in related technologies. Figure 2 for Figure 1 A schematic diagram of the steering trapezoidal mechanism in the vehicle steering control system, for reference. Figure 1 and Figure 2 As shown, the vehicle steering control system 100 includes: a steering wheel 101, a drive shaft 102, a steering gear 103, a steering drop arm 104, multiple steering tie rod rocker arm mechanisms 105, multiple tie rods 106, steering tie rods 107 corresponding to the number of steering shafts, multiple power steering cylinders 108, a steering transmission or locking mechanism 109, and multiple steering trapezoidal mechanisms 110 integrated on the steering shaft. During operation, the steering wheels on the steering shaft are steered by the swinging of the steering drop arm 104 and the power steering cylinders 108. Due to the complexity of the steering mechanism, the probability of steering system failure increases, and the force transmission path during steering is relatively long. Therefore, the free play between various hinge points must be overcome during force transmission, resulting in steering lag at the rear steering axle.

[0036] Figure 3This is a schematic diagram of the vehicle steering control system of a steering device that combines a crane's linkage steering axle with an electro-hydraulic control steering axle in related technologies. Figure 4 for Figure 3 A schematic diagram of the steering trapezoidal mechanism in the vehicle steering control system, for reference. Figure 3 and Figure 4 As shown, the vehicle steering control system 200 includes: a steering wheel 201, a drive shaft 202, a steering gear 203, a steering drop arm 204, a steering tie rod rocker arm mechanism 205, multiple tie rods 206, steering tie rods 207 corresponding to the steering shaft, a hydraulic cylinder 208, a steering control unit 209, multiple steering trapezoidal mechanisms 210 integrated on the steering shaft, and one or more angle sensors 211. Figure 1 Compared to the pure linkage plus power steering control mode shown, Figure 3 The steering mechanism in this design uses hydraulic cylinders 208, a steering control unit 209, an angle sensor 211, and a tie rod 206 instead of the steering transmission or locking mechanism 109 and the tie rod 106. During operation, the angle sensor 211 acquires angle signals from the multiple steering trapezoidal mechanisms 210 integrated on the steering shaft and sends these signals to the steering controller 209. The steering controller 209, based on these angle signals, controls the extension and retraction of the hydraulic cylinders 208 on each steering shaft via electro-hydraulic proportional solenoid valves, thereby steering the steering wheels. In this structure, due to limitations imposed by the response frequency of the electro-hydraulic proportional solenoid valves and mechanical transmission, steering errors occur, particularly large dynamic errors, leading to tire slippage and wear. This severely affects steering performance and tire life. Furthermore, the lack of feedback signals prevents precise control of the steering wheels.

[0037] Based on this, this application provides a vehicle steering control method that not only enables precise control of the steering wheels in automatic control mode, but also reduces slippage, tire wear, and effectively prevents rollover or fishtailing during cornering, thereby improving driving safety.

[0038] Figure 5 A flowchart of a vehicle steering control method according to an embodiment of the present invention is shown below. Figure 5 As shown, the vehicle steering control method may include the following steps:

[0039] Step S301: Receive steering control mode command.

[0040] Specifically, the vehicle steering control system can receive three steering control mode commands: manual steering mode, automatic steering mode, and override control mode. When the steering control mode command is set to manual, manual steering mode is activated, and the driver can further select from seven steering modes: normal driving mode, fine-turn driving mode, crab driving mode, anti-swing driving mode, rear axle independent driving mode, and center-lock driving mode. When the steering control mode command is set to automatic, automatic steering mode is activated. In this mode, the status of each steering wheel is monitored in real time during driving, and when the vehicle approaches or reaches a turning section, it can automatically and precisely steer each steering wheel according to road conditions and specific driving situations. When the steering control mode command is set to override control mode, override control mode is activated, and the vehicle is automatically controlled for safe operation based on road conditions and specific driving situations.

[0041] It should be noted that, in some embodiments, the steering control mode and the steering mode of normal driving can be used by default when the user does not select the steering control mode and the steering mode. In other embodiments, a memory function can be provided to use the last selected steering control mode and steering mode to improve usability.

[0042] Step S302: When the steering control mode command is the automatic control mode command, obtain the vehicle's position information.

[0043] In other words, when steering control enters automatic control mode, the vehicle needs to be located first to obtain the vehicle's position information. This position information can then be used as the basis for determining whether the vehicle needs to be controlled to turn, as well as the required turning radius and arc.

[0044] Step S303: When it is determined that the vehicle is about to reach the turning section based on the location information, the vehicle speed is obtained, the minimum allowable turning radius of the vehicle is obtained based on the vehicle speed, and each steering wheel is controlled according to the minimum allowable turning radius to control the vehicle steering.

[0045] Specifically, different vehicle speeds correspond to different minimum permissible turning radii. When a vehicle is traveling at a certain speed, if it turns with a turning radius smaller than the current minimum permissible turning radius, it is prone to traffic accidents such as rollover and fishtailing. Therefore, the system can determine whether a vehicle is about to reach a turning section based on its location information. When the vehicle is about to reach a turning section, it can automatically obtain the vehicle's current speed and calculate its corresponding minimum permissible turning radius based on the speed. Then, it can control the steering of each steering wheel based on the minimum permissible turning radius.

[0046] Furthermore, each steering wheel is controlled according to the minimum permissible turning radius to control the vehicle steering, including: if the minimum permissible turning radius is greater than the maximum permissible turning radius corresponding to the turning segment, the vehicle is controlled to reduce its speed so that the minimum permissible turning radius corresponding to the reduced speed is less than the maximum permissible turning radius; the target steering information of each steering wheel is obtained according to the reduced speed; and the steering of each steering wheel is controlled according to the target steering information to control the vehicle steering.

[0047] In other words, when controlling each steering wheel based on the minimum permissible turning radius, if the minimum permissible turning radius is less than or equal to the maximum permissible turning radius corresponding to the turning segment, the current speed can be maintained or the speed reduced to turn along the permissible turning radius of that turning segment. If the minimum permissible turning radius is greater than the maximum permissible turning radius corresponding to the turning segment, maintaining the current speed while turning could easily lead to safety accidents such as rollover or fishtailing. Therefore, it is necessary to reduce the speed, and the minimum permissible turning radius corresponding to the reduced speed should be less than the maximum permissible turning radius. Then, the target steering information for each steering wheel is obtained based on the reduced speed. This target steering information may include information such as the required turning angle and turning direction for each steering wheel. By controlling the steering of each steering wheel based on the target steering information, the steering of the vehicle can be controlled.

[0048] It should be noted that the control system of the vehicle steering control method using the embodiments of the present invention may include an input module, a main controller, a steering controller, and a steering wheel detection module.

[0049] The input module may include a steering wheel input unit, a remote input / output unit, an operation mode selection unit, a steering mode selection unit, and units for vehicle environmental information, engine and transmission status information, etc. The steering mode selection unit is used to select different steering control modes and steering modes. The steering wheel input unit can convert the steering wheel angle modulus and state modulus into numerical modulus and output the numerical modulus to the main steering controller. The remote input / output unit can transmit signals received by the system or vehicle to the main controller and send the vehicle steering status processed by the main controller to the monitoring center in real time. The main controller is the core of intelligent control. It processes the received information and information fed back from the system using calculation methods set in the control program, and converts the angle required for each steering shaft and steering wheel to achieve pure rolling into digital signals of control voltage or current magnitude, outputting them to the steering controller. The steering controller converts the received digital signals into analog signals and amplifies them to control the electro-hydraulic proportional solenoid valve, thereby driving the extension and retraction of the steering cylinder, achieving precise steering control. The steering wheel detection module may consist of a detection unit and a signal processing and conversion unit. The signal processing and conversion unit converts the analog steering angle signals of each steering wheel into digital signals and feeds them back to the main controller. The main controller then controls the steering wheels to make appropriate adjustments based on the feedback signals.

[0050] It's important to further explain that the main controller can be divided into hardware and software components. The hardware component includes a pre-processor, a post-processor, an arithmetic logic unit (ALU), and a programming controller. The pre-processor compiles and converts received signals regarding steering control mode, steering mode, steering wheel angle, and the magnitude and direction of each steering wheel's angle into signals acceptable to the ALU or programming controller, and outputs this signal to the ALU or programming controller. The ALU or programming controller then performs calculations and outputs the results (information on the instantaneous required angles of each wheel) to the post-processor. The post-processor compiles and converts these signals into signals acceptable to the steering controller and outputs them to the steering controller. The software component, the control program, is the core of the entire steering control system. When the ALU or programming controller receives data such as steering wheel angle and steering mode, it calculates the corresponding angle for each steering wheel using a pre-defined formula. Specifically, to ensure the vehicle's steering is close to ideal, the angle of each steering wheel should maximally satisfy the Ackermann steering conditions required for pure rolling, thereby reducing slippage and preventing tire wear.

[0051] In specific examples, such as Figure 6 As shown, when a vehicle is turning, if the lateral deviation of the tires is not considered, in order to satisfy the requirement that all steering wheels rotate around the same instantaneous steering center, the ideal steering angle relationship between the inner and outer steering wheels can be expressed by the Ackermann formula. The results show that θ0 is the outer steering wheel angle, θ1 is the inner steering wheel angle, K is the distance between the intersection of the center lines of the two steering kingpins and the ground, and L is the wheelbase. Therefore, by collecting, detecting, and feeding back the state of the steering wheels in real time during driving, and adjusting the state of the steering wheels in real time, precise control of the steering wheels is achieved. This maximizes the fulfillment of the Ackermann steering conditions required for pure rolling, thereby reducing slippage, reducing tire wear, and improving driving safety.

[0052] As can be seen from the above, the vehicle steering control method according to embodiments of the present invention receives a steering control mode command, acquires the vehicle's position information when the steering control mode command is an automatic control mode command, acquires the vehicle speed when it is determined from the position information that the vehicle is about to reach a turning section, acquires the minimum permissible turning radius of the vehicle based on the vehicle speed, and controls each steering wheel according to the minimum permissible turning radius to control the vehicle's steering. Therefore, it not only achieves precise control of the steering wheels in automatic control mode, but also reduces slippage, reduces tire wear, and effectively prevents rollovers or fishtailing during turns, thus improving driving safety.

[0053] In one embodiment, the method further includes: when it is determined from the location information that the vehicle has not reached the turning section, determining whether the vehicle has deviated from the lane; if the vehicle deviates from the lane, obtaining deviation information of the vehicle deviating from the lane, and obtaining target steering information for each steering wheel based on the deviation information; controlling the steering of each steering wheel based on the target steering information to control the vehicle steering so that the vehicle remains in the lane.

[0054] In other words, when the steering mode is in automatic control mode, the vehicle acquires its position information in real time. This position information can also be used to determine whether the vehicle has deviated from its lane before reaching the turning section. If the vehicle deviates from its lane, it can automatically correct its course in conjunction with the Lane Departure Warning System (LDWS), keeping the vehicle within its lane. This not only helps the vehicle maintain its lane position before reaching the turning section but also facilitates precise target steering control when the vehicle reaches the turning section.

[0055] In one embodiment, the method further includes: when the steering control mode command is a manual control mode command or an override control mode command, acquiring the vehicle's steering mode and steering wheel steering information; acquiring target steering information for each steering wheel based on the steering mode and steering wheel steering information; and controlling the steering of each steering wheel based on the target steering information to control the vehicle's steering.

[0056] Specifically, when the steering control mode command is a manual control mode command or an override control mode command, the driver can further select one of seven steering modes for steering control: normal driving mode, fine-turn driving mode, crab driving mode, anti-swing driving mode, rear axle independent driving mode, and center-lock driving mode. In the specific example, if the driver does not further select a steering mode, the normal driving mode will be used by default. Specifically, after entering the manual control mode or override control mode, the vehicle's current steering mode and steering information such as the steering wheel angle and direction are obtained, and the vehicle is controlled to steer according to the corresponding target direction.

[0057] In one embodiment, when controlling the steering of each steering wheel according to the target steering information to control the vehicle steering, the method further includes: acquiring the actual steering information of each steering wheel; acquiring the steering adjustment amount of each steering wheel according to the actual steering information and the target steering information; and adjusting the target steering information according to the steering adjustment amount.

[0058] Specifically, the actual steering information of each steering wheel can be acquired in real time using either an angle sensor or a position sensor located at the corresponding steering wheel. After acquiring the actual steering information, the main controller compares the actual steering information with the target steering information and makes appropriate adjustments to the steering output value of the steering wheels based on the comparison result. Specifically, if the measured steering value is the same as the target steering value, the current steering angle is maintained; if the measured steering value is less than the target steering value, the main controller increases the corresponding output value, with the increase being larger as the difference increases, until the two are equal; if the measured steering value is greater than the target steering value, the main controller decreases the corresponding output value, with the decrease being larger as the difference increases, until the two are equal, so that the vehicle steering approaches the ideal state.

[0059] In one embodiment, when the steering control mode command is the override control mode command, the method further includes: obtaining the actual steering information of each steering wheel, obtaining the actual turning radius based on the actual steering information, and obtaining the maximum permissible speed corresponding to the actual turning radius; if the vehicle speed is greater than the maximum permissible speed, controlling the vehicle to reduce its speed so that the reduced speed is less than or equal to the maximum permissible speed.

[0060] In other words, in overdrive control mode, the system can perform safe operation control of steering. Specifically, during vehicle turning, it can obtain actual steering information such as the turning direction and size of each steering wheel, and obtain the actual turning radius accordingly. Then, it calculates the maximum permissible speed corresponding to the actual turning radius. If the current vehicle speed is greater than the maximum permissible speed, it is easy to cause safety accidents such as rollover or fishtailing. Therefore, it can control the vehicle speed to reduce the speed so that the current vehicle speed is less than or equal to the above-mentioned maximum permissible speed, thereby improving driving safety.

[0061] In one embodiment, when the steering control mode command is an override control mode command, the method further includes: when the vehicle speed is greater than a preset vehicle speed threshold or the road surface adhesion coefficient is less than a coefficient threshold, prohibiting the use of the first type of steering mode in the preset steering modes to control the vehicle steering, and using the second type of steering mode in the preset steering modes to control the vehicle steering, wherein the first type of steering mode includes a small turning driving mode and a crab driving mode, and the second type of steering mode is a steering mode other than the first type of steering mode in the preset steering modes.

[0062] Specifically, when vehicle speed is high or the road surface friction coefficient is low, the fine-turn and crab-walking steering modes can easily cause accidents. Therefore, fine-turn and crab-walking modes are designated as the first type of steering mode, and all other steering modes are designated as the second type. When vehicle speed is high or the road surface friction coefficient is low, the second type of steering mode is used to control vehicle steering, avoiding the use of the first type of steering mode. Even if the driver initially selects the first type of steering mode, it will automatically deactivate when the vehicle speed is high or the road surface friction coefficient is low, switching to the second type of steering mode and simultaneously issuing a warning to the driver.

[0063] Furthermore, when the steering control mode command is the override control mode command, the method further includes: acquiring obstacle information around the vehicle; when it is determined that there is a safety risk to the vehicle based on the obstacle information, controlling the vehicle to reduce speed, and controlling each steering wheel based on the obstacle information to control the vehicle steering.

[0064] In other words, when in overdrive control mode, information about obstacles around the vehicle can be acquired. This information may include the distance, location, and type of obstacles. The main controller then determines whether the vehicle can avoid these obstacles based on its current speed and direction. If the obstacle can be avoided, no safety risk is considered, and the vehicle can maintain its original speed and direction. If the obstacle cannot be avoided, a safety risk is considered, and the vehicle will automatically reduce its speed, adjust its steering to avoid the obstacle, and issue a warning to the driver.

[0065] It is understood that this application applies to both driver-driven vehicles and driverless vehicles.

[0066] The present application will be further explained and illustrated below through two specific embodiments.

[0067] Figure 7 This is a schematic diagram of a vehicle steering control system according to an embodiment of the present invention. (Refer to...) Figure 7As shown, the vehicle steering control system 400 may include: a steering wheel 401, a steering wheel angle sensor 402, a steering gear 403, a steering drop arm 404, and five axles, wherein one end of each axle is connected to a first steering wheel and the other end is connected to a second steering wheel. It also includes an operation control panel 405, a communication and positioning module 406, a steering controller 407, a display module 408, a main controller 409, an input module 410, angle sensors 411-420 corresponding to the steering wheels, a steering oil pump 421, hydraulic cylinders 422-431 corresponding to the steering wheels, and electro-hydraulic proportional solenoid valves 432-441 corresponding to the steering wheels.

[0068] The driver can first select a steering control mode from manual steering mode, automatic steering mode and overdrive control mode by operating the control panel 405.

[0069] When the driver selects manual steering mode via the control panel 405, they can choose from seven steering modes: normal driving mode, fine-turn driving mode, crab driving mode, anti-swing driving mode, rear axle independent driving mode, and center-lock driving mode. If no specific steering mode is selected, it will automatically switch to normal driving mode. After the engine starts, the driver turns the steering wheel 401. The steering wheel angle sensor 402 detects the steering wheel angle and transmits the signal to the input module 410 in real time. The input module 410 processes this signal through analog-to-digital conversion and outputs it as an output signal to the main controller 409. The main controller 409 calculates and transmits the instantaneous steering angle and direction information of each steering wheel to the steering controller 407. The steering controller 407 compiles, performs digital-to-analog conversion, and amplifies the received information to control the corresponding electro-hydraulic proportional solenoid valves 432-441 of each steering wheel. When energized, the electro-hydraulic proportional solenoid valves 432-441 operate to control the flow rate to the hydraulic cylinders 422-431 according to the current magnitude, thereby controlling the extension and retraction length and speed of the hydraulic cylinders 422-431 to achieve the purpose of controlling the steering of the steering wheels.

[0070] Specifically, the electro-hydraulic proportional solenoid valve 441 controls the steering of the left wheel of the first axle by controlling the extension and retraction of the hydraulic cylinder 431 of the first axle left wheel; the electro-hydraulic proportional solenoid valve 432 controls the steering of the right wheel of the first axle by controlling the extension and retraction of the hydraulic cylinder 422 of the first axle right wheel; the electro-hydraulic proportional solenoid valve 440 controls the steering of the left wheel of the second axle by controlling the extension and retraction of the hydraulic cylinder 430 of the second axle left wheel; the electro-hydraulic proportional solenoid valve 433 controls the steering of the right wheel of the second axle by controlling the extension and retraction of the hydraulic cylinder 423 of the second axle right wheel; and the electro-hydraulic proportional solenoid valve 439 controls the steering of the left wheel of the third axle by controlling the extension and retraction of the hydraulic cylinder 429 of the third axle left wheel. The electro-hydraulic proportional solenoid valve 434 controls the steering of the three-axis right wheel by controlling the extension and retraction of the three-axis right wheel hydraulic cylinder 424; the electro-hydraulic proportional solenoid valve 438 controls the steering of the four-axis left wheel by controlling the extension and retraction of the four-axis left wheel hydraulic cylinder 428; the electro-hydraulic proportional solenoid valve 435 controls the steering of the four-axis right wheel by controlling the extension and retraction of the four-axis right wheel hydraulic cylinder 425; the electro-hydraulic proportional solenoid valve 437 controls the steering of the five-axis left wheel by controlling the extension and retraction of the five-axis left wheel hydraulic cylinder 427; and the electro-hydraulic proportional solenoid valve 436 controls the steering of the five-axis right wheel by controlling the extension and retraction of the five-axis right wheel hydraulic cylinder 426. Meanwhile, the steering angle sensors 411-420 mounted on the steering wheels of the axle sense the steering angle of the corresponding steering wheel in real time. Specifically, the steering angle sensor 420 on one axle senses the steering angle of the left wheel of the first axle, the steering angle sensor 411 on one axle senses the steering angle of the right wheel of the first axle, the steering angle sensor 419 on the second axle senses the steering angle of the left wheel of the second axle, the steering angle sensor 412 on the second axle senses the steering angle of the right wheel of the second axle, the steering angle sensor 418 on the third axle senses the steering angle of the left wheel of the third axle, the steering angle sensor 413 on the third axle senses the steering angle of the right wheel of the third axle, the steering angle sensor 417 on the fourth axle senses the steering angle of the left wheel of the fourth axle, the steering angle sensor 414 on the fourth axle senses the steering angle of the right wheel of the fourth axle, the steering angle sensor 416 on the fifth axle senses the steering angle of the left wheel of the fifth axle, and the steering angle sensor 415 on the fifth axle senses the steering angle of the right wheel of the fifth axle. The input module 410 collects these signals in real time, performs analog-to-digital conversion and compilation, and outputs them to the main controller 409. The main controller 409 compares these steering angle values ​​with the control values, adjusts the steering control value of each steering wheel according to the comparison results, and outputs it to the steering controller 407, thereby controlling each steering wheel to turn accurately or maintain its original state, so as to achieve the purpose of highly intelligent and precise control of the vehicle steering.

[0071] When the driver selects the automatic operation mode through the control panel 405, the main controller 409 can obtain the vehicle's location information through the communication and positioning module 406. During driving, the main controller 409 monitors the status of each steering wheel in real time. When the vehicle approaches or reaches a section of road requiring a turn, the main controller 409 calculates the minimum turning radius for safe driving based on the vehicle speed and compares the calculation result with the maximum turning radius allowed by the road. When the minimum turning radius is greater than the maximum turning radius allowed by the road, the main controller 409 sends a signal to the engine to reduce the speed, making the minimum turning radius corresponding to the vehicle speed less than the maximum turning radius allowed by the road. Then, the main controller 409 transmits the instantaneous turning angle and direction information required by each steering wheel to the steering controller 407 by calling the stored turning data. The steering controller 407 compiles, performs digital-to-analog conversion, and amplifies the received information, and then controls the electro-hydraulic proportional solenoid valves 432-441 of the steering wheels respectively. When the electro-hydraulic proportional solenoid valves 432-441 are energized, they operate by controlling the flow rate of the hydraulic cylinder according to the current magnitude, thereby controlling the extension and retraction length and speed of the hydraulic cylinder, thus controlling the steering of the corresponding steering wheel and achieving the purpose of controlling the vehicle's steering. Meanwhile, the steering angles of the corresponding steering wheels are sensed in real time by steering angle sensors 411-420 installed on the axle. Specifically, steering wheel angle sensor 420 senses the steering angle of the left wheel of the first axle, steering wheel angle sensor 411 senses the steering angle of the right wheel of the first axle, steering wheel angle sensor 419 senses the steering angle of the left wheel of the second axle, steering wheel angle sensor 412 senses the steering angle of the right wheel of the second axle, steering wheel angle sensor 418 senses the steering angle of the left wheel of the third axle, steering wheel angle sensor 413 senses the steering angle of the right wheel of the third axle, steering wheel angle sensor 417 senses the steering angle of the left wheel of the fourth axle, steering wheel angle sensor 414 senses the steering angle of the right wheel of the fourth axle, steering wheel angle sensor 416 senses the steering angle of the left wheel of the fifth axle, and steering wheel angle sensor 415 senses the steering angle of the right wheel of the fifth axle. Then, the input module 410 performs analog-to-digital conversion and compilation on these signals before outputting them to the main controller 409. The main controller 409 compares these angle values ​​with the control values, adjusts the steering control value of each steering wheel based on the comparison result, and transmits the adjustment to the steering controller 407 to accurately control the steering of each steering wheel. After completing the vehicle steering in the above manner, the vehicle returns to a straight-line driving state and continues driving. During this process, the vehicle's steering status can also be displayed on the screen via the display module 408.

[0072] When the driver selects the overdrive control mode through the control panel 405, the main controller 409 can control the vehicle to operate safely according to the vehicle's operating conditions during the vehicle's driving and turning process. In a specific example, safe operation control can be implemented in three situations: First, the main controller 409 calculates the turning radius by collecting the turning angle feedback signals of each steering wheel in real time, retrieves the maximum safe speed at this turning angle corresponding to the stored information, compares it with the current speed, and if the current speed is greater than the maximum safe speed, the main controller 409 issues a speed reduction signal to reduce the speed to a safe speed; Second, when the speed is high, the second type of steering mode is used to control the vehicle's steering, avoiding the use of the first type of steering mode (such as small turning driving mode and crab driving mode) to control the vehicle's steering. Even if the driver initially selected the first type of steering mode, it will automatically lock the first type of steering mode at high speeds, switch to the second type of steering mode to control the vehicle's steering, and issue an alarm reminder; Third, the main controller 409 obtains obstacle information around the vehicle, determines whether the obstacle can be avoided based on the vehicle's current speed and driving direction, and if it cannot be avoided, it forcibly reduces the speed, automatically adjusts the steering to avoid the obstacle, and issues an alarm reminder.

[0073] Figure 8 A flowchart of a vehicle steering control method according to a specific embodiment of the present invention is provided, with reference to... Figure 8 As shown, the vehicle steering control method may include the following steps:

[0074] Step S501: Select steering control mode: Select automatic steering mode, or select manual steering mode and call manual steering mode, or select override control mode and call override control mode, and then execute step S502.

[0075] Step S502: Determine whether the pre-turn section has been reached. If yes, proceed to step S503; otherwise, proceed to step S504.

[0076] Step S503: Determine whether the vehicle speed meets the maximum permissible turning diameter. If yes, call the turning program, control the vehicle to turn, and execute step S505; if no, reduce the vehicle speed until the vehicle speed meets the maximum permissible turning diameter.

[0077] Step S504: Determine whether the vehicle has deviated from the lane. If yes, call the lane correction module to correct the vehicle's deviation; otherwise, return to step S502.

[0078] Step S505: Determine whether the predetermined location has been reached. If yes, end the process; otherwise, return to step S502.

[0079] It should be understood that, although Figure 5 and Figure 8 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 5 and Figure 8 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0080] In summary, the vehicle steering control method according to embodiments of the present invention receives a steering control mode command, acquires the vehicle's position information when the steering control mode command is an automatic control mode command, acquires the vehicle speed when the vehicle is about to reach a turning section based on the position information, acquires the vehicle's minimum permissible turning radius based on the vehicle speed, and controls each steering wheel according to the minimum permissible turning radius to control the vehicle's steering. Therefore, it not only achieves precise control of the steering wheels in automatic control mode, but also reduces slippage, reduces tire wear, and effectively prevents rollovers or fishtailing during turns, thus improving driving safety.

[0081] Figure 9 This is a structural block diagram of a vehicle steering control system according to an embodiment of the present invention. (Reference) Figure 9 As shown, the vehicle includes multiple axles, each axle is connected to multiple steering wheels, and the multiple steering wheels can steer synchronously or independently. The vehicle steering control system 600 includes an input module 601, a communication and positioning module 602 and a main control module 603.

[0082] The input module 601 is used to receive steering control mode commands; the communication and positioning module 602 is used to obtain the vehicle's position information when the steering control mode command is an automatic control mode command; the main control module 603 is used to obtain the vehicle's speed when it is determined from the position information that the vehicle is about to reach a turning section, and obtain the vehicle's minimum permissible turning radius based on the vehicle speed, and control each steering wheel based on the minimum permissible turning radius to control the vehicle's steering.

[0083] In one embodiment, the main control module 603 is specifically used to: if the minimum permissible turning radius is greater than the maximum permissible turning radius corresponding to the turning segment, control the vehicle to reduce its speed so that the minimum permissible turning radius corresponding to the reduced speed is less than the maximum permissible turning radius; obtain the target steering information of each steering wheel based on the reduced speed; and control the steering of each steering wheel based on the target steering information to control the vehicle steering.

[0084] In one embodiment, the communication and positioning module 602 is further configured to: determine whether the vehicle has deviated from the lane when it is determined from the location information that the vehicle has not reached the turning section; if the vehicle deviates from the lane, obtain the deviation information of the vehicle deviating from the lane, and obtain the target steering information of each steering wheel according to the deviation information; control the steering of each steering wheel according to the target steering information to control the vehicle steering so that the vehicle stays in the lane.

[0085] In one embodiment, the main control module 603 is further configured to: acquire the vehicle's steering mode and steering wheel steering information when the steering control mode command is a manual control mode command or an override control mode command; acquire target steering information for each steering wheel based on the steering mode and steering wheel steering information; and control the steering of each steering wheel based on the target steering information to control the vehicle's steering.

[0086] In one embodiment, the main control module 603 is further configured to: acquire the actual steering information of each steering wheel; acquire the steering adjustment amount of each steering wheel based on the actual steering information and the target steering information; and adjust the target steering information based on the steering adjustment amount.

[0087] In one embodiment, the main control module 603 is further configured to: obtain the actual steering information of each steering wheel, obtain the actual turning radius based on the actual steering information, and obtain the maximum permissible speed corresponding to the actual turning radius; if the vehicle speed is greater than the maximum permissible speed, control the vehicle to reduce its speed so that the reduced speed is less than or equal to the maximum permissible speed.

[0088] In one embodiment, the main control module 603 is further configured to: prohibit the use of the first type of steering mode in the preset steering modes to control the vehicle steering when the vehicle speed is greater than the preset vehicle speed threshold or the road surface adhesion coefficient is less than the coefficient threshold, and use the second type of steering mode in the preset steering modes to control the vehicle steering, wherein the first type of steering mode includes a small turning driving mode and a crab driving mode, and the second type of steering mode is a steering mode other than the first type of steering mode in the preset steering modes.

[0089] In one embodiment, the main control module 603 is further configured to: acquire obstacle information around the vehicle; when it is determined that there is a safety risk to the vehicle based on the obstacle information, control the vehicle to reduce its speed, and control each steering wheel based on the obstacle information to control the vehicle's steering.

[0090] It should be noted that for the description of the vehicle steering control system in this application, please refer to the description of the vehicle steering control method in this application, and will not be repeated here.

[0091] According to an embodiment of the present invention, the vehicle steering control system receives steering control mode commands through an input module, and acquires vehicle position information through a communication and positioning module when the steering control mode command is an automatic control mode command. Furthermore, when the main control module determines that the vehicle is about to reach a turning section based on the position information, it acquires the vehicle speed and, based on the vehicle speed, obtains the minimum permissible turning radius. Then, it controls each steering wheel according to the minimum permissible turning radius to control the vehicle's steering. Therefore, it not only achieves precise control of the steering wheels in automatic control mode, but also reduces slippage, reduces tire wear, and effectively prevents rollovers or fishtailing during turns, thus improving driving safety.

[0092] Figure 10 This is a structural block diagram of a vehicle according to an embodiment of the present invention. (Reference) Figure 10 As shown, the vehicle 700 includes: a memory 701, a processor 702, and a vehicle steering control program stored in the memory 701 and executable on the processor 702. When the processor 702 executes the program, it implements the aforementioned vehicle steering control method.

[0093] According to embodiments of the present invention, a vehicle receives a steering control mode command, and when the steering control mode command is an automatic control mode command, acquires the vehicle's position information, and when it is determined from the position information that the vehicle is about to reach a turning section, acquires the vehicle's speed, and acquires the vehicle's minimum permissible turning radius based on the speed. Then, it controls each steering wheel according to the minimum permissible turning radius to control the vehicle's steering. Therefore, it not only achieves precise control of the steering wheels in automatic control mode, but also reduces slippage, reduces tire wear, and effectively prevents rollovers or fishtailing during turns, thus improving driving safety.

[0094] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus or device (such as a computer-based system, a processor-included system or other system that can fetch and execute instructions from, an instruction execution system, apparatus or device).

[0095] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0096] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0097] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0098] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0099] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A vehicle steering control method, characterized in that, The vehicle includes multiple axles, and multiple steering wheels are connected to each axle. The multiple steering wheels steer synchronously or independently. The method includes: Receive steering control mode command; When the steering control mode command is an automatic control mode command, the vehicle's position information is obtained; When it is determined that the vehicle is about to reach a turning section based on the location information, the vehicle speed is obtained, and the minimum allowable turning radius of the vehicle is obtained based on the vehicle speed. If the minimum permissible turning radius is greater than the maximum permissible turning radius corresponding to the turning section, then the vehicle is controlled to reduce its speed so that the minimum permissible turning radius corresponding to the reduced speed is less than the maximum permissible turning radius. The target steering information for each steering wheel is obtained based on the vehicle speed after the speed reduction. The target steering information includes the angle and direction of each steering wheel; The vehicle steering is controlled by steering each of the steering wheels according to the target steering information, such that the steering angle of each steering wheel satisfies the Ackermann steering condition required for pure rolling.

2. The vehicle steering control method according to claim 1, characterized in that, The method further includes: When it is determined from the location information that the vehicle has not reached the turning section, it is determined whether the vehicle has deviated from the lane; If the vehicle deviates from the lane, deviation information of the vehicle deviating from the lane is obtained, and target steering information of each steering wheel is obtained based on the deviation information; The steering of each steering wheel is controlled according to the target steering information to control the steering of the vehicle so that the vehicle remains in the lane.

3. The vehicle steering control method according to claim 1, characterized in that, The method further includes: When the steering control mode command is a manual control mode command or an overdrive control mode command, the vehicle's steering mode and steering wheel steering information are obtained. Target steering information for each steering wheel is obtained based on the steering mode and the steering wheel steering information; The vehicle steering is controlled by steering each of the steering wheels according to the target steering information.

4. The vehicle steering control method according to any one of claims 1-3, characterized in that, When controlling the steering of each steering wheel according to the target steering information to control the vehicle steering, the method further includes: Obtain the actual steering information for each of the steering wheels; The steering adjustment amount for each steering wheel is obtained based on the actual steering information and the target steering information; The target steering information is adjusted according to the steering adjustment amount.

5. The vehicle steering control method according to claim 3, characterized in that, When the steering control mode command is the override control mode command, the method further includes: Obtain the actual steering information of each steering wheel, and obtain the actual turning radius based on the actual steering information, as well as the maximum permissible speed corresponding to the actual turning radius; If the vehicle speed is greater than the maximum permissible speed, then the vehicle is controlled to reduce its speed so that the reduced speed is less than or equal to the maximum permissible speed.

6. The vehicle steering control method according to claim 3, characterized in that, When the steering control mode command is the override control mode command, the method further includes: When the vehicle speed is greater than a preset speed threshold or the road surface adhesion coefficient is less than a coefficient threshold, the first type of steering mode in the preset steering modes is prohibited from being used to control the vehicle steering, and the second type of steering mode in the preset steering modes is used to control the vehicle steering. The first type of steering mode includes a small turning driving mode and a crab driving mode, and the second type of steering mode is a steering mode other than the first type of steering mode in the preset steering modes.

7. The vehicle steering control method according to claim 3, characterized in that, When the steering control mode command is the override control mode command, the method further includes: Obtain obstacle information around the vehicle; When it is determined that the vehicle poses a safety risk based on the obstacle information, the vehicle is controlled to slow down, and each steering wheel is controlled based on the obstacle information to control the vehicle's steering.

8. A vehicle steering control system for performing the method as described in any one of claims 1-7, characterized in that, The vehicle includes multiple axles, and each axle is connected to multiple steering wheels. The multiple steering wheels steer synchronously or independently. The system includes: The input module is used to receive steering control mode commands; The communication and positioning module is used to obtain the vehicle's position information when the steering control mode command is an automatic control mode command; The main control module is used to obtain the vehicle speed when it is determined that the vehicle is about to reach a turning section based on the location information, obtain the minimum permissible turning radius of the vehicle based on the vehicle speed, and control each steering wheel based on the minimum permissible turning radius to control the steering of the vehicle.

9. A vehicle, characterized in that, include: A memory, a processor, and a vehicle steering control program stored in the memory and executable on the processor, wherein when the processor executes the program, it implements the vehicle steering control method according to any one of claims 1-7.

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