Vehicle steering control method and device

Abstract

The embodiment of the invention provides a vehicle steering control method and device, and the method comprises the steps: responding to a steering control request, and determining a target rotation direction; and in the vehicle steering control process, front wheels of the vehicle are controlled to rotate to the maximum rotating angle in the target rotating direction, and wheel speed control is conducted on all the wheels of the vehicle so that the target rotating speed can be achieved. According to the embodiment of the invention, the optimization of the pivot steering function of the vehicle is realized, the complexity of the pivot steering scheme is reduced, and the implementation is easier.

Description

Technical Field

[0001] The present invention relates to the field of automobile technology, and in particular to a method and device for vehicle steering control. Background Art

[0002] With the development of automobile technology, users have increasing demands for automobile functions, and vehicle turning on the spot is one of the important functional requirements. However, the existing solutions for turning on the spot are too complicated and difficult to implement, and cannot greatly reduce the turning radius, and have little effect on improving the passability. For the solutions that can reduce the turning radius, there are problems such as large tire wear. Summary of the invention

[0003] In view of the above problems, a method and device for vehicle steering control is proposed to overcome the above problems or at least partially solve the above problems, including:

[0004] A method for vehicle steering control, the method comprising:

[0005] In response to a steering control request, determining a target rotation direction;

[0006] During the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum rotation angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

[0007] Optionally, during the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum rotation angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0008] During the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum angle, the rear wheels on the first side of the vehicle corresponding to the target rotation direction are controlled to be stationary relative to the vehicle, and the wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

[0009] Optionally, during the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum rotation angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0010] During the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum angle, the rear wheels on the first side of the vehicle corresponding to the target rotation direction are braked so that the rear wheels on the first side are in a locked state, and the wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

[0011] Optionally, controlling the wheel speeds of other wheels of the vehicle to achieve a target rotation speed includes:

[0012] According to the target rotation speed, the wheel speed of other wheels of the vehicle is controlled;

[0013] During the process of controlling the wheel speeds of other wheels of the vehicle, the front wheels on the first side are controlled so that the wheel speed of the front wheels on the first side is smaller than the wheel speed of the front wheels on the second side.

[0014] Optionally, controlling the wheel speeds of other wheels of the vehicle according to the target rotation speed includes:

[0015] According to the target rotation speed, the target wheel speeds of other wheels of the vehicle are determined;

[0016] The wheel speeds of other wheels of the vehicle are controlled according to the target wheel speeds.

[0017] Optionally, during the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum rotation angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0018] When the current state of the vehicle steering control system is an activated state, the vehicle steering control process is executed, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

[0019] Optionally, the method further includes: providing feedback to a user when the current state of the vehicle steering control system is an inactive state.

[0020] Optionally, when one or more of the following conditions are met, the current state of the vehicle steering control system is an activated state:

[0021] A steering control request is detected, the indicator light is on, the target gear is forward gear, the steering wheel angle is valid, the left front wheel speed is valid, the right front wheel speed is valid, the left rear wheel speed is valid, and the right rear wheel speed is valid.

[0022] Optionally, during the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum rotation angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0023] When the vehicle enters the first state, executing the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed;

[0024] The first state is a state of entering steering control.

[0025] Optionally, the vehicle enters the first state when one or more of the following conditions are met: the vehicle steering control system is in an activated state, the vehicle speed is less than a first threshold, and the braking depth is less than a second threshold.

[0026] Optionally, it also includes:

[0027] When the vehicle enters a second state, the vehicle is controlled to perform a specified operation to exit the steering control; wherein the second state is a state of exiting the steering control.

[0028] Optionally, the designated operation includes one or more of the following operations: returning the vehicle steering wheel to center, unloading the drive motor torque, and restoring the braking system to basic braking.

[0029] Optionally, the vehicle enters the second state when any of the following conditions is met:

[0030] The vehicle steering control system is in an inactive state, the vehicle speed is greater than or equal to a first threshold, the braking depth is greater than or equal to a second threshold, and the steering wheel angle is less than a third threshold.

[0031] Optionally, before determining the target rotation direction in response to the steering control request, the method further includes:

[0032] Get steering control request based on user input.

[0033] A vehicle steering control device, the device is used for:

[0034] In response to a steering control request, determining a target rotation direction;

[0035] During the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum rotation angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

[0036] An electronic device comprises a processor, a memory and a computer program stored in the memory and capable of running on the processor, wherein the computer program implements the method described above when executed by the processor.

[0037] A vehicle comprises the above-mentioned device, or the above-mentioned electronic device. A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned method is implemented.

[0038] A computer program product comprises a computer program, wherein when the computer program is executed by a processor, the computer program implements the method as described above.

[0039] The embodiments of the present invention have the following advantages:

[0040] In an embodiment of the present invention, by responding to a steering control request, determining a target turning direction, and during the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target turning direction to a maximum turning angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target turning speed, the vehicle's on-the-spot steering function is optimized, the complexity of the on-the-spot steering scheme is reduced, and it is easier to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0042] Figure 1 is a schematic diagram of a vehicle system provided by some embodiments of the present invention;

[0043] Figure 2 is a schematic diagram of another vehicle system provided by some embodiments of the present invention;

[0044] Figure 3 is a schematic diagram of vehicle steering provided by some embodiments of the present invention;

[0045] Figure 4 is a flowchart of the steps of a vehicle steering control method provided by some embodiments of the present invention;

[0046] Figure 5 is a schematic diagram of a display interface provided by some embodiments of the present invention;

[0047] Figure 6 It is a flowchart of the steps of another method for vehicle steering control provided by some embodiments of the present invention. DETAILED DESCRIPTION

[0048] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] In a related technology, by equipping the vehicle with front and rear dual motors, the two motors are controlled to drive independently, and the characteristics of the front and rear dual motor electric vehicles that can independently control the front and rear power output direction and output torque are utilized. When turning, the inner front wheel and the outer rear wheel are locked, and a positive torque is applied to the outer front wheel, and a reverse torque is applied to the inner rear wheel, thereby achieving the vehicle's approximate rotation in place around the center of mass, shortening the turning radius to 1 / 2 of the cross axis, and thus making the vehicle turn in place.

[0050] For this solution, although the vehicle only needs to be equipped with front and rear dual motors, the inner front wheel and outer rear wheel are locked, and a positive torque is applied to the outer front wheel and a negative torque is applied to the inner rear wheel. First, the wheel to which the torque is applied may not have enough adhesion to turn the vehicle around on the spot. Second, when the vehicle turns on the spot, the locked wheel will inevitably be dragged and the drive wheel will slip significantly. This will cause serious wear on the tires in practical applications and is difficult to achieve.

[0051] In another related technology, by equipping the vehicle with a single front motor and dual rear motors, the electric vehicle can independently control the power output direction and output torque of the front axle and the rear left and right wheels by using a single motor on the front axle and dual motors on the rear axle; or the vehicle can be equipped with four distributed drive motors, and the four motors are controlled to drive independently to enable the vehicle to turn on the spot, and the target yaw velocity is obtained through the accelerator pedal opening, and then the target yaw torque of each wheel motor is determined based on the actual yaw velocity, road adhesion coefficient, and target yaw velocity. Based on the target yaw torque of each wheel motor, the inner front wheel and the inner rear wheel are controlled to reverse, and the outer front wheel and the outer rear wheel are controlled to rotate forward, thereby making the vehicle turn on the spot.

[0052] For this solution, the most basic condition is that the vehicle needs to have three or four motors, and the four wheels can be driven independently as much as possible. This type of distributed drive vehicle is currently only used by a few OEMs on top-level cars, and is not as common as dual-motor models.

[0053] In another related technology, the vehicle is turned in place around the inner rear wheel by braking or locking the inner rear wheel when turning, and the target wheel is determined according to the turning direction, and braking force is applied to the target wheel or the target wheel is locked to make the vehicle turn in place around the inner rear wheel.

[0054] With this solution, except for the inner rear wheel which is braked or locked, all other wheels are driven, which will cause the inner rear wheel to be dragged and slide. The turning radius of on-the-spot steering will basically be larger than the cross axis, and the on-the-spot steering effect of significantly reducing the turning radius cannot be stably achieved.

[0055] In the embodiment of the present invention, the system components only need to meet the requirements of having one motor at the front and one motor at the rear to drive the front and rear wheels respectively through an inter-wheel differential and having an electronic parking system. Other braking, steering, suspension, etc. are similar to those of existing common vehicles and there are no other special requirements.

[0056] Moreover, the control strategy in the embodiment of the present invention is mainly that after pressing the in-situ steering button or receiving the in-situ steering signal, the steering motor turns the wheel angle to the maximum in the steering direction, and then locks the inner rear wheel through the hydraulic braking system or the electronic parking system, brakes the inner front wheel, and controls its wheel speed. In addition, the front and rear motors are controlled to output positive torque at the same time, and the wheel speed of the outer front and rear wheels is controlled under the action of the differential; under the action of the hydraulic braking system and the front and rear motor drive, the inner wheel is subjected to a backward longitudinal force, while the outer wheel is subjected to a forward longitudinal force, and a yaw torque is generated while suppressing the vehicle's forward movement, thereby achieving in-situ steering.

[0057] During this process, the front and rear outer wheels of the vehicle using the present invention may both require a driving force close to the ground adhesion. Therefore, there are certain requirements for the torque of the front and rear motors or the deceleration and torque-increasing mechanism on high-speed roads. In addition, the steering motor is also required when the front wheels are turned. The torque of the existing steering motor may need to be increased to a certain extent. However, most existing vehicles with motors at the front and rear can meet the requirements, and the changes required for those that cannot be met are relatively small. Compared with the existing technical solutions, the requirements for the vehicle are relatively low and easier to achieve.

[0058] Furthermore, during the execution of the control strategy of the embodiment of the present invention, the steering motor is first used to turn the wheel angle to the maximum in the steering direction, and then the inner rear wheel is locked and the inner front wheel is braked through the hydraulic braking system to control its wheel speed; in addition, the front and rear motors are simultaneously controlled to output positive torque, and under the action of the differential, the wheel speed of the outer front and rear wheels is controlled; under the action of the hydraulic braking system and the front and rear motor drives, the inner wheel is subjected to a rearward longitudinal force, while the outer wheel is subjected to a forward longitudinal force, which generates a yaw moment while suppressing the forward movement of the vehicle, and because the inner rear wheel is locked, the outer wheel is slightly slipped and the inner front wheel is slightly slipped while controlling the wheel speeds of the inner front wheel and the outer wheel, so that the vehicle rotates around the inner rear wheel as the center, thereby greatly reducing the turning radius, improving the vehicle's passability in a narrow environment, and increasing the convenience of the driver's steering. In this process, except for the fixed-point rotation of the inner rear wheel, the other wheels are in a rolling state, which is beneficial to reducing tire wear.

[0059] The present invention will be described below in conjunction with the accompanying drawings:

[0060] like Figure 1The vehicle includes an auxiliary steering request input device, an auxiliary steering control unit, a steering motor controller, a front drive motor controller, a rear drive motor controller, a steering motor, a front drive motor, a rear drive motor, an electronic hydraulic brake control unit and an electronic hydraulic brake system.

[0061] Among them, the steering request input device can be directly activated by voice, or it can be a physical button set on the dashboard, center console and other driver-accessible positions or steering wheel, or it can be a virtual button, and the driver can select the on-the-spot steering function through the car display screen.

[0062] The auxiliary steering control unit is the core part of the vehicle to achieve on-the-spot steering. This part is responsible for receiving the function-on signal input by the steering request input device, and then judging whether the entry conditions are met. It calculates the output required steering, driving and braking signals to the steering and driving motor controller and the electronic hydraulic brake unit through the control algorithm. When the function exit conditions are met, it controls the driving force, braking force unloading and steering return to the center, and exits the function.

[0063] The motor controller receives the torque signal from the on-the-spot steering control unit, controls the motor to output the corresponding torque, and drives the wheels to rotate.

[0064] The electronic hydraulic brake control unit receives the brake request from the on-the-spot steering control unit and controls the inner rear wheel locking and inner front wheel braking.

[0065] In an embodiment of the present invention, a vehicle having a front and rear drive motor and an electronic power steering comprises the above structure. The present invention can achieve the purpose of greatly reducing the turning radius simply by controlling the driving force and braking force of the above structure.

[0066] like Figure 2 , an electronic parking control unit is added to the above vehicle in-situ steering control system, and the rest of the structure is the same and will not be described here. The difference from the previous solution is that the braking force source of the inner rear wheel is different. The previous solution uses the braking force generated by the electronic hydraulic brake system to lock the inner rear wheel, while this solution uses the braking force generated by the parking brake control system to lock the inner rear wheel. Both solutions can achieve the goal of locking the inner rear wheel.

[0067] The solution of the embodiment of the present invention is applied, such as Figure 3, the front wheels are turned to the maximum turning angle through the steering system, and then the braking system locks the inner rear wheel and applies brakes to the inner front wheel, controls the rear motor to output positive torque, and makes the outer rear wheel rotate forward under the action of the differential, controls the front motor to output positive torque, drives the front wheels to rotate forward, and makes the inner front wheel rotate forward a certain proportion lower than the outer front wheel under the action of the differential and braking, so that the inner front wheel obtains backward braking force, thereby suppressing the forward trend of the vehicle and better realizing yaw rotation. Finally, except for the inner rear wheel, the combined force of the ground on the other three wheels is less than the adhesion of the inner rear wheel. When the inner rear wheel is locked, the inner rear wheel is used as the center of the circle, and the distance from the inner rear wheel to the outer front wheel is the maximum radius. Turning in place is achieved, thereby sharply reducing the turning radius of the vehicle.

[0068] For example, when the vehicle turns left, by locking the left rear wheel, controlling motor 2 to output positive torque, driving the right rear wheel to rotate forward, controlling motor 1 to output positive torque, driving the front wheels to rotate forward, and braking the left front wheel, the longitudinal force on the left side is negative and the longitudinal force on the right side is positive, which greatly increases the vehicle's yaw moment and reduces the forward tendency, achieving the effect of turning on the spot.

[0069] Reference Figure 4 , shows a flowchart of the steps of a method for steering control of a vehicle provided by some embodiments of the present invention, wherein the vehicle has a first drive motor for driving the front wheels of the vehicle and a second drive motor for driving the rear wheels of the vehicle, and specifically may include the following steps:

[0070] Step 401, in response to a steering control request, determining a target rotation direction.

[0071] In practical applications, the steering control request may be a request to control the vehicle to turn in place, such as steering with one of the rear wheels of the vehicle as the rotation axis. The steering control request may carry a target rotation direction, which may be the requested rotation direction, such as left turn or right turn.

[0072] In some examples, the steering control request may also carry a target rotation speed, which is a speed to be maintained when turning. The target rotation speed may be set to a specific speed value or a speed level, such as slow, normal, or fast.

[0073] In some embodiments of the present invention, before determining the target rotation direction in response to the steering control request, the method further includes: obtaining the steering control request according to user input.

[0074] like Figure 5The vehicle is equipped with a central control display interface. Users can select automatic, manual or turn off the on-the-spot steering function on the central control display interface through the vehicle display screen, and can select the target turning speed. The target turning speed can be set to a specific speed value or a speed level, such as slow, normal speed, and fast. The target turning direction can also be selected, such as turn left or turn right.

[0075] In some examples, the target rotation speed may be related to the on-site environment in which the vehicle is located. When the on-site environment is more complex, such as when the turning space is smaller and there are more obstacles such as vehicles and pedestrians nearby, a lower target rotation speed may be used. When the turning space is larger and there are fewer obstacles such as vehicles and pedestrians nearby, a higher target rotation speed may be used.

[0076] After the user completes the selection, the vehicle display screen sends the relevant information to the on-the-spot steering control unit and the instrument, and the on-the-spot steering control unit controls the vehicle to complete the on-the-spot U-turn according to the target turning speed and target turning direction. In some examples, the instrument displays the corresponding animation, torque, brake pressure, wheel speed and other information.

[0077] Step 402, during the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

[0078] After determining the target rotation direction, in order to achieve on-the-spot turning, the front wheels of the vehicle can be controlled to rotate to the maximum angle in the target rotation direction, and the wheel speed of each wheel of the vehicle can be controlled so that the vehicle can reach the target rotation speed during rotation and adapt to the on-site environment.

[0079] In some embodiments of the present invention, during the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0080] During the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum angle, the rear wheels on the first side of the vehicle corresponding to the target rotation direction are controlled to be stationary relative to the vehicle, and the wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

[0081] The first side is the inner side of the in-situ turn, that is, the side close to the rotation axis.

[0082] In practical applications, on the one hand, the front wheels of the vehicle can be controlled to rotate toward the target rotation direction to the maximum rotation angle, and on the other hand, the rear wheels on the first side of the vehicle corresponding to the target rotation direction can be controlled to be stationary relative to the vehicle, and then the stationary rear wheels can be used as the rotation axis to perform on-the-spot turning, and on the other hand, the wheel speeds of other wheels of the vehicle can be controlled to achieve the target rotation speed when turning on the spot.

[0083] In some embodiments of the present invention, during the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0084] During the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum angle, the rear wheels on the first side of the vehicle corresponding to the target rotation direction are braked so that the rear wheels on the first side are in a locked state, and the wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

[0085] In practical applications, on the one hand, the front wheels of the vehicle can be controlled to rotate toward the target rotation direction to the maximum rotation angle, and on the other hand, the rear wheels on the first side of the vehicle corresponding to the target rotation direction can be braked to lock the rear wheels on the first side, and then the rear wheels in the locked state can be used as the rotation axis to turn in situ, and on the other hand, the wheel speeds of other wheels of the vehicle can be controlled to achieve the target rotation speed when turning in situ.

[0086] In some examples, the vehicle may be braked by an electronic hydraulic brake system or a parking brake control system, such as Figure 1 , the braking force generated by the electronic hydraulic brake system locks the inner rear wheel, such as Figure 2 , the inner rear wheel is locked through the braking force generated by the parking brake control system.

[0087] In actual applications, the front wheel angle is turned to the maximum by controlling the output torque of the steering motor, and then the wheel speed of the outer rear wheel is controlled by the torque of the rear motor, and the wheel speed of the outer front wheel is controlled by the torque of the front motor. At the same time, the left rear wheel is locked and the left front wheel is braked through braking control.

[0088] In the electronic hydraulic braking system, the master cylinder is controlled to output the maximum pressure, the inner rear wheel boost valve is controlled to open, and the pressure relief valve is closed. When the maximum pressure is reached, the pressure is maintained. The inner front wheel boost valve is opened, and the pressure relief valve is closed. When the target wheel speed is reached, the boost valve is closed to maintain the pressure, and the outer wheel boost and relief valves are closed.

[0089] In some embodiments of the present invention, the wheel speed control of other wheels of the vehicle to achieve the target rotation speed includes: controlling the wheel speed of other wheels of the vehicle according to the target rotation speed; and in the process of controlling the wheel speed of other wheels of the vehicle, controlling the front wheels on a first side so that the wheel speed of the front wheels on the first side is less than the wheel speed of the front wheels on the second side.

[0090] The second side is a side opposite to the first side, that is, an outer side of the in-situ turn.

[0091] In some embodiments of the present invention, controlling the wheel speed of other wheels of the vehicle according to the target rotational speed includes: determining the target wheel speed of other wheels of the vehicle according to the target rotational speed; and controlling the wheel speed of other wheels of the vehicle according to the target wheel speed.

[0092] In practical applications, there is a correlation between the target rotation speed of the on-the-spot turning and the wheel speed of the vehicle wheels. The target conversion speed can be mapped to the target wheel speed of the other wheels of the vehicle, and then the corresponding target wheel speed can be used to control the wheel speed of the other wheels of the vehicle.

[0093] Moreover, in the process of controlling the wheel speed of other wheels of the vehicle, the speeds of the two front wheels can be differentially controlled so that the front wheel speed on the first side is smaller than the front wheel speed on the second side, thereby enabling the vehicle to achieve the effect of turning in situ toward the first side.

[0094] For example, when a vehicle turns left, Figure 3 First, the steering motor output torque is controlled to turn the front wheel angle to the left to the maximum. At this time, according to the selected mode, the target wheel speed corresponding to the right front wheel is ω4. According to the geometric relationship, the target wheel speed of each wheel is controlled to meet the following relationship:

[0095]

[0096] ω2=0

[0097] Wherein, L is the wheelbase, d is the track width, ω1, ω2, ω3, ω4 are the target wheel speeds of the left front, left rear, right rear, and right front respectively, and δ is half of the sum of the left and right front wheel turning angles.

[0098] In actual application, by controlling the maximum pressure output by the master cylinder, the boost valve of the left rear wheel is opened and the pressure relief valve is closed. When the maximum pressure is reached, the pressure is maintained, the boost and relief valves of the outer wheels are closed, and the front and rear motors increase torque at the same time. The wheel speed of the right front wheel is controlled to be ω4, and the wheel speed of the right rear wheel is controlled to be ω3. At the same time, the boost valve of the left front wheel is opened and the pressure relief valve is closed. When the target wheel speed ω1 is reached, the boost valve is closed to maintain the pressure.

[0099] The torque distribution of the front and rear motors and the left front wheel brake pressure control must satisfy the requirement that the left rear wheel tire force is less than the adhesion force and the total longitudinal force F of the vehicle.x is 0, suppressing the vehicle's forward tendency, and the total longitudinal force F x It can be expressed as: F x = -F1cosδ -F2+F3+F4cosδ = 0

[0100] Among them, F1, F2, F3, and F4 are the tangential forces on the left front, left rear, right rear, and right front wheels respectively. The left front wheel speed, front and rear motor torque distribution, and left front wheel brake pressure control all need to be debugged, calibrated, and confirmed according to actual conditions.

[0101] In the embodiment of the present invention, when turning, the inner rear wheel is locked, the front wheel is braked, and the outer front and rear wheels rotate forward to achieve rotation around the inner rear wheel, which greatly reduces the turning radius, improves the vehicle's passability, reduces the driver's burden and tire wear, and can stably achieve an effect similar to turning the vehicle on the spot.

[0102] In some embodiments of the present invention, during the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0103] When the current state of the vehicle steering control system is an activated state, the vehicle steering control process is executed, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

[0104] In some embodiments of the present invention, the current state of the vehicle steering control system is an activated state when one or more of the following conditions are met:

[0105] A steering control request is detected, the indicator light is on, the target gear is forward gear, the steering wheel angle is valid, the left front wheel speed is valid, the right front wheel speed is valid, the left rear wheel speed is valid, and the right rear wheel speed is valid.

[0106] In some embodiments of the present invention, the method further includes: providing feedback to a user when the current state of the vehicle steering control system is an inactive state.

[0107] In actual application, whether the vehicle's on-site steering control system can be activated or not can be judged by conditions. When all the following conditions are met, the vehicle's on-site steering system activation flag is 1 (activation is allowed), otherwise, the vehicle's on-site steering system activation flag is 0 (activation is not allowed), and the vehicle display screen prompts that activation is not allowed and the reasons are as follows:

[0108] 1. The on-site turn request flag is 1 (the driver issues a request)

[0109] 2. The OK light is on

[0110] 3. The target gear is D gear

[0111] 4. Steering wheel angle is effective

[0112] 5. Left front wheel speed is effective

[0113] 6. Right front wheel speed is effective

[0114] 7. Left rear wheel speed is effective

[0115] 8. Right rear wheel speed is effective

[0116] In some embodiments of the present invention, during the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0117] When the vehicle enters the first state, the vehicle steering control process is executed to control the front wheels of the vehicle to rotate toward the target rotation direction to a maximum angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

[0118] The first state is a state of entering steering control.

[0119] In some embodiments of the present invention, the vehicle enters the first state when one or more of the following conditions are met: the vehicle steering control system is in an activated state, the vehicle speed is less than a first threshold, and the braking depth is less than a second threshold.

[0120] In some embodiments of the present invention, it also includes:

[0121] When the vehicle enters a second state, the vehicle is controlled to perform a specified operation to exit the steering control; wherein the second state is a state of exiting the steering control.

[0122] In some embodiments of the present invention, the vehicle enters the second state when any of the following conditions is met: the vehicle steering control system is in an inactive state, the vehicle speed is greater than or equal to a first threshold, the braking depth is greater than or equal to a second threshold, and the steering wheel angle is less than a third threshold.

[0123] In some embodiments of the present invention, the designated operation includes one or more of the following operations: returning the vehicle steering wheel to center, unloading the drive motor torque, and restoring the braking system to basic braking.

[0124] When the vehicle's on-the-spot steering system allows activation flag to emit 1, the vehicle control state is judged. The vehicle control state is divided into three states, namely state 0 (no control state), state 1 (entering control, i.e. the first state), and state 2 (direction return, torque, hydraulic unloading, i.e. the second state).

[0125] In actual applications, the default initial control state of the vehicle control is 0. When the following conditions are met, the vehicle enters control state 1. The conditions include:

[0126] 1. The vehicle's on-site steering system allows activation flag to be 1

[0127] 2. Vehicle speed is less than threshold 1

[0128] 3. Braking depth is less than threshold 2

[0129] When any of the above conditions is not met, the vehicle control state enters state 2:

[0130] 1. The vehicle's on-site steering system activation flag is 0;

[0131] 2. Vehicle speed is greater than or equal to threshold 1

[0132] 3. Braking depth is greater than or equal to threshold 2

[0133] 4. Steering wheel angle is less than threshold 3

[0134] When the vehicle enters state 1, the vehicle steering, drive and brake systems are controlled to achieve on-site steering. When the vehicle enters state 2, the vehicle steering motor controls the steering wheel to return to the center position, the front and rear motor torques are unloaded, and the master cylinder and wheel cylinder brake pressures respond to the basic brake pressure. When the torque is unloaded and the hydraulic brake response is basic braking, it enters state 0 and exits the on-site steering function.

[0135] In an embodiment of the present invention, by responding to a steering control request, determining a target turning direction, and during the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target turning direction to a maximum turning angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target turning speed, the vehicle's on-the-spot steering function is optimized, the complexity of the on-the-spot steering scheme is reduced, and it is easier to implement.

[0136] Moreover, without making major changes to the vehicle structure, the purpose of greatly reducing the turning radius and reducing tire wear is achieved.

[0137] The following combination Figure 6 The present invention is exemplified as follows:

[0138] 1. The driver chooses to enter the on-the-spot steering function;

[0139] 2. Select the corresponding mode and direction;

[0140] 3. The vehicle's on-site steering control system determines whether the function entry conditions are met. If so, it proceeds to step 4. If not, it exits the function and generates a prompt on the vehicle display screen;

[0141] 4. Calculate the master cylinder target pressure or electronic parking pressure, determine the braking command of each wheel, the solenoid valve control command, and calculate the target torque of the steering motor, front motor, and rear motor according to the target speed;

[0142] 5. Output the steering motor control command to the actuator for execution. After execution, proceed to step 6;

[0143] 6. Output the target torque of the front motor and the rear motor, the master cylinder pressure, the valve body, the electronic parking motor control command, etc. to the actuator for execution. After the execution is completed, go to step 7;

[0144] 7. Whether the exit condition is met, if yes, go to step 8, if not, go back to step 4;

[0145] 8. The torque is unloaded to 0, and the pressure responds to the basic brake pressure;

[0146] 9. Exit function.

[0147] It should be noted that, for the sake of simplicity, the method embodiments are described as a series of action combinations, but those skilled in the art should be aware that the embodiments of the present invention are not limited by the order of the actions described, because according to the embodiments of the present invention, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present invention.

[0148] Some embodiments of the present invention also provide a vehicle steering control device, which is used for:

[0149] In response to a steering control request, determining a target rotation direction;

[0150] During the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum rotation angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

[0151] In some embodiments of the present invention, during the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0152] During the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum angle, the rear wheels on the first side of the vehicle corresponding to the target rotation direction are controlled to be stationary relative to the vehicle, and the wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

[0153] In some embodiments of the present invention, during the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0154] During the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum angle, the rear wheels on the first side of the vehicle corresponding to the target rotation direction are braked so that the rear wheels on the first side are in a locked state, and the wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

[0155] In some embodiments of the present invention, controlling the wheel speed of other wheels of the vehicle to achieve the target rotation speed includes:

[0156] According to the target rotation speed, the wheel speed of other wheels of the vehicle is controlled;

[0157] During the process of controlling the wheel speeds of other wheels of the vehicle, the front wheels on the first side are controlled so that the wheel speed of the front wheels on the first side is smaller than the wheel speed of the front wheels on the second side.

[0158] In some embodiments of the present invention, the step of controlling the wheel speed of other wheels of the vehicle according to the target rotation speed includes:

[0159] According to the target rotation speed, the target wheel speeds of other wheels of the vehicle are determined;

[0160] The wheel speeds of other wheels of the vehicle are controlled according to the target wheel speeds.

[0161] In some embodiments of the present invention, during the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0162] When the current state of the vehicle steering control system is an activated state, the vehicle steering control process is executed, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

[0163] In some embodiments of the present invention, it is also used to: provide feedback to the user when the current state of the vehicle steering control system is an inactive state.

[0164] In some embodiments of the present invention, the current state of the vehicle steering control system is an activated state when one or more of the following conditions are met:

[0165] A steering control request is detected, the indicator light is on, the target gear is forward gear, the steering wheel angle is valid, the left front wheel speed is valid, the right front wheel speed is valid, the left rear wheel speed is valid, and the right rear wheel speed is valid.

[0166] In some embodiments of the present invention, during the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed, includes:

[0167] When the vehicle enters the first state, executing the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed;

[0168] The first state is a state of entering steering control.

[0169] In some embodiments of the present invention, the vehicle enters the first state when one or more of the following conditions are met: the vehicle steering control system is in an activated state, the vehicle speed is less than a first threshold, and the braking depth is less than a second threshold.

[0170] In some embodiments of the present invention, it is also used for:

[0171] When the vehicle enters a second state, the vehicle is controlled to perform a specified operation to exit the steering control; wherein the second state is a state of exiting the steering control.

[0172] In some embodiments of the present invention, the designated operation includes one or more of the following operations: returning the vehicle steering wheel to center, unloading the drive motor torque, and restoring the braking system to basic braking.

[0173] In some embodiments of the present invention, the vehicle enters the second state when any of the following conditions is met: the vehicle steering control system is in an inactive state, the vehicle speed is greater than or equal to a first threshold, the braking depth is greater than or equal to a second threshold, and the steering wheel angle is less than a third threshold.

[0174] In some embodiments of the present invention, before determining the target rotation direction in response to the steering control request, the method is further configured to:

[0175] Get steering control request based on user input.

[0176] Some embodiments of the present invention further provide an electronic device, comprising a processor, a memory, and a computer program stored in the memory and capable of running on the processor, wherein the above method is implemented when the computer program is executed by the processor.

[0177] Some embodiments of the present invention further provide a vehicle, comprising the apparatus as described above, or the electronic device as described above.

[0178] Some embodiments of the present invention further provide a computer-readable storage medium, on which a computer program is stored, and the computer program implements the above method when executed by a processor.

[0179] Some embodiments of the present invention further provide a computer program product, including a computer program, which implements the above method when executed by a processor.

[0180] As for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0181] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0182] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0183] Those skilled in the art will appreciate that the embodiments of the present invention may be provided as methods, devices, or computer program products. Therefore, the embodiments of the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the embodiments of the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0184] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0185] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0186] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device so that a series of operating steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable terminal device to implement the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0187] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0188] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the above elements.

[0189] The above is a detailed introduction to a method and device for vehicle steering control. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for vehicle steering control, characterized in that: The method comprises: In response to a steering control request, determining a target rotation direction; During the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum rotation angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

2. The method according to claim 1, characterized in that In the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum rotation angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed, including: During the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum angle, the rear wheels on the first side of the vehicle corresponding to the target rotation direction are controlled to be stationary relative to the vehicle, and the wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

3. The method according to claim 1, characterized in that In the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum rotation angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed, including: During the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum rotation angle, the rear wheels on the first side of the vehicle corresponding to the target rotation direction are braked so that the rear wheels on the first side are in a locked state, and the wheel speeds of the other wheels of the vehicle are controlled to achieve the target rotation speed.

4. The method according to claim 2 or 3, characterized in that: The wheel speed control of other wheels of the vehicle to achieve the target rotation speed includes: According to the target rotation speed, the wheel speed of other wheels of the vehicle is controlled; During the process of controlling the wheel speeds of other wheels of the vehicle, the front wheels on the first side are controlled so that the wheel speed of the front wheels on the first side is smaller than the wheel speed of the front wheels on the second side.

5. The method according to claim 4, characterized in that The step of controlling the wheel speeds of other wheels of the vehicle according to the target rotation speed includes: According to the target rotation speed, the target wheel speeds of other wheels of the vehicle are determined; The wheel speeds of other wheels of the vehicle are controlled according to the target wheel speeds.

6. The method according to claim 1, characterized in that In the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum rotation angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed, including: When the current state of the vehicle steering control system is an activated state, the vehicle steering control process is executed, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

7. The method according to claim 6, characterized in that Also includes: When the current state of the vehicle steering control system is an inactive state, feedback is provided to the user.

8. The method according to claim 6, characterized in that The current state of the vehicle steering control system is an active state when one or more of the following conditions are met: A steering control request is detected, the indicator light is on, the target gear is forward gear, the steering wheel angle is valid, the left front wheel speed is valid, the right front wheel speed is valid, the left rear wheel speed is valid, and the right rear wheel speed is valid.

9. The method according to claim 1, characterized in that: In the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum rotation angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed, including: When the vehicle enters the first state, executing the vehicle steering control process, controlling the front wheels of the vehicle to rotate toward the target rotation direction to a maximum angle, and controlling the wheel speed of each wheel of the vehicle to achieve the target rotation speed; The first state is a state of entering steering control.

10. The method according to claim 9, characterized in that The vehicle enters the first state when one or more of the following conditions are met: the vehicle steering control system is in an activated state, the vehicle speed is less than a first threshold, and the braking depth is less than a second threshold.

11. The method according to claim 9, characterized in that Also includes: When the vehicle enters a second state, the vehicle is controlled to perform a specified operation to exit the steering control; wherein the second state is a state of exiting the steering control.

12. The method according to claim 11, characterized in that The specified operation includes one or more of the following operations: returning the vehicle steering wheel to center, unloading the drive motor torque, and restoring the braking system to basic braking.

13. The method according to claim 11, characterized in that When any of the following conditions is met, the vehicle enters the second state: The vehicle steering control system is in an inactive state, the vehicle speed is greater than or equal to a first threshold, the braking depth is greater than or equal to a second threshold, and the steering wheel angle is less than a third threshold.

14. The method according to claim 1, characterized in that Before determining the target rotation direction in response to the steering control request, the method further includes: Get steering control request based on user input.

15. A vehicle steering control device, characterized in that: The device is used for: In response to a steering control request, determining a target rotation direction; During the vehicle steering control process, the front wheels of the vehicle are controlled to rotate toward the target rotation direction to a maximum rotation angle, and the wheel speed of each wheel of the vehicle is controlled to achieve the target rotation speed.

16. An electronic device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and capable of running on the processor, wherein the computer program implements the method according to any one of claims 1 to 14 when executed by the processor.

17. A vehicle, characterized in that: Comprising the apparatus as claimed in claim 15, or, the electronic device as claimed in claim 16.

18. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 14 is implemented.

19. A computer program product, characterized in that A computer program is included which, when executed by a processor, implements the method according to any one of claims 1 to 14.

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