Vehicle steering control method and apparatus, and vehicle

Abstract

Disclosed is a vehicle steering control method (200), comprising: obtaining a rear-axle target motor torque and a rear-axle basic differential torque on the basis of state information of a vehicle; and obtaining a left-rear target motor torque and a right-rear target motor torque on the basis of the rear-axle basic differential torque and the rear-axle target motor torque, and applying the left-rear target motor torque and the right-rear target motor torque to a left-rear drive motor and a right-rear drive motor of the vehicle, thereby controlling the vehicle to perform steering. Further disclosed are a vehicle steering control apparatus (500), a vehicle, a storage medium, and a computer instruction. A left-rear drive motor and a right-rear drive motor of a vehicle are used to output different torques, such that the capability of controlling the pose of the vehicle body is enhanced, and the turning radius of the vehicle is reduced to a greater extent, thereby avoiding tire wear of the vehicle.

Description

Vehicle steering control method, device and vehicle

[0001] This application claims priority to Chinese application No. 202410895842.1, filed on July 4, 2024, entitled "Vehicle steering control method, device and vehicle", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to, but is not limited to, the technical field of automobiles, and more illustratively relates to a vehicle steering control method, device and vehicle. BACKGROUND

[0003] The vehicle usually needs to be steered during driving. The traditional steering function is realized by controlling the front wheel steering angle through the steering wheel operated by the driver. The turning radius of the vehicle is large.

[0004] In the related art, a target wheel to be braked is determined from a plurality of rear wheels of a vehicle, a wheel control signal corresponding to the target wheel is output to control the vehicle to perform a preset braking action on the target wheel, and the braking on the inner rear wheel of the vehicle is realized by single-sided clamping to control it within a set slip ratio, thereby reducing the turning radius of the vehicle. However, this method has large wear on the vehicle tires and limited application scenarios. TECHNICAL SOLUTION

[0005] The present application is proposed to solve the above problems. According to one aspect of the present application, a vehicle steering control method is provided, which comprises: obtaining a rear axle motor target torque and a rear axle basic differential torque based on state information of a vehicle; and

[0006] Obtaining a left rear motor target torque and a right rear motor target torque based on the rear axle basic differential torque and the rear axle motor target torque, for applying to left and right rear drive motors of the vehicle, so as to control the vehicle to steer.

[0007] In one embodiment of the present application, the rear axle basic differential torque is obtained based on the state information of the vehicle, comprising: obtaining the rear axle basic differential torque based on a steering wheel steering angle in the state information and a preset relationship table.

[0008] In one embodiment of the present application, the rear axle basic differential torque is obtained based on the steering wheel steering angle in the state information and the preset relationship table, comprising: obtaining the rear axle basic differential torque based on a vehicle speed, the steering wheel steering angle in the state information and a first preset relationship table, wherein the first preset relationship table records a corresponding numerical relationship between the vehicle speed and the steering wheel steering angle and the rear axle basic differential torque.

[0009] In an embodiment of the present application, the obtaining the left rear motor target torque and the right rear motor target torque based on the rear axle basic differential torque and the rear axle motor target torque comprises: obtaining a vehicle rotation direction, a left rear wheel torque coefficient and a right rear wheel torque coefficient; obtaining a left rear wheel compensation torque based on a relationship between the rear axle basic differential torque, the vehicle rotation direction and the left rear wheel torque coefficient, and obtaining a right rear wheel compensation torque based on a relationship between the rear axle basic differential torque, the vehicle rotation direction and the right rear wheel torque coefficient; and obtaining the left rear motor target torque based on the left rear wheel compensation torque and the rear axle motor target torque, and obtaining the right rear motor target torque based on the right rear wheel compensation torque and the rear axle motor target torque.

[0010] In an embodiment of the present application, the obtaining the left rear wheel compensation torque based on the relationship between the rear axle basic differential torque, the vehicle rotation direction and the left rear wheel torque coefficient, and the obtaining the right rear wheel compensation torque based on the relationship between the rear axle basic differential torque, the vehicle rotation direction and the right rear wheel torque coefficient comprises: obtaining a brake attenuation coefficient and a slope attenuation coefficient; obtaining the left rear wheel compensation torque based on the rear axle basic differential torque, the vehicle rotation direction, the brake attenuation coefficient, the left rear wheel torque coefficient and the slope attenuation coefficient; and obtaining the right rear wheel compensation torque based on the rear axle basic differential torque, the vehicle rotation direction, the brake attenuation coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient.

[0011] In an embodiment of the present application, the obtaining the brake attenuation coefficient and the slope attenuation coefficient comprises: obtaining the brake attenuation coefficient based on a brake depth of the state information and a second preset relationship table, wherein the second preset relationship table records a corresponding numerical relationship between the brake depth and the brake attenuation coefficient; and obtaining the slope attenuation coefficient based on a slope of the state information and a third preset relationship table, wherein the third preset relationship table records a corresponding numerical relationship between the slope and the slope attenuation coefficient.

[0012] In an embodiment of the present application, the obtaining the left rear wheel torque coefficient and the right rear wheel torque coefficient based on the rear axle basic differential torque and a fourth preset relationship table comprises: obtaining the left rear wheel torque coefficient and the right rear wheel torque coefficient based on the rear axle basic differential torque and the fourth preset relationship table, wherein the fourth preset relationship table records a corresponding numerical relationship between the rear axle basic differential torque and the left rear wheel torque coefficient and the right rear wheel torque coefficient.

[0013] In an embodiment of the present application, the obtaining the rear axle motor target torque and the rear axle base differential torque based on the state information of the vehicle comprises: obtaining the state information of the vehicle; determining a state of a vehicle auxiliary steering function based on the state information; and obtaining the rear axle motor target torque and the rear axle base differential torque based on the state information when the vehicle auxiliary steering function enters an active state.

[0014] In an embodiment of the present application, the method further comprises: obtaining a front axle motor target torque based on the state information, and applying the front axle motor target torque to a front drive motor of the vehicle.

[0015] In an embodiment of the present application, the method further comprises: performing zero-crossing smoothing and torque limiting processing on the front axle motor target torque, the left rear motor target torque and the right rear motor target torque; and applying the processed front axle motor target torque, the processed left rear motor target torque and the processed right rear motor target torque to the front drive motor, the left rear drive motor and the right rear drive motor respectively, so as to make the vehicle steer smoothly.

[0016] In an embodiment of the present application, the state information comprises at least one of the following: a steering wheel angle, a brake depth, a vehicle speed, a gear information, a slope, a throttle depth.

[0017] In an embodiment of the present application, the conditions for the vehicle auxiliary steering function to be in the active state comprise one or more of the following: the steering wheel angle is greater than a first angle threshold, and a rear wheel angle is greater than a second angle threshold, wherein the rear wheel angle is obtained based on the steering wheel angle; the brake depth is less than a brake depth threshold; the vehicle speed is less than a vehicle speed threshold; the gear information is a forward gear; the slope is less than a slope threshold; and the throttle depth is greater than a throttle threshold.

[0018] According to another aspect of the present application, there is provided a vehicle steering control device, the device comprising a processor and a memory, wherein the memory has stored thereon computer executable instructions which, when executed by the processor, cause the processor to perform the vehicle steering control method described above.

[0019] According to yet another aspect of the present application, there is provided a vehicle comprising the vehicle steering control device described above.

[0020] According to another aspect of the present application, there is provided a storage medium having stored thereon computer instructions executable by a processor, the computer instructions, when executed by the processor, causing the processor to perform the vehicle steering control method described above.

[0021] According to another aspect of the present application, a computer instruction is provided, which, when executed by the processor, causes the processor to perform the vehicle steering control method described above.

[0022] The vehicle steering control method, device and vehicle of the present application control the vehicle to steer by confirming that the vehicle auxiliary steering function has entered an activated state, obtaining a left rear motor target torque and a right rear motor target torque, and applying the left rear motor target torque and the right rear motor target torque to the left rear drive motor and the right rear drive motor of the vehicle respectively. The use of the left rear drive motor and the right rear drive motor of the vehicle to output different torques enhances the control ability of the vehicle body posture, greatly reduces the turning radius of the vehicle, and avoids tire wear of the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0023] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description of embodiments of the present application taken in conjunction with the accompanying drawings. The accompanying drawings are provided to aid in understanding the embodiments of the present application, and constitute a part of the specification. The accompanying drawings, together with the specification, serve to explain the embodiments of the present application, and do not limit the present application. In the drawings, like reference numerals refer to like parts or steps throughout.

[0024] FIG. 1 shows a schematic block diagram of an example electronic device of a vehicle steering control method and device according to an embodiment of the present application.

[0025] FIG. 2 shows a schematic flowchart of a vehicle steering control method according to an embodiment of the present application.

[0026] FIG. 3 shows a schematic diagram of a vehicle steering according to an embodiment of the present application.

[0027] FIG. 4 shows a schematic diagram of another vehicle steering according to an embodiment of the present application.

[0028] FIG. 5 shows a schematic structural block diagram of a vehicle steering control device according to an embodiment of the present application.

[0029] Embodiments of the present application

[0030] In order to make the objects, technical solutions and advantages of the present application more apparent, example embodiments according to the present application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the example embodiments described herein. Based on the embodiments of the present application described in the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present application.

[0031] In view of the situation that the vehicle needs to turn on the narrow road, the ordinary normal steering is limited by the too large turning diameter and cannot complete the steering, especially when the vehicle turns on the place with many vehicles, the driver needs to adjust the vehicle posture for many times due to the surrounding environmental factors, which is easy to cause road traffic congestion, and may also scratch the surrounding articles or pedestrians, causing harm to the person or property. Therefore, it is necessary to develop a function of reducing the turning radius of turning and passing to improve the vehicle maneuverability.

[0032] First, referring to FIG. 1, an example electronic device 100 for implementing a vehicle steering control method and apparatus according to an embodiment of the present application is described.

[0033] As shown in FIG. 1, the electronic device 100 includes one or more processors 102, one or more storage devices 104, an input device 106, and an output device 108, which are interconnected through a bus system 110 and / or other forms of connection mechanisms (not shown). It can be noted that the components and structures of the electronic device 100 shown in FIG. 1 are only exemplary and are not limiting, and the electronic device can also have other components and structures as needed.

[0034] The processor 102 can be a central processing unit (CPU) or other forms of processing units having data processing and / or instruction execution capabilities, and can control other components in the electronic device 100 to perform desired functions.

[0035] The storage device 104 can include one or more computer program products, which can include various forms of computer readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM), cache memory, and the like. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, and the like. One or more computer program instructions can be stored on the computer readable storage medium, and the processor 102 can run the program instructions to implement the client functions (implemented by the processor) in the embodiments of the present application described below and / or other desired functions. Various application programs and various data, such as various data used and / or generated by the application programs, and the like, can also be stored in the computer readable storage medium.

[0036] The input device 106 can be a device used by a user to input instructions, and can include one or more of a keyboard, a mouse, a microphone, a touch screen, and the like. In addition, the input device 106 can also be any interface that receives information.

[0037] The output device 108 can output various information (e.g., images or sounds) to the outside (e.g., a user), and can include one or more of a display, a speaker, etc. Also, the output device 108 can be any other device having an output function.

[0038] Exemplarily, an example electronic device for implementing the vehicle steering control method and device according to the embodiments of the present application can be implemented such as a smart vehicle terminal, etc.

[0039] Next, a vehicle steering control method 200 according to an embodiment of the present application will be described with reference to FIG. 2. FIG. 2 shows a schematic flowchart of the vehicle steering control method 200 according to an embodiment of the present application. As shown in FIG. 2, the vehicle steering control method 200 according to an embodiment of the present application can include the following steps:

[0040] In step S210, a rear axle motor target torque and a rear axle base differential torque are obtained based on state information of the vehicle.

[0041] In step S220, a left rear motor target torque and a right rear motor target torque are obtained based on the rear axle base differential torque and the rear axle motor target torque, for being applied to left and right rear drive motors of the vehicle, so as to control the vehicle to steer.

[0042] In the embodiments of the present application, when the vehicle needs to steer while driving, first, the state information of the vehicle under the current driving condition needs to be obtained, which represents the parameter information collected by the sensors of the active parts of the vehicle. The rear axle motor target torque and the rear axle base differential torque can be obtained through the parameter information in the state information of the vehicle, and the left rear motor target torque and the right rear motor target torque of the vehicle can be calculated respectively through the rear axle base differential torque and the rear axle motor target torque. The left rear motor target torque and the right rear motor target torque are applied to the left and right rear drive motors of the vehicle respectively, so as to control the vehicle to steer. By outputting different torques (i.e., the left rear motor target torque and the right rear motor target torque) through the left and right rear wheel motors (i.e., the left rear drive motor and the right rear drive motor) of the vehicle, the control ability of the vehicle body posture is enhanced, and the turning radius of the vehicle is reduced.

[0043] Therefore, the vehicle steering control method 200 according to the embodiments of the present application controls the vehicle to steer by confirming that the vehicle auxiliary steering function has entered the activated state, obtaining the left rear motor target torque and the right rear motor target torque, and applying the left rear motor target torque and the right rear motor target torque to the left and right rear drive motors of the vehicle respectively. By outputting different torques through the left and right rear drive motors of the vehicle, the control ability of the vehicle body posture is enhanced, the turning radius of the vehicle is further reduced, and the wear of the vehicle tires is avoided.

[0044] In the embodiments of the present application, obtaining the rear axle motor target torque and the rear axle basic differential torque based on the state information of the vehicle in step S210 comprises: obtaining the state information of the vehicle, determining the state of the vehicle auxiliary steering function based on the state information; when the vehicle auxiliary steering function enters the activated state, obtaining the rear axle motor target torque and the rear axle basic differential torque based on the state information. Specifically, when the vehicle needs to turn during driving, normal turning or lane changing, the vehicle can smoothly complete in the normal state, however, when the vehicle turns in a narrow road space, the ordinary normal vehicle steering is limited by the too large turning diameter and cannot complete the steering, especially when the vehicle turns in a place with many vehicles, the driver needs to adjust the vehicle posture many times due to the surrounding environmental factors, which easily causes road traffic congestion and driving safety problems, so it is necessary to reduce the turning radius of the vehicle to solve the problem. When the vehicle needs to turn, at this time the user can turn on the auxiliary steering function through the multimedia host switch on the vehicle, at this time the vehicle control unit (VCU) accepts the instruction of turning on the auxiliary steering function. Then the state of the vehicle auxiliary steering function needs to be determined, the state of the vehicle auxiliary steering function is determined by the state information collected by the vehicle control unit in the current driving state. When the vehicle auxiliary steering function is in the activated state, the rear axle motor target torque and the rear axle basic differential torque can be obtained through the plurality of state information collected by the vehicle control unit. The rear axle motor target torque is the torque required by the rear axle of the vehicle when the vehicle turns according to the intention of the driver.

[0045] In embodiments of the present application, the state information of the vehicle comprises at least one of the following: steering wheel angle, brake depth, vehicle speed, gear information, slope, and throttle depth. Specifically, the steering wheel angle is used to realize the steering of the wheels of the vehicle, and the steering wheel angle can generally rotate 360 degrees, but according to different vehicle models and designs, it can sometimes rotate more. In actual driving, there is a certain proportional relationship between the steering wheel angle and the turning angle of the wheels, and in general, the steering wheel rotates one circle, and the turning angle of the wheels is about 40 to 42 degrees, and in certain driving conditions, such as turning in a narrow space, the angle of the steering wheel may need to be adjusted to be larger, for example, more than one circle, i.e. about 270 degrees, to adapt to the specific driving needs. The brake depth refers to the depth of the brake pedal of the vehicle being stepped down by the driver, and is used to reduce the speed of the vehicle; the throttle depth refers to the depth of the throttle pedal of the vehicle being stepped down by the driver, and the deeper the throttle depth, the faster the speed of the vehicle and the faster the engine speed; the gear information refers to the gear state of the vehicle, and the gears of the vehicle generally have a parking gear (i.e. P gear), at which time the wheels are in a mechanical lock state to prevent rolling, a reverse gear (i.e. R gear) which is used when the vehicle needs to reverse, a neutral gear (i.e. N gear) which is used when temporarily stopping (such as a red light), a forward gear (i.e. D gear) which is used when the vehicle is moving forward; the vehicle slope refers to the slope information of the flat ground at this time. Of course, the state information of the vehicle can also be other suitable vehicle parameter information, for example, steering wheel torque, road adhesion coefficient, etc. The state information can be one or more of the above listed state information, which is not specifically limited. The state information of the vehicle can be obtained through sensors inside the vehicle (such as a vehicle speed sensor, a steering wheel angle sensor, etc.).

[0046] In the embodiments of the present application, based on the state information, the vehicle auxiliary steering function state is determined. Specifically, the vehicle auxiliary steering function state is divided into multiple function states, including: a closed state, a standby state, an activated state and a quit state. In one example, the OK indicator light of the vehicle is OK, the front motor control module, the left rear motor control module and the right rear motor control module motor allow open wave flags are allowed, the front motor control module, the left rear motor control module and the right rear motor control module speed effective flag bits are valid, the front motor control module, the left rear motor control module and the right rear motor control module maximum torque effective flag bits are valid, the drive motor transmission ratio fault state is fault-free, the steering wheel angle effective flag bit is valid, the steering wheel angle calibration flag bit is calibrated, the vehicle speed signal state is fault-free, the brake depth effective flag is valid, the gear system state is normal, the left rear wheel angle and the right rear wheel angle effective flag are valid, then the vehicle auxiliary steering function is in standby state at this time; when the steering wheel angle meets a certain angle threshold, the brake depth meets a certain depth threshold, the vehicle speed meets a certain speed threshold, the throttle depth meets a certain throttle depth threshold, and some vehicle state information such as gear information is in forward gear, all meet the conditions, then it is determined that the vehicle brake function state is in activated state at this time; when some of the above vehicle state information does not meet the condition and the duration meets a certain time threshold, then the vehicle auxiliary steering function state is in the quit state.

[0047] In the embodiments of the present application, the vehicle auxiliary steering function state is in the active state, and the condition for the vehicle auxiliary steering function being in the active state is one or more of the following: the steering wheel angle is greater than a first angle threshold, and the rear wheel angle is greater than a second angle threshold, wherein the rear wheel angle is obtained based on the steering wheel angle; the brake depth is less than a brake depth threshold; the vehicle speed is less than a vehicle speed threshold; the gear information is in the forward gear; the slope is less than a slope threshold; and the throttle depth is greater than a throttle threshold. In some examples, the steering wheel angle can be 400°, 450°, 500°, or any other suitable steering wheel angle, without being limited thereto; the brake depth of the vehicle needs to be less than a certain threshold, and the vehicle needs to reduce the speed when steering, so the brake depth needs to meet a certain brake depth; when the vehicle is steering, it is generally necessary to reduce the speed when turning to avoid traffic accidents, so the vehicle speed needs to be less than a certain value, for example, the vehicle speed can be less than 10 km / h when steering, or any other suitable vehicle speed, without being limited thereto; the gear information is the gear state of the vehicle, and the gear of the vehicle generally has a parking gear (i.e., P gear), at which time the wheels are in a mechanical lock state to prevent rolling, a reverse gear (i.e., R gear) which is used when the vehicle needs to reverse, a neutral gear (i.e., N gear) which is used when temporarily stopping (such as a red light), a forward gear (i.e., D gear) which is used when the vehicle is moving forward; the slope refers to the slope information of the road on which the vehicle is currently driving; and the throttle depth refers to the depth of the accelerator pedal of the vehicle being stepped down by the driver, and the greater the throttle depth, the faster the vehicle speed, so the throttle depth needs to be kept at a small value when turning.

[0048] In this embodiment, since the auxiliary steering function of the vehicle is turned on, the rear wheel steering system (RWS) function of the vehicle is also turned on synchronously, and when the user of the vehicle steering system operates the steering wheel, the front wheels of the vehicle will rotate with the steering wheel angle changing, and the rear wheel steering system will control the left and right rear wheels of the vehicle to steer at the same time, and real-time feedback the actual steering angle and state of the rear wheels to the vehicle control module. The following will be described with reference to FIG. 3. As shown in FIG. 3, the rear wheels of the vehicle adopt the same direction of the front and rear wheels to adjust the steering center to reduce the turning radius. For example, when the steering wheel is turned to the left by a certain angle, the front wheels of the vehicle will turn to the left by a certain angle according to the steering angle, and the rear wheels of the vehicle will also turn to the left by a certain angle under the control of the rear wheel steering system. When the steering wheel is turned to the right by a certain angle, the front wheels of the vehicle will turn to the right by a certain angle according to the steering angle, and the rear wheels of the vehicle will also turn to the right by a certain angle under the control of the rear wheel steering system. The front wheel angle and the rear wheel angle are in a linear relationship, and in an example, the linear relationship can be the ratio of the maximum front wheel angle and the maximum rear wheel angle. The rear wheel angle is obtained by looking up the table according to the relationship table of the vehicle speed and the steering wheel, and is fed back to the vehicle control module in real time. When the rear wheel angle reaches a certain angle, and some state information collected by the front vehicle meets the activation state condition, the auxiliary steering function of the vehicle is activated at this time.

[0049] In the embodiment of the present application, the rear axle basic differential torque is obtained based on the state information in step S210, which includes obtaining the rear axle basic differential torque based on the steering wheel angle and the preset relationship table in the state information. Wherein, the rear axle basic differential torque is obtained based on the steering wheel angle and the preset relationship table in the state information, which includes obtaining the rear axle basic differential torque based on the vehicle speed, the steering wheel angle and the first preset relationship table, and the first preset relationship table records the corresponding numerical relationship between the vehicle speed and the steering wheel angle and the rear axle basic differential torque. Specifically, when the steering wheel angle and the vehicle speed under the current driving condition are obtained by the steering wheel angle sensor and the vehicle speed sensor of the vehicle during the vehicle steering process, the steering torque refers to the torque currently applied to the steering wheel by the driver, which can be obtained by the steering torque sensor. When the absolute value of the steering wheel angle is greater than a certain angle threshold and the absolute value of the steering torque is greater than a certain torque threshold, the rear axle basic differential torque can be obtained by looking up the relationship table between the steering wheel angle and the vehicle speed (i.e. the first preset relationship table). For example, when the steering wheel angle is greater than or equal to 90 degrees and the steering torque is greater than or equal to 3 Nm, the rear axle basic differential torque is obtained by looking up the relationship table between the vehicle speed and the steering wheel angle; when the steering wheel angle is greater than 90 degrees, the steering torque is less than 1 Nm and the duration exceeds 100 ms, the rear axle basic differential torque is unloaded to 0 Nm according to the unloading slope table.

[0050] In the embodiments of the present application, the left rear motor target torque and the right rear motor target torque based on the rear axle basic differential torque and the rear axle motor target torque in step S220 include: obtaining a vehicle rotation direction, a left rear wheel torque coefficient and a right rear wheel torque coefficient; obtaining a left rear wheel compensation torque based on a relationship of the rear axle basic differential torque, the vehicle rotation direction and the left rear wheel torque coefficient; obtaining a right rear wheel compensation torque based on a relationship of the rear axle basic differential torque, the vehicle rotation direction and the right rear wheel torque coefficient; obtaining the left rear motor target torque based on the left rear wheel compensation torque and the rear axle motor target torque, and obtaining the right rear motor target torque based on the right rear wheel compensation torque and the rear axle motor target torque. Wherein, the left rear wheel compensation torque obtained based on the relationship of the rear axle basic differential torque, the vehicle rotation direction and the left rear wheel torque coefficient is obtained based on the rear axle basic differential torque, the vehicle rotation direction, a brake attenuation coefficient, the left rear wheel torque coefficient and a slope attenuation coefficient; and the right rear wheel compensation torque obtained based on the relationship of the rear axle basic differential torque, the vehicle rotation direction and the right rear wheel torque coefficient is obtained based on the rear axle basic differential torque, the vehicle rotation direction, the brake attenuation coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient.

[0051] Specifically, the vehicle rotation direction can be obtained through vehicle state information, and the brake attenuation coefficient, the left rear wheel torque coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient can be obtained by table lookup. Then, the left rear wheel compensation torque is obtained based on the rear axle basic differential torque, the vehicle rotation direction, the brake attenuation coefficient, the left rear wheel torque coefficient and the slope attenuation coefficient; and the right rear wheel compensation torque is obtained based on the rear axle basic differential torque, the vehicle rotation direction, the brake attenuation coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient.

[0052] In this embodiment, it is set that the driver turns left, the turning direction of the vehicle is positive, the driver turns right, the turning direction of the vehicle is negative, the left rear wheel compensation torque is the opposite of the product of the rear axle basic differential torque, the turning direction of the vehicle, the brake attenuation coefficient, the left rear wheel torque coefficient and the slope attenuation coefficient, and the right rear wheel compensation torque is the product of the rear axle basic differential torque, the turning direction of the vehicle, the brake attenuation coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient. When the vehicle turns left, the turning direction of the vehicle is positive, the left rear wheel compensation torque obtained by the left rear wheel compensation torque is the opposite of the product of the rear axle basic differential torque, the turning direction of the vehicle, the brake attenuation coefficient, the left rear wheel torque coefficient and the slope attenuation coefficient is negative, and the right rear wheel compensation torque obtained by the right rear wheel compensation torque is positive. In another example, it can also be set that the driver turns right, the turning direction of the vehicle is positive, the driver turns left, the turning direction of the vehicle is negative, at this time the left rear wheel compensation torque is the product of the rear axle basic differential torque, the turning direction of the vehicle, the brake attenuation coefficient, the left rear wheel torque coefficient and the slope attenuation coefficient, and the right rear wheel compensation torque is the opposite of the product of the rear axle basic differential torque, the turning direction of the vehicle, the brake attenuation coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient.

[0053] Specifically, in one example, when the vehicle turns left, taking the vehicle turning left as positive and turning right as negative as reference, the left rear motor target torque is obtained according to the sum of the left rear wheel compensation torque and one half of the rear axle motor target torque, and the left rear wheel torque is reduced because the left rear wheel compensation torque is negative; the right rear motor target torque is obtained according to the sum of the right rear wheel compensation torque and one half of the rear axle motor target torque, and the right rear wheel torque is increased because the right rear wheel compensation torque is positive; that is, when the vehicle turns left, the auxiliary steering function state is activated and the rear wheel angle meets the angle condition, the vehicle turning radius is reduced by reducing the left rear wheel torque and increasing the right rear wheel torque, and the tire wear is also reduced. When the vehicle turns right, the same is true, the vehicle turning radius is reduced by reducing the right rear wheel torque and increasing the left rear wheel torque. In another example, the vehicle rear wheel torque distribution when the driver turns right, the turning direction of the vehicle is positive, and the driver turns left, the turning direction of the vehicle is negative can also be set in the same principle as the vehicle wheel torque when the driver turns left, the turning direction of the vehicle is positive, and the driver turns right, the turning direction of the vehicle is negative, and this will not be specifically described.

[0054] In the embodiments of the present application, the braking attenuation coefficient, the left rear wheel torque coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient are obtained, comprising: obtaining the braking attenuation coefficient based on the braking depth of the state information and a second preset relationship table, wherein the second preset relationship table records the corresponding numerical relationship between the braking depth and the braking attenuation coefficient; obtaining the slope attenuation coefficient based on the slope of the state information and a third preset relationship table, wherein the third preset relationship table records the corresponding numerical relationship between the slope and the slope attenuation coefficient; obtaining the left rear wheel torque coefficient and the right rear wheel torque coefficient based on the rear axle basic differential torque and a fourth preset relationship table, wherein the fourth preset relationship table records the corresponding numerical relationship between the rear axle basic differential torque and the left rear wheel torque coefficient and the right rear wheel torque. Specifically, before calculating the left rear wheel compensation torque and the right rear wheel compensation torque, the braking attenuation coefficient, the left rear wheel torque coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient also need to be obtained. The braking attenuation coefficient refers to the change relationship of the braking force with time, which describes the persistence and stability of the braking force of the braking system during operation, and is obtained by table lookup based on the collected braking depth and the preset relationship table (i.e. the second preset relationship table); the slope attenuation coefficient is obtained by table lookup based on the collected slope and the preset table (i.e. the third preset relationship table); the left rear wheel torque coefficient and the right rear wheel torque coefficient are obtained by table lookup based on the previously calculated rear axle basic differential torque and the preset relationship table (i.e. the fourth preset relationship table). The left rear wheel compensation torque and the right rear wheel compensation torque are calculated based on the obtained braking attenuation coefficient, the left rear wheel torque coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient, and the left rear motor target torque and the right rear motor target torque are obtained based on the calculated left rear wheel compensation torque and the right rear wheel compensation torque. The left rear motor target torque and the right rear motor target torque are applied to the left rear drive motor and the right rear drive motor of the vehicle respectively, so as to reduce the turning radius of the vehicle during turning.

[0055] In the embodiments of the present application, the front axle motor target torque is obtained based on the state information, and the front axle motor target torque is applied to the front drive motor of the vehicle. Specifically, the front axle motor target torque of the vehicle, i.e. the front axle motor demand torque of the vehicle during turning, is obtained based on the state information of the vehicle according to the intention of the driver. In one example, as shown in FIG. 4, when the vehicle auxiliary steering function satisfies the active state, the rear wheel angle of the vehicle in the active state also satisfies a certain angle threshold (i.e. the second angle threshold). The rear wheel angle of the vehicle is controlled by independent left rear wheel steering gear and right rear wheel steering gear. The obtained front axle motor target torque is applied to the front drive motor, wherein the front drive motor controls the front wheel of the vehicle; the obtained left rear motor target torque and the right rear motor target torque are applied to the left rear drive motor and the right rear drive motor respectively, wherein the left rear drive motor and the right rear drive motor control the left rear wheel and the right rear wheel of the vehicle respectively, so as to control the turning of the vehicle.

[0056] In the embodiments of the present application, the method further comprises zero-crossing smoothing and torque limiting processing on the front axle motor target torque, the left rear motor target torque and the right rear motor target torque; and the processed front axle motor target torque, left rear motor target torque and right rear motor target torque are respectively applied to the front wheel, left rear wheel and right rear wheel of the vehicle to make the vehicle turn smoothly. For example, when the vehicle is running on a poor road, the vehicle may vibrate due to the road bumps when running, which may cause torque mutation and affect the smoothness and reliability of the vehicle. Therefore, the torque needs to be subjected to zero-crossing smoothing and torque limiting processing to achieve smooth running of the vehicle and improve the riding experience.

[0057] Therefore, according to the vehicle turning control method of the embodiments of the present application, the left rear motor target torque and the right rear motor target torque are obtained by confirming that the vehicle auxiliary turning function has entered the activated state, and the left rear motor target torque and the right rear motor target torque are respectively applied to the left rear drive motor and the right rear drive motor of the vehicle to control the vehicle to turn. The different torques output by the left rear drive motor and the right rear drive motor of the vehicle enhance the control ability of the vehicle body posture, greatly reduce the turning radius of the vehicle, and avoid tire wear of the vehicle.

[0058] The vehicle turning control device according to another aspect of the present application is described below in conjunction with FIG. 5. FIG. 5 shows a schematic structural block diagram of a vehicle turning control device 500 according to an embodiment of the present application. As shown in FIG. 5, the vehicle turning control device 500 comprises a memory 510 and a processor 520, wherein the memory 510 stores a computer executable program run by the processor 520, and the computer executable program, when run by the processor 520, causes the processor 520 to execute the vehicle turning control method 200 described above. Those skilled in the art can understand the structure and specific operations of each module in the vehicle turning control device 500 according to the embodiments of the present application in conjunction with the foregoing description, and for the sake of brevity, will not be described here. Therefore, according to the vehicle turning device of the embodiments of the present application, the left rear motor target torque and the right rear motor target torque are obtained by confirming that the vehicle auxiliary turning function has entered the activated state, and the left rear motor target torque and the right rear motor target torque are respectively applied to the left rear drive motor and the right rear drive motor of the vehicle to control the vehicle to turn. The different torques output by the left rear drive motor and the right rear drive motor of the vehicle enhance the control ability of the vehicle body posture, greatly reduce the turning radius of the vehicle, and avoid tire wear of the vehicle.

[0059] In addition, according to the embodiments of the present application, a vehicle is also provided, which can comprise the vehicle turning control device 500 described above.

[0060] Further, the present application also provides a storage medium having stored thereon a computer program, which, when executed by a processor, causes the processor to perform the vehicle steering control method 200 according to the embodiments of the present application described above. The storage medium may, for example, include a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a personal computer, a read only memory (ROM), an erasable programmable read only memory (EPROM), a compact disc read only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer readable storage medium can be any combination of one or more computer readable storage media.

[0061] Further, the present application also provides a computer program having stored thereon a computer program, which, when executed by a processor, causes the processor to perform the vehicle steering control method 200 described above.

[0062] Based on the above description, the vehicle steering control method, device and vehicle according to the embodiments of the present application control the vehicle to steer by confirming that the vehicle auxiliary steering function has entered an activated state, obtaining a left rear motor target torque and a right rear motor target torque, and applying the left rear motor target torque and the right rear motor target torque to the left rear drive motor and the right rear drive motor of the vehicle, respectively. The use of the left rear drive motor and the right rear drive motor of the vehicle to output different torques enhances the control ability of the vehicle body posture, and greatly reduces the turning radius of the vehicle, thereby avoiding the wear of the vehicle tires.

[0063] Although the example embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the example embodiments are exemplary and are not intended to limit the scope of the present application. Those of ordinary skill in the art can make various changes and modifications without departing from the scope and spirit of the present application. All such changes and modifications are intended to be included within the scope of the present application as claimed in the appended claims.

[0064] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in connection with the embodiments disclosed herein can be realized by electronic hardware, or a combination of computer software and electronic hardware. Whether the functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Those of ordinary skill in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0065] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the above-described device embodiments are illustrative. The division into units is, for example, a logical function division. Actual implementation can have another division manner. For example, a plurality of units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0066] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the application can be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been described in detail in order to not obscure the understanding of this description.

[0067] Similarly, it is to be understood that the mechanical details of the various features of the application are sometimes grouped together in a single embodiment, figure or description of related embodiments in this disclosure. However, this method of disclosure should not be interpreted as reflecting an intention that the application requires more features than are explicitly recited in each claim. Rather, inventive aspects lie in less than all features of any single disclosed embodiment. Thus, the claims at the end of the detailed description are to be read in conjunction with the corresponding specification, and are to be given their broadest interpretation. In this regard, each claim is to be interpreted to include alternative embodiments of the invention falling within the scope of the claim.

[0068] Those skilled in the art will appreciate that all features described in this specification (including the summary of the application, abstract and drawings) and / or all processes or steps described in any method or process disclosed herein can be combined in any combination. Each feature disclosed in this specification (including the summary of the application, abstract and drawings), can be replaced by alternative features serving the same, equivalent or a similar purpose, unless expressly stated otherwise.

[0069] Furthermore, those skilled in the art will recognize that references in this specification to "one embodiment", "an embodiment", "an example embodiment", "some embodiments", and the like, are not intended to be interpreted as meaning that each and every embodiment described herein is the same or identical. Further, although process steps, algorithms or operations can be described in a sequential order, in some embodiments, unless explicitly stated otherwise, certain process steps, algorithms or operations can be skipped, reversed, or performed concurrently.

[0070] The various component embodiments of the present application can be implemented in hardware, or as software modules running in one or more processors, or in combinations thereof. As will be appreciated by one skilled in the art, a microprocessor or digital signal processor (DSP) can be used in practice to implement some or all of the functionality of some of the modules according to embodiments of the present application. The present application can also be implemented as a program (for example, a computer program and computer program product) for executing any one of the methods described herein on a computer. Such a program can be stored on a computer readable medium, or can be in the form of one or more signals. Such a signal can be downloaded from an Internet website, or can be available for copying from a carrier medium. The present application can also be implemented as a computer data signal embodied in a carrier wave, a data signal being a product of a transitory signal per se.

[0071] It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that one skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word 'comprising' does not exclude the presence of elements or steps other than those listed in a claim. The word 'a' or 'an' preceding an element does not exclude the presence of a plurality of such elements. The application can be implemented by means of both hardware and software, and any combination thereof.

[0072] The above description is only specific embodiments of the present application or specific explanations of the specific embodiments, and the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, and all such changes or replacements should be covered within the protection scope of the present application. The protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A vehicle steering control method in which, The method comprises: obtaining a rear axle motor target torque and a rear axle base differential torque based on state information of a vehicle; and obtaining a left rear motor target torque and a right rear motor target torque based on the rear axle base differential torque and the rear axle motor target torque, for applying to a left rear drive motor and a right rear drive motor of the vehicle, so as to control the vehicle to steer.

2. The method of claim 1, wherein, The obtaining of the rear axle base differential torque based on state information of a vehicle comprises: obtaining the rear axle base differential torque based on a steering wheel angle in the state information and a preset relationship table.

3. The method of claim 2, wherein, The obtaining of the rear axle base differential torque based on a steering wheel angle in the state information and a preset relationship table comprises: obtaining the rear axle base differential torque based on a vehicle speed, the steering wheel angle in the state information and a first preset relationship table, wherein the first preset relationship table records a corresponding numerical relationship between the vehicle speed and the steering wheel angle and the rear axle base differential torque.

4. The method according to any one of claims 1 to 3, wherein, The obtaining of the left rear motor target torque and the right rear motor target torque based on the rear axle base differential torque and the rear axle motor target torque comprises: obtaining a vehicle rotation direction, a left rear wheel torque coefficient and a right rear wheel torque coefficient; obtaining a left rear wheel compensation torque based on a relationship between the rear axle base differential torque, the vehicle rotation direction and the left rear wheel torque coefficient, and obtaining a right rear wheel compensation torque based on a relationship between the rear axle base differential torque, the vehicle rotation direction and the right rear wheel torque coefficient; and obtaining the left rear motor target torque based on the left rear wheel compensation torque and the rear axle motor target torque, and obtaining the right rear motor target torque based on the right rear wheel compensation torque and the rear axle motor target torque.

5. The method of claim 4, wherein, The obtaining of the left rear wheel compensation torque based on a relationship between the rear axle base differential torque, the vehicle rotation direction and the left rear wheel torque coefficient, and the obtaining of the right rear wheel compensation torque based on a relationship between the rear axle base differential torque, the vehicle rotation direction and the right rear wheel torque coefficient, comprise: obtaining a brake attenuation coefficient and a slope attenuation coefficient; obtaining the left rear wheel compensation torque based on the rear axle base differential torque, the vehicle rotation direction, the brake attenuation coefficient, the left rear wheel torque coefficient and the slope attenuation coefficient; and obtaining the right rear wheel compensation torque based on the rear axle base differential torque, the vehicle rotation direction, the brake attenuation coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient.

6. The method of claim 5, wherein, The obtaining of the brake attenuation coefficient and the slope attenuation coefficient comprises: obtaining the brake attenuation coefficient based on a brake depth of the state information and a second preset relationship table, wherein the second preset relationship table records a corresponding numerical relationship between the brake depth and the brake attenuation coefficient; and obtaining the slope attenuation coefficient based on a slope of the state information and a third preset relationship table, wherein the third preset relationship table records a corresponding numerical relationship between the slope and the slope attenuation coefficient.

7. The method according to any one of claims 4-6, wherein, The obtaining of the left rear wheel torque coefficient and the right rear wheel torque coefficient comprises: The left rear wheel torque coefficient and the right rear wheel torque coefficient are obtained based on the rear axle basic differential torque and a fourth preset relationship table, wherein the fourth preset relationship table records a corresponding numerical relationship between the rear axle basic differential torque and the left rear wheel torque coefficient and the right rear wheel torque coefficient.

8. The method of any one of claims 1-7, wherein, The rear axle motor target torque and the rear axle basic differential torque are obtained based on the state information of the vehicle, including: obtaining state information of the vehicle; determining a state of a vehicle auxiliary steering function based on the state information; and when the vehicle auxiliary steering function enters an active state, obtaining the rear axle motor target torque and the rear axle basic differential torque based on the state information.

9. The method of any one of claims 1-8, wherein, The method further includes: obtaining a front axle motor target torque based on the state information, and applying the front axle motor target torque to a front drive motor of the vehicle.

10. The method of claim 9, wherein, The method further includes: performing zero-crossing smoothing and torque limiting processing on the front axle motor target torque, the left rear motor target torque, and the right rear motor target torque; and applying the processed front axle motor target torque, the processed left rear motor target torque, and the processed right rear motor target torque to the front drive motor, the left rear drive motor, and the right rear drive motor, respectively, to make the vehicle steering smooth.

11. The method of claim 9, wherein, The state information includes at least one of the following: steering wheel angle, brake depth, vehicle speed, gear information, slope, and throttle depth.

12. The method of claim 11, wherein, The conditions for the vehicle auxiliary steering function to be in the active state include one or more of the following: the steering wheel angle is greater than a first angle threshold, and a rear wheel angle is greater than a second angle threshold, wherein the rear wheel angle is obtained based on the steering wheel angle; the brake depth is less than a brake depth threshold; the vehicle speed is less than a vehicle speed threshold; the gear information is a forward gear; the slope is less than a slope threshold; and the throttle depth is greater than a throttle threshold.

13. A vehicle steering control device, wherein, The device includes a memory and a processor, wherein the memory has computer executable instructions stored thereon for execution by the processor, and the computer executable instructions, when executed by the processor, cause the processor to perform the vehicle steering control method of any one of claims 1-12.

14. A vehicle, wherein, The vehicle includes the vehicle steering control device of claim 13.

15. A storage medium, wherein, The storage medium has computer instructions stored thereon for execution by a processor, and the computer instructions, when executed by the processor, cause the processor to perform the vehicle steering control method of any one of claims 1-12.

16. A computer program comprising instructions wherein, The computer instructions, when executed by the processor, cause the processor to perform the vehicle steering control method of any one of claims 1-12.

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