Vehicle steering control method and device and vehicle

Abstract

The invention discloses a vehicle steering control method and device and a vehicle. The method comprises the steps that a rear axle motor target torque and a rear axle basic differential torque are obtained based on state information of the vehicle; and based on the rear axle basic differential torque and the rear axle motor target torque, a left rear motor target torque and a right rear motor target torque are obtained to be applied to a left rear driving motor and a right rear driving motor of the vehicle, and therefore the vehicle is controlled to steer. According to the method, the device and the vehicle, the target torque of a left rear motor and the target torque of a right rear motor act on a left rear driving motor and a right rear driving motor of the vehicle correspondingly, and the vehicle is controlled to steer. The left rear driving motor and the right rear driving motor of the vehicle are used for outputting different torques, so that the control capacity for the vehicle body posture is enhanced, the turning radius of the vehicle is greatly reduced, and vehicle tire abrasion is avoided.

Description

Technical Field

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

[0002] Vehicles usually need to turn while driving. Traditional steering is achieved by the driver manipulating the steering wheel to control the front wheel angle, and the vehicle has a large turning radius. For vehicles that need to turn on narrow roads, ordinary normal steering is limited by the large turning diameter and cannot be completed. Especially when turning in places with many vehicles, the driver needs to adjust the vehicle posture many times due to surrounding environmental factors, which can easily cause road traffic congestion and may cause scratches with surrounding objects or pedestrians, causing damage to people or property. Therefore, it is necessary to develop functions for turning and passing to reduce the turning radius to improve vehicle maneuverability.

[0003] In the related art, a target wheel to be braked is determined from multiple rear wheels of the vehicle, and 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. The inner rear wheel of the vehicle is braked through unilateral clamping to control it within a set slip rate and reduce the turning radius of the vehicle. However, this method causes great wear on the vehicle tires and is limited in application scenarios. Summary of the invention

[0004] 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, the method comprising: obtaining a rear axle motor target torque and a rear axle basic differential torque based on vehicle state information; 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 the left rear drive motor and the right rear drive motor of the vehicle, thereby controlling the vehicle to steer.

[0005] In one embodiment of the present application, obtaining a rear axle basic differential torque based on vehicle status information includes: obtaining the rear axle basic differential torque based on a steering wheel angle in the status information and a preset relationship table.

[0006] In one embodiment of the present application, the rear axle basic differential torque is obtained based on the steering wheel angle in the status information and a preset relationship table, including: obtaining the rear axle basic differential torque based on the vehicle speed in the status information, the steering wheel angle and a first preset relationship table, wherein 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.

[0007] In one embodiment of the present application, the left rear motor target torque and the right rear motor target torque are obtained based on the rear axle basic differential torque and the rear axle motor target torque, including: acquiring the vehicle rotation direction, the left rear wheel torque coefficient and the right rear wheel torque coefficient; 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 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; 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.

[0008] In one embodiment of the present application, the left rear wheel compensation torque is obtained based on the relationship between the rear axle basic differential torque, the vehicle rotation direction and the left rear wheel torque coefficient, and the right rear wheel compensation torque is obtained based on the relationship between the rear axle basic differential torque, the vehicle rotation direction and the right rear wheel torque coefficient, including: obtaining a braking 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 braking attenuation coefficient, the left rear wheel torque coefficient and the slope attenuation coefficient; obtaining the right rear wheel compensation torque based on the rear axle basic differential torque, the vehicle rotation direction, the braking attenuation coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient.

[0009] In one embodiment of the present application, obtaining the braking attenuation coefficient and the slope attenuation coefficient includes: obtaining the braking attenuation coefficient based on the braking depth of the status 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 status 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.

[0010] In one embodiment of the present application, obtaining the left rear wheel torque coefficient and the right rear wheel torque coefficient includes: 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 rear wheel torque coefficient and the right rear wheel torque.

[0011] In one embodiment of the present application, the rear axle motor target torque and the rear axle basic differential torque are obtained based on the vehicle status information, including: acquiring the vehicle status information; determining the status of the vehicle auxiliary steering function based on the status information; and when the vehicle auxiliary steering function enters an activated state, obtaining the rear axle motor target torque and the rear axle basic differential torque based on the status information.

[0012] In one embodiment of the present application, 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.

[0013] In one embodiment of the present application, the method also 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; 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 steer smoothly.

[0014] In one embodiment of the present application, the status information includes at least one of the following: steering wheel angle, braking depth, vehicle speed, gear information, slope, and throttle depth.

[0015] In one embodiment of the present application, the conditions for the vehicle assisted steering function to be activated include 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 braking depth is less than a braking 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.

[0016] According to another aspect of the present application, a vehicle steering control device is provided, the device comprising a processor and a memory, wherein the memory stores a computer executable program run by the processor, and when the computer executable program is run by the processor, the processor executes the above-mentioned vehicle steering control method.

[0017] According to yet another aspect of the present application, a vehicle is provided, comprising the above-mentioned vehicle steering control device.

[0018] According to another aspect of the present application, a storage medium is provided, on which a computer program executed by a processor is stored. When the computer program is executed by the processor, the processor executes the above-mentioned vehicle steering control method.

[0019] According to another aspect of the present application, a computer program is provided. When the computer program is executed by the processor, the processor executes the above-mentioned vehicle steering control method.

[0020] The vehicle steering control method, device and vehicle of the present application obtain the target torque of the left rear motor and the target torque of the right rear motor by confirming that the auxiliary steering function of the vehicle has entered the activated state, and apply the target torque of the left rear motor and the target torque of the right rear motor to the left rear drive motor and the right rear drive motor of the vehicle respectively to control the vehicle to steer. The control ability of the vehicle body posture is enhanced by using the different torques output by the left rear drive motor and the right rear drive motor of the vehicle, and the turning radius of the vehicle is greatly reduced, which avoids the wear of the vehicle tires. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0022] Figure 1 A schematic block diagram of an example electronic device of a vehicle steering control method and apparatus according to an embodiment of the present application is shown.

[0023] Figure 2 A schematic flow chart of a vehicle steering control method according to an embodiment of the present application is shown.

[0024] Figure 3 A schematic diagram of a vehicle showing vehicle steering according to an embodiment of the present application.

[0025] Figure 4 A schematic diagram of a vehicle showing another vehicle turning according to an embodiment of the present application.

[0026] Figure 5 A schematic structural block diagram of a vehicle steering control device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present application more obvious, the example embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only 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 work should fall within the scope of protection of the present application.

[0028] First, refer to Figure 1 An exemplary electronic device 100 for implementing the vehicle steering control method and apparatus according to the embodiments of the present invention is described.

[0029] like Figure 1 As shown, 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, and these components are interconnected through a bus system 110 and / or other forms of connection mechanisms (not shown). It should be noted that Figure 1 The components and structures of the electronic device 100 shown are merely exemplary and non-limiting. The electronic device may also have other components and structures as required.

[0030] The processor 102 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 100 to perform desired functions.

[0031] The storage device 104 may include one or more computer program products, and the computer program product may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 102 may run the program instructions to implement the client functions (implemented by the processor) and / or other desired functions in the embodiments of the present invention described below. Various applications and various data, such as various data used and / or generated by the application, may also be stored in the computer-readable storage medium.

[0032] The input device 106 may be a device used by a user to input instructions, and may include one or more of a keyboard, a mouse, a microphone, a touch screen, etc. In addition, the input device 106 may also be any interface for receiving information.

[0033] The output device 108 can output various information (such as images or sounds) to the outside (such as a user), and can include one or more of a display, a speaker, etc. In addition, the output device 108 can also be any other device with an output function.

[0034] For example, an example electronic device for implementing the vehicle steering control method and apparatus according to an embodiment of the present invention may be implemented as a smart vehicle terminal or the like.

[0035] Next, we will refer to Figure 2 To describe the vehicle steering control method 200 according to an embodiment of the present application. Figure 2 FIG. 2 shows a schematic flow chart of a vehicle steering control method 200 according to an embodiment of the present application. Figure 2 As shown, the vehicle steering control method 200 according to the embodiment of the present application may include the following steps:

[0036] In step S210 , the rear axle motor target torque and the rear axle basic differential torque are obtained based on the vehicle state information.

[0037] In step S220 , the left rear motor target torque and the right rear motor target torque are obtained based on the rear axle basic differential torque and the rear axle motor target torque, so as to be applied to the left rear drive motor and the right rear drive motor of the vehicle, thereby controlling the vehicle to steer.

[0038] In an embodiment of the present application, when the vehicle needs to turn while driving, it is first necessary to obtain the state information of the vehicle under the current driving conditions. The state information of the vehicle represents the parameter information collected by the sensors of some active parts of the vehicle while driving. The target torque of the rear axle motor and the basic differential torque of the rear axle can be obtained through the parameter information in the state information of the vehicle. Then, the target torque of the left rear motor and the target torque of the right rear motor of the vehicle can be calculated by the basic differential torque of the rear axle and the target torque of the rear axle motor respectively. The target torque of the left rear motor and the target torque of the right rear motor are applied to the left rear drive motor and the right rear drive motor of the vehicle respectively, so as to control the vehicle to turn. By outputting different torques (i.e., the target torque of the left rear motor and the target torque of the right rear motor) to the left and right rear wheel motors of the vehicle (i.e., the left rear drive motor and the right rear drive motor), the control ability of the vehicle body posture is enhanced and the turning radius of the vehicle is reduced.

[0039] Therefore, the vehicle steering control method 200 according to the embodiment of the present application obtains the target torque of the left rear motor and the target torque of the right rear motor by confirming that the auxiliary steering function of the vehicle has entered the activated state, and applies the target torque of the left rear motor and the target torque of the right rear motor to the left rear drive motor and the right rear drive motor of the vehicle respectively to control the vehicle to steer. The different torque outputs of the left rear drive motor and the right rear drive motor of the vehicle enhance the control ability of the vehicle body posture, further reduce the turning radius of the vehicle, and avoid wear of the vehicle tires.

[0040] In an embodiment of the present application, the rear axle motor target torque and the rear axle basic differential torque are obtained based on the vehicle state information in step S210, including: obtaining the vehicle state information, determining the state of the vehicle auxiliary steering function based on the state information; when the vehicle auxiliary steering function enters the activation state, the rear axle motor target torque and the rear axle basic differential torque are obtained based on the state information. Specifically, when the vehicle needs to turn during driving, the normal turning or lane change can be completed smoothly in the normal state. However, when the vehicle turns in a narrow road space, the ordinary normal vehicle steering is limited by the large turning diameter and cannot complete the turning. Especially when turning in places with many vehicles, the driver needs to call back the vehicle posture many times due to the surrounding environmental factors, which is easy to cause road traffic congestion and driving safety problems. Therefore, it is necessary to reduce the vehicle turning radius to solve this problem. When the vehicle needs to turn, the user can turn on the auxiliary steering function through the multimedia host switch on the vehicle. At this time, the vehicle's vehicle control unit (VCU) receives the instruction to turn on the auxiliary steering function. Next, it is necessary to judge the state of the vehicle auxiliary steering function. The state of the vehicle auxiliary steering function is determined by the state information collected by the vehicle controller of the vehicle in the current driving state. When the vehicle's assisted steering function is activated, the target torque of the rear axle motor and the basic differential torque of the rear axle can be obtained through multiple status information collected by the vehicle controller. The target torque of the rear axle motor is the torque required by the rear axle of the vehicle according to the driver's intention when the vehicle is turning.

[0041] In an embodiment of the present application, the status information of the vehicle includes 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 vehicle's wheels. The steering wheel angle can usually rotate 360 ​​degrees, but sometimes it can rotate more depending on the vehicle model and design. In actual driving, there is a certain proportional relationship between the steering wheel angle and the wheel angle. Normally, when the steering wheel rotates one circle, the wheel rotation angle is approximately between 40 degrees and 42 degrees. Under specific driving conditions, such as when turning in a narrow space, it may be necessary to adjust the steering wheel angle to a larger extent, such as rotating more than one circle, that is, about 270 degrees, to meet specific driving needs. Braking depth refers to the depth of the vehicle's brake pedal being stepped on by the driver, which is used to reduce the vehicle's speed; throttle depth refers to the depth of the vehicle's throttle pedal being stepped on by the driver. The deeper the throttle depth, the faster the vehicle's speed and the faster the engine speed; gear information refers to the gear status of the vehicle. The vehicle's gears generally include parking gear (also known as P gear), at which time the wheels are in a mechanically locked state to prevent slipping, reverse gear (also known as R gear) is used when the vehicle needs to reverse, neutral gear (also known as N gear), this gear is used when temporarily parking (such as a red light), and forward gear (also known as D gear) is used when the vehicle is moving forward; vehicle slope refers to the slope information of the flat ground where the vehicle is at this time. Of course, the vehicle's state information can also be other suitable vehicle parameter information, such as steering wheel torque, road adhesion coefficient, etc. The state information can be one or more of the state information listed above, and there is no specific limitation on this. The vehicle's state information can be obtained through sensors inside the vehicle (such as a speed sensor, a steering wheel angle sensor, etc.).

[0042] In an embodiment of the present application, the state of the vehicle's assisted steering function is determined based on the state information. Specifically, the vehicle's assisted steering function state is divided into multiple function states, including: an off state, a standby state, an activated state, and an exit state. In one example, the vehicle's OK indicator light is OK, the motor start-up flag of the front motor control module, the left rear motor control module, and the right rear motor control module is allowed, the front motor control module, the left rear motor control module, and the right rear motor control module speed valid flag is valid, the front motor control module, the left rear motor control module, and the right rear motor control module maximum torque valid flag is valid, the drive motor transmission ratio fault state is no fault, the steering wheel angle valid flag is valid, the steering wheel angle calibration flag is calibrated, the vehicle speed signal state is no fault, the braking depth valid flag is valid, the gear system If the system status is normal, the left rear wheel angle and the right rear wheel angle valid flags are valid, the vehicle auxiliary steering function is in the standby state at this time; when the steering wheel angle meets a certain angle threshold, the braking depth meets a certain depth threshold, the vehicle speed meets a certain speed threshold, the throttle depth meets a certain throttle depth threshold, the gear information is the forward gear and other vehicle status information all meet the conditions, then it is determined that the vehicle braking function status is the activated state at this time; when a condition in the above vehicle status information is not met and the duration meets a certain time threshold, the vehicle auxiliary steering function status is the exit state.

[0043] In the embodiment of the present application, the vehicle auxiliary steering function is in an activated state, and the conditions for the vehicle auxiliary steering function to be activated are one or more of the following: the steering wheel angle is greater than the first angle threshold, and the rear wheel angle is greater than the second angle threshold, wherein the rear wheel angle is obtained based on the steering wheel angle; the braking depth is less than the braking depth threshold; the vehicle speed is less than the vehicle speed threshold; the gear information is the forward gear; the slope is less than the slope threshold; the throttle depth is greater than the throttle threshold. In some examples, the steering wheel angle can be 400°, 450°, 500°, and of course it can also be other suitable steering wheel angles, which are not specifically limited; the braking depth of the vehicle needs to be less than a certain threshold, and the vehicle needs to reduce the speed when turning. The larger the braking depth, the smaller the speed, so a certain braking depth needs to be met; when the vehicle turns, it is usually necessary to reduce the speed to turn to avoid traffic accidents, so the speed needs to be less than a certain value, for example, the speed can be less than 10km / h when turning, or it can be other suitable speeds, which are not specifically limited; The gear information is the gear status of the vehicle. The gears of the vehicle generally include parking gear (also known as P gear), in which the wheels are in a mechanically locked state to prevent slipping, reverse gear (also known as R gear) is used when the vehicle needs to reverse, neutral gear (also known as N gear), used for temporary parking (such as a red light), and forward gear (also known as D gear), used when the vehicle is moving forward; slope refers to the slope information of the road the vehicle is traveling on at this time; throttle depth refers to the depth to which the driver presses the vehicle's accelerator pedal. The greater the throttle depth, the faster the vehicle speed. Therefore, the throttle depth needs to be kept at a small value when turning.

[0044] In this embodiment, after the auxiliary steering function of the vehicle is turned on, the rear wheel steering system (RearWheel Steer, RWS) function of the vehicle is turned on simultaneously. When the user operates the steering wheel to turn the vehicle, the front wheels of the vehicle will turn as the steering wheel angle changes. The rear wheel steering system controls the steering of the left and right rear wheels of the vehicle at the same time, and feeds back the actual steering angle and status of the rear wheels to the vehicle control module in real time. Figure 3 To describe the rotation of the front and rear wheels when the vehicle turns. Figure 3As shown, the rear wheels of the vehicle use 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 turns to the left by a certain angle, the front wheels of the vehicle turn to the left by a certain angle according to the steering wheel angle, and the rear wheels of the vehicle also turn to the left by a certain angle at the same time under the control of the rear wheel steering system; when the steering wheel turns to the right by a certain angle, the front wheels of the vehicle turn to the right by a certain angle according to the steering wheel angle, and the rear wheels of the vehicle also turn to the right by a certain angle at the same time under the control of the rear wheel steering system. The front wheel angle and the rear wheel angle are linearly related. In one example, this linear relationship can be the ratio of the maximum front wheel angle to the maximum rear wheel angle. The rear wheel angle is obtained by looking up the table based on the vehicle speed and steering wheel relationship table, and is fed back to the vehicle control module in real time. When the rear wheel angle reaches a certain angle, and some status information collected by the front vehicle meets the activation status conditions, the vehicle auxiliary steering function is activated.

[0045] In an embodiment of the present application, obtaining the rear axle basic differential torque based on the state information in step S210 includes: obtaining the rear axle basic differential torque based on the steering wheel angle in the state information and a preset relationship table. Wherein, obtaining the rear axle basic differential torque based on the steering wheel angle in the state information and the preset relationship table includes: obtaining the rear axle basic differential torque based on the vehicle speed, the steering wheel angle and the first preset relationship table in the state information, 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 conditions are obtained through the vehicle's steering process through the vehicle's steering wheel angle sensor and the vehicle speed sensor, the steering wheel torque refers to the torque currently applied by the driver to the steering wheel, which can be obtained through the steering wheel 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 wheel 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 (that is, the first preset relationship table). For example, when the steering wheel angle is greater than or equal to 90 degrees and the steering wheel torque is greater than or equal to 3Nm, the basic differential torque of the rear axle is obtained by looking up the relationship table between vehicle speed and steering wheel angle; when the steering wheel angle is greater than 90 degrees, the steering wheel torque is less than 1Nm and the duration exceeds 100ms, the basic differential torque of the rear axle is unloaded to 0Nm according to the unloading slope table.

[0046] In an embodiment of the present application, the left rear motor target torque and the right rear motor target torque are obtained based on the rear axle basic differential torque and the rear axle motor target torque in step S220, including: acquiring the vehicle rotation direction, the left rear wheel torque coefficient and the right rear wheel torque coefficient; 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; 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; 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. Among them, the relationship between the basic differential torque of the rear axle, the vehicle's rotation direction and the left rear wheel torque coefficient obtains the left rear wheel compensation torque, which is based on the basic differential torque of the rear axle, the vehicle's rotation direction, the braking attenuation coefficient, the left rear wheel torque coefficient and the slope attenuation coefficient to obtain the left rear wheel compensation torque; the relationship between the basic differential torque of the rear axle, the vehicle's rotation direction and the right rear wheel torque coefficient obtains the right rear wheel compensation torque, which is based on the basic differential torque of the rear axle, the vehicle's rotation direction, the braking attenuation coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient to obtain the right rear wheel compensation torque.

[0047] Specifically, the vehicle's rotation direction can be obtained through the vehicle state information, and the braking attenuation coefficient, the left rear wheel torque coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient can be obtained by looking up the table. Then, the left rear wheel compensation torque is obtained through the rear axle basic differential torque, the vehicle's rotation direction, the braking attenuation coefficient, the left rear wheel torque coefficient and the slope attenuation coefficient; the right rear wheel compensation torque is obtained through the rear axle basic differential torque, the vehicle's rotation direction, the braking attenuation coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient.

[0048] In this embodiment, it is assumed that when the driver turns the steering wheel to the left, the rotation direction of the vehicle is positive, and when the driver turns the steering wheel to the right, the rotation direction of the vehicle is negative. The left rear wheel compensation torque is the inverse of the product of the rear axle basic differential torque, the vehicle rotation direction, the braking attenuation coefficient, the left rear wheel torque coefficient and the slope attenuation coefficient; the right rear wheel compensation torque is the product of the rear axle basic differential torque, the vehicle rotation direction, the braking attenuation coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient. When the vehicle turns left, the vehicle rotation direction is positive, and the left rear wheel compensation torque obtained by the left rear wheel compensation torque being the inverse of the product of the rear axle basic differential torque, the vehicle rotation direction, the braking attenuation coefficient, the left rear wheel torque coefficient and the slope attenuation coefficient is a negative value; the right rear wheel compensation torque obtained by the right rear wheel compensation torque being the product of the rear axle basic differential torque, the vehicle rotation direction, the braking attenuation coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient is a positive value. In another example, it can also be set that when the driver steers right, the vehicle's turning direction is positive, and when the driver steers left, the vehicle's turning direction is negative. At this time, the left rear wheel compensation torque is the product of the rear axle basic differential torque, the vehicle's turning direction, the braking attenuation coefficient, the left rear wheel torque coefficient and the slope attenuation coefficient, and the right rear wheel compensation torque is the inverse of the product of the rear axle basic differential torque, the vehicle's turning direction, the braking attenuation coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient.

[0049] Specifically, in one example, when the vehicle turns left, the vehicle turns left as positive and turns right as negative as reference. At this time, 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. Since the left rear wheel compensation torque is a negative value, the left rear wheel torque is reduced; then 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. Since the right rear wheel compensation torque is a positive value, the right rear wheel torque is increased; 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, it is the same as when turning left. The vehicle turning radius is reduced by reducing the right rear wheel torque and increasing the left rear wheel torque. In another example, the rear wheel torque distribution of the vehicle can be set so that when the driver steers right, the vehicle's turning direction is positive, and when the driver steers left, the vehicle's turning direction is negative. The principle is the same as setting the vehicle's wheel torque situation so that when the driver steers left, the vehicle's turning direction is positive, and when the driver steers right, the vehicle's turning direction is negative. This will not be elaborated on in detail.

[0050] In the embodiment 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, including: obtaining the braking attenuation coefficient based on the braking depth of the state information and the 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 the 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 the fourth preset relationship table, wherein the fourth preset relationship table records the corresponding numerical relationship between the rear axle basic differential torque and the 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 need to be obtained. Among them, the braking attenuation coefficient refers to the relationship between the braking force and time, which describes the continuity and stability of the braking force of the braking system during operation. The braking attenuation coefficient is obtained by looking up the collected braking depth and the preset relationship table (i.e., the second preset relationship table); the slope attenuation coefficient is obtained by looking up 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 looking up the rear axle basic differential torque calculated previously 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 by the obtained braking attenuation coefficient, the left rear wheel torque coefficient, the right rear wheel torque coefficient and the slope attenuation coefficient, and then the left rear motor target torque and the right rear motor target torque can be obtained according to 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 when the vehicle turns.

[0051] In an embodiment 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 is also the front axle motor required torque of the vehicle according to the driver's intention when the vehicle turns, which is obtained through the vehicle state information. In one example, Figure 4 As shown, when the vehicle auxiliary steering function meets the activation state, the rear wheel steering angle of the vehicle in the activation state also meets a certain angle threshold (i.e., the second angle threshold). The rear wheel steering angle of the vehicle is controlled by an independent left rear wheel steering gear and a right rear wheel steering gear, and the obtained front axle motor target torque is applied to the front drive motor, wherein the front drive motor controls the front wheels of the vehicle; the obtained left rear motor target torque and 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 respectively control the left rear wheel and the right rear wheel of the vehicle, thereby controlling the steering of the vehicle.

[0052] In an embodiment of the present application, the method further includes performing zero-smoothing and torque limiting processing on the target torque of the front axle motor, the target torque of the left rear motor, and the target torque of the right rear motor; applying the processed target torque of the front axle motor, the target torque of the left rear motor, and the target torque of the right rear motor to the front wheel, the left rear wheel, and the right rear wheel of the vehicle, respectively, so as to make the vehicle steer smoothly. For example, when the road condition of the vehicle is poor, due to the bumpy road, the vehicle may experience sudden torque changes and jitters when driving, which affects the smoothness and reliability of the whole vehicle. Therefore, it is necessary to perform zero-smoothing and torque limiting processing on the torque to achieve the smoothness of the vehicle when driving and improve the riding experience.

[0053] Therefore, the vehicle steering control method according to the embodiment of the present application obtains the target torque of the left rear motor and the target torque of the right rear motor by confirming that the auxiliary steering function of the vehicle has entered the activated state, and applies the target torque of the left rear motor and the target torque of the right rear motor to the left rear drive motor and the right rear drive motor of the vehicle respectively to control the vehicle to steer. The different torque outputs of the left rear drive motor and the right rear drive motor of the vehicle enhance the control ability of the vehicle body posture, further reduce the turning radius of the vehicle, and avoid wear of the vehicle tires.

[0054] Combine the following Figure 5 A vehicle steering control device is described according to another aspect of the present application. Figure 5 FIG. 5 shows a schematic structural block diagram of a vehicle steering control device 500 according to an embodiment of the present application. Figure 5 As shown, the vehicle steering control device 500 includes a memory 510 and a processor 520, wherein: the memory 510 stores a computer executable program run by the processor 520, and when the computer executable program is run by the processor 520, the processor 520 executes the vehicle steering control method 200 described above. Those skilled in the art can understand the structure and specific operation of each module in the vehicle steering control device 500 according to the embodiment of the present application in combination with the content described above, and for the sake of brevity, it is not repeated here. Therefore, the vehicle steering device according to the embodiment of the present application obtains the left rear motor target torque and the right rear motor target torque by confirming that the vehicle auxiliary steering function has entered the activation state, and applies 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, and controls 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, further reduce the turning radius of the vehicle, and avoid wear of the vehicle tires.

[0055] In addition, according to an embodiment of the present application, a vehicle is also provided, which may include the vehicle steering control device 500 described above.

[0056] In addition, the present application also provides a storage medium on which a computer program is stored. When the computer program is executed by a processor, the processor executes the vehicle steering control method 200 according to the embodiment of the present application described above. The storage medium may include, for example, 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 portable compact disk read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

[0057] In addition, the present application also provides a computer program, on which a computer program to be run by a processor is stored. When the computer program is run by the processor, the processor executes the vehicle steering control method 200 described above.

[0058] Based on the above description, the vehicle steering control method, device and vehicle of the embodiment of the present application obtain the target torque of the left rear motor and the target torque of the right rear motor by confirming that the vehicle auxiliary steering function has entered the activated state, and apply the target torque of the left rear motor and the target torque of the right rear motor to the left rear drive motor and the right rear drive motor of the vehicle respectively to control the vehicle to steer. The different torque outputs of 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 wear of the vehicle tires.

[0059] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application to this. Those of ordinary skill in the art may make various changes and modifications therein without departing from the scope and spirit of the present application. All these changes and modifications are intended to be included within the scope of the present application as required by the appended claims.

[0060] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0061] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of the units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0062] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0063] Similarly, it should be understood that in order to streamline the present application and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present application should not be interpreted as reflecting the following intention: the claimed application requires more features than the features clearly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with features less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby explicitly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present application.

[0064] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0065] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0066] The various component embodiments of the present application can be implemented in hardware, or implemented in software modules running on one or more processors, or implemented in a combination thereof. It should be understood by those skilled in the art that a microprocessor or digital signal processor (DSP) can be used in practice to implement some or all functions of some modules according to the embodiments of the present application. The application can also be implemented as a part or all of a program (e.g., a computer program and a computer program product) for performing the method described herein. Such a program implementing the present application can be stored on a computer-readable medium, or can have the form of one or more signals. Such a signal can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0067] It should be noted that the above embodiments illustrate the present application rather than limit the present application, and that those skilled in the art may design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets should not be constructed as a limitation to the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present application may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer.

[0068] The above is only a specific implementation or description of a specific implementation of the present application, and the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A vehicle steering control method, characterized in that: The method comprises: Obtaining a rear axle motor target torque and a rear axle basic differential torque based on vehicle status information; A left rear motor target torque and a right rear motor target torque are obtained based on the rear axle basic differential torque and the rear axle motor target torque, so as to be applied to the left rear drive motor and the right rear drive motor of the vehicle, thereby controlling the vehicle to steer.

2. The method according to claim 1, characterized in that The rear axle basic differential torque is obtained based on the vehicle status information, including: The rear axle basic differential torque is obtained based on the steering wheel angle in the state information and a preset relationship table.

3. The method according to claim 2, characterized in that The obtaining the rear axle basic differential torque based on the steering wheel angle in the state information and a preset relationship table includes: The rear axle basic differential torque is obtained based on the vehicle speed in the state information, the steering wheel angle and a first preset relationship table, wherein 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.

4. The method according to claim 1, characterized in that: The obtaining of 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 includes: Obtain the vehicle's rotation direction, left rear wheel torque coefficient, and right rear wheel torque coefficient; Obtaining a 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 obtaining a 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; The left rear motor target torque is obtained based on the left rear wheel compensation torque and the rear axle motor target torque, and the right rear motor target torque is obtained based on the right rear wheel compensation torque and the rear axle motor target torque.

5. The method according to claim 4, characterized in that The method of 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 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, includes: Get the braking attenuation coefficient and the slope attenuation coefficient; Obtaining a 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; 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.

6. The method according to claim 5, characterized in that: Obtaining the braking attenuation coefficient and the slope attenuation coefficient includes: The braking attenuation coefficient is obtained 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; The slope attenuation coefficient is obtained 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.

7. The method according to claim 4, characterized in that: Obtaining the left rear wheel torque coefficient and the right rear wheel torque coefficient includes: 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 the corresponding numerical relationship between the rear axle basic differential torque and the rear wheel torque coefficient and the right rear wheel torque.

8. The method according to claim 1, characterized in that The obtaining of the rear axle motor target torque and the rear axle basic differential torque based on the vehicle state information includes: Get vehicle status information; Based on the status information, determining a status of a vehicle assisted steering function; When the vehicle auxiliary steering function enters an activated state, the rear axle motor target torque and the rear axle basic differential torque are obtained based on the state information.

9. The method according to claim 1, characterized in that: The method further comprises: A front axle motor target torque is obtained based on the state information, and the front axle motor target torque is applied to a front drive motor of the vehicle.

10. The method according to claim 9, characterized in that 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; The processed front axle motor target torque, the processed left rear motor target torque and the processed right rear motor target torque are applied to the front drive motor, the left rear drive motor and the right rear drive motor respectively to make the vehicle steer smoothly.

11. The method according to claim 9, characterized in that The state information includes at least one of the following: steering wheel angle, braking depth, vehicle speed, gear information, slope, and throttle depth.

12. The method according to claim 11, characterized in that The conditions for the vehicle assisted steering function to be in an activated state include 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 braking depth is less than a braking 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; The throttle depth is greater than a throttle threshold.

13. A vehicle steering control device, characterized in that: The device includes a memory and a processor, wherein the memory stores a computer executable program executed by the processor, and when the computer executable program is executed by the processor, the processor executes the vehicle steering control method as described in any one of claims 1-12.

14. A vehicle, characterized in that: The vehicle includes the vehicle steering control device according to claim 13.

15. A storage medium, characterized in that: The storage medium stores a computer program executed by a processor, and when the computer program is executed by the processor, the processor executes the vehicle steering control method according to any one of claims 1 to 12.

16. A computer program, characterized in that When the computer program is executed by a processor, the processor is caused to execute the vehicle steering control method according to any one of claims 1 to 12.

Images