Wheel steering control method, control device, electronic device, and vehicle

Abstract

The present disclosure relates to a wheel steering control method, a wheel steering control device, an electronic device and a vehicle, and the method comprises: receiving a wheel steering instruction, wherein the wheel steering instruction comprises a target steering angle value of a wheel; determining a friction compensation torque, wherein the friction compensation torque is a torque corresponding to an axial frictional force between the wheel and a road surface; determining an output torque of an electric machine according to the friction compensation torque, wherein the output torque of the electric machine is a torque corresponding to a steering angle value of the wheel reaching the target steering angle value; and controlling wheel steering according to the output torque of the electric machine.

Description

Technical Field

[0001] This disclosure relates to vehicle steering technology, and more specifically, to a wheel steering control method, control device, electronic equipment, and vehicle. Background Technology

[0002] In recent years, the trends of electrification and intelligentization in automobiles have become increasingly apparent. Electric Power Steering (EPS), as a crucial aspect of electrification, plays an increasingly significant role. EPS not only facilitates driver operation and improves passenger comfort, but also ensures safety and reliability during driving. Furthermore, EPS forms the basis for many other advanced functions, such as the increasingly popular advanced driver assistance systems (ADAS) and autonomous driving features. Remote driving...

[0003] As one of the technologies for autonomous driving, electric power steering is also closely related to the system. By receiving infrared signals from a remote control device operated by the driver at a certain distance, the car follows the operator's instructions. During vehicle movement, if the vehicle is going straight or maintaining a constant steering angle, the electric power steering controller maintains the steering angle while outputting motor torque. If the turning radius is changed, the electric power steering controller outputs corresponding motor torque to increase or decrease the steering angle.

[0004] The motor torque output by the electric power steering controller has a significant impact on the accuracy of the vehicle's movement according to the driver's driving intentions. Therefore, the calculation of the motor output torque is extremely important in order to improve the reliability and safety of operation. Summary of the Invention

[0005] One objective of this invention is to provide a new technical solution for a wheel steering control method.

[0006] According to a first aspect of the present invention, a wheel steering control method is provided, comprising:

[0007] Receive wheel steering command, wherein the wheel steering command includes a target steering angle value for the wheel;

[0008] Determine the friction compensation torque, wherein the friction compensation torque is the torque corresponding to the axial friction force between the wheel and the road surface;

[0009] Based on the friction compensation torque, the output torque of the motor is determined, wherein the output torque of the motor is the torque that makes the wheel's rotation angle reach the target rotation angle value;

[0010] The wheel steering is controlled based on the output torque of the motor.

[0011] Optionally, determining the friction compensation torque includes:

[0012] Obtain information on road surface friction coefficient and road surface slope;

[0013] Based on the road surface friction coefficient, the vehicle mass, and the road surface slope information, determine the axial friction force between the wheel and the road surface when the wheel turns;

[0014] The friction compensation torque is determined based on the axial friction force and the wheel radius.

[0015] Optionally, the road surface friction coefficient is determined according to the following method:

[0016] Obtain road surface information of the current location of the vehicle;

[0017] The road surface information of the vehicle's current location is input into the trained neural network model to obtain the road surface friction coefficient.

[0018] Optionally, the road surface friction coefficient is determined according to the following method:

[0019] Obtain the road surface information at the time of the vehicle's most recent braking and the road surface information of the vehicle's current location;

[0020] If the road surface information at the time of the vehicle's most recent braking is the same as the road surface information of the vehicle's current location, obtain the ground braking force and brake force at the time of the vehicle's most recent braking.

[0021] If the ground braking force during the vehicle's most recent braking is less than the brake force, the road surface adhesion coefficient is determined based on the ground braking force during the vehicle's most recent braking, and this road surface adhesion coefficient is used as the road surface friction coefficient; or...

[0022] Based on the road surface adhesion coefficient and the first road surface friction coefficient, the second road surface friction coefficient is determined, and the second road surface friction coefficient is used as the road surface friction coefficient; wherein, the first road surface friction coefficient is data obtained by inputting the road surface information of the road surface where the vehicle is currently located into the trained neural network model.

[0023] Optionally, the ground braking force during the vehicle's most recent braking is determined as follows:

[0024] Acquire the vehicle's speed at the start of braking, the vehicle's speed at the end of braking, and the braking duration;

[0025] The vehicle's acceleration value during braking is obtained based on the vehicle's speed value at the start of braking, the vehicle's speed value at the end of braking, and the braking duration.

[0026] The ground braking force during the vehicle's most recent braking event is obtained based on the vehicle's acceleration value during braking and the vehicle's mass.

[0027] Optionally, before determining the motor output torque based on the friction compensation torque, the method further includes:

[0028] Obtain the preset turning angle value and the actual turning angle value of the wheel;

[0029] If the actual turning angle of the wheel is less than the preset turning angle, the vehicle is determined to enter remote steering mode.

[0030] When the vehicle enters remote steering mode, the torque required for angular velocity control is determined, wherein the torque required for angular velocity control is the torque corresponding to the angular velocity of the wheel when the wheel is steering;

[0031] The step of determining the motor output torque based on the friction compensation torque includes:

[0032] The output torque of the motor is determined based on the friction compensation torque and the torque required for angular velocity control.

[0033] Optionally, determining the output torque of the motor based on the friction compensation torque and the torque required for angular velocity control includes:

[0034] The friction compensation torque and the torque required for angular velocity control are added together to obtain the output torque of the motor.

[0035] Optionally, determining the torque required for angular velocity control includes:

[0036] Obtain the target angular velocity value and the actual angular velocity value of the wheel;

[0037] The torque required for angular velocity control is determined based on the target angular velocity value of the wheel and the actual angular velocity value of the wheel.

[0038] Optionally, the method further includes:

[0039] If the actual turning angle of the wheel is not less than the preset turning angle value, the vehicle is determined to enter the remote control holding state;

[0040] When the vehicle is in remote holding mode, the torque required to control the turning angle of the wheels is determined, and the torque required to control the turning angle of the wheels is used as the output torque of the motor.

[0041] Optionally, determining the torque required to control the steering angle of the wheel includes:

[0042] The torque required to control the rotation angle of the wheel is determined based on the preset rotation angle value and the actual rotation angle value of the wheel.

[0043] According to a second aspect of the present invention, a wheel steering control device is provided, comprising:

[0044] A receiving module is used to receive wheel steering commands, wherein the wheel steering commands include a target steering angle value for the wheel;

[0045] A friction compensation torque determination module is used to determine the friction compensation torque, wherein the friction compensation torque is the torque corresponding to overcoming the axial friction force between the wheel and the road surface;

[0046] The motor output torque determination module is used to determine the motor output torque corresponding to the wheel's rotation angle value reaching the target rotation angle value, in conjunction with the friction compensation torque.

[0047] The control module is used to control the steering of the wheels based on the output torque of the motor.

[0048] According to a third aspect of the present invention, an electronic device is provided, comprising a memory and a processor, the memory storing a computer program for controlling the processor to operate in order to perform the wheel steering control method according to any one of the first aspects of the present invention.

[0049] According to a fourth aspect of the invention, a vehicle is provided, including a wheel steering control device as described in the second aspect or an electronic device as described in the third aspect.

[0050] The wheel steering control method provided by this invention involves receiving a wheel steering command, wherein the wheel steering command includes a target turning angle value of the wheel; determining a friction compensation torque, wherein the friction compensation torque is the torque corresponding to overcoming the axial friction force between the wheel and the road surface; determining the output torque of a motor based on the friction compensation torque, wherein the output torque of the motor is the torque corresponding to making the turning angle value of the wheel reach the target turning angle value; and controlling the wheel steering based on the output torque of the motor to eliminate the influence of the axial friction force between the wheel and the road surface, so that the output torque of the motor can ensure that the steering result of the vehicle meets the expected effect.

[0051] The features and advantages of the embodiments of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0052] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of these embodiments.

[0053] Figure 1 This is a flowchart of a wheel steering control method according to an embodiment of the present invention.

[0054] Figure 2 A schematic diagram showing the relationship between ground braking force, brake force and adhesion force when a vehicle brakes.

[0055] Figure 3 A flowchart illustrating a method for determining the road surface friction coefficient according to an embodiment of the present invention is shown.

[0056] Figure 4 A schematic diagram of various remote control states of a vehicle according to an embodiment of the present invention is shown.

[0057] Figure 5 This is another processing flowchart of a wheel steering control method according to an embodiment of the present invention.

[0058] Figure 6 This is another processing flowchart of a wheel steering control method according to an embodiment of the present invention.

[0059] Figure 7 This is a schematic diagram of a wheel steering control device according to an embodiment of the present invention.

[0060] Figure 8 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0061] Various exemplary embodiments of this specification will now be described in detail with reference to the accompanying drawings.

[0062] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the embodiments of this specification or their application or use.

[0063] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0064] <Method Implementation>

[0065] This embodiment provides a wheel steering control method. This wheel steering control method is applicable to both manual driving and autonomous driving, such as remote-controlled driving. Wheel steering can occur when the vehicle is in motion or when the vehicle is not in motion.

[0066] according to Figure 1As shown, the wheel steering control method of this embodiment may include the following steps S110 to S140.

[0067] Step S110: Receive wheel steering command, wherein the wheel steering command includes the target steering angle value of the wheel.

[0068] When the vehicle is manually driven, the driver turns the steering wheel, and the torque sensor collects the corresponding steering angle value and sends this angle value to the wheel steering control device. This angle value is the target steering angle value for the wheels.

[0069] When the vehicle is remotely controlled, the driver sends wheel steering signals to the vehicle by operating the remote control device. This steering signal carries the target steering angle value of the wheels and the direction of steering.

[0070] Step S120: Determine the friction compensation torque, where the friction compensation torque is the torque used to overcome the axial friction force between the wheel and the road surface.

[0071] The axial friction force is the friction force between the wheel and the ground along the axial direction of the wheel.

[0072] Step S130: Determine the output torque of the motor based on the friction compensation torque, wherein the output torque of the motor is the torque corresponding to making the wheel's rotation angle reach the target rotation angle.

[0073] Step S140: Control the wheel steering according to the output torque of the motor.

[0074] The wheel steering control device determines the target current value of the motor based on the motor's output torque. Then, it obtains the actual current value of the motor. Based on the target current value and the actual current value, a current control algorithm calculates the control voltage. According to this control voltage, a drive signal is output to control the inverter, causing the inverter to drive the motor to output the corresponding torque, thereby steering the wheels and achieving the target steering angle.

[0075] When a wheel turns, the steering angle changes continuously, and the influence of axial friction between the wheel and the road surface must be considered. Therefore, the output torque of the motor needs to be compensated. This compensation is used to overcome the axial friction between the wheel and the road surface, ensuring that the motor's output torque can guarantee that the wheel's steering result meets expectations.

[0076] In one embodiment, step S120 specifically includes: acquiring road surface friction coefficient and road surface slope information; determining the axial friction force between the wheel and the road surface when the wheel is turning based on the road surface friction coefficient, the vehicle's mass and the road surface slope information; and determining the friction compensation torque based on the friction force and the wheel radius value.

[0077] In one embodiment, the road surface friction coefficient can be determined by: acquiring road surface information; inputting the road surface information into a trained neural network model to obtain the road surface friction coefficient.

[0078] Road surface information can be road surface images captured by a 2D camera or point cloud data captured by a 3D LiDAR (Light Detection and Ranging) sensor.

[0079] For example, road surface images captured by a 2D camera are input into a corresponding trained neural network model to obtain the road surface friction coefficient. This trained neural network model reflects the correspondence between the road surface image and the road surface friction coefficient. This trained neural network model can identify road surface material information and pothole information in the road surface image, and obtain the road surface friction coefficient based on the road surface material information and pothole information.

[0080] For example, point cloud data acquired by 3D LiDAR is input into a corresponding trained neural network model to obtain the road surface friction coefficient. This trained neural network model reflects the correspondence between the point cloud data and the road surface friction coefficient.

[0081] In one embodiment, the road surface friction coefficient can also be determined as follows: obtaining road surface information at the time of the vehicle's most recent braking and road surface information of the road surface where the vehicle is currently located; if the road surface information at the time of the vehicle's most recent braking and the road surface information of the road surface where the vehicle is currently located are the same, obtaining the ground braking force and brake braking force at the time of the vehicle's most recent braking; if the ground braking force at the time of the vehicle's most recent braking is less than the brake braking force, determining the road surface adhesion coefficient based on the ground braking force at the time of the vehicle's most recent braking, and using the road surface adhesion coefficient as the road surface friction coefficient; or, determining a second road surface friction coefficient based on the road surface adhesion coefficient and a first road surface friction coefficient, and using the second road surface friction coefficient as the road surface friction coefficient; wherein the first road surface friction coefficient is data obtained by inputting the road surface information of the road surface where the vehicle is currently located into a trained neural network model.

[0082] The second road surface friction coefficient is the average value obtained based on the road surface adhesion coefficient and the first road surface friction coefficient.

[0083] The specific method for determining the friction coefficient of the first road surface can be found in the example above, and will not be elaborated further here.

[0084] Figure 2 A schematic diagram showing the relationship between ground braking force, brake force and adhesion force when a vehicle brakes.

[0085] See Figure 2 When the vehicle brakes, when the brake pedal force F p When it is small, the ground braking force Fxb The friction between the road surface and the wheel can overcome the braking torque, causing the wheel to roll. The braking force F from the ground when the wheel is rolling is... xb Equal to the braking force F of the brake μ And with the braking pedal force F p The increase is also proportional to the increase. When the brake pedal force F... p Rise to F p1 At that time, the braking force F of the brake μ It continues to rise. However, the ground braking force F xb Once a maximum value is reached, it stops increasing; this maximum value is equal to the adhesion force.

[0086] Depend on Figure 2 It can be concluded that the vehicle's ground braking force F xb Firstly, it depends on the braking force F of the brake. μ However, it is also subject to adhesion. Restrictions.

[0087] In this embodiment, the ground braking force F during the vehicle's most recent braking action xb Less than the braking force F of the brake μ , combined Figure 2 This indicates that the ground braking force during the vehicle's most recent braking action reached its maximum value, which is equal to the adhesion force. Therefore, the adhesion force can be determined based on the ground braking force during the vehicle's most recent braking, and then the road adhesion coefficient can be determined based on the adhesion force.

[0088] The ground braking force during the vehicle's most recent braking is determined as follows: the vehicle's speed at the start of braking, the vehicle's speed at the end of braking, and the braking duration are obtained; the vehicle's acceleration during braking is obtained based on the vehicle's speed at the start of braking, the vehicle's speed at the end of braking, and the braking duration; and the ground braking force during the vehicle's most recent braking is obtained based on the vehicle's acceleration during braking and the vehicle's mass.

[0089] The speed values ​​at the start of braking and at the end of braking can be determined by data collected by speed sensors installed on the vehicle.

[0090] Based on the following formula (1), the acceleration value a during vehicle braking is calculated.

[0091]

[0092] Where V1 is the vehicle's speed at the start of braking, V2 is the vehicle's speed at the end of braking, and t is the braking duration.

[0093] Based on the following calculation formula (2), the ground braking force F during the vehicle's most recent braking is calculated.

[0094] F = ma — calculation formula (2), where m is the mass of the vehicle and a is the acceleration value of the vehicle when braking.

[0095] Based on the following formula (3), the road surface adhesion coefficient μ is calculated.

[0096]

[0097] Where F is the ground braking force during the vehicle's most recent braking, m is the mass of the vehicle, and g is the acceleration due to gravity.

[0098] The road surface adhesion coefficient can be directly used as the road surface friction coefficient. Alternatively, the average value between the road surface adhesion coefficient and the first road surface friction coefficient can be calculated, and this average value can be used as the road surface friction coefficient. The first road surface friction coefficient is obtained by inputting road surface information of the vehicle's current location into a trained neural network model.

[0099] Figure 3 A flowchart illustrating a method for determining the road surface friction coefficient according to an embodiment of the present invention is shown. See also... Figure 3 The methods for determining the road surface friction coefficient include S301 to S308.

[0100] S301, obtain road surface information.

[0101] S302, input the road surface information into the trained neural network model to obtain the first road surface friction coefficient.

[0102] S303 obtains the ground braking force and brake force during the vehicle's most recent braking action.

[0103] S304: When the ground braking force during the vehicle's most recent braking is less than the brake force, obtain the vehicle's speed at the start of braking, the vehicle's speed at the end of braking, and the braking duration.

[0104] S305: Based on the vehicle's speed at the start of braking, the vehicle's speed at the end of braking, and the braking duration, the acceleration value of the vehicle during braking is obtained.

[0105] S306, based on the vehicle's acceleration value during braking and the vehicle's mass, obtains the ground braking force during the vehicle's most recent braking.

[0106] S307 determines the road adhesion coefficient based on the ground braking force during the vehicle's most recent braking.

[0107] S308 is the average value calculated based on the road surface adhesion coefficient and the first road surface friction coefficient, and this average value is used as the road surface friction coefficient.

[0108] The axial friction force f between the wheel and the road surface when the wheel is turning can be obtained based on the following formula (4). 轴 ,

[0109] f 轴 =μ′×m×g×cosθ—Calculation formula (4),

[0110] Where μ' is the road surface friction coefficient, m is the mass of the vehicle, g is the gravitational acceleration, and θ is the angle between the road surface and the ground plane where the vehicle is currently located.

[0111] The friction compensation torque M1 can be obtained based on the following calculation formula (5).

[0112] M1 = f 轴 ×r—Calculation formula (5),

[0113] Where r is the wheel radius.

[0114] The vehicle's mass and wheel radius values ​​are information pre-stored in the wheel steering control device.

[0115] Road surface slope information can be determined based on data collected by slope sensors. The data collected by slope sensors can be the angle between the road surface and the ground plane where the vehicle is currently located.

[0116] Taking remote driving as an example, the conditions that a vehicle must meet to enter the remote control preparation state from the remote control exit state include at least the following: no permanent faults in the EPS, no temporary faults in the EPS, no communication faults related to remote driving in the EPS, vehicle speed below 2km / s, driver input force less than 3Nm, and gear shift lever in P gear.

[0117] When all the conditions listed above are met, the vehicle moves from the remote control off state to the remote control ready state. When any of the conditions listed above are not met, the vehicle moves from the remote control ready state back to the remote control off state.

[0118] When the vehicle enters remote control ready state and receives a wheel steering signal from the remote control device, it acquires the preset steering angle value and the actual wheel steering angle value. Based on the preset steering angle value and the actual wheel steering angle value, it determines whether the vehicle enters remote control steering mode or remote control holding mode. In remote control steering mode, the wheel steering angle value continuously changes. In remote control holding mode, the wheel steering angle value remains at the preset steering angle value.

[0119] When the actual steering angle of the wheels is less than the preset steering angle, the vehicle enters remote steering mode. When the actual steering angle of the wheels is not less than the preset steering angle, the vehicle enters remote hold mode.

[0120] The actual steering angle of a wheel can be determined by data collected from steering angle sensors installed on the vehicle.

[0121] The preset steering angle value is pre-calibrated data and stored in the wheel steering control device. For example, the preset steering angle value is the steering angle value corresponding to 90% of the maximum allowable steering angle value.

[0122] Setting a preset steering angle value is to prevent the wheel from turning too much and causing damage to the vehicle, thus protecting the vehicle.

[0123] The actual steering angle of the wheel is real-time data. Accordingly, the comparison step between the actual steering angle of the wheel and the preset steering angle value can be performed once every preset time interval.

[0124] When the vehicle is in remote steering mode, if the actual wheel angle exceeds the preset angle, the vehicle will switch from remote steering mode to remote hold mode. When the vehicle is in remote hold mode, if the actual wheel angle does not exceed the preset angle, the vehicle will switch from remote hold mode to remote steering mode.

[0125] Once the vehicle completes the wheel steering signal sent by the remote control device, the vehicle returns to the remote control ready state.

[0126] Figure 4 A schematic diagram illustrating various remote control states of a vehicle according to an embodiment of the present invention is shown. See also Figure 4 The vehicle can switch between remote control off state, remote control ready state, remote control steering state, and remote control hold state. Figure 4 It also shows the conditions for switching between each state.

[0127] In one embodiment, when the vehicle enters remote steering mode, in addition to determining the friction compensation torque, it is also necessary to determine the torque required for angular velocity control. The torque required for angular velocity control is the torque corresponding to the angular velocity of the wheel used to control the wheel's steering. Based on the friction compensation torque and the torque required for angular velocity control, the output torque of the motor corresponding to achieving the target steering angle value of the wheel is determined.

[0128] Determining the torque required for angular velocity control includes: obtaining the target angular velocity value and the actual angular velocity value of the wheel; and determining the torque required for angular velocity control based on the target angular velocity value and the actual angular velocity value of the wheel.

[0129] Specifically, the difference between the target angular velocity value and the actual angular velocity value of the wheel is used as the input value to perform PI (proportional integral) control, thereby determining the torque required for angular velocity control.

[0130] The target angular velocity value of the wheel is pre-calibrated data and stored in the wheel steering control device. For example, the target angular velocity value of the wheel can be set to 120 degrees / second.

[0131] The actual angular velocity of a wheel can be determined by data collected from angular velocity sensors installed on the vehicle.

[0132] The friction compensation torque and the torque required for angular velocity control are added together to obtain the motor output torque corresponding to the wheel's rotation angle value reaching the target rotation angle value.

[0133] In one embodiment, when the vehicle is in remote hold mode, the wheel angle remains constant, and the influence of axial friction between the wheel and the road surface does not need to be considered. Therefore, there is no need to compensate for the motor's output torque.

[0134] When the vehicle is in remote hold mode, the torque required to control the wheel angle is determined, and the torque required to control the wheel angle is used as the output torque of the motor.

[0135] Determining the torque required to control the wheel's rotation angle includes: determining the torque required to control the wheel's rotation angle based on the wheel's preset rotation angle value and the wheel's actual rotation angle value.

[0136] Specifically, the difference between the preset steering angle value and the actual steering angle value of the wheel is used as the input value for PI control to determine the torque required to control the steering angle of the wheel.

[0137] The actual steering angle of a wheel can be determined by data collected from steering angle sensors installed on the vehicle.

[0138] Figure 5 Another processing flowchart of the wheel steering control method according to an embodiment of the present invention is shown.

[0139] In this embodiment, the actual steering angle of the vehicle is 0 before receiving the wheel steering signal sent by the remote control device.

[0140] according to Figure 5 The wheel steering control method includes steps S501 to S508.

[0141] Step S501: Receive the wheel steering signal sent by the remote control device. This steering signal carries the target turning angle value of the wheel and the steering direction of the wheel.

[0142] Step S502: Obtain the preset angle value.

[0143] Step S503: Determine whether the target turning angle value of the wheel is less than the preset turning angle value.

[0144] If the judgment result in step S503 is that the target steering angle value of the wheel is less than the preset steering angle value, then step S504 is executed, the vehicle enters remote steering state, and the friction compensation torque and the torque required for the first angular velocity control are determined. The torque required for the first angular velocity control is the torque required to make the wheel's steering angle value reach the target steering angle value.

[0145] Step S505: Add the friction compensation torque and the torque required for the first angular velocity control to obtain the output torque of the motor that makes the wheel's rotation angle reach the target rotation angle value, and control the wheel steering according to the output torque of the motor.

[0146] If the judgment result in step S503 is that the target steering angle value of the wheel is not less than the preset steering angle value, then step S506 is executed. The vehicle first enters the remote steering state, and the friction compensation torque and the torque required for the second angular velocity control are determined. The torque required for the second angular velocity control is the torque determined to make the wheel steering angle value reach the preset steering angle value.

[0147] Step S507: Add the friction compensation torque and the torque required for the second angular velocity control to obtain the output torque of the motor that makes the wheel's rotation angle reach the preset rotation angle value, and control the wheel steering according to the output torque of the motor.

[0148] Step S508: Real-time detection of the actual wheel angle value. When the actual wheel angle value reaches the preset angle value, the vehicle enters the remote control holding state, determines the torque required to control the wheel angle, and uses the torque required to control the wheel angle as the output torque of the motor. Based on the output torque of the motor, the wheel steering is controlled.

[0149] Figure 6 Another processing flowchart of the wheel steering control method according to an embodiment of the present invention is shown.

[0150] In this embodiment, the actual turning angle of the vehicle is greater than the preset turning angle value before the wheel steering signal sent by the remote control device is received.

[0151] according to Figure 6 The wheel steering control method includes steps S601 to S603.

[0152] Step S601: Receive the wheel steering signal sent by the remote control device. This steering signal carries the target turning angle value of the wheel and the steering direction of the wheel.

[0153] In step S602, the vehicle enters the remote control holding state, determines the torque required to control the wheel angle, and uses the torque required to control the wheel angle as the output torque of the motor.

[0154] Step S603: Control the wheel steering according to the output torque of the motor.

[0155] <Device Embodiment>

[0156] One embodiment of the present invention provides a wheel steering control device, such as... Figure 7 As shown. The wheel steering control device 700 includes a receiving module 710, a friction compensation torque determination module 720, a motor output torque determination module 730, and a control module 740.

[0157] The receiving module 710 is used to receive wheel steering commands, wherein the wheel steering commands include the target steering angle value of the wheel.

[0158] The friction compensation torque determination module 720 is used to determine the friction compensation torque, which is the torque used to overcome the axial friction force between the wheel and the road surface.

[0159] The motor output torque determination module 730 is used to determine the motor output torque based on the friction compensation torque, wherein the motor output torque is the torque corresponding to making the wheel's rotation angle reach the target rotation angle value.

[0160] The control module 740 is used to control the wheel steering based on the output torque of the motor.

[0161] In one embodiment, the friction compensation torque determination module 720 is further configured to acquire road surface friction coefficient and road surface slope information; determine the axial friction force between the wheel and the road surface when the wheel is turning based on the road surface friction coefficient, the vehicle mass and the road surface slope information; and determine the friction compensation torque based on the axial friction force and the wheel radius value.

[0162] In one embodiment, the road surface friction coefficient is determined by: obtaining road surface information of the road surface where the vehicle is currently located; inputting the road surface information of the road surface where the vehicle is currently located into a trained neural network model to obtain the road surface friction coefficient.

[0163] In one embodiment, the road surface friction coefficient is determined by: acquiring road surface information at the time of the vehicle's most recent braking and road surface information of the road surface where the vehicle is currently located; if the road surface information at the time of the vehicle's most recent braking and the road surface information of the road surface where the vehicle is currently located are the same, acquiring the ground braking force and the brake braking force at the time of the vehicle's most recent braking; if the ground braking force at the time of the vehicle's most recent braking is less than the brake braking force, determining the road surface friction coefficient based on the ground braking force at the time of the vehicle's most recent braking.

[0164] In this embodiment, the ground braking force during the vehicle's most recent braking is determined as follows: the vehicle's speed value at the start of braking, the vehicle's speed value at the end of braking, and the braking duration are obtained; the vehicle's acceleration value during braking is obtained based on the vehicle's speed value at the start of braking, the vehicle's speed value at the end of braking, and the braking duration; and the ground braking force during the vehicle's most recent braking is obtained based on the vehicle's acceleration value during braking and the vehicle's mass.

[0165] In one embodiment, the wheel steering control device further includes: an acquisition module, a remote control status determination module, a torque determination module required for angular velocity control, and a torque determination module required for controlling the wheel's turning angle.

[0166] The acquisition module is used to obtain the preset turning angle value and the actual turning angle value of the wheel.

[0167] The remote control status determination module is used to determine that the vehicle has entered remote steering state when the actual turning angle of the wheels is less than the preset turning angle value.

[0168] The angular velocity control required torque determination module is used to determine the required torque for angular velocity control when the vehicle enters remote steering mode. The required torque for angular velocity control is the torque corresponding to the angular velocity used to control the wheels when steering. The motor output torque determination module 530 is also used to determine the motor output torque based on the friction compensation torque and the required torque for angular velocity control.

[0169] The motor output torque determination module 530 is also used to add the friction compensation torque and the torque required for angular velocity control to obtain the motor output torque.

[0170] The torque determination module for angular velocity control is also used to obtain the target angular velocity value and the actual angular velocity value of the wheel; and to determine the torque required for angular velocity control based on the target angular velocity value and the actual angular velocity value of the wheel.

[0171] The remote control status determination module is also used to determine that the vehicle has entered the remote control holding state when the actual turning angle of the wheel is not less than the preset turning angle value.

[0172] The torque determination module for controlling the wheel angle is used to determine the torque required to control the wheel angle when the vehicle is in remote holding mode, and uses the torque required to control the wheel angle as the output torque of the motor.

[0173] The torque determination module for controlling the wheel's rotation angle is also used to determine the torque required to control the wheel's rotation angle based on the wheel's preset rotation angle value and the wheel's actual rotation angle value.

[0174] One embodiment of the present invention provides an electronic device, such as... Figure 8As shown. The electronic device 800 includes a memory 820 and a processor 810. The memory 820 stores a computer program for controlling the processor 810 to operate and execute the wheel steering control method in any of the above embodiments.

[0175] One embodiment of the present invention provides a vehicle. The vehicle includes a wheel steering control device or an electronic device as described in any of the above embodiments.

[0176] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. For the electric vehicle embodiments, relevant parts can be found in the descriptions of the method embodiments.

[0177] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0178] Embodiments of this specification may be systems, methods, and / or computer program products. A computer program product may include a computer-readable storage medium having computer instructions stored thereon for causing a processor to implement various aspects of the embodiments of this specification.

[0179] Computer-readable storage media can be tangible devices capable of holding and storing computer instructions for use by computer instruction execution devices. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing computer instructions thereon, and any suitable combination thereof. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0180] The computer instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper cables, fiber optic cables, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives computer instructions from the network and forwards them to computer-readable storage media within the respective computing / processing device.

[0181] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this specification. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of computer instructions, which contains one or more executable computer instructions for implementing a specified logical function. In some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions. It will be known to those skilled in the art that implementation in hardware, implementation in software, and implementation using a combination of software and hardware are equivalent.

[0182] Various embodiments of this specification have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for controlling wheel steering, characterized in that, include: Receive wheel steering command, wherein the wheel steering command includes a target steering angle value for the wheel; Determine the friction compensation torque, wherein the friction compensation torque is the torque corresponding to the axial friction force between the wheel and the road surface; Obtain the preset turning angle value and the actual turning angle value of the wheel; If the actual turning angle of the wheel is less than the preset turning angle, the vehicle is determined to enter remote steering mode. When the vehicle enters remote steering mode, the torque required for angular velocity control is determined, wherein the torque required for angular velocity control is the torque corresponding to the angular velocity of the wheel when the wheel is steering; The output torque of the motor is determined based on the friction compensation torque and the torque required for angular velocity control, wherein the output torque of the motor is the torque that makes the wheel's rotation angle reach the target rotation angle value; The wheel steering is controlled based on the output torque of the motor.

2. The method according to claim 1, characterized in that, The determination of the friction compensation torque includes: Obtain information on road surface friction coefficient and road surface slope; Based on the road surface friction coefficient, the vehicle mass, and the road surface slope information, determine the axial friction force between the wheel and the road surface when the wheel turns; The friction compensation torque is determined based on the axial friction force and the wheel radius.

3. The method according to claim 2, characterized in that, The road surface friction coefficient is determined according to the following method: Obtain road surface information of the current location of the vehicle; The road surface information of the vehicle's current location is input into the trained neural network model to obtain the road surface friction coefficient.

4. The method according to claim 2, characterized in that, The road surface friction coefficient is determined according to the following method: Obtain the road surface information at the time of the vehicle's most recent braking and the road surface information of the vehicle's current location; If the road surface information at the time of the vehicle's most recent braking is the same as the road surface information of the vehicle's current location, obtain the ground braking force and brake force at the time of the vehicle's most recent braking. If the ground braking force during the vehicle's most recent braking is less than the brake force, the road surface adhesion coefficient is determined based on the ground braking force during the vehicle's most recent braking, and the road surface adhesion coefficient is used as the road surface friction coefficient. or, Based on the road surface adhesion coefficient and the first road surface friction coefficient, a second road surface friction coefficient is determined, and the second road surface friction coefficient is used as the road surface friction coefficient; wherein, the first road surface friction coefficient is data obtained by inputting the road surface information of the road surface where the vehicle is currently located into the trained neural network model.

5. The method according to claim 4, characterized in that, The ground braking force during the vehicle's most recent braking was determined in the following manner: Acquire the vehicle's speed at the start of braking, the vehicle's speed at the end of braking, and the braking duration; The vehicle's acceleration value during braking is obtained based on the vehicle's speed value at the start of braking, the vehicle's speed value at the end of braking, and the braking duration. The ground braking force during the vehicle's most recent braking event is obtained based on the vehicle's acceleration value during braking and the vehicle's mass.

6. The method according to claim 1, characterized in that, The step of determining the output torque of the motor based on the friction compensation torque and the torque required for angular velocity control includes: The friction compensation torque and the torque required for angular velocity control are added together to obtain the output torque of the motor.

7. The method according to claim 1, characterized in that, The torque required for determining angular velocity control includes: Obtain the target angular velocity value and the actual angular velocity value of the wheel; The torque required for angular velocity control is determined based on the target angular velocity value of the wheel and the actual angular velocity value of the wheel.

8. The method according to any one of claims 1, 6, and 7, characterized in that, The method further includes: If the actual turning angle of the wheel is not less than the preset turning angle value, the vehicle is determined to enter the remote control holding state; When the vehicle is in remote holding mode, the torque required to control the turning angle of the wheels is determined, and the torque required to control the turning angle of the wheels is used as the output torque of the motor.

9. The method according to claim 8, characterized in that, The torque required to determine the steering angle of the control wheel includes: The torque required to control the rotation angle of the wheel is determined based on the preset rotation angle value and the actual rotation angle value of the wheel.

10. A wheel steering control device, characterized in that, The device includes: A receiving module is used to receive wheel steering commands, wherein the wheel steering commands include a target steering angle value for the wheel; The acquisition module is used to acquire the preset turning angle value and the actual turning angle value of the wheel; The remote control status determination module is used to determine that the vehicle has entered the remote control steering state when the actual turning angle of the wheels is less than the preset turning angle value. The torque required for angular velocity control is determined when the vehicle enters remote steering mode. The torque required for angular velocity control is the torque corresponding to the angular velocity of the wheel when the wheel is steering. A friction compensation torque determination module is used to determine the friction compensation torque, wherein the friction compensation torque is the torque corresponding to overcoming the axial friction force between the wheel and the road surface; The motor output torque determination module is used to determine the output torque of the motor based on the friction compensation torque and the torque required for angular velocity control, wherein the output torque of the motor is the torque corresponding to making the wheel's rotation angle value reach the target rotation angle value; The control module is used to control the steering of the wheels based on the output torque of the motor.

11. An electronic device, characterized in that, It includes a memory and a processor, the memory storing a computer program for controlling the processor to operate in order to perform the method according to any one of claims 1-9.

12. A vehicle, characterized in that, This includes the wheel steering control device as described in claim 10 or the electronic device as described in claim 11.

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