Front wheel independent steering control method and front wheel independent steering control device

Abstract

The embodiment of the invention provides a front wheel independent steering control method and a front wheel independent steering control device. The front wheel independent steering control method comprises the steps that whether a vehicle deviates or not is determined; under the condition that it is determined that the vehicle deviates, the front axle rotation angle of the vehicle is corrected; under the condition that it is determined that the vehicle does not deviate, whether a left front wheel and a right front wheel of the vehicle are in a deviating state or not is determined; and performing zero correction on the left front wheel and the right front wheel of the vehicle in the deviated state.

Description

Technical Field

[0001] The present application relates to the field of automobile control technology, and more specifically, to a front wheel independent steering control method and a front wheel independent steering control device. Background Art

[0002] In order to improve the freedom of vehicle layout, vehicles have begun to adopt wire-controlled steering solutions, that is, steering without using mechanical components such as steering columns, gear racks, etc. Some solutions even install a steering motor on each side of the wheel for independent steering.

[0003] In order to achieve steer-by-wire, some existing solutions calculate the steering angle required for each wheel based on the steering wheel angle and vehicle speed, and then perform four-wheel control on the vehicle, while some existing solutions estimate the vehicle yaw interference term and adjust the interference term through steering or braking. However, the existing solutions are all designed for four-wheel control strategies, without considering whether the zero angle of the wheel is correct during the actual driving of the vehicle, and whether the actual rotation angle of the wheel is the angle required by the control strategy. Summary of the invention

[0004] In one aspect, an embodiment of the present application provides a front-wheel independent steering control method, including: determining whether a vehicle is deviating; if it is determined that the vehicle is deviating, performing a correction on the front axle angle of the vehicle; determining whether the left front wheel and the right front wheel of the vehicle are in a deviated state; and performing a zero-position correction on the left front wheel and the right front wheel of the vehicle that are in a deviated state.

[0005] In some implementations, determining whether the vehicle is running off the track includes: when the target wheel angle is zero or the target steering wheel angle is zero, if the vehicle heading angle changes, then determining that the vehicle is running off the track.

[0006] In some implementations, performing correction on the front axle angle of the vehicle includes: correcting the front axle angle using a deviation value between the vehicle heading angle and a zero heading angle until the deviation value is zero.

[0007] In some implementations, the vehicle heading angle may be obtained by integrating the yaw rate measured by a yaw rate sensor of the vehicle.

[0008] In some implementations, determining whether the left front wheel and the right front wheel of the vehicle are in a deviated state includes: calculating the slip rates of the left front wheel and the right front wheel of the vehicle; determining whether the calculated slip rates of the left front wheel and the right front wheel are both zero; and, when the calculated slip rate of the left front wheel or the slip rate of the right front wheel is not zero, determining that the left front wheel and the right front wheel of the vehicle are in a deviated state.

[0009] In some implementations, determining that the left front wheel and the right front wheel of the vehicle are in a deviation state includes: preliminarily controlling the left front wheel to turn right and controlling the right front wheel to turn left; when the slip rate of the left front wheel and the slip rate of the right front wheel both decrease, determining that the left front wheel and the right front wheel are in an outside eight deviation state; and when the slip rate of the left front wheel and the slip rate of the right front wheel both increase, determining that the left front wheel and the right front wheel are in an inside eight deviation state.

[0010] In some implementations, performing zero-position correction on the left front wheel and the right front wheel of the vehicle includes: when the left front wheel and the right front wheel are in an outward-facing deviation state, controlling the left front wheel to turn right and controlling the right front wheel to turn left until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero; and when the left front wheel and the right front wheel are in an inward-facing deviation state, controlling the left front wheel to turn left and controlling the right front wheel to turn right until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero.

[0011] On the other hand, according to an embodiment of the present application, a front-wheel independent steering control device is provided, including: a vehicle deviation determination module, configured to determine whether the vehicle is deviation; a front axle angle correction module, configured to perform correction on the front axle angle of the vehicle when it is determined that the vehicle is deviation; a deviation state determination module, configured to determine whether the left front wheel and the right front wheel of the vehicle are in a deviation state when it is determined that the vehicle is not deviation; and a wheel zero position correction module, configured to perform zero position correction on the left front wheel and the right front wheel of the vehicle that are in a deviation state.

[0012] In some implementations, the vehicle deviation determination module is configured to determine that the vehicle is deviation if the vehicle heading angle changes when the target wheel angle is zero or the target steering wheel angle is zero.

[0013] In some implementations, the front axle angle correction module is configured to correct the front axle angle using a deviation value between the vehicle heading angle and the zero heading angle until the deviation value is zero.

[0014] In some implementations, the vehicle heading angle yaw is obtained by integrating the yaw rate measured by a yaw rate sensor of the vehicle.

[0015] In some implementations, the deviation state determination module is configured to: calculate a slip rate of a left front wheel and a slip rate of a right front wheel of the vehicle; determine whether the calculated slip rate of the left front wheel and the calculated slip rate of the right front wheel are both zero; and, when the calculated slip rate of the left front wheel or the calculated slip rate of the right front wheel is not zero, determine that the left front wheel and the right front wheel of the vehicle are in a deviation state.

[0016] In some implementations, the deviation state determination module is configured to: preliminarily control the left front wheel of the vehicle to turn right and control the right front wheel to turn left; determine that the left front wheel and the right front wheel are in an outside-toe deviation state when the slip rate of the left front wheel and the slip rate of the right front wheel both decrease; and determine that the left front wheel and the right front wheel are in an inside-toe deviation state when the slip rate of the left front wheel and the slip rate of the right front wheel both increase.

[0017] In some implementations, the wheel zero position correction module is configured to: when the left front wheel and the right front wheel are in an outward-toed deviation state, control the left front wheel to turn right and control the right front wheel to turn left until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero; and when the left front wheel and the right front wheel are in an inward-toed deviation state, control the left front wheel to turn left and control the right front wheel to turn right until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero.

[0018] In another aspect, a controller is provided according to an embodiment of the present application, comprising: a processor; a memory storing program instructions, wherein the processor is configured to execute the program instructions stored in the memory to execute the front wheel independent steering control method according to an embodiment of the present application.

[0019] According to the front-wheel independent steering control method and control device of the embodiment of the present application, it is possible to perform self-learning of the wheel zero angle during vehicle driving, so that when the vehicle is driving in a straight line, the wheels can travel in a pure rolling state, the slip rate is reduced, and the wear is reduced; during the steering process of the vehicle, the wheels can respond to the steering angle requirements more accurately, thereby improving the drivability of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the embodiment of the present application, the following briefly describes the drawings involved in the embodiment of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings without creative work. In the drawings:

[0021] Figure 1 is a schematic diagram of a front wheel independent steering control system according to an embodiment of the present application;

[0022] Figure 2 A schematic flow chart of a front wheel independent steering control method according to an embodiment of the present application is shown;

[0023] Figure 3 A specific schematic flow chart of a front wheel independent steering control method according to an embodiment of the present application is shown;

[0024] Figure 4 A schematic diagram of wheel adjustment according to a front wheel independent steering control method according to an embodiment of the present application is shown;

[0025] Figure 5 A schematic block diagram of a front wheel independent steering control device according to an embodiment of the present application is shown;

[0026] Figure 6 A schematic block diagram of a controller that can be used to implement a front wheel independent steering control device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0027] The features and exemplary embodiments of various aspects of the application will be described in detail below. In order to make the purpose, scheme, and advantages of the application clearer, the details of the application are further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the application and are not intended to limit the application. For those skilled in the art, the application can be implemented without some of the details in these specific details. The following description of the embodiments is only to provide a better understanding of the application by illustrating the example of the application.

[0028] It should be noted that, in this article, relational terms such as first, second, third, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In addition, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, including a process, method, article or device of a series of elements not only including these elements, but also including other elements not explicitly listed, or also including elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the statement "include..." do not exclude the presence of other elements in the process, method, article or device including the elements.

[0029] The embodiments of the present application relate to the control of an independently steered vehicle. Independent steering means that the wheels of the vehicle are independently controlled. As the vehicle mileage increases, the independent steering mechanism may wear out, and the calibrated wheel zero angle δsteer_zero_angle changes, which may cause the following two problems:

[0030] 1) When the vehicle is traveling in a straight line, when the wheel requests a target angle of δsteer_zero_angle, the actual position of the wheel is no longer the zero position of the wheel, but deviates from the zero position by a certain angle, causing the vehicle to deviate and fail to travel in a straight line;

[0031] 2) When the vehicle is turning and the wheel requests a target angle of δsteer_zero_angle+(10deg), the actual rotation angle of the wheel is not 10 degrees, but a little more or less than 10 degrees. The vehicle cannot accurately meet the steering requirements.

[0032] Based on the above, the present application proposes a front wheel independent steering control method and control device, which can timely update the wheel zero angle δsteer_zero_angle to ensure that the actual angle turned during vehicle driving is the required wheel rotation angle to achieve precise control.

[0033] Figure 1 Schematic diagram of a front wheel independent steering control system according to an embodiment of the present application. Figure 1 As shown, the control system 100 according to the embodiment of the present application includes: a control unit (electronic control unit, ECU) 101, a sensor unit 102 and an execution unit 103. The sensor unit 102 includes: a steering wheel angle sensor, a yaw rate sensor, an angle sensor (left front wheel, right front wheel, left rear wheel, right rear wheel), and a wheel speed sensor (left front wheel, right front wheel, left rear wheel, right rear wheel). The execution unit 103 includes a steering actuator (left front wheel actuator, right front wheel actuator, left rear wheel actuator, right rear wheel actuator).

[0034] It should be understood that the above diagrams are only examples, and the specific contents of the sensor unit / actuator unit are determined according to the vehicle steering configuration. For example, a front-wheel independent steering vehicle only includes the left front wheel and the right front wheel angle sensors and a steering actuator; a rear-wheel independent steering vehicle only includes the left rear wheel and the right rear wheel angle sensors and a steering actuator; a four-wheel independent steering configuration vehicle includes the left front wheel, the right front wheel, the left rear wheel, the right rear wheel angle sensors and a steering actuator.

[0035] Figure 2 FIG. 2 shows a schematic flow chart of a front wheel independent steering control method according to an embodiment of the present application. Figure 2 As shown, the front wheel independent steering control method 200 according to the embodiment of the present application includes:

[0036] Step S201, determining whether the vehicle is running off the track;

[0037] Step S202, when it is determined that the vehicle is running off the track, correcting the front axle angle of the vehicle;

[0038] Step S203, when it is determined that the vehicle is not deviating, determining whether the left front wheel and the right front wheel of the vehicle are in a deviated state; and

[0039] Step S204, performing zero position correction on the left front wheel and the right front wheel of the vehicle that are in a deviated state.

[0040] In some implementations, determining whether the vehicle is running off the track includes: when the target wheel angle is zero or the target steering wheel angle is zero, if the vehicle heading angle changes, then determining that the vehicle is running off the track.

[0041] In some implementations, performing correction on the front axle angle of the vehicle includes: correcting the front axle angle using a deviation value between the vehicle heading angle and a zero heading angle until the deviation value is zero.

[0042] In some implementations, the vehicle heading angle may be obtained by integrating the yaw rate measured by a yaw rate sensor of the vehicle.

[0043] In some implementations, determining whether the left front wheel and the right front wheel of the vehicle are in a deviated state includes: calculating the slip rates of the left front wheel and the right front wheel of the vehicle; determining whether the calculated slip rates of the left front wheel and the right front wheel are both zero; and, when the calculated slip rate of the left front wheel or the slip rate of the right front wheel is not zero, determining that the left front wheel and the right front wheel of the vehicle are in a deviated state.

[0044] In some implementations, determining that the left front wheel and the right front wheel of the vehicle are in a deviation state includes: preliminarily controlling the left front wheel of the vehicle to turn right and controlling the right front wheel to turn left; when the slip rate of the left front wheel and the slip rate of the right front wheel both decrease, determining that the left front wheel and the right front wheel are in an outside eight deviation state; and when the slip rate of the left front wheel and the slip rate of the right front wheel both increase, determining that the left front wheel and the right front wheel are in an inside eight deviation state.

[0045] In some implementations, ensuring zero-position correction of the left front wheel and the right front wheel of the vehicle includes: when the left front wheel and the right front wheel are in an outward-facing deviation state, controlling the left front wheel to turn right and controlling the right front wheel to turn left until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero; and when the left front wheel and the right front wheel are in an inward-facing deviation state, controlling the left front wheel to turn left and controlling the right front wheel to turn right until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero.

[0046] Figure 3 FIG. 2 shows a specific schematic flow chart of the front wheel independent steering control method according to an embodiment of the present application. Figure 3 As shown, the front wheel independent steering control method 300 according to the embodiment of the present application includes steps S301-S306.

[0047] According to the embodiment of the present application, the front wheel independent steering control method 300 enters step S301 after starting, where it is determined whether the vehicle is running off the track.

[0048] In some implementations, determining whether the vehicle is running off the track includes: when the target wheel angle is zero or the target steering wheel angle is zero, if the vehicle heading angle changes, then determining that the vehicle is running off the track. In some implementations, the vehicle heading angle is obtained by integrating the yaw rate measured by the yaw rate sensor of the vehicle.

[0049] Next, in the case where it is determined in step S301 that the vehicle is running off the track, the method proceeds to step S302. In step S302, in the case where it is determined that the vehicle is running off the track, a correction is performed on the front axle angle of the vehicle. The front axle of the vehicle refers to the axle between the front wheels on both sides of the vehicle (the left front wheel and the right front wheel). In some implementations, performing a correction on the front axle angle of the vehicle includes: correcting the front axle angle using a deviation value between the vehicle heading angle and the zero heading angle. Next, the method proceeds to step S303 to determine again whether the vehicle is running off the track.

[0050] If it is determined in step S301 or step S303 that the vehicle is not deviating, the method proceeds to step S304, where it is determined whether the left front wheel and the right front wheel of the vehicle are in a deviating state. In some implementations, determining whether the left front wheel and the right front wheel of the vehicle are in a deviating state includes: calculating the slip rate of the left front wheel and the slip rate of the right front wheel of the vehicle; determining whether the calculated slip rate of the left front wheel and the slip rate of the right front wheel are both zero; and when the calculated slip rate of the left front wheel or the slip rate of the right front wheel is not zero, determining that the left front wheel and the right front wheel of the vehicle are in a deviating state.

[0051] In some implementations, when it is determined that the vehicle is in a deviation state, the left front wheel of the vehicle is initially controlled to turn right and the right front wheel is controlled to turn left; when the slip rate of the left front wheel and the slip rate of the right front wheel both decrease, it is determined that the left front wheel and the right front wheel are in an outside eight deviation state; and when the slip rate of the left front wheel and the slip rate of the right front wheel both increase, it is determined that the left front wheel and the right front wheel are in an inside eight deviation state.

[0052] Next, the method proceeds to step S305, where a zero position correction is performed on the left front wheel and the right front wheel of the vehicle that are in a deviated state. In some implementations, performing a zero position correction on the left front wheel and the right front wheel of the vehicle includes: when the left front wheel and the right front wheel are in an outward eight deviation state, controlling the left front wheel to turn right and controlling the right front wheel to turn left until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero; and when the left front wheel and the right front wheel are in an inner eight deviation state, controlling the left front wheel to turn left and controlling the right front wheel to turn right until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero.

[0053] Figure 4 FIG. 2 shows a schematic diagram of wheel adjustment according to the front wheel independent steering control method according to an embodiment of the present application. Figure 4As shown in the figure, the left half shows that the left front wheel and the right front wheel are in an outward deviation state. First, the left front wheel turns right and the right front wheel turns left, so that the deviation state is adjusted from state ① to state ②. Since it is still in an outward deviation state, the left front wheel continues to turn right and the right front wheel turns left until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero, and the two wheels return to zero position, that is, the state is adjusted from state ② to state ③. Figure 4 As shown, the right half illustrates that the left front wheel and the right front wheel are in an inner-toed deviation state. At this time, the left front wheel is controlled to turn left and the right front wheel is controlled to turn right, so that the deviation state is adjusted from ① to ②. Since it is still in the inner-toed deviation state, the left front wheel continues to be controlled to turn left and the right front wheel continues to turn right until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero, and the two wheels return to zero position, that is, the state is adjusted from ② to ③.

[0054] In the case where the correction has been performed in step S305, the method proceeds to step S306, where the steering angle sensor values ​​corresponding to the left front wheel and the right front wheel are updated as new wheel zero angles and saved, for example, in a memory (such as a flash memory) of the controller, so that the correction information can be used to quickly complete the zero adjustment when the vehicle is powered on next time. Thus, the zero adjustment of the vehicle is completed, and the method 300 ends.

[0055] If it is determined in step S304 that the vehicle is not in a deviation state, there is no need to perform zero position correction of the vehicle, and the method 300 ends.

[0056] According to the front-wheel independent steering control method of the embodiment of the present application, the wheel zero angle self-learning can be performed during vehicle driving, so that when the vehicle is driving in a straight line, the wheels can travel in a pure rolling state, the slip rate is reduced, and the wear is reduced; during the steering process of the vehicle, the wheels can respond to the steering angle requirements more accurately, thereby improving the drivability of the vehicle.

[0057] Figure 5 A schematic block diagram of a front wheel independent steering control device according to an embodiment of the present application is shown.

[0058] like Figure 5 As shown, the front wheel independent steering control device 500 according to an embodiment of the present application includes:

[0059] The vehicle deviation determination module 501 is configured to determine whether the vehicle is deviation;

[0060] The front axle angle correction module 502 is configured to correct the front axle angle of the vehicle when it is determined that the vehicle is running off the track;

[0061] The deviation state determination module 503 is configured to determine whether the left front wheel and the right front wheel of the vehicle are in a deviation state when it is determined that the vehicle is not deviating; and

[0062] The wheel zero position correction module 504 is configured to perform zero position correction on the left front wheel and the right front wheel of the vehicle that are in a deviated state.

[0063] In some implementations, the vehicle deviation determination module 501 is configured to determine that the vehicle is deviation if the vehicle heading angle changes when the target wheel angle is zero or the target steering wheel angle is zero.

[0064] In some implementations, the front axle angle correction module 502 is configured to correct the front axle angle using a deviation value between the vehicle heading angle and the zero heading angle until the deviation value is zero.

[0065] In some implementations, the vehicle heading angle is obtained by integrating the yaw rate measured by a yaw rate sensor of the vehicle.

[0066] In some implementations, the deviation state determination module 503 is configured to:

[0067] Calculating the slip rate of the left front wheel and the slip rate of the right front wheel of the vehicle;

[0068] determining whether the calculated slip ratio of the left front wheel and the calculated slip ratio of the right front wheel are both zero; and

[0069] When the calculated slip ratio of the left front wheel or the right front wheel is not zero, it is determined that the left front wheel and the right front wheel of the vehicle are in a deviation state.

[0070] In some implementations, the deviation state determination module 503 is configured to:

[0071] Preliminarily controlling the left front wheel of the vehicle to turn right and controlling the right front wheel to turn left;

[0072] When the slip ratio of the left front wheel and the slip ratio of the right front wheel are both reduced, determining that the left front wheel and the right front wheel are in an out-toe state; and

[0073] When the slip ratio of the left front wheel and the slip ratio of the right front wheel both increase, it is determined that the left front wheel and the right front wheel are in an inner-toe deviation state.

[0074] In some implementations, the wheel zero position correction module 504 is configured to:

[0075] When the left front wheel and the right front wheel are in an outward-toed state, controlling the left front wheel to turn right and controlling the right front wheel to turn left until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero; and

[0076] When the left front wheel and the right front wheel are in an inner-to-eight deviation state, the left front wheel is controlled to turn left and the right front wheel is controlled to turn right until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero.

[0077] According to the front-wheel independent steering control device of the embodiment of the present application, it is possible to perform self-learning of the wheel zero angle during vehicle driving, so that when the vehicle is driving in a straight line, the wheels can travel in a pure rolling state, the slip rate is reduced, and the wear is reduced; during the steering process of the vehicle, the wheels can respond to the steering angle requirements more accurately, thereby improving the drivability of the vehicle.

[0078] An embodiment of the present application also provides a controller, comprising: a processor; a memory storing program instructions, wherein the processor is configured to execute the program instructions stored in the memory to execute the front wheel independent steering control method according to the embodiment of the present application.

[0079] Figure 6 FIG. 2 shows a schematic block diagram of a controller that can be used to implement a front wheel independent steering control device according to an embodiment of the present application. Figure 6 As shown, the controller 600 according to an embodiment of the present application may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 601, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 602 or a program loaded from a storage device 603 to a random access memory (RAM) 604. Various programs and data required for the operation of the controller 600 are also stored in the RAM 604. The processing device 601, the ROM 602, and the RAM 604 are connected to each other via a bus 605. An interface 606 is also connected to the bus 605. A peripheral device can be connected via the interface 606. It should be understood that the number of interfaces is not limited to one, but there can be more, so as to connect to corresponding peripheral devices respectively. It should be understood that Figure 6 The block diagram shown is only an example to provide an understanding of the embodiments of the present application. There may be more or fewer components. For example, the microcontroller also includes a master clock circuit and a slave clock circuit.

[0080] Although Figure 6 The controller 600 is shown with various devices, but it should be understood that it is not required to implement or have all of the devices shown. More or fewer devices may be implemented or have instead. Figure 6 Each block shown in the figure may represent one device, or may represent multiple devices as required.

[0081] In particular, according to an embodiment of the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present disclosure provides a computer readable storage medium storing a computer program, the computer program including a method for executing Figure 2In such an embodiment, the computer program may be installed from the storage device 606, or installed from the ROM 602, or downloaded and installed from the network. When the computer program is executed by the processing device 601, the implementation Figure 2 The method shown.

[0082] It should be noted that the computer-readable medium according to an embodiment of the present invention may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. The computer-readable storage medium according to an embodiment of the present invention may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, device or device.

[0083] Computer program code for performing operations according to embodiments of the present invention may be written in one or more programming languages, or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages.

[0084] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions, and operations of the systems and methods according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram may represent a module, a program segment, or a portion of a code, which contains one or more executable instructions for implementing a specified logical function.

[0085] Those skilled in the art will appreciate that the present application is not limited to the specific structures and steps described above and shown in the accompanying drawings. For the sake of simplicity, the description of known structures and methods is omitted herein. In the above-described embodiments, several specific steps are described and shown as examples. However, the method of the present application is not limited to the specific steps described and shown, and without departing from the scope of the present application, those skilled in the art can make various changes, modifications and additions to the embodiments of the present application, or change the order between the steps.

[0086] The above disclosed contents are only some specific embodiments of the present application. Those skilled in the art can understand that the protection scope of the present application is not limited thereto. Rather, various equivalent modifications or substitutions can be thought of within the technical scope disclosed in the present application, and these equivalent modifications or substitutions are all covered within the protection scope of the present application.

Claims

1. A front wheel independent steering control method, include: Determine if the vehicle is running off the track; When it is determined that the vehicle is running off the track, correcting the front axle angle of the vehicle; In the case where it is determined that the vehicle is not deviating, determining whether the left front wheel and the right front wheel of the vehicle are in a deviated state; as well as Zero position correction is performed on the left front wheel and the right front wheel of the vehicle which are in a deviated state.

2. The front wheel independent steering control method according to claim 1, in, Determining whether the vehicle is running off track includes: When the target wheel angle is zero or the target steering wheel angle is zero, if the vehicle heading angle changes, it is determined that the vehicle is running off the track.

3. The front wheel independent steering control method according to claim 1, in, Corrections to the vehicle's front axle angle include: The front axle angle is corrected using a deviation between the vehicle heading angle and the zero heading angle until the deviation is zero.

4. The front wheel independent steering control method according to claim 2 or 3, in, The vehicle heading angle is obtained by integrating the yaw rate measured by a yaw rate sensor of the vehicle.

5. The front wheel independent steering control method according to claim 1, in, Determining whether the left front wheel and the right front wheel of the vehicle are in a deviated state includes: Calculating the slip rates of the left front wheel and the right front wheel of the vehicle; determining whether the calculated slip ratio of the left front wheel and the calculated slip ratio of the right front wheel are both zero; and When the slip ratio of the left front wheel or the slip ratio of the right front wheel is not zero, it is determined that the left front wheel and the right front wheel of the vehicle are in a deviated state.

6. The front wheel independent steering control method according to claim 5, in, Determining that the left front wheel and the right front wheel of the vehicle are in a deviated state includes: Preliminarily controlling the left front wheel to turn right and controlling the right front wheel to turn left; In a case where the slip ratio of the left front wheel and the slip ratio of the right front wheel are both reduced, determining that the left front wheel and the right front wheel are in an outward-toe deviation state; and In a case where the slip ratio of the left front wheel and the slip ratio of the right front wheel both increase, it is determined that the left front wheel and the right front wheel are in an inward-toed deviation state.

7. The front wheel independent steering control method according to claim 1, in, Performing zero position correction on the left front wheel and the right front wheel of the vehicle includes: When the left front wheel and the right front wheel are in an outward-toed state, controlling the left front wheel to turn right and controlling the right front wheel to turn left until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero; and When the left front wheel and the right front wheel are in an inner-to-eight deviation state, the left front wheel is controlled to turn left and the right front wheel is controlled to turn right until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero.

8. A front wheel independent steering control device, include: A vehicle deviation determination module is configured to determine whether the vehicle is deviation; A front axle angle correction module is configured to correct the front axle angle of the vehicle when it is determined that the vehicle is running off the track; a deviation state determination module, configured to determine whether the left front wheel and the right front wheel of the vehicle are in a deviation state when it is determined that the vehicle is not deviating; as well as The wheel zero position correction module is configured to perform zero position correction on the left front wheel and the right front wheel of the vehicle that are in a deviated state.

9. The front wheel independent steering control device according to claim 8, in, The vehicle deviation determination module is configured to determine that the vehicle is deviation if the vehicle heading angle changes when the target wheel angle is zero or the target steering wheel angle is zero.

10. The front wheel independent steering control device according to claim 8, in, The front axle angle correction module is configured as follows: The front axle angle is corrected using a deviation between the vehicle heading angle and the zero heading angle until the deviation is zero.

11. The front wheel independent steering control device according to claim 8, in, The vehicle heading angle is obtained by integrating the yaw rate measured by a yaw rate sensor of the vehicle.

12. The front wheel independent steering control device according to claim 8, in, The deviation state determination module is configured to: calculating a slip ratio of the left front wheel and a slip ratio of the right front wheel of the vehicle; determining whether the calculated slip ratio of the left front wheel and the calculated slip ratio of the right front wheel are both zero; and When the calculated slip ratio of the left front wheel or the right front wheel is not zero, it is determined that the left front wheel and the right front wheel of the vehicle are in a deviation state.

13. The front wheel independent steering control device according to claim 12, in, The deviation state determination module is configured to: Preliminarily controlling the left front wheel of the vehicle to turn right and controlling the right front wheel to turn left; When the slip rate of the left front wheel and the slip rate of the right front wheel are both reduced, determining that the left front wheel and the right front wheel are in an outward toe deviation state; In a case where the slip ratio of the left front wheel and the slip ratio of the right front wheel both increase, it is determined that the left front wheel and the right front wheel are in an inward-toed deviation state.

14. The front wheel independent steering control device according to claim 8, in, The wheel zero position correction module is configured as follows: When the left front wheel and the right front wheel are in an outward-toed state, controlling the left front wheel to turn right and controlling the right front wheel to turn left until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero; as well as When the left front wheel and the right front wheel are in an inner-to-eight deviation state, the left front wheel is controlled to turn left and the right front wheel is controlled to turn right until the slip rate of the left front wheel and the slip rate of the right front wheel are both zero.

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