Control method and apparatus for in-situ steering of vehicle

Abstract

A control method and apparatus for in-situ steering of a vehicle, a computer-readable storage medium, a controller, and a vehicle. In the control method, when a vehicle meets an in-situ steering condition, a controller controlling both front wheels of the vehicle to periodically rotate forwards and backwards (101); and controlling two rear wheels of the vehicle to rotate (102), wherein the rotating directions of the two rear wheels are opposite, and the rotating speeds of the two rear wheels are both greater than the rotating speeds of the two front wheels.

Description

Control method and device for vehicle turning in place

[0001] Priority information

[0002] This application claims priority and benefits of patent application No. 2024103812387 filed with the State Intellectual Property Office of China on March 28, 2024, and the entire text of which is incorporated herein by reference. Technical Field

[0003] The present application relates to the field of vehicles, and in particular to a control method and device for vehicle on-the-spot steering. Background Art

[0004] In the related art, special mechanical components (such as universal wheels and omni-directional wheels) can usually be set in the vehicle, and the controller in the vehicle can use the mechanical components to drive the vehicle to achieve on-the-spot turning.

[0005] However, since mechanical components need to be installed in the vehicle, the hardware cost of controlling the vehicle's on-the-spot steering is relatively high. Summary of the Invention

[0006] This application provides a method and device for controlling vehicle pivot steering, which can solve the problem of high hardware cost for controlling vehicle pivot steering in related technologies. The technical solution is as follows:

[0007] In one aspect, a method for controlling vehicle pivoting is provided, the method comprising:

[0008] When the vehicle meets the conditions for turning in place, the two front wheels of the vehicle are controlled to rotate forward and reverse periodically;

[0009] Control the rotation of the two rear wheels of the vehicle;

[0010] The two rear wheels rotate in opposite directions, and the rotation speeds of the two rear wheels are greater than the rotation speeds of the two front wheels.

[0011] In some embodiments of the present application, for each rear wheel, when the reference torque is within the torque range, the torque of the rear wheel motor of the rear wheel is the reference torque;

[0012] The reference torque is determined according to a target wheel speed, which is selected from a plurality of wheel speeds.

[0013] In some embodiments of the present application, when the reference torque is less than the lower limit of the torque range, the torque of the rear wheel motor of the rear wheel is the lower limit;

[0014] When the reference torque is greater than the upper limit of the torque range, the torque of the rear wheel motor of the rear wheel is at the upper limit.

[0015] In some embodiments of the present application, the lower limit of the torque range is determined according to the ratio of the first product to the second product.

[0016] The upper limit of the torque range is determined by the ratio of the third product to the speed ratio; wherein,

[0017] The first product is determined by the rolling radius of the rear wheels and the stationary steering resistance torque, the second product is determined by the speed ratio and the rear wheel track, and the third product is determined by the rolling radius, the vehicle's sprung mass, and the road adhesion coefficient.

[0018] In some embodiments of the present application, the road surface adhesion coefficient is an adhesion coefficient corresponding to the target road surface type in the correspondence data between road surface types and adhesion coefficients;

[0019] The target road surface type is selected from multiple road surface types.

[0020] In some embodiments of the present application, the torque of the front wheel motors of the two front wheels is determined according to the product of the target value and the preset value;

[0021] The target value is the smaller value of the torque of the two rear wheel motors, and the preset value is less than 1.

[0022] In some embodiments of the present application, the period of the forward and reverse rotation of the front wheel motor is a target period corresponding to the target in-place steering mode in the corresponding data of the steering mode and period;

[0023] The target in-place turning mode is selected from a plurality of in-place turning modes.

[0024] In some embodiments of the present application, the pivoting condition includes: the vehicle is stationary, and the turning angles of the two front wheels and the turning angles of the two rear wheels are both within an angle range.

[0025] In some embodiments of the present application, the following conditions are met when the vehicle is stationary:

[0026] The lateral speed of the vehicle is less than or equal to a first speed threshold, the longitudinal speed of the vehicle is less than or equal to a second speed threshold, the lateral acceleration of the vehicle is less than or equal to a first acceleration threshold, and the longitudinal acceleration of the vehicle is less than or equal to a second acceleration threshold.

[0027] In some embodiments of the present application, the method further comprises:

[0028] In response to the stationary turn exit instruction, when the lateral swing angular velocity of the vehicle is less than or equal to a first preset angular velocity and the longitudinal swing angular velocity of the vehicle is less than or equal to a second preset angular velocity, the vehicle is controlled to brake.

[0029] On the other hand, a computer-readable storage medium is provided, on which a control program for vehicle pivoting is stored. When the control program for vehicle pivoting is executed by a processor, the above-mentioned control method for vehicle pivoting is implemented.

[0030] On the other hand, a controller is provided, comprising a memory, a processor, and a control program for vehicle steering on the spot stored in the memory and runnable on the processor. When the processor executes the control program for vehicle steering on the spot, the above-mentioned control method for vehicle steering on the spot is implemented.

[0031] In another aspect, a control device for turning a vehicle in place is provided, the device comprising:

[0032] A first control module is configured to control both front wheels of the vehicle to periodically rotate forward and reverse when the vehicle satisfies a turning condition in situ; and

[0033] a second control module, for controlling the rotation of two rear wheels of the vehicle;

[0034] The two rear wheels rotate in opposite directions, and the rotation speeds of the two rear wheels are greater than the rotation speeds of the two front wheels.

[0035] On the other hand, a vehicle is provided, comprising: the above-mentioned controller; or the above-mentioned control device for vehicle turning on the spot.

[0036] In summary, the embodiments of the present application provide a method and apparatus for controlling a vehicle pivoting. In this method, upon determining that the vehicle satisfies pivoting conditions, a controller controls both front wheels of the vehicle to periodically rotate forward and reverse, and controls both rear wheels of the vehicle to rotate. The rear wheels rotate in opposite directions, and the speeds of the rear wheels are both greater than the speeds of the front wheels.

[0037] Because the speed of both rear wheels is greater than that of the front wheels, the controller controls both front wheels to periodically rotate forward and reverse. During this process, the rear wheels can drive the front wheels to rotate in opposite directions, achieving a near-in-place steering of the vehicle around the front axle. Compared to related technologies, this reduces the hardware cost of controlling the vehicle's in-place steering by eliminating the need for mechanical components within the vehicle.

[0038] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG1 is a flow chart of a method for controlling vehicle pivoting according to an embodiment of the present application;

[0040] FIG2 is a flow chart of another method for controlling vehicle pivoting according to an embodiment of the present application;

[0041] FIG3 is a schematic diagram of a trajectory of a vehicle turning in place provided by an embodiment of the present application;

[0042] FIG4 is a schematic diagram of the structure of a controller provided in an embodiment of the present application;

[0043] FIG5 is a block diagram of a control device for vehicle pivot steering provided by an embodiment of the present application;

[0044] FIG6 is a schematic structural diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0046] FIG1 is a flow chart of a method for controlling a vehicle turning in place according to an embodiment of the present application. The method can be applied to a controller 40 (shown in FIG4 ) in a vehicle 100 (shown in FIG6 ). Referring to FIG1 , FIG4 and FIG6 , the method includes:

[0047] Step 101: When the vehicle 100 meets the in-situ turning condition, control both front wheels of the vehicle 100 to rotate forward and reverse periodically.

[0048] When the controller 40 determines that the vehicle 100 meets the on-the-spot turning condition, the controller 40 may control both front wheels of the vehicle 100 to rotate forward and reverse periodically.

[0049] Step 102: Control the two rear wheels of the vehicle 100 to rotate.

[0050] The controller 40 controls the two front wheels of the vehicle 100 to rotate forward and reverse periodically, and can also control the two rear wheels of the vehicle 100 to rotate. The rotation directions of the two rear wheels are opposite, and the rotation speeds of the two rear wheels are greater than the rotation speeds of the two front wheels.

[0051] In summary, an embodiment of the present application provides a control method for turning a vehicle in place, in which the controller 40 controls the two front wheels of the vehicle 100 to rotate forward and reverse periodically, and controls the two rear wheels of the vehicle 100 to rotate, when determining that the vehicle 100 meets the turning-in-place conditions. The two rear wheels rotate in opposite directions, and the rotation speeds of the two rear wheels are both greater than the rotation speeds of the two front wheels. Since the rotation speeds of the two rear wheels are both greater than the rotation speeds of the two front wheels, the controller 40 controls the two front wheels of the vehicle 100 to rotate forward and reverse periodically, and controls the two rear wheels to rotate in opposite directions. In this process, the two rear wheels can drive the two front wheels to rotate, so as to achieve approximate turning-in-place of the vehicle 100 around the center of the front axle. Compared with the related art, since the vehicle 100 can be controlled to turn in place without setting mechanical components in the vehicle 100, the hardware cost of controlling the vehicle 100 to turn in place is reduced.

[0052] Optionally, for each rear wheel, when the reference torque is within the torque range, the torque of the rear wheel motor of the rear wheel is the reference torque;

[0053] The reference torque is determined according to a target wheel speed, which is selected from a plurality of wheel speeds.

[0054] Optionally, when the reference torque is less than the lower limit of the torque range, the torque of the rear wheel motor of the rear wheel is the lower limit; when the reference torque is greater than the upper limit of the torque range, the torque of the rear wheel motor of the rear wheel is the upper limit.

[0055] The lower limit of the torque range is determined according to the ratio of the first product to the second product.

[0056] The upper limit of the torque range is determined by the ratio of the third product to the speed ratio; wherein,

[0057] The first product is determined by the rolling radius of the rear wheels and the stationary steering resistance torque, the second product is determined by the speed ratio and the rear wheel track, and the third product is determined by the rolling radius, the vehicle's sprung mass, and the road adhesion coefficient.

[0058] Optionally, the road surface adhesion coefficient is an adhesion coefficient corresponding to the target road surface type in the correspondence data between road surface types and adhesion coefficients;

[0059] The target road surface type is selected from multiple road surface types.

[0060] Optionally, the torque of the front wheel motors of the two front wheels is determined according to the product of the target value and a preset value;

[0061] The target value is the smaller value of the torque of the two rear wheel motors, and the preset value is less than 1.

[0062] Optionally, the forward and reverse rotation period of the front wheel motor is a target period corresponding to the target in-situ steering mode in the corresponding data of the steering mode and period;

[0063] The target in-place turning mode is selected from a plurality of in-place turning modes.

[0064] Optionally, the pivoting condition includes: the vehicle 100 is stationary, and the turning angles of the two front wheels and the turning angles of the two rear wheels are both within an angle range.

[0065] Optionally, the vehicle 100 satisfies the following conditions when it is stationary:

[0066] The lateral speed of the vehicle 100 is less than or equal to the first speed threshold, the longitudinal speed of the vehicle 100 is less than or equal to the second speed threshold, the lateral acceleration of the vehicle 100 is less than or equal to the first acceleration threshold, and the longitudinal acceleration of the vehicle 100 is less than or equal to the second acceleration threshold.

[0067] FIG2 is a flow chart of another method for controlling vehicle pivoting according to an embodiment of the present application. This method can be applied to the controller 40 (shown in FIG4 ) of the vehicle 100 (shown in FIG6 ). Referring to FIG2 , FIG4 and FIG6 , this method may include:

[0068] Step 201: Detect whether the vehicle 100 meets the on-the-spot turning condition.

[0069] In response to the pivot instruction, the controller 40 may detect whether the vehicle 100 satisfies the pivot condition. If it is determined that the vehicle 100 satisfies the pivot condition, step 202 may be executed. If it is determined that the vehicle 100 does not satisfy the pivot condition, step 206 and / or step 207 may be executed.

[0070] Optionally, if the controller 40 determines that the vehicle 100 is stationary and the steering angles of the two front wheels and the steering angles of the two rear wheels are both within an angle range, the controller 40 may determine that the vehicle 100 meets the pivoting condition. If the controller 40 determines that the vehicle 100 is not stationary and / or the steering angle of at least one of the two front wheels and the two rear wheels is not within the angle range, the controller 40 may determine that the vehicle 100 does not meet the pivoting condition. The vehicle 100 may pre-store the angle range. For example, the lower limit of the angle range may be 0 degrees and the upper limit may be 5 degrees.

[0071] Optionally, if it is determined that the vehicle 100 is not in a stationary state, step 206 may be executed. If it is determined that the turning angle of at least one of the two front wheels and the two rear wheels is not within the angle range, step 207 may be executed.

[0072] The controller 40 may obtain the lateral velocity, longitudinal velocity, lateral acceleration, and longitudinal acceleration of the vehicle 100. If the lateral velocity is less than or equal to a first velocity threshold, the longitudinal velocity is less than or equal to a second velocity threshold, the lateral acceleration is less than or equal to the first acceleration threshold, and the longitudinal acceleration is less than or equal to the second acceleration threshold, then it may be determined that the vehicle 100 is stationary.

[0073] If the vehicle 100 satisfies at least one of the following target conditions, it can be determined that the vehicle 100 is not stationary. The target conditions may include: a lateral speed greater than a first speed threshold, a longitudinal speed greater than a second speed threshold, a lateral acceleration greater than a first acceleration threshold, and a longitudinal acceleration greater than a second acceleration threshold.

[0074] The controller 40 may pre-store a first speed threshold, a second speed threshold, a first acceleration threshold, and a second acceleration threshold. The first speed threshold and the second speed threshold may be the same or different, and the first acceleration threshold and the second acceleration threshold may be the same or different, which is not limited in the present embodiment.

[0075] Optionally, a speed sensor may be provided on the surface of the vehicle 100, and an angle sensor may be provided on the wheel. The controller 40 may obtain the lateral speed, longitudinal speed, lateral acceleration and longitudinal acceleration through the speed sensor. An angle sensor may be provided on each of the two front wheels and the two rear wheels. The controller 40 may obtain the turning angle of the corresponding wheel through each angle sensor.

[0076] Step 202: Obtain a first torque of the first rear wheel motor, a second torque of the second rear wheel motor, and a third torque of the front wheel motor.

[0077] When the controller 40 determines that the vehicle 100 satisfies the pivoting condition, the controller 40 may obtain the first torque of the first rear wheel motor, the second torque of the second rear wheel motor, and the third torque of the front wheel motor.

[0078] There may be two front wheels, and the two front wheels share a single front wheel motor, i.e., the single front wheel motor drives the two front wheels. The rear wheels may include a first rear wheel and a second rear wheel, with the first rear wheel motor driving the first rear wheel and the second rear wheel motor driving the second rear wheel. The first torque and the second torque are both greater than the third torque, i.e., the rotational speed of the two rear wheels is greater than the rotational speed of the two front wheels. For example, the rotational speed of the front wheels may be 0.25 times that of the rear wheels.

[0079] Optionally, for each of the first rear wheel motor and the second rear wheel motor, the vehicle 100 can select a target wheel speed of the rear wheel corresponding to the rear wheel motor from a plurality of wheel speeds, and determine a reference torque of the rear wheel motor based on the target wheel speed. If the reference torque is within the torque range, the reference torque can be determined as the torque of the rear wheel motor.

[0080] If the reference torque is less than the lower limit of the torque range, the lower limit can be determined as the torque of the rear wheel motor. If the reference torque is greater than the upper limit of the torque range, the upper limit can be determined as the torque of the rear wheel motor. The controller 40 can pre-store data corresponding to wheel speeds and torques. The controller 40 can determine the reference torque corresponding to the target wheel speed from the data corresponding to wheel speeds and torques.

[0081] In an embodiment of the present application, the controller 40 may display a plurality of wheel speeds on the central console of the vehicle 100 in response to an on-the-spot steering instruction, and may determine the wheel speed selected by the driver from the plurality of wheel speeds as the target wheel speed.

[0082] Optionally, the torque range determination process of the controller 40 may include the following steps:

[0083] Step A1: Obtain the stationary steering resistance torque of the vehicle 100, the rolling radius of the rear wheels, the speed ratio of the wheel-side reducer, the track width of the rear wheels, and the sprung mass of the entire vehicle.

[0084] The controller 40 can obtain the stationary steering resistance torque, the rolling radius of the rear wheels, the speed ratio of the wheel-side speed reducer, the track width of the rear wheels, the sprung mass of the entire vehicle, and the road adhesion coefficient of the vehicle 100. The controller 40 can pre-store the rear wheel rolling radius, the speed ratio of the wheel-side speed reducer, the track width of the rear wheels, and the sprung mass of the entire vehicle.

[0085] In the embodiment of the present application, the main factors affecting the stationary steering resistance may include the sprung mass of the vehicle, the selected tires, the actual tire pressure, and the road adhesion coefficient. Therefore, the stationary steering resistance torque M0 may satisfy:

[0086] Wherein, f is the road adhesion coefficient, G is the sprung mass of the entire vehicle, and P is the tire pressure of the rear wheel. The controller 40 may pre-store the tire pressure of the rear wheel.

[0087] The controller 40 can select a target road surface type from a plurality of road surface types and determine the road surface adhesion coefficient corresponding to the target road surface type from the corresponding data between road surface types and adhesion coefficients. The plurality of road surface types can include good road surfaces (e.g., various paved roads), medium road surfaces (e.g., dirt and gravel roads), and poor road surfaces (e.g., icy and snowy roads). The controller 40 can pre-store the corresponding data between road surface types and adhesion coefficients. For example, if the road surface type in the corresponding data is good, the adhesion coefficient corresponding to this road surface type may be 0.9; if the road surface type in the corresponding data is medium, the adhesion coefficient corresponding to this road surface type may be 0.6; and if the road surface type in the corresponding data is poor, the adhesion coefficient corresponding to this road surface type may be 0.3.

[0088] In an embodiment of the present application, the controller 40 can display multiple road surface types on the central console of the vehicle 100 in response to an on-the-spot steering instruction, and can determine the road surface type selected by the driver from the multiple road surface types as the target road surface type.

[0089] Step A2: Determine a first product of the rolling radius and the stationary steering resistance torque, determine a second product of the speed ratio and the wheelbase, and determine a third product of the rolling radius, the sprung mass of the vehicle, and the road adhesion coefficient.

[0090] After the controller 40 obtains the vehicle 100's stationary steering resistance torque, the rolling radius of the rear wheels, the speed ratio of the wheel-side reducer, the wheelbase of the rear wheels, the sprung mass of the entire vehicle and the road adhesion coefficient, it can determine the first product of the rolling radius and the stationary steering resistance torque, determine the second product of the speed ratio and the wheelbase, and determine the third product of the rolling radius, the sprung mass of the entire vehicle and the road adhesion coefficient.

[0091] Among them, the first product p1 can satisfy: p1=i×M0

[0092] The second product p2 can satisfy: p2=i×b

[0093] The third product p3 can satisfy: p3 = r × G × f

[0094] i is the speed ratio of the wheel-end reducer, M0 is the in-situ steering resistance torque in nanometers (nm), b is the track width of the rear wheels, r is the rolling radius in meters (m), and G is the sprung mass of the vehicle.

[0095] Step A3: Determine a lower limit of the torque range based on the ratio of the first product to the second product, and determine an upper limit of the torque range based on the ratio of the third product to the speed ratio.

[0096] After determining a first product of the rolling radius and the stationary steering torque, a second product of the speed ratio and the wheelbase, and a third product of the rolling radius, the sprung mass of the entire vehicle, and the road adhesion coefficient, the vehicle 100 can determine a lower limit of the torque range based on the ratio of the first product to the second product, and determine an upper limit of the torque range based on the ratio of the third product to the speed ratio.

[0097] Optionally, the controller 40 can determine the fourth product of the speed ratio and the preset value, and determine the ratio of the third product to the fourth product as the upper limit value of the torque range. The preset value can be pre-stored in the controller 40. For example, the preset value can be 2.

[0098] Among them, the lower limit of the torque range M min Can satisfy:

[0099] If the preset value is equal to 2, the upper limit value of the torque range M max Can satisfy:

[0100] In the embodiment of the present application, the vehicle 100 may determine only the first torque of the first rear-wheel motor and determine the first torque as the second torque of the second rear-wheel motor. Alternatively, the vehicle 100 may determine only the second torque of the second rear-wheel motor and determine the second torque as the first torque of the first rear-wheel motor.

[0101] After determining the first and second torques, the controller 40 may determine the smaller of the first and second torques and set the smaller value as the target value. The controller 40 may determine the third torque for the front wheel motor based on the product of the target value and a preset value, where the preset value is less than 1, for example, 0.25. Accordingly, the front wheel rotation speed may be 0.25 times that of the rear wheel.

[0102] Step 203: Control the first rear wheel motor to rotate in a first direction according to the first torque, control the second rear wheel motor to rotate in a second direction according to the second torque, and control the front wheel motor to periodically rotate forward and reverse according to the third torque.

[0103] After obtaining the first torque of the first rear-wheel motor, the second torque of the second rear-wheel motor, and the third torque of the front-wheel motor, the controller 40 controls the first rear-wheel motor to rotate in a first direction according to the first torque, and controls the second rear-wheel motor to rotate in a second direction opposite to the first direction according to the second torque, thereby controlling the two rear wheels of the vehicle 100 to rotate in opposite directions. The controller also controls the front-wheel motor to periodically rotate forward and reverse according to the third torque, thereby controlling both front wheels to periodically rotate forward and reverse.

[0104] Optionally, the controller 40 may select a target stationary steering mode from multiple stationary steering modes in response to a stationary steering instruction before detecting whether the vehicle 100 meets the stationary steering conditions, determine a target cycle corresponding to the target stationary steering mode from the corresponding data of the steering mode and the cycle, and control the front wheel motor to rotate forward and reverse periodically according to the third torque, and the cycle of the forward and reverse rotation of the front wheel motor is the target cycle.

[0105] The plurality of in-place steering modes may include a fast mode and a smooth mode, and the controller 40 may pre-store corresponding data of the steering modes and cycles.

[0106] In the embodiment of the present application, the period corresponding to the fast mode can be greater than the period corresponding to the smooth mode. It is understood that if the target stationary steering mode is the fast mode, the front wheel motors rotate forward and reverse at a larger period, the two front wheels alternate between forward and reverse rotations more slowly, the vehicle 100 rotates faster, and the center of rotation of the vehicle 100 exhibits a small amplitude jitter along the longitudinal mass symmetry axis of the vehicle 100. If the target stationary steering mode is the smooth mode, the front wheel motors alternate direction at a smaller period, the two front wheels alternate between forward and reverse rotations more quickly, the vehicle 100 rotates more slowly, and the center of rotation is relatively stable.

[0107] FIG3 is a schematic diagram of a trajectory of a vehicle 100 turning in place provided by an embodiment of the present application. As shown in FIG3 , the two front wheels of the vehicle 100 may include a first front wheel 11 and a second front wheel 12. When the vehicle 100 turns in place, the first front wheel 11 and the second front wheel 12 both periodically rotate forward and reverse (the forward and reverse rotation is first in a first direction X and then in a second direction Y), and the forward and reverse rotation period is a target period. The first rear wheel 21 rotates in the first direction X, and the second rear wheel 22 rotates in the second direction Y, thereby achieving rotation of the vehicle 100 about the center of the front axle.

[0108] In an embodiment of the present application, the controller 40 can display multiple pivoting modes on the central console of the vehicle 100 in response to a pivoting instruction, and can determine the pivoting mode selected by the driver from the multiple pivoting modes as the target pivoting mode.

[0109] Step 204 : In response to the stationary turn exit instruction, obtain the swing angular velocity of the vehicle 100 .

[0110] After the controller 40 controls the front wheel motor to periodically rotate forward and reverse according to the third torque, controls the first rear wheel motor to rotate in the first direction according to the first torque, and controls the second rear wheel motor to rotate in the second direction according to the second torque, it can obtain the swing angular velocity of the vehicle 100 in response to the pivot exit command. The swing angular velocity can include the lateral swing angular velocity and the longitudinal swing angular velocity of the vehicle 100.

[0111] Optionally, the vehicle 100 may be provided with an angular velocity sensor on its surface, and the vehicle 100 may obtain its lateral swing angular velocity and longitudinal swing angular velocity through the angular velocity sensor.

[0112] Step 205: Detect whether the swing angular velocity is less than or equal to a preset angular velocity.

[0113] In response to the pivot exit command, the controller 40 obtains the swing angular velocity of the vehicle 100 and then determines whether the swing angular velocity is less than or equal to a preset angular velocity. If the swing angular velocity of the vehicle 100 is less than or equal to the preset angular velocity, step 206 may be executed. If the swing angular velocity of the vehicle 100 is greater than the preset angular velocity, the process may terminate. The controller 40 may pre-store the preset angular velocity.

[0114] The swing angular velocity may include a lateral swing angular velocity and a longitudinal swing angular velocity of the vehicle, and the preset angular velocity may include a first preset angular velocity and a second preset angular velocity.

[0115] It will be appreciated that if the lateral angular velocity of the vehicle 100 is less than or equal to the first preset angular velocity, and the longitudinal angular velocity is less than or equal to the second preset angular velocity, then it can be determined that the angular velocity of the vehicle 100 is less than or equal to the preset angular velocity. If the lateral angular velocity of the vehicle 100 is greater than the first preset angular velocity, and / or the longitudinal angular velocity is greater than the second preset angular velocity, then it can be determined that the angular velocity of the vehicle 100 is greater than the preset angular velocity.

[0116] Step 206: Control the vehicle 100 to brake.

[0117] If the controller 40 determines in step 201 that the vehicle 100 is not in a stationary state, the controller 40 may control the vehicle 100 to brake. After controlling the vehicle 100 to brake, the controller 40 continues to execute step 201 until the vehicle 100 is in a stationary state.

[0118] If the controller 40 determines in step 205 that the swing angular velocity of the vehicle 100 is less than or equal to the preset angular velocity, the controller 40 may control the vehicle 100 to brake and continue to execute step 205 until the swing angular velocity of the vehicle 100 is greater than the preset angular velocity.

[0119] Step 207: Adjust the steering angle of at least one wheel.

[0120] If the controller 40 determines in step 201 that the steering angle of at least one of the two front wheels and the two rear wheels is not within the angle range, it can adjust the steering angle of at least one wheel and continue to execute step 201 until the steering angles of the two front wheels and the steering angles of the two rear wheels are all within the angle range.

[0121] In summary, the embodiments of the present application provide a method for controlling a vehicle pivoting. In this method, upon determining that the vehicle 100 meets pivoting conditions, the controller 40 controls both front wheels of the vehicle 100 to periodically rotate forward and reverse, and controls both rear wheels of the vehicle 100 to rotate. The two rear wheels rotate in opposite directions, and the rotation speeds of the two rear wheels are both greater than the rotation speeds of the two front wheels.

[0122] Because the rotational speed of both rear wheels is greater than that of the two front wheels, the controller 40 controls both front wheels of the vehicle 100 to periodically rotate forward and reverse. During the process of controlling the two rear wheels to rotate in opposite directions, the two rear wheels can drive the two front wheels to rotate, thereby achieving a near-in-place turn of the vehicle 100 about the center of the front axle. Compared to related art, since the vehicle 100 can be controlled to turn in-place without the need for mechanical components in the vehicle, the hardware cost for controlling the vehicle 100 to turn in-place is reduced.

[0123] The present invention provides a computer-readable storage medium storing a control program for pivoting a vehicle. When the control program for pivoting a vehicle 100 is executed by a processor, the pivoting control method for the vehicle described in the above embodiments is implemented. For example, the pivoting control method for the vehicle shown in FIG. 1 or FIG. 2 is provided.

[0124] FIG4 is a schematic diagram of the structure of a controller 40 provided in an embodiment of the present application. As shown in FIG4 , the controller 40 includes a memory 401, a processor 402, and a vehicle pivot steering control program stored in the memory 401 and executable on the processor 402. When the processor 402 executes the vehicle pivot steering control program, the vehicle pivot steering control method described in the above embodiments is implemented. For example, the vehicle pivot steering control method shown in FIG1 or FIG2 is implemented.

[0125] FIG5 is a block diagram of a control device 50 for vehicle pivoting provided by an embodiment of the present application. As shown in FIG5 , the device includes:

[0126] The first control module 501 is configured to control both front wheels of the vehicle 100 to periodically rotate forward and reverse when the vehicle 100 satisfies a turning condition in situ; and

[0127] A second control module 502 is used to control the rotation of the two rear wheels of the vehicle 100;

[0128] The two rear wheels rotate in opposite directions, and the rotation speeds of the two rear wheels are greater than the rotation speeds of the two front wheels.

[0129] Optionally, for each rear wheel, when the reference torque is within the torque range, the torque of the rear wheel motor of the rear wheel is the reference torque;

[0130] The reference torque is determined according to a target wheel speed, which is selected from a plurality of wheel speeds.

[0131] Optionally, when the reference torque is less than the lower limit of the torque range, the torque of the rear wheel motor of the rear wheel is the lower limit;

[0132] When the reference torque is greater than the upper limit of the torque range, the torque of the rear wheel motor of the rear wheel is at the upper limit.

[0133] Optionally, the lower limit of the torque range is determined according to the ratio of the first product to the second product.

[0134] The upper limit of the torque range is determined by the ratio of the third product and the speed ratio of the wheel reducer; wherein,

[0135] The first product is determined by the rolling radius of the rear wheels and the stationary steering resistance torque, the second product is determined by the speed ratio and the rear wheel track, and the third product is determined by the rolling radius, the vehicle's sprung mass, and the road adhesion coefficient.

[0136] Optionally, the road surface adhesion coefficient is an adhesion coefficient corresponding to the target road surface type in the correspondence data between road surface types and adhesion coefficients;

[0137] The target road surface type is selected from multiple road surface types.

[0138] Optionally, the torque of the front wheel motors of the two front wheels is determined according to the product of the target value and a preset value;

[0139] The target value is the smaller value of the torque of the two rear wheel motors, and the preset value is less than 1.

[0140] Optionally, the forward and reverse rotation period of the front wheel motor is a target period corresponding to the target in-situ steering mode in the corresponding data of the steering mode and period;

[0141] The target in-place turning mode is selected from a plurality of in-place turning modes.

[0142] Optionally, the pivoting condition includes: the vehicle 100 is stationary, and the turning angles of the two front wheels and the turning angles of the two rear wheels are both within an angle range.

[0143] Optionally, the vehicle 100 satisfies the following conditions when it is stationary:

[0144] The lateral speed of the vehicle 100 is less than or equal to the first speed threshold, the longitudinal speed of the vehicle 100 is less than or equal to the second speed threshold, the lateral acceleration of the vehicle 100 is less than or equal to the first acceleration threshold, and the longitudinal acceleration of the vehicle 100 is less than or equal to the second acceleration threshold.

[0145] Optionally, the control device 50 may further include a detection module 503, configured to:

[0146] In response to the pivot exit instruction, when the lateral swing angular velocity of the vehicle 100 is less than or equal to a first preset angular velocity and the longitudinal swing angular velocity of the vehicle is less than or equal to a second preset angular velocity, the vehicle is controlled to brake.

[0147] In summary, the present embodiment provides a control device for pivoting a vehicle. In the control device 50, upon determining that the vehicle 100 meets pivoting conditions, the controller 40 controls both front wheels of the vehicle 100 to periodically rotate forward and reverse, and controls both rear wheels of the vehicle 100 to rotate. The two rear wheels rotate in opposite directions, and the rotation speeds of the two rear wheels are both greater than the rotation speeds of the two front wheels.

[0148] Because the rotational speed of both rear wheels is greater than that of the two front wheels, the controller 40 controls both front wheels of the vehicle 100 to periodically rotate forward and reverse. During the process of controlling the two rear wheels to rotate in opposite directions, the two rear wheels can drive the two front wheels to rotate, thereby achieving a near-in-place turn of the vehicle 100 about the center of the front axle. Compared to related art, since no mechanical components are required in the vehicle 100 to control the vehicle's in-place turn, the hardware cost for controlling the vehicle's in-place turn is reduced.

[0149] FIG6 is a schematic diagram of the structure of a vehicle 100 provided in an embodiment of the present application. Referring to FIG6 , the vehicle 100 may include the aforementioned controller 40, such as the controller 40 shown in FIG4 . Alternatively, the vehicle 100 may include the aforementioned control device 50 for turning the vehicle 100 in place.

[0150] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device), or in conjunction with such instruction execution system, apparatus, or device. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by an instruction execution system, apparatus, or device, or in conjunction with such instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion having one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0151] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0152] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0153] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0154] In addition, the terms "first" and "second" used in the embodiments of the present application are for descriptive purposes only and should not be understood as indicating or implying relative importance, or implicitly indicating the number of technical features indicated in the embodiments. Therefore, the features defined in the embodiments of the present application by terms such as "first" and "second" can explicitly or implicitly indicate that at least one of the features is included in the embodiment. In the description of the present application, the word "multiple" means at least two or two or more, such as two, three, four, etc., unless otherwise clearly and specifically defined in the embodiments.

[0155] In this application, unless otherwise specified or limited in the embodiments, the terms "installed", "connected", "connected", and "fixed" appearing in the embodiments should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integral connection. It can also be a mechanical connection, an electrical connection, etc.; of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication between two elements, or the interaction between two elements. For those skilled in the art, the specific meanings of the above terms in this application can be understood based on the specific implementation.

[0156] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0157] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for controlling vehicle turning in place, wherein: The method comprises: When the vehicle (100) satisfies a turning-in-place condition, controlling both front wheels of the vehicle (100) to periodically rotate forward and reverse; Controlling the rotation of two rear wheels of the vehicle (100); The two rear wheels rotate in opposite directions, and the rotation speeds of the two rear wheels are greater than the rotation speed of the two front wheels.

2. The method according to claim 1, wherein For each rear wheel, when the reference torque is within the torque range, the torque of the rear wheel motor of the rear wheel is the reference torque; The reference torque is determined according to a target wheel speed, and the target wheel speed is selected from a plurality of wheel speeds.

3. The method according to claim 2, wherein: When the reference torque is less than the lower limit of the torque range, the torque of the rear wheel motor of the rear wheel is the lower limit; When the reference torque is greater than the upper limit of the torque range, the torque of the rear wheel motor of the rear wheel is the upper limit.

4. The method according to claim 2, wherein: The lower limit of the torque range is determined according to the ratio of the first product to the second product. The upper limit of the torque range is determined according to the ratio of the third product and the speed ratio; wherein, The first product is determined based on the rolling radius of the rear wheels and the stationary steering resistance torque, the second product is determined based on the speed ratio and the wheelbase of the rear wheels, and the third product is determined based on the rolling radius, the sprung mass of the entire vehicle, and the road adhesion coefficient.

5. The method according to claim 4, wherein The road surface adhesion coefficient is the adhesion coefficient corresponding to the target road surface type in the corresponding data of road surface types and adhesion coefficients; The target road surface type is selected from a plurality of road surface types.

6. The method according to claim 2, wherein: The torque of the front wheel motors of the two front wheels is determined according to the product of the target value and the preset value; The target value is the smaller value of the torques of the two rear wheel motors, and the preset value is less than 1.

7. The method according to claim 6, wherein: The period of the forward and reverse rotation of the front wheel motor is a target period corresponding to the target in-situ steering mode in the corresponding data of the steering mode and the period; The target in-place turning mode is selected from a plurality of in-place turning modes.

8. The method according to any one of claims 1 to 7, wherein: The in-situ turning condition includes: the vehicle (100) is in a stationary state, and the turning angles of the two front wheels and the turning angles of the two rear wheels are both within an angle range.

9. The method according to claim 8, wherein The vehicle (100) satisfies the following conditions when it is in a stationary state: The lateral speed of the vehicle (100) is less than or equal to a first speed threshold, the longitudinal speed of the vehicle (100) is less than or equal to a second speed threshold, the lateral acceleration of the vehicle (100) is less than or equal to a first acceleration threshold, and the longitudinal acceleration of the vehicle (100) is less than or equal to a second acceleration threshold.

10. The method according to any one of claims 1 to 7, wherein: The method further comprises: In response to a stationary turn exit instruction, when the lateral swing angular velocity of the vehicle (100) is less than or equal to a first preset angular velocity and the longitudinal swing angular velocity of the vehicle (100) is less than or equal to a second preset angular velocity, the vehicle (100) is controlled to brake.

11. A computer-readable storage medium, wherein: A control program for turning the vehicle (100) in place is stored thereon, and when the control program for turning the vehicle (100) in place is executed by a processor, the control method for turning the vehicle in place according to any one of claims 1 to 10 is implemented.

12. A controller (40), wherein: The invention comprises a memory (401), a processor (402), and a control program for turning the vehicle (100) in place, which is stored in the memory (401) and can be run on the processor (402); when the processor (402) executes the control program for turning the vehicle in place, the control method for turning the vehicle in place according to any one of claims 1 to 10 is implemented.

13. A control device (50) for turning in place of a vehicle, wherein: The device comprises: A first control module (501) is used to control both front wheels of the vehicle (100) to periodically rotate forward and reverse when the vehicle (100) meets the in-situ turning condition; and a second control module (502) for controlling the rotation of two rear wheels of the vehicle (100); The two rear wheels rotate in opposite directions, and the rotation speeds of the two rear wheels are greater than the rotation speed of the two front wheels.

14. A vehicle (100), wherein: The vehicle (100) comprises: the controller (40) according to claim 12; or the control device for turning on the spot of the vehicle (100) according to claim 13.

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