Vehicle steering control method, vehicle steering system and vehicle

Abstract

The invention provides a vehicle steering control method, a vehicle steering system and a vehicle. The vehicle steering system comprises a steering driving unit and an electronic control unit, the steering driving unit comprises a plurality of steering motors, the steering motors are independently connected with a plurality of steering wheels of the vehicle respectively, and the electronic control unit is electrically connected with the steering motors and used for obtaining rotation angle signals of a steering wheel of the vehicle. The electronic control unit obtains the rotation angle signals of the steering wheel and controls the steering motors to drive the corresponding steering wheels to steer according to the rotation angle signals, so that the electronic control unit can directly control the steering motors to drive the corresponding steering wheels to steer according to the obtained rotation angle signals of the steering wheel, independent steering of the steering wheels is achieved, and no mechanical connection exists between the steering wheel and the steering wheels. The chassis system is simple in structure and low in cost, and parts of the chassis system can be conveniently arranged.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control, and particularly to a vehicle steering control method, a vehicle steering system and a vehicle. Background Art

[0002] A vehicle steering system is a series of devices used to change or maintain the driving or reversing direction of a vehicle, and is crucial for the driving safety of the vehicle. Due to its ability to improve the convenience of steering, the independent steering function of the left and right wheels has gradually been applied in the vehicle steering system.

[0003] However, currently, the vehicle steering system with the independent wheel steering function has a complex structure and excessive system redundancy, and cannot achieve direct and convenient independent steering control. Summary of the Invention

[0004] Embodiments of the present invention provide a vehicle steering control method, a vehicle steering system and a vehicle, so as to solve the problems of complex structure and excessive system redundancy of the existing vehicle steering system with the independent wheel steering function.

[0005] In a first aspect, an embodiment of the present invention provides a vehicle steering system, and the system includes:

[0006] A steering drive unit, the steering drive unit includes a plurality of steering motors, and the plurality of steering motors are respectively independently connected to a plurality of steering wheels of the vehicle;

[0007] An electronic control unit, the electronic control unit is electrically connected to each of the steering motors, and is configured to obtain a rotation angle signal of the vehicle's steering wheel, and control each of the steering motors to drive the corresponding steering wheel to steer according to the rotation angle signal.

[0008] Optionally, the system further includes:

[0009] A steering operation unit, the steering operation unit includes an angle sensor, and the angle sensor is connected to the vehicle's steering wheel;

[0010] The electronic control unit is connected to the angle sensor to obtain the rotation angle signal.

[0011] Optionally, in the system, the steering motor is a linear motor, an output shaft of the linear motor is connected to the steering wheel, and the output shaft of the linear motor can move along the lateral direction of the vehicle to drive the steering wheel to steer.

[0012] Optionally, in the system, the steering drive unit further includes a steering tie rod;

[0013] One end of the steering tie rod is connected to the output shaft of the linear motor, and the other end of the steering tie rod is connected to the steering wheel, and is used to move under the drive of the linear motor to drive the steering wheel to turn.

[0014] Optionally, in the system, the steering drive unit further includes a steering end ball pin and a motor end ball pin. One end of the steering tie rod is connected to the output shaft of the linear motor through the motor end ball pin, and the other end of the steering tie rod is connected to the steering wheel through the steering end ball pin.

[0015] Optionally, in the system, the steering drive unit further includes a steering knuckle and a kingpin;

[0016] The steering wheel is mounted on the vehicle frame through the steering knuckle, and the other end of the steering tie rod is connected to the steering knuckle, and is used to drive the steering knuckle to rotate around the kingpin to drive the steering wheel to turn.

[0017] Optionally, in the system, the steering operation unit further includes a plurality of corner sensors,

[0018] The plurality of corner sensors are respectively arranged corresponding to the plurality of steering wheels and are electrically connected to the electronic control unit, and are used to detect the steering angle of the steering wheel.

[0019] Optionally, in the system, the steering operation unit further includes: a steering column, the steering column is rotatably arranged on the vehicle frame, the steering wheel is fixed to the top end of the steering column, and the angle sensor is arranged on the steering column and is used to obtain the rotation angle signal.

[0020] Optionally, in the system, the steering operation unit further includes: a steering wheel motor, the steering wheel motor is fixed on the vehicle frame, and the output shaft of the steering wheel motor is connected to the bottom end of the steering column.

[0021] In a second aspect, an embodiment of the present invention provides a vehicle steering control method, which is applied to the vehicle steering system as described above. The method includes:

[0022] Obtain the rotation angle signal of the steering wheel;

[0023] Determine the theoretical rotation angles of the plurality of steering wheels according to the rotation angle signal;

[0024] Control the steering motor corresponding to the steering wheel to drive the steering wheel to turn according to the theoretical rotation angle of each steering wheel.

[0025] Optionally, in the control method, the plurality of steering wheels include a first front steering wheel and a second front steering wheel respectively located at both ends of the front axle of the vehicle;

[0026] Determine the theoretical angles of the respective steering wheels according to the angle signals, including:

[0027] Determine the first theoretical angle of the first front steering wheel according to the angle signal;

[0028] Determine the second theoretical angle of the second front steering wheel according to the first theoretical angle, the kingpin offset between the first front steering wheel and the second front steering wheel, the wheelbase of the vehicle, and the Ackermann steering principle.

[0029] Optionally, in the control method, the plurality of steering motors include a first steering motor and a second steering motor. The first steering motor is used to drive the first front steering wheel to steer, and the second steering motor is used to drive the second front steering wheel to steer. After controlling the steering motor corresponding to each steering wheel to drive the steering wheel to steer according to the theoretical angle of each steering wheel, the method further includes:

[0030] Obtain the first actual angle of the first front steering wheel and the second actual angle of the second front steering wheel;

[0031] Determine the Ackermann ratio according to the first actual angle, the second theoretical angle, and the second actual angle;

[0032] In the case where the Ackermann ratio is not within the range of the Ackermann compliance ratio, control the second steering motor to correct the angle of the second front steering wheel.

[0033] Optionally, in the control method, controlling the second steering motor to correct the angle of the second front steering wheel includes:

[0034] In the case where the first front steering wheel is the inner wheel and the Ackermann ratio is less than the lower limit value of the Ackermann compliance ratio range, control the second steering motor to reduce the angle of the second front steering wheel;

[0035] And / or

[0036] In the case where the first front steering wheel is the inner wheel and the Ackermann ratio is greater than the upper limit value of the Ackermann compliance ratio range, control the second steering wheel to increase the angle of the second front steering wheel;

[0037] And / or

[0038] In the case where the first front steering wheel is the outer wheel and the Ackermann ratio is greater than the upper limit value of the Ackermann compliance ratio range, control the second steering wheel to reduce the angle of the second front steering wheel;

[0039] And / or

[0040] When the first front steering wheel is an outer wheel and the Ackerman rate is less than a lower limit value of the Ackerman coincidence rate range, the second steering wheel is controlled to reduce a turning angle of the second front steering wheel.

[0041] Optionally, in the control method, before determining the theoretical turning angle of each steering wheel according to the angle signal, the method further includes:

[0042] Get vehicle speed;

[0043] Determining a steering transmission ratio according to the vehicle speed, wherein the steering transmission ratio is positively correlated with the vehicle speed;

[0044] Determining the theoretical turning angle of each steering wheel according to the angle signal includes:

[0045] The theoretical steering angle of each steering wheel is determined according to the steering transmission ratio and the angle signal.

[0046] Optionally, in the control method, the vehicle further includes a steering wheel motor, and the steering wheel is drivingly connected to an output end of the steering wheel motor; the method further includes:

[0047] Determining a return torque according to the steering transmission ratio, wherein the return torque is positively correlated with the steering transmission ratio;

[0048] The steering wheel motor output is controlled according to the return torque.

[0049] Optionally, in the control method, the plurality of steering wheels further include a rear steering wheel;

[0050] Determining the theoretical turning angle of each steering wheel according to the angle signal also includes:

[0051] determining a third theoretical turning angle of the rear steering wheel according to the vehicle speed and the first theoretical turning angle;

[0052] Among them, when the vehicle speed is less than or equal to the first vehicle speed threshold, the third theoretical turning angle is in the opposite direction to the first theoretical turning angle; when the vehicle speed is greater than or equal to the second vehicle speed threshold, the third theoretical turning angle is in the same direction as the first theoretical turning angle; and the second vehicle speed threshold is greater than the first vehicle speed threshold.

[0053] In a third aspect, an embodiment of the present invention provides an electronic device, comprising: a processor, a communication interface, a memory, and a communication bus; wherein the processor, the communication interface, and the memory communicate with each other via the communication bus;

[0054] Memory, used to store computer programs;

[0055] A processor, when executing a program stored in a memory, implements the steps in the vehicle steering control method described in the first aspect above.

[0056] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the steps in the vehicle steering control method described in the first aspect above are implemented.

[0057] In a fifth aspect, an embodiment of the present invention provides a vehicle, which includes the vehicle steering system described above.

[0058] Regarding the prior art, the present invention has the following advantages:

[0059] In an embodiment of the present invention, the vehicle steering system includes a steering drive unit and an electronic control unit. The steering drive unit includes a plurality of steering motors, and the plurality of steering motors are respectively independently connected to a plurality of steering wheels of the vehicle. The electronic control unit is electrically connected to each steering motor and is used to obtain a rotation angle signal of the vehicle's steering wheel, and control each steering motor to drive the corresponding steering wheel to turn according to the rotation angle signal, so that the electronic control unit can directly control each steering motor to drive the corresponding steering wheel to turn according to the obtained rotation angle signal of the steering wheel, realizing the independent turning of each steering wheel. Moreover, there is no mechanical connection between the steering wheel and the steering wheels, and its structure is simple, which is convenient for arranging the components of the chassis system and has a lower cost.

[0060] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the description. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following specific embodiments of the present invention are specifically exemplified. Description of the Drawings

[0061] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments.

[0062] Figure 1 It is a schematic structural diagram of a vehicle steering system provided by an embodiment of the present invention;

[0063] Figure 2 It is a flowchart of a vehicle steering control method provided by an embodiment of the present invention;

[0064] Figure 3 It is a schematic diagram of the Ackermann steering principle in an embodiment of the present invention;

[0065] Figure 4 It is a schematic diagram of a vehicle control device provided by an embodiment of the present invention;

[0066] Figure 5Block diagram of the electronic device provided by the embodiment of the present invention. Detailed implementation manners

[0067] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided so that the present invention can be more thoroughly understood and the scope of the present invention can be completely conveyed to those skilled in the art.

[0068] Figure 1 It is a schematic diagram of a vehicle steering system provided by an embodiment of the present invention, including a steering drive unit 12 and an electronic control unit 16; the steering drive unit 12 includes a plurality of steering motors 23, and the plurality of steering motors 23 are respectively independently connected to a plurality of steering wheels 21 of the vehicle; the electronic control unit 16 is electrically connected to each steering motor 23, and is used to obtain the rotation angle signal of the steering wheel 13 of the vehicle, and control each steering motor 23 to drive the corresponding steering wheel 21 to steer according to the rotation angle signal.

[0069] Among them, since the electronic control unit 16 can directly control each steering motor 23 to drive the corresponding steering wheel 21 to steer according to the obtained rotation angle signal of the steering wheel 13, realizing the independent steering of each steering wheel 21, there is no need for a mechanical connection between the steering wheel 13 and the steering wheels 21, its structure is simple, which is convenient for arranging the components of the chassis system, and the cost is relatively low.

[0070] Optionally, in an implementation manner, the vehicle steering system provided by the embodiment of the present invention further includes a steering operation unit, and the steering operation unit includes an angle sensor 15, and the angle sensor 15 is connected to the steering wheel 13 of the vehicle; the electronic control unit 16 is connected to the angle sensor 15 to obtain the rotation angle signal.

[0071] Among them, since the angle sensor 15 is connected to the steering wheel, the angle sensor 15 obtains the rotation angle signal of the steering wheel by sensing the steering of the steering wheel 13; and the electronic control unit 16 is electrically connected to the angle sensor 15 through the angle sensor signal line 18 and is also electrically connected to each steering motor 23, so that the electronic control unit 16 can directly control each steering motor 23 to drive the corresponding steering wheel 21 to steer according to the angle signal obtained by the angle sensor 15, realizing the independent steering of each steering wheel 21.

[0072] It can be seen that the vehicle steering system provided by the embodiment of the present invention cancels the traditional mechanical steering structure and electronic power steering. There is no mechanical connection between the steering wheel 13 and the steering wheels 21, its structure is simple, which is convenient for arranging the components of the chassis system, and the cost is relatively low.

[0073] Optionally, in one embodiment, the above-mentioned steering operation unit further includes a steering column 14. The steering column 14 is rotatably arranged on the vehicle frame 11. The steering wheel 13 is fixed to the top end of the steering column 14. An angle sensor 15 is arranged on the steering column 14 and is used to obtain a rotation angle signal. Among them, since the angle sensor 15 is arranged on the steering column 14, and the steering wheel 13 is rotatably arranged on the vehicle frame 11 through the steering column 14, that is, the rotation of the steering wheel 13 will drive the rotation of the steering column 14. The angle sensor 15 senses the steering of the steering wheel 13 by detecting the rotation of the steering column 14, so as to obtain the above-mentioned rotation angle signal.

[0074] Optionally, in a specific embodiment, the above-mentioned steering operation unit further includes a steering wheel motor 18. The steering wheel motor 18 is fixed to the vehicle frame 11. The output shaft of the steering wheel motor 18 is connected to the bottom end of the steering column 14, so that the steering wheel motor 18 can output a return torque. The direction of the return torque is opposite to the direction of the torque generated by the rotation of the steering wheel 13, which not only makes the vehicle steering more damped and increases the stability of vehicle steering, but also can achieve the automatic return effect of the steering wheel 13.

[0075] Optionally, in one embodiment, the above-mentioned steering motor 23 is a linear motor. The output shaft of the steering motor 23 is connected to the steering wheel 21. The output shaft of the linear motor can move along the transverse direction of the vehicle to drive the steering wheel 21 to steer. Among them, the linear motor can change the rotary motion into a linear motion without any commutation device, which not only has higher transmission efficiency, but also can directly pull the steering wheel 21 to rotate around the kingpin (not shown) along the Y direction (transverse direction) of the whole vehicle, so as to change the driving direction of the vehicle.

[0076] Optionally, in one embodiment, the steering drive unit further includes a steering tie rod 24. One end of the steering tie rod 24 is connected to the output shaft of the linear motor, and the other end of the steering tie rod 24 is connected to the steering wheel 21, and is used to move under the drive of the linear motor to drive the steering wheel to steer. In this embodiment, the linear motor directly drives the steering tie rod 24 to move along the Y direction (transverse direction) of the whole vehicle, and pulls the steering wheel 21 to rotate around the kingpin (not shown), so as to change the driving direction of the vehicle.

[0077] Optionally, in one embodiment, the steering drive unit 12 further includes a steering end ball joint 10 and a motor end ball joint 20. One end of the steering tie rod 24 is connected to the output shaft of the linear motor through the motor end ball joint 20, and the other end of the steering tie rod 24 is connected to the steering wheel 21 through the steering end ball joint 10, that is, both ends of the steering tie rod 24 are connected to the steering wheel 21 and the output shaft of the linear motor through ball joints respectively, which ensures the stability, ride comfort, comfort and safety of vehicle operation, and also enables the vehicle to accurately drive according to the target direction.

[0078] Optionally, in one embodiment, the above-mentioned steering drive unit 12 further includes a knuckle 22 and a kingpin (not shown); the steering wheel 21 is mounted on the vehicle frame 11 through the knuckle 22, and the other end of the steering tie rod 24 is connected to the knuckle 22 for driving the knuckle 22 to rotate around the kingpin to drive the steering wheel 21 to turn.

[0079] Wherein, since each steering drive unit 12 includes a steering wheel 21, a knuckle 22, a kingpin and a steering motor 23, and the steering wheel 21 in each steering drive unit 12 is rotatably connected to the vehicle frame 11 through the knuckle 22 and the kingpin, the output shaft of the steering motor 23 is connected to the knuckle 22, and the angle sensor 15 provided on the steering column 14 can obtain the steering angle signal conveyed by the user through the steering wheel 13, and the electronic control unit 16 is electrically connected to the angle sensor 15 through the angle sensor signal line 17 and is also electrically connected to each steering motor 23, so that the electronic control unit 16 can directly control each steering motor 23 to drive the corresponding steering wheel 21 to turn according to the angle signal obtained by the angle sensor 15, realizing the independent turning of each steering wheel 21.

[0080] Optionally, the above-mentioned steering motor 23 further includes a locking structure (not shown). When the steering wheel 13 rotates, the locking structure is unlocked, and then the controller (not shown) in the steering motor 23 makes the linear motor move by controlling the current signal according to the theoretical rotation angle sent by the electronic control unit 16. The output shaft of the linear motor moves along the vehicle's Y direction (lateral), driving the steering tie rod 24 to move. The steering tie rod 24 pulls the steering wheel 21 to rotate around the kingpin, changing the vehicle's driving direction; when the steering wheel 13 returns to the straight position, the linear motor drives the steering wheel 21 to return to the straight position, and then the locking structure locks the steering tie rod 24.

[0081] Optionally, in one embodiment, the above-mentioned steering drive unit 12 further includes a plurality of corner sensors 25. The plurality of corner sensors 25 are respectively arranged corresponding to the plurality of steering wheels and are electrically connected to the electronic control unit 16, and are used for detecting the steering angle of the steering wheel 21. In this embodiment, by setting the corner sensors 25 electrically connected to the electronic control unit 16, the steering angle of the corresponding steering wheel 21 can be detected in real time, and then it can be judged whether the steering wheel 21 has turned in place, and then the steering angle can be corrected when the target steering angle is not met. Among them, the corner sensor 25 can be specifically arranged on the above-mentioned steering wheel 21 or on the above-mentioned knuckle 22.

[0082] Wherein, the above-mentioned plurality of steering wheels 21 can be 2, 3, 4, etc., and can respectively realize two-wheel independent steering, three-wheel independent steering or four-wheel independent steering.

[0083] Optionally, in a specific embodiment, the vehicle is a four-wheel vehicle, and the steering drive unit 12 may specifically include a left front steering drive unit 121, a right front steering drive unit 122, a left rear steering drive unit 123, and a right rear steering drive unit 124 respectively located in the left front direction, right front direction, left rear direction, and right rear direction of the vehicle;

[0084] Among them, the left front steering drive unit 121 may include a left front steering knuckle 32, a left front kingpin, and a left front steering motor 33 located in the left front direction of the vehicle; the left front steering wheel 31 is rotationally connected to the vehicle frame 11 through the left front steering knuckle 32 and the left front kingpin, and the output shaft of the left front steering motor 33 is connected to the left front steering knuckle 32 and is used to drive the left front steering knuckle 32 to rotate around the kingpin;

[0085] Among them, the right front steering drive unit 122 may include a right front steering knuckle 42, a right front kingpin, and a right front steering motor 43 located in the right front direction of the vehicle; the right front steering wheel 41 is rotationally connected to the vehicle frame 11 through the right front steering knuckle 42 and the right front kingpin, and the output shaft of the right front steering motor 43 is connected to the right front steering knuckle 42 and is used to drive the right front steering knuckle 42 to rotate around the kingpin;

[0086] Among them, the left rear steering drive unit 123 may include a left rear steering knuckle 52, a left rear kingpin, and a left rear steering motor 53 located in the left rear direction of the vehicle; the left rear steering wheel 51 is rotationally connected to the vehicle frame 11 through the left rear steering knuckle 52 and the left rear kingpin, and the output shaft of the left rear steering motor 53 is connected to the left rear steering knuckle 52 and is used to drive the left rear steering knuckle 52 to rotate around the kingpin;

[0087] Among them, the right rear steering drive unit 124 may include a right rear steering knuckle 62, a right rear kingpin, and a right rear steering motor 63 located in the right rear direction of the vehicle; the right rear steering wheel 61 is rotationally connected to the vehicle frame 11 through the right rear steering knuckle 62 and the right rear kingpin, and the output shaft of the right rear steering motor 63 is connected to the right rear steering knuckle 62 and is used to drive the right rear steering knuckle 62 to rotate around the kingpin.

[0088] In the embodiment of the present invention, since the steering system has the function of rear-wheel steering, operations such as turning and U-turning in a narrow space at low speeds can be achieved, and at the same time, the ideal understeering characteristics of the vehicle at high speeds can be ensured, improving the stability of the vehicle during high-speed driving.

[0089] In addition, because each steering wheel 21 can be independently steered, by controlling the steering angles of the left front steering wheel 31 and the right front steering wheel 41 during steering, the ideal Ackermann angle of the vehicle can be ensured, and it can ensure to the greatest extent that the vehicle can perform pure rolling steering motion under various road conditions, realizing the ideal steering motion of the four wheels of the vehicle.

[0090] Optionally, in one embodiment, the above-mentioned vehicle frame 11 includes a main vehicle frame 71 and a sub-vehicle frame 72, and the sub-vehicle frame 72 is fixedly connected to the main vehicle frame 11; the steering wheel 21 is rotatably connected to the sub-vehicle frame 72 through a knuckle 22 and a kingpin; the steering motor 23 is arranged on the sub-vehicle frame 72; and the steering wheel 13 motor is fixed to the main vehicle frame 71 through the instrument crossbeam of the vehicle.

[0091] Optionally, in a specific embodiment, the above-mentioned sub-vehicle frame 72 includes a front sub-vehicle frame 81 and a rear sub-vehicle frame 82;

[0092] Among them, the left front steering motor 33 and the steering wheel 31 are connected through a wheel bolt and a left front knuckle 32. The left front knuckle 32 is connected to a left front steering tie rod 34 through a left front knuckle end ball pin assembly 36. A left front wheel angle sensor 35 is connected to the left front knuckle 32. The left front steering tie rod 34 is connected to the output shaft 38 of the left front steering motor 33 through a left front steering motor end ball pin assembly 37. The left front steering motor 33 is fixedly connected to the front sub-vehicle frame 81 through an assembly hole of the left front steering motor housing 39;

[0093] The right front steering motor 43 and the steering wheel 41 are connected through a wheel bolt and a right front steering knuckle 42. The right front knuckle 42 is connected to a right front steering tie rod 44 through a right front knuckle end ball pin assembly 46. A right front wheel angle sensor 45 is connected to the right front knuckle 42. The right front steering tie rod 44 is connected to the output shaft 48 of the right front steering motor 43 through a right front steering motor end ball pin assembly 47. The right front steering motor 43 is fixedly connected to the front sub-vehicle frame 81 through an assembly hole of the right front steering motor housing 49;

[0094] The left rear steering motor 53 and the steering wheel 51 are connected through a wheel bolt and a left rear steering knuckle 54. The left rear knuckle 52 is connected to a left rear steering tie rod 54 through a left rear knuckle end ball pin assembly 56. A left rear wheel angle sensor 55 is connected to the left rear knuckle 52. The left rear steering tie rod 54 is connected to the output shaft 58 of the left rear steering motor 53 through a left rear steering motor end ball pin assembly 57. The left rear steering motor 53 is fixedly connected to the rear sub-vehicle frame 82 through an assembly hole of the left rear steering motor housing 59;

[0095] The right rear steering wheel 61 is connected through a wheel bolt and a right rear knuckle 62. The right rear knuckle 62 is connected to a right rear steering tie rod 64 through a right rear knuckle end ball pin assembly 65. A right rear wheel angle sensor 64 is connected to the right rear knuckle 62. The right rear steering tie rod 62 is connected to the output shaft 68 of the right rear steering motor 63 through a right rear steering motor end ball pin assembly 66. The right rear steering motor 63 is fixedly connected to the rear sub-vehicle frame 82 through an assembly hole of the right rear steering motor housing 69.

[0096] Figure 2It is a schematic diagram of a vehicle steering control method provided by an embodiment of the present invention, which is applied to the vehicle steering system as described above. This method includes steps 201 to 203.

[0097] The method provided by the embodiment of the present invention is specifically applied to an electronic control unit.

[0098] Step 201: Obtain the rotation angle signal of the steering wheel.

[0099] In this step, the electronic control unit can obtain the rotation angle signal of the steering wheel 13 through an angle sensor or other means. The angle sensor can be directly connected to the steering wheel of the vehicle and connected to the electronic control unit. The angle sensor detects the steering of the steering wheel, thereby obtaining the above angle signal and transmitting the above angle signal to the electronic control unit. Of course, the angle sensor can be arranged on the steering column and connected to the electronic control unit, and the steering wheel is rotatably arranged on the vehicle frame through the steering column, that is, the rotation of the steering wheel will drive the rotation of the steering column. The angle sensor detects the steering of the steering wheel, thereby obtaining the above angle signal and transmitting the above angle signal to the electronic control unit.

[0100] Step 202: Determine the theoretical rotation angles of multiple steering wheels according to the rotation angle signal.

[0101] In this step, the electronic control unit calculates according to the above angle signal to determine the angles that each steering wheel needs to rotate when steering according to the steering radius corresponding to the above angle signal, that is, the above theoretical rotation angles.

[0102] Optionally, the above step 202 specifically includes: determining the theoretical rotation angles of multiple steering wheels according to the angle signal according to the Ackermann steering principle. That is, the electronic control unit calculates the angles that each steering wheel needs to rotate to ensure the ideal Ackermann angle of the vehicle, so as to ensure that the vehicle makes a pure rolling steering motion to the greatest extent and realize the ideal steering motion of the four wheels of the vehicle.

[0103] Step 203: Control the steering motor corresponding to each steering wheel to drive the steering wheel to steer according to the theoretical rotation angle of each steering wheel.

[0104] In this step, since each steering motor is electrically connected to the electronic control unit, and each steering motor can drive a steering wheel to rotate around the kingpin respectively, the theoretical rotation angle of each steering wheel can be sent to the controller in the corresponding steering motor, and then the controller can control the operation of the steering motor according to the above theoretical rotation angle to drive the corresponding steering wheel to rotate around the kingpin, so that the vehicle can achieve the steering effect corresponding to the above angle information.

[0105] In the embodiments of the present invention, since the steering drive unit of the vehicle steering system includes a plurality of steering motors, the plurality of steering motors are respectively and independently connected to a plurality of steering wheels of the vehicle, and the electronic control unit is electrically connected to each steering motor, and is used to obtain the rotation angle signal of the vehicle's steering wheel, and control each steering motor to drive the corresponding steering wheel to steer according to the rotation angle signal, so that the electronic control unit can directly control each steering motor to drive the corresponding steering wheel to steer according to the obtained rotation angle signal of the steering wheel, and conveniently realize the independent steering of each steering wheel.

[0106] Optionally, in one embodiment, the plurality of steering wheels include a first front steering wheel and a second front steering wheel respectively located at both ends of the front axle of the vehicle; the above step 202 includes steps 221 to 222.

[0107] Step 221, determine the first theoretical rotation angle of the first front steering wheel according to the angle signal.

[0108] In this step, the first front steering wheel is used as the steering reference wheel, and then based on the angle signal of the steering wheel and the steering ratio, the ideal rotation angle of the steering reference wheel is calculated, that is, the above first theoretical rotation angle. Among them, the first front steering wheel can be a left steering wheel or a right steering wheel, and can be used as either the inner wheel or the outer wheel.

[0109] Step 222, determine the second theoretical rotation angle of the second front steering wheel according to the first theoretical rotation angle, the kingpin offset between the first front steering wheel and the second front steering wheel, the wheelbase of the vehicle, and the Ackermann steering principle.

[0110] In this step, the ideal inner and outer wheel rotation angles are as Figure 3 shown, and the ideal inner and outer wheel rotation angle formula is:

[0111]

[0112] Among them:

[0113]

[0114]

[0115]

[0116] In the formula: A and B are the intersections of the extended lines of the kingpin axes of the left and right front wheel suspension systems with the ground; C is the instantaneous center of rotation of the vehicle; D is the intersection of the extended line of the instantaneous center of rotation C along the vehicle body X direction (longitudinal direction) and the extended line of AB; b is the distance between point A and point B; L is the wheelbase.

[0117] The ideal Ackermann angle is:

[0118] δ(Ackermann angle) = α - β (5)

[0119] b is the distance between point A and point B, that is, the kingpin offset between the first front steering wheel and the second front steering wheel, and it and L are known numbers; when the first front steering wheel is the inner wheel, α is the first theoretical angle of rotation, then β is calculated as the second theoretical angle of rotation through equations 1 - 5. When the first front steering wheel is the outer wheel, β is the first theoretical angle of rotation, then α is calculated as the second theoretical angle of rotation through equations 1 - 5.

[0120] Optionally, in a specific embodiment, the multiple steering motors include a first steering motor and a second steering motor. The first steering motor is used to drive the first front steering wheel to steer, and the second steering motor is used to drive the second front steering wheel to steer. The above step 203 includes steps 231 - 232:

[0121] Step 231: Control the first steering motor to drive the first front steering wheel to steer according to the first theoretical angle of rotation.

[0122] In this step, the electronic control unit sends a first control signal to the first steering electrode according to the first theoretical angle of rotation. After receiving this control signal, the first steering motor drives the first front steering wheel to steer with the first theoretical angle of rotation as the target angle of rotation.

[0123] Step 232: Control the second steering motor to drive the second front steering wheel to steer according to the second theoretical angle of rotation.

[0124] In this step, the electronic control unit sends a second control signal to the second steering electrode according to the second theoretical angle of rotation. After receiving this control signal, the second steering motor drives the second front steering wheel to steer with the second theoretical angle of rotation as the target angle of rotation.

[0125] In the above embodiment, because each steering wheel can steer independently, by controlling the different steering angles obtained by the left and right front wheels during steering and ensuring the ideal Ackermann angle of the vehicle, it can ensure to the greatest extent that the vehicle can perform pure rolling steering motion under various road conditions and realize the ideal steering motion of the vehicle's steering wheels.

[0126] Optionally, in an embodiment, the multiple steering wheels further include rear steering wheels located on the rear axle of the vehicle; the multiple steering motors further include a third steering motor for driving the rear steering wheels to steer; the above step 202 further includes step 223, and the above step 203 further includes step 233.

[0127] Step 223: Determine the third theoretical angle of rotation of the rear steering wheels according to the vehicle speed and the first theoretical angle of rotation.

[0128] Wherein, when the vehicle speed is less than or equal to the first vehicle speed threshold, the third theoretical rotation angle is opposite to the first theoretical rotation angle; when the vehicle speed is greater than or equal to the second vehicle speed threshold, the fourth theoretical rotation angle is the same as the first theoretical rotation angle; the second vehicle speed threshold is greater than the first vehicle speed threshold.

[0129] In this step, the first vehicle speed threshold is the vehicle speed threshold for defining that the vehicle needs to enhance the steering maneuverability. When the vehicle speed is less than or equal to the first vehicle speed threshold, it is determined that the vehicle needs to perform a large-angle turn, so the third theoretical rotation angle opposite to the first theoretical rotation angle is determined; the second vehicle speed threshold is the vehicle speed threshold for defining that the vehicle needs to enhance the handling performance. When the vehicle speed is greater than or equal to the second vehicle speed threshold, it is determined that the vehicle needs to perform a large-angle turn, so the third theoretical rotation angle opposite to the first theoretical rotation angle is determined. Among them, the angular value of the third theoretical rotation angle can be less than or equal to the angular value of the first theoretical rotation angle.

[0130] Step 233: Control the third steering motor to drive the rear steering wheel to turn according to the third theoretical rotation angle.

[0131] In this step, according to the third theoretical rotation angle, the third steering motor is controlled to drive the rear steering wheel to turn, so that after the vehicle is in a driving state not higher than the first vehicle speed threshold, the rear wheels turn in the opposite direction to the front wheels, enabling the vehicle to obtain a smaller turning radius; and after the vehicle is in a driving state not lower than the second vehicle speed threshold, the rear wheels turn in the same direction as the front wheels, ensuring the ideal understeering characteristics of the vehicle and improving the stability and safety of the vehicle during high-speed driving.

[0132] Optionally, in an implementation manner, the vehicle steering control method provided by the embodiments of the present invention further includes steps 204 to 206 after the above step 203:

[0133] Step 204: Obtain the first actual rotation angle of the first front steering wheel and the second actual rotation angle of the second front steering wheel.

[0134] In this step, a rotation angle sensor electrically connected to the electronic control unit is provided on the steering knuckle at each steering wheel and is used to detect the steering angle of the steering wheel. Therefore, the electronic control unit can obtain the actual rotation angle of each front steering wheel in real time.

[0135] Step 205: Determine the Ackermann ratio according to the first actual rotation angle, the second theoretical rotation angle, and the second actual rotation angle.

[0136] In this step, the actual rotation angle is transmitted to the ECU (37) to calculate the Ackermann ratio. The definition formula of the Ackermann ratio is:

[0137]

[0138] Where: θ i is the actual inner wheel rotation angle; θ or is the actual outer wheel rotation angle; θ o is the ideal outer wheel rotation angle.

[0139] Step 206: When the Ackermann ratio is not within the Ackermann compliance ratio range, control the second steering motor to correct the rotation angle of the second front steering wheel.

[0140] In this step, the Ackermann compliance ratio range is a pre-set and acceptable Ackermann ratio range value. When the Ackermann ratio is within the Ackermann compliance ratio range, the steering angle of the second steering wheel is reasonable and the wheels can perform rolling steering. Therefore, when the Ackermann ratio is not within the Ackermann compliance ratio range, it indicates that the second steering wheel is under-steering or over-steering. Thus, control the second steering motor to correct the rotation angle of the second front steering wheel until the Ackermann ratio is within the above-mentioned Ackermann compliance ratio range.

[0141] Optionally, when the theoretical rotation angle of the inner wheel is less than or equal to the angle threshold, the Ackermann compliance ratio range is the first range; when the theoretical rotation angle of the inner wheel is greater than the angle threshold, the Ackermann compliance ratio range is the second range; wherein, the lower limit value of the second range is greater than or equal to the upper limit value of the first range. By setting a lower Ackermann ratio requirement when the theoretical rotation angle of the inner wheel is small, the handling performance during high-speed driving is ensured, and by setting a higher Ackermann ratio requirement when the theoretical rotation angle of the inner wheel is large, the turning performance during low-speed driving is ensured.

[0142] Optionally, the above-mentioned angle threshold is 20°, the above-mentioned first range is 40% - 60%, and the above-mentioned second range is 60% - 80%.

[0143] In this embodiment, after controlling the front steering wheel to turn, the actual rotation angle of the steering wheel is detected and transmitted to the electronic control unit, and the Ackermann ratio is calculated to determine whether the steering wheel reaches the ideal Ackermann angle. When the Ackermann ratio does not meet the Ackermann compliance ratio range, the angle is corrected to make it reach the Ackermann compliance ratio range.

[0144] Optionally, in a specific embodiment, the above-mentioned step 206 includes steps 261 to 264:

[0145] Step 261: When the first front steering wheel is the inner wheel and the Ackermann ratio is less than the lower limit value of the Ackermann compliance ratio range, control the second steering motor to reduce the rotation angle of the second front steering wheel.

[0146] In this step, when the first front steering wheel is the inner wheel and the Ackermann ratio is less than the lower limit value of the above Ackermann compliance ratio range, it indicates that the second steering wheel is over-steered. Therefore, the second steering motor is controlled to reduce the steering angle of the second front steering wheel. Optionally, the second steering motor reduces the steering angle of the second front steering wheel by a fixed step or proportion.

[0147] Step 262, when the first front steering wheel is the inner wheel and the Ackermann ratio is greater than the upper limit value of the Ackermann compliance ratio range, control the second steering wheel to increase the steering angle of the second front steering wheel.

[0148] In this step, when the first front steering wheel is the inner wheel and the Ackermann ratio is greater than the upper limit value of the above Ackermann compliance ratio range, it indicates that the second steering wheel is under-steered. Therefore, the second steering motor is controlled to increase the steering angle of the second front steering wheel. Optionally, the second steering motor increases the steering angle of the second front steering wheel by a fixed step or proportion.

[0149] Step 263, when the first front steering wheel is the outer wheel and the Ackermann ratio is greater than the upper limit value of the Ackermann compliance ratio range, control the second steering wheel to reduce the steering angle of the second front steering wheel.

[0150] In this step, when the first front steering wheel is the outer wheel and the Ackermann ratio is greater than the upper limit value of the above Ackermann compliance ratio range, it indicates that the second steering wheel is under-steered. Therefore, the second steering motor is controlled to increase the steering angle of the second front steering wheel. Optionally, the second steering motor increases the steering angle of the second front steering wheel by a fixed step or proportion.

[0151] Step 264, when the first front steering wheel is the outer wheel and the Ackermann ratio is less than the lower limit value of the Ackermann compliance ratio range, control the second steering wheel to reduce the steering angle of the second front steering wheel.

[0152] In this step, when the first front steering wheel is the outer wheel and the Ackermann ratio is less than the lower limit value of the above Ackermann compliance ratio range, it indicates that the second steering wheel is over-steered. Therefore, the second steering motor is controlled to reduce the steering angle of the second front steering wheel. Optionally, the second steering motor reduces the steering angle of the second front steering wheel by a fixed step or proportion.

[0153] Optionally, in an embodiment, for the vehicle steering control method provided by the embodiment of the present invention, before the above step 202, steps 2011 to 2012 are further included, and the above step 202 includes step 2021:

[0154] Step 2011, obtain the vehicle speed.

[0155] In this step, the electronic control unit is communicatively connected to the vehicle stability control unit, so that the electronic control unit can obtain the vehicle speed through the vehicle stability control unit.

[0156] Step 2012: Determine a steering transmission ratio according to the vehicle speed, wherein the steering transmission ratio is positively correlated with the vehicle speed.

[0157] In this step, the corresponding steering transmission ratio is determined according to a corresponding relationship that is positively correlated with the vehicle speed, that is, the greater the vehicle speed, the greater the steering transmission ratio, and the smaller the vehicle speed, the smaller the steering transmission ratio.

[0158] Step 2021: Determine the theoretical steering angle of each steering wheel according to the steering transmission ratio and the angle signal.

[0159] In this step, the angle signal is amplified using the steering transmission ratio, and then calculation is performed based on the amplified angle signal to determine the angle that each steering wheel needs to rotate when steering according to the steering radius corresponding to the amplified angle signal, that is, the above-mentioned theoretical turning angle.

[0160] In the above-mentioned embodiment, the steering transmission ratio is determined in a positive correlation with the vehicle speed, so that when the vehicle is in a stopped state, the vehicle speed is low, and a large-angle steering can be performed, the electronic control unit (Electronic Control Unit, ECU) provides a smaller steering transmission ratio, so that the steering wheel is turned a smaller angle to obtain a larger wheel turning angle; and when the vehicle is driving at a high speed and only a small angle of steering can be performed, the ECU provides a larger steering transmission ratio, so that when achieving the same wheel turning angle, the steering wheel needs to be turned a larger angle, thereby increasing the stability of the vehicle steering, thereby improving the stability and safety of the vehicle when driving at high speed.

[0161] Optionally, in a specific implementation, the vehicle further includes a steering wheel motor, and the steering wheel is drivingly connected to an output end of the steering wheel motor. After the above step 201, the method further includes steps 207 to 208:

[0162] Step 207: Determine a return torque according to the steering transmission ratio, wherein the return torque is positively correlated with the steering transmission ratio.

[0163] In this step, the corresponding return torque is determined according to a corresponding relationship that is positively correlated with the steering transmission ratio, that is, the larger the steering transmission ratio, the larger the return torque, and the smaller the steering transmission ratio, the smaller the return torque.

[0164] Step 208: Control the steering wheel motor output according to the return torque.

[0165] In this step, the steering wheel motor is controlled to output the above-mentioned return torque in the direction opposite to the rotation of the steering wheel.

[0166] In the above embodiments, the steering transmission ratio is determined to be positively correlated with the vehicle speed, and the return torque is determined to be positively correlated with the steering transmission ratio. When the vehicle is in a stopped state or has a low vehicle speed and can perform large-angle steering, the Electronic Control Unit (ECU) controls the steering wheel motor to output a small return torque, making the vehicle steering lighter; while in the case of high-speed driving or only small-angle steering, the ECU controls the steering wheel motor to output a large return torque, making the vehicle steering more damped and increasing the stability of vehicle steering.

[0167] Figure 4 FIG. 4 is a schematic diagram of a vehicle steering control device provided by an embodiment of the present invention, which is applied to the above vehicle steering system. The device includes:

[0168] A first acquisition module 401, configured to acquire a rotation angle signal of the steering wheel;

[0169] A first determination module 402, configured to determine the theoretical rotation angles of a plurality of steering wheels according to the angle signal;

[0170] A first control module 403, configured to control the steering motor corresponding to each steering wheel to drive the steering wheel to turn according to the theoretical rotation angle of each steering wheel.

[0171] Optionally, the plurality of steering wheels include a first front steering wheel and a second front steering wheel respectively located at both ends of the front axle of the vehicle;

[0172] The first determination module 402 includes:

[0173] A first determination unit, configured to determine a first theoretical rotation angle of the first front steering wheel according to the angle signal;

[0174] A second determination unit, configured to determine a second theoretical rotation angle of the second front steering wheel according to the first theoretical rotation angle, the kingpin offset between the two first front steering wheels and the second front steering wheel, the wheelbase of the vehicle, and the Ackermann steering principle.

[0175] Optionally, the plurality of steering motors include a first steering motor and a second steering motor. The first steering motor is used to drive the first front steering wheel to turn, and the second steering motor is used to drive the second front steering wheel to turn. The device further includes:

[0176] A second acquisition module, configured to acquire a first actual rotation angle of the first front steering wheel and a second actual rotation angle of the second front steering wheel after controlling the steering motor corresponding to each steering wheel to drive the steering wheel to turn according to the theoretical rotation angle of each steering wheel;

[0177] A second determination module, configured to determine an Ackermann rate according to the first actual rotation angle, the second theoretical rotation angle, and the second actual rotation angle;

[0178] A second control module, configured to control the second steering motor to correct the rotation angle of the second front steering wheel when the Ackermann rate is not within the Ackermann compliance rate range.

[0179] Optionally, the second control module is specifically configured to control the second steering motor to reduce the rotation angle of the second front steering wheel when the first front steering wheel is an inner wheel and the Ackermann rate is less than the lower limit value of the Ackermann compliance rate range;

[0180] and / or

[0181] When the first front steering wheel is an inner wheel and the Ackermann rate is greater than the upper limit value of the Ackermann compliance rate range, control the second steering wheel to increase the rotation angle of the second front steering wheel;

[0182] and / or

[0183] When the first front steering wheel is an outer wheel and the Ackermann rate is greater than the upper limit value of the Ackermann compliance rate range, control the second steering wheel to reduce the rotation angle of the second front steering wheel;

[0184] and / or

[0185] When the first front steering wheel is an outer wheel and the Ackermann rate is less than the lower limit value of the Ackermann compliance rate range, control the second steering wheel to reduce the rotation angle of the second front steering wheel.

[0186] Optionally, the device further includes:

[0187] A third acquisition module, configured to acquire a vehicle speed before determining the theoretical rotation angles of the steering wheels according to the angle signals;

[0188] A third determination module, configured to determine a steering transmission ratio according to the vehicle speed, where the steering transmission ratio is positively correlated with the vehicle speed;

[0189] The first determination module 402 is specifically configured to determine the theoretical rotation angles of the steering wheels according to the steering transmission ratio and the angle signals.

[0190] Optionally, the vehicle further includes a steering wheel motor, and the steering wheel is in transmission connection with the output end of the steering wheel motor; the device further includes:

[0191] A fourth determination module, configured to determine a return-to-center torque according to the steering transmission ratio, where the return-to-center torque is positively correlated with the steering transmission ratio;

[0192] A third control module, configured to control the output of the steering wheel motor according to the return torque.

[0193] Optionally, the plurality of steering wheels further includes rear steering wheels;

[0194] The first determination module 402 further includes:

[0195] A third determination unit, configured to determine a third theoretical angle of the rear steering wheel according to the vehicle speed and the first theoretical angle;

[0196] Wherein, when the vehicle speed is less than or equal to a first vehicle speed threshold, the third theoretical angle is opposite to the first theoretical angle; when the vehicle speed is greater than or equal to a second vehicle speed threshold, the third theoretical angle is the same as the first theoretical angle; the second vehicle speed threshold is greater than the first vehicle speed threshold.

[0197] An embodiment of the present invention further provides a vehicle, which includes the vehicle steering control device or vehicle steering system as described above.

[0198] For the above device and vehicle embodiments, since they are basically similar to the vehicle control method embodiments, for the related parts, reference may be made to the partial description of the method embodiments.

[0199] The vehicle steering control device provided by the embodiment of the present invention, the vehicle steering system includes a steering drive unit and an electronic control unit. The steering drive unit includes a plurality of steering motors, and the plurality of steering motors are respectively independently connected to a plurality of steering wheels of the vehicle. The electronic control unit is electrically connected to each steering motor and is configured to obtain a rotation angle signal of the steering wheel of the vehicle, and control each steering motor to drive the corresponding steering wheel to steer according to the rotation angle signal, so that the electronic control unit can directly control each steering motor to drive the corresponding steering wheel to steer according to the obtained rotation angle signal of the steering wheel, realize the independent steering of each steering wheel, and there is no mechanical connection between the steering wheel and the steering wheels. Its structure is simple, which is convenient for arranging the components of the chassis system and has a lower cost.

[0200] An embodiment of the present invention further provides an electronic device, as Figure 5 shown, including a processor 501, a communication interface 502, a memory 503, and a communication bus 504. Among them, the processor 501, the communication interface 502, and the memory 503 communicate with each other through the communication bus 504.

[0201] The memory 503 is used for storing computer programs.

[0202] When the processor 501 is configured to execute the program stored on the memory 503, the following steps are implemented:

[0203] Obtain the rotation angle signal of the steering wheel;

[0204] Determine the theoretical rotation angles of a plurality of steering wheels according to the rotation angle signals;

[0205] Control the steering motors corresponding to the steering wheels to drive the steering wheels to steer according to the theoretical rotation angles of each of the steering wheels.

[0206] Among them, the processor 501 can also implement other steps in the above vehicle steering control method, which will not be elaborated here.

[0207] The communication bus mentioned in the above electronic device can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of convenience of representation, only a thick line is shown in the figure, but it does not mean that there is only one bus or one type of bus.

[0208] The communication interface is used for communication between the above electronic device and other devices.

[0209] The memory may include a Random Access Memory (RAM), and may also include a non-volatile memory, such as at least one disk memory. Optionally, the memory may also be at least one storage device located far from the aforementioned processor.

[0210] The above-mentioned processor may be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it may also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0211] In another embodiment provided by the present invention, there is also provided a computer-readable storage medium, in which instructions are stored, and when it runs on a computer, it causes the computer to execute the vehicle steering control method described in the above embodiment.

[0212] In another embodiment provided by the present invention, there is also provided a computer program product including instructions, which, when running on a computer, causes the computer to execute the vehicle steering control method described in the above embodiments.

[0213] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present invention are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired manner (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or a wireless manner (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer, or a data storage device such as a server or data center that includes one or more integrated available media. The available medium can be a magnetic medium (such as a floppy disk, hard disk, magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid state disk (SSD)).

[0214] It should be noted that in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including", or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article, or device. Without further limitation, an element defined by the statement "including a..." does not exclude the presence of additional identical elements in the process, method, article, or device including the element.

[0215] Each embodiment in this specification is described in a related manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. For the embodiments of the device, electronic device, computer-readable storage medium, and computer program product containing instructions, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiments.

[0216] The above description is only for the preferred embodiments of the present invention and is not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A vehicle steering system, characterized in that, comprising: a steering drive unit, the steering drive unit includes a plurality of steering motors, and the plurality of steering motors are respectively independently connected to a plurality of steering wheels of the vehicle; an electronic control unit, the electronic control unit is electrically connected to each of the steering motors, and is configured to obtain a rotation angle signal of the steering wheel of the vehicle, and control each of the steering motors to drive the corresponding steering wheel to steer according to the rotation angle signal.

2. The system according to claim 1, characterized in that, further comprising: a steering operation unit, the steering operation unit includes an angle sensor, and the angle sensor is connected to the steering wheel of the vehicle; the electronic control unit is electrically connected to the angle sensor to obtain the rotation angle signal.

3. The system according to claim 1, characterized in that, the steering motor is a linear motor, an output shaft of the linear motor is connected to the steering wheel, and the output shaft of the linear motor can move along the transverse direction of the vehicle to drive the steering wheel to steer.

4. The system according to claim 3, characterized in that, the steering drive unit further includes a steering tie rod; one end of the steering tie rod is connected to the output shaft of the linear motor, and the other end of the steering tie rod is connected to the steering wheel, and is configured to move under the drive of the linear motor to drive the steering wheel to steer.

5. The system according to claim 4, characterized in that, the steering drive unit further includes a steering end ball joint and a motor end ball joint, one end of the steering tie rod is connected to the output shaft of the linear motor through the motor end ball joint, and the other end of the steering tie rod is connected to the steering wheel through the steering end ball joint.

6. The system according to claim 4, characterized in that, the steering drive unit further includes a steering knuckle and a kingpin; the steering wheel is mounted on the vehicle frame through the steering knuckle, and the other end of the steering tie rod is connected to the steering knuckle, and is configured to drive the steering knuckle to rotate around the kingpin to drive the steering wheel to steer.

7. The system according to claim 1, characterized in that, the steering drive unit further includes a plurality of corner sensors, the plurality of corner sensors are respectively arranged corresponding to the plurality of steering wheels, and are electrically connected to the electronic control unit, and are configured to respectively detect the steering angles of the plurality of steering wheels.

8. The system according to claim 2, characterized in that, the steering operation unit further includes: a steering column, the steering column is rotatably arranged on the vehicle frame, the steering wheel is fixed to the top end of the steering column, and the angle sensor is arranged on the steering column and is configured to obtain the rotation angle signal.

9. The system according to claim 8, characterized in that, the steering operation unit further includes: a steering wheel motor, the steering wheel motor is fixed on the vehicle frame, and an output shaft of the steering wheel motor is connected to the bottom end of the steering column.

10. A vehicle steering control method, characterized in that, applied to the vehicle steering system according to any one of claims 1 to 9, the method includes: obtaining a rotation angle signal of the steering wheel; Determine the theoretical angles of multiple steering wheels according to the rotation angle signal; Control the steering motors corresponding to the steering wheels to drive the steering wheels to steer according to the theoretical angles of each steering wheel.

11. The control method according to claim 10, wherein, the multiple steering wheels include a first front steering wheel and a second front steering wheel respectively located at both ends of the front axle of the vehicle; Determining the theoretical angles of multiple steering wheels according to the angle signal includes: Determine the first theoretical angle of the first front steering wheel according to the angle signal; Determine the second theoretical angle of the second front steering wheel according to the first theoretical angle, the kingpin offset between the first front steering wheel and the second front steering wheel, the wheelbase of the vehicle, and the Ackermann steering principle.

12. The control method according to claim 11, wherein, the multiple steering motors include a first steering motor and a second steering motor. The first steering motor is used to drive the first front steering wheel to steer, and the second steering motor is used to drive the second front steering wheel to steer. After controlling the steering motors corresponding to the steering wheels to drive the steering wheels to steer according to the theoretical angles of each steering wheel, the method further includes: Obtain the first actual angle of the first front steering wheel and the second actual angle of the second front steering wheel; Determine the Ackermann ratio according to the first actual angle, the second theoretical angle, and the second actual angle; When the Ackermann ratio is not within the Ackermann compliance ratio range, control the second steering motor to correct the angle of the second front steering wheel.

13. The control method according to claim 12, wherein, Controlling the second steering motor to correct the angle of the second front steering wheel includes: When the first front steering wheel is the inner wheel and the Ackermann ratio is less than the lower limit value of the Ackermann compliance ratio range, control the second steering motor to reduce the angle of the second front steering wheel; and / or When the first front steering wheel is the inner wheel and the Ackermann ratio is greater than the upper limit value of the Ackermann compliance ratio range, control the second steering wheel to increase the angle of the second front steering wheel; and / or When the first front steering wheel is the outer wheel and the Ackermann ratio is greater than the upper limit value of the Ackermann compliance ratio range, control the second steering wheel to reduce the angle of the second front steering wheel; and / or When the first front steering wheel is the outer wheel and the Ackermann ratio is less than the lower limit value of the Ackermann compliance ratio range, control the second steering wheel to reduce the angle of the second front steering wheel.

14. The control method according to claim 11, wherein, Before determining the theoretical angles of each steering wheel according to the angle signal, the method further includes: Obtain the vehicle speed; Determine the steering gear ratio according to the vehicle speed, and the steering gear ratio is positively correlated with the vehicle speed; Determining the theoretical angles of each steering wheel according to the angle signal includes: Determine the theoretical angles of each steering wheel according to the steering gear ratio and the angle signal.

15. The control method according to claim 14, wherein, The vehicle further includes a steering wheel motor, and the steering wheel is drivingly connected to the output end of the steering wheel motor; the method further includes: Determining a return torque according to the steering transmission ratio, where the return torque is positively correlated with the steering transmission ratio; Controlling the output of the steering wheel motor according to the return torque.

16. The control method according to claim 14, wherein, The plurality of steering wheels further includes rear steering wheels; The step of determining the theoretical rotation angles of the respective steering wheels according to the angle signal further includes: Determining a third theoretical rotation angle of the rear steering wheel according to the vehicle speed and the first theoretical rotation angle; wherein, when the vehicle speed is less than or equal to a first vehicle speed threshold, the third theoretical rotation angle is opposite to the first theoretical rotation angle in direction; when the vehicle speed is greater than or equal to a second vehicle speed threshold, the third theoretical rotation angle is the same as the first theoretical rotation angle in direction; wherein, the second vehicle speed threshold is greater than the first vehicle speed threshold.

17. An electronic device, wherein, it includes: A processor, a communication interface, a memory, and a communication bus; wherein, the processor, the communication interface, and the memory complete mutual communication through the communication bus; The memory is used for storing a computer program; The processor, when executing the program stored on the memory, implements the steps in the vehicle steering control method according to any one of claims 10 to 16.

18. A computer-readable storage medium, on which a computer program is stored, wherein, When the program is executed by a processor, it implements the steps in the vehicle steering control method according to any one of claims 10 to 16.

19. A vehicle, wherein, It includes the vehicle steering system according to any one of claims 1 to 9.

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