Crab running mode control method based on rear wheel steering and automobile

Abstract

The crabbing mode control method based on rear wheel steering comprises the steps that after a driver inputs an opening instruction through voice or a vehicle-mounted large screen, whether the opening condition of the crabbing mode is met or not is judged, if yes, the crabbing mode is started, and the vehicle-mounted large screen displays angle information of front and rear wheels in real time; and after entering the crabbing mode, acquiring the rotation angle of the front wheel in real time, and controlling the rear wheel to rotate in the same direction at the same angle along with the front wheel. The method has the advantages that the user experience, the safety and the reliability of crab mode work are improved through visual interaction control and safety control logic implementation of the crab mode.

Description

Technical Field

[0001] The invention relates to the field of automobile steering control, and in particular to a crab mode control method based on rear wheel steering and an automobile. Background Art

[0002] Crab mode control based on rear-wheel steering is an advanced technology for automobile steering systems, a special vehicle operation mode that imitates the lateral movement of crabs. In crab mode, the vehicle can use a specific steering system to deflect the rear wheels in the same direction as the front wheels, so that the entire vehicle body can achieve the effect of moving diagonally forward. To achieve crab mode on a car, a four-wheel independent steering system or similar technology is usually required, so in a car without rear-wheel steering, it is impossible to deflect in the same direction at low speed, which may lead to limitations in handling performance and improvement in driving experience.

[0003] With the upgrading of technology and the improvement of production processes, rear-wheel steering in existing technologies has gradually become a function that can be installed on vehicles, which provides a basis for the line of sight of the crab mode. After the crab mode is realized, the vehicle can be translated at special angles in special circumstances to meet the needs of users.

[0004] Although the crab mode of the prior art can meet the special driving requirements of the vehicle, the prior art often only focuses on the vehicle operation in the crab mode, and does not involve the start control, interactive control, safety control and other aspects of the crab mode, resulting in the defects of insufficient user experience and safety in the control of the crab mode. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a crab mode control method and a vehicle based on rear-wheel steering, which improves the user experience, safety and reliability of the crab mode by visual interactive control of the crab mode and implementation of safety control logic.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a crab mode control method based on rear-wheel steering. After the driver enters the start command through voice or the on-board large screen, it is determined whether the crab mode start conditions are met. If so, the crab mode is entered, and the on-board large screen displays the front and rear wheel angle information in real time.

[0007] After entering the crab mode, the steering angle of the front wheels is collected in real time, and the rear wheels are controlled to rotate in the same direction and angle as the front wheels.

[0008] After entering the crab mode, if it is detected that the vehicle has turned on the intelligent assisted driving function, the rear-wheel steering system acts as an actuator, receives the rear-wheel steering command sent by the intelligent assisted driving system in real time and executes the corresponding target turning angle.

[0009] Determining whether the crab mode activation conditions are met includes: collecting the current vehicle speed signal and steering wheel angle signal. Only when the vehicle speed signal is less than a set threshold and the steering wheel angle is less than a set angle threshold, is it determined that the crab mode activation conditions are met. Otherwise, it is determined that the crab mode activation conditions are not met.

[0010] The rear-wheel steering system responds to the steering wheel angle signal to deflect the rear wheel angle or responds to the intelligent driving assistance system command to execute angle deflection. At the same time, the vehicle-mounted large screen will receive the rear wheel angle in real time for display, predict the trajectory of the rear wheel and display the rear wheel angle trajectory.

[0011] After the Crab Mode is activated, the vehicle's operating status is monitored in real time, and a determination is made based on the operating status whether the safe operating conditions of the Crab Mode have been exceeded. If the safe operating conditions have been exceeded, the Crab Mode is exited.

[0012] The safe operating conditions of the crab mode are that the vehicle speed is ≤ the safety threshold speed and the steering wheel angle is less than the safety angle threshold.

[0013] In Crab Mode, if the automatic assisted driving function is turned on, the intelligent assisted driving system will send a speed limit instruction to the vehicle power system. In Crab Mode, the vehicle power system will control the vehicle power output and limit the vehicle speed to the set speed threshold.

[0014] After determining that the safe operating conditions of the Crab Mode have been exceeded, the Crab Mode is exited. At this time, an exit reminder is issued through the on-board large screen and the vehicle brakes are controlled at the same time. After the vehicle brakes, the rear wheel angle is adjusted to the initial state through the rear-wheel drive system to complete the exit from the Crab Mode.

[0015] A car has a built-in crab mode, and the crab mode is controlled by a crab mode control method based on rear wheel steering.

[0016] The advantages of the present invention are: the user experience, safety and reliability of the crab mode are improved through the visual interactive control of the crab mode and the implementation of safety control logic. The crab mode control method based on rear-wheel steering combines the front wheel steering and rear wheel steering of the car to rotate in the same direction, making parking and maneuvering in a small space easier and more efficient, and can respond to the request of the intelligent driving assistance system to perform vehicle cooperative control, giving the driver more advanced control and more driving experience. In some cases, the crab mode can simplify the driver's operation. For example, when parallel parking, the driver does not need to adjust the position and angle of the vehicle many times, and can easily park the vehicle in the designated position by using the crab mode. The crab mode provides the driver with a more flexible and convenient driving method by improving the maneuverability of the vehicle, shortening the turning radius, improving safety, enhancing the driving experience and expanding the application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following is a brief description of the contents expressed in the drawings of the present invention and the symbols in the drawings:

[0018] Figure 1 It is a schematic diagram of the overall structure of the crab mode control method based on rear wheel steering of the present invention;

[0019] Figure 2 The figure is a flow chart of the crab mode control method based on rear wheel steering of the present invention. DETAILED DESCRIPTION

[0020] The specific implementation of the present invention will be further explained in detail below by describing the optimal embodiment with reference to the accompanying drawings.

[0021] This embodiment is aimed at the logic design of starting control of the crab mode in the prior art, and the line of sight satisfies the user to participate in control or obtain control information or reminder information to improve the user experience of the crab mode control method, and improves the user experience, safety and reliability of the crab mode through visual interactive control of the crab mode and implementation of safety control logic. The specific control scheme of this scheme is as follows:

[0022] A method for controlling a crab mode based on rear-wheel steering determines whether the crab mode activation conditions are met after the driver enters an activation command through voice or a large in-vehicle screen. If the conditions are met, the crab mode is entered, and the large in-vehicle screen displays the front and rear wheel angle information in real time. If the conditions are not met, the shoe mode is prohibited. The driver can activate the crab mode by pressing an activation button on the large in-vehicle screen or by entering a voice command through in-vehicle voice interaction. The driver's intention is determined by identifying the driver's voice command or the button activation status on the large in-vehicle screen, thereby providing multiple activation methods that meet the driver's needs and improving the user experience.

[0023] After detecting the driver's intention to start, it is determined whether the current vehicle meets the conditions for starting the crab mode, because the crab mode is actually a special mode that cannot meet the requirements of fast and large-angle driving. Therefore, it is necessary to judge the vehicle state at this time to determine whether the crab mode can be turned on. Judging whether the conditions for turning on the crab mode are met include: collecting the vehicle speed signal and steering wheel angle signal of the current vehicle. Only when the vehicle speed signal is less than the set threshold and the steering wheel angle is less than the set angle threshold, it is determined that the conditions for turning on the crab mode are met. Otherwise, it is determined that the conditions for turning on the crab mode are not met, otherwise the crab mode is not turned on. The current vehicle's shape is judged by the crab mode start condition, thereby avoiding the safety hazards caused by the crab mode when the speed is too high or the angle is too large, and improving the safety of the crab mode. The speed threshold and the set angle threshold in this scheme can be calibrated according to the actual situation. Generally, the vehicle speed is 3-5km / h and the angle is 3-5°. The design can be calibrated according to the actual situation.

[0024] After entering the crab mode, the steering angle of the front wheels is collected in real time, and the rear wheels are controlled to follow the front wheels to rotate in the same direction and angle, so as to meet the requirements of the crab mode. After entering the crab mode, if it is detected that the vehicle has turned on the intelligent assisted driving function, the rear wheel steering system acts as an actuator, receives the rear wheel steering command sent by the intelligent assisted driving system in real time and executes the corresponding target turning angle. In the crab mode, there are generally two control methods, driver active control and automatic control of the automatic assisted driving system. When the driver actively controls, the front wheel angle is rotated through the steering wheel, and the rear wheel angle runs in the same direction and angle, so as to realize the control of the direction of the crab mode. At this time, the throttle speed is controlled by the driver himself; when using the intelligent assisted driving system, such as assisted driving such as breaking the car into the warehouse, the control of the vehicle is realized by the assisted driving software. At this time, the rear wheel angle is also controlled by the assisted driving system, and the front and rear wheels are dynamically adjusted to follow the movement according to the control of the assisted driving system.

[0025] When the rear-wheel steering system responds to the steering wheel angle signal to deflect the rear wheel angle or responds to the intelligent driving assistance system command to execute the angle deflection, the vehicle-mounted large screen will be controlled to receive the rear wheel angle in real time for display, and the rear wheel trajectory will be predicted and displayed, so as to facilitate the driver to understand the crab mode operation status information. The rotation angle is directly displayed on the large screen, and the rear wheel movement trajectory is collected by the panoramic camera through the panoramic image data of the vehicle, and then the collected rear wheel angle data is predicted. When running at this angle, the running trajectory of the rear wheel is added to the panoramic image through lines, which is convenient for the driver to view. The panoramic image is taken by the panoramic camera. Taking the top view around the vehicle as an example, the running trajectory of the vehicle is added to the top view, which is convenient for the driver to view, thereby improving the user experience.

[0026] After the crab mode is started, the vehicle's operating status is monitored in real time, and based on the operating status, it is determined whether the safe operating conditions of the crab mode are exceeded. If the safe operating conditions are exceeded, the crab mode is exited. The safe operating conditions of the crab mode are that the vehicle speed is ≤ the safety threshold speed and the steering wheel angle is less than the safety angle threshold. In the crab mode, due to the special circumstances of the crab mode, it cannot operate at a large angle or high speed, otherwise it will cause a safety accident and affect the driver's driving safety. Therefore, the maximum speed and maximum turning angle are designed to limit the safe operation of the crab mode, that is, when the vehicle speed is ≤ the safety threshold speed and the steering wheel angle is less than the safety angle threshold, it is the safe operating condition of the crab mode. If this condition is exceeded, the crab mode is exited.

[0027] In a preferred embodiment, it is allowed to exceed the safety threshold for a short time, such as when getting out of trouble, a large throttle is required, which may cause the vehicle to exceed the speed limit for a short time. Therefore, when it is detected that the safety operating conditions of the crab mode are exceeded, a reminder message is immediately sent through the vehicle-mounted large screen, and a delay is performed at the same time. If the duration of exceeding the crab mode operating conditions reaches the delay setting time, the brake is applied and the crab mode is exited. The purpose of this is to remind when the safety conditions are exceeded, and the real-time status of the crab mode can be reminded in time, providing basic information for the driver, and facilitating the subsequent processing and prejudgment of the driver's driving; after the delay, the brake is applied and the crab mode exit operation is performed, which can improve the safety of the crab mode operation and avoid safety accidents caused by long-term overspeed and over-angle crab mode. The delay setting time can be a delay of several seconds. The purpose of this is to meet the needs of getting out of trouble in some extreme situations. It is allowed to exceed 10km per hour suddenly, and then recover in a few short days. At this time, the crab mode will not be exited. If the duration of several seconds and greater than the set time threshold exceeds the safety operating conditions of the crab mode, it is judged that there is a safety hazard at this time, and the vehicle is braked and then the crab mode exit operation is performed.

[0028] After determining that the safe operating conditions of the Crab Mode are exceeded, the Crab Mode is exited. At this time, an exit reminder is issued through the on-board large screen and the vehicle brakes are controlled at the same time. After the vehicle brakes, the rear wheel angle is adjusted to the initial state through the rear-wheel drive system to complete the exit from the Crab Mode. Since the Crab Mode is exited, the rear wheels need to be adjusted to the initial state, that is, the rear wheel steering angle is 0 or the initial non-steering state. In order to improve safety, the vehicle needs to be braked when the steering angle of the rear wheels is restored to the initial state. The steering is controlled only when the vehicle speed is low to improve safety. The low speed here is to meet safety requirements, and the rear wheel angle can even be controlled to be restored when the vehicle speed is 0, thereby completing the exit operation from the Crab Mode.

[0029] In a preferred embodiment, in crab mode, if the automatic assisted driving function is turned on, the intelligent assisted driving system sends a speed limiting instruction to the vehicle power system. The vehicle power system controls the vehicle power output in crab mode and limits the vehicle speed to a set speed threshold, thereby improving safety. Since the automatic assisted driving system can control the vehicle speed, the automatic driving system directly limits the vehicle speed in crab mode at this time, ensuring that the vehicle power output does not exceed this speed, thereby improving safety in crab mode operation.

[0030] The present solution also provides a car having a built-in crab mode. The crab mode adopts the crab mode control method based on rear wheel steering in the above embodiment to control the crab mode. Since the car has all the features of the crab mode control method, it has all the technical advantages of the control method in the above embodiment.

[0031] The crab mode control method based on rear-wheel steering of the present invention combines front-wheel steering and rear-wheel steering to provide more flexible steering control. The driver can turn on the crab mode through the touch screen or voice command to improve the driving experience. The crab mode is very useful in narrow and complex road environments, such as jungles, gullies and other off-road environments. It can help the vehicle easily cross the tree obstacles in front and complete actions that are difficult for conventional vehicles to complete, such as parallel parking.

[0032] Crab mode is a special vehicle operation mode that improves the maneuverability and flexibility of the vehicle in complex road environments by imitating the lateral movement of crabs. Although this technology is currently mainly used on some specially designed vehicles, with the continuous advancement of technology, it may be applied to more types of vehicles in the future. The present invention provides a crab mode control method based on rear-wheel steering, including the following components: vehicle driving data, rear-wheel steering system, intelligent driving assistance system, large screen, and steering wheel. The driver turns on the crab mode function through the large screen. After the rear-wheel steering system confirms that the crab mode is turned on, the rear-wheel steering system enters the crab mode, and the large screen displays the current front and rear wheel angles for the driver to view and confirm. The driver can also take corresponding collaborative control by clicking on the intelligent driving assistance system on the large screen after the crab mode is turned on.

[0033] The control logic of the Crab Mode is as follows: After the rear-wheel steering system receives the driver's signal from clicking the large-screen Crab Mode switch, and confirms that the Crab Mode can be entered, the rear wheels will follow the angle of the front wheels in this mode and rotate in the same direction and angle, allowing the vehicle to travel sideways. If the intelligent driving assistance is turned on at the same time in the Crab Mode, such as one-button exit and one-button parking, the rear-wheel steering system, as an actuator, receives the rear wheel angle command sent by the intelligent driving assistance and executes the target angle, and cooperates with other systems to achieve advanced functions.

[0034] The crab mode control method based on rear-wheel steering combines the front-wheel steering and rear-wheel steering of the car to rotate in the same direction, making parking and maneuvering in narrow spaces easier and more efficient, and can respond to the request of the intelligent driving assistance system for vehicle cooperative control, giving the driver more advanced control and more driving experience. In some cases, the crab mode can simplify the driver's operation. For example, when parallel parking, the driver does not need to adjust the position and angle of the vehicle many times, just use the crab mode to easily park the vehicle in the designated position. The crab mode provides drivers with a more flexible and convenient driving method by improving the vehicle's maneuverability, shortening the turning radius, improving safety, enhancing the driving experience, and expanding application scenarios.

[0035] like Figure 1 As shown, the overall structure of the crab mode control method based on rear-wheel steering is shown. The connection relationship between the system large screen, rear-wheel steering system, vehicle driving, intelligent driving assistance system, and steering wheel. The driver turns on the rear-wheel steering and crab mode through the large screen, and the rear-wheel steering system responds according to the host computer command. If the driver turns the steering wheel, the front wheels rotate according to the transmission ratio, and the rear wheels follow according to the steering wheel angle, maintaining the same angle as the front wheels. The driver can control the vehicle speed and steering wheel angle to make the vehicle drive in a certain posture. If the driver turns on the intelligent assisted driving system, such as one-button exit, one-button parking and other functions, the rear-wheel steering system, as an actuator, receives the rear wheel angle command sent by the intelligent driving assistance and executes the target angle, and cooperates with other systems to control, which can greatly improve the driving experience.

[0036] like Figure 2 As shown, the control process of the crab mode based on rear-wheel steering is demonstrated. First, the driver needs to turn on the rear-wheel steering. The crab mode can only be operated after the rear-wheel steering function is turned on. The crab mode needs to be judged by the vehicle speed <= 3kmh && steering wheel angle (absolute value) <= 3°. It can be turned on only after the conditions are met. The rear-wheel steering system responds to the steering wheel angle signal to deflect the rear wheel angle or responds to the intelligent driving assistance system command to perform angle deflection. The large screen will also receive the rear wheel angle in real time for trajectory display. At the same time, during the real-time driving of the vehicle, the driving status of the vehicle will be judged. If the speed is > 10kmh or the front wheel angle (absolute value) >= 10° or the rear wheel steering is turned off, the crab mode will be exited. If the conditions are always met, the crab mode can be driven all the time.

[0037] Through the above implementation, the driver can turn on the rear-wheel steering and crab mode and drive within the conditions of function implementation, so that the vehicle can move sideways like a crab, that is, the front and rear wheels keep moving at the same angle, which is very useful in some narrow or complex road environments. For example, when driving off-road, when encountering obstacles or needing to avoid other vehicles, the crab mode can help the vehicle bypass them more easily; in urban environments, the crab mode can also help the vehicle park more easily in narrow parking spaces, or flexibly adjust its position on busy streets. The crab mode can respond to both the driver's operation and the angle command of the intelligent driving assistance system, giving the driver more advanced control and more driving experience.

[0038] Figure 1 This is a schematic diagram of the overall structure of the crab mode control method based on rear-wheel steering, showing the connection between the car's large screen, rear-wheel steering system, vehicle driving, intelligent driving assistance system, and steering wheel. Figure 2 This is a flow chart of the crab mode control method based on rear-wheel steering. It shows that after the driver sets the rear-wheel steering and crab mode functions to be turned on, the rear-wheel steering system responds to the driver's steering wheel angle signal or the command signal of the intelligent driving assistance system, as well as the process of entering and exiting the crab mode under set conditions.

[0039] The crab mode control method based on rear wheel steering in the above embodiment can be implemented in different ways according to specific needs and actual conditions. The following are some specific use scenarios and functions of the crab mode according to the real-time situation of the car:

[0040] 1. Off-road driving: Vehicles often need to cross complex terrains, such as rugged mountain roads, sand dunes, muddy areas, etc. In these environments, the crab mode can significantly improve the vehicle's maneuverability and passability. For example, when encountering ruts while off-roading, the front and rear wheels need to drive along the ruts. When it is necessary to cut out of the ruts, if there is no rear wheel steering, the front wheels may have left the ruts, but the rear wheels are still stuck in the ruts, causing the vehicle to slip. At this time, the crab mode can help the vehicle get out of trouble smoothly.

[0041] 2. Narrow roads and sharp turns: On narrow roads or sharp turns, traditional vehicle turning methods may be limited, but the crab mode allows the vehicle to cope with these scenarios more flexibly. Through the coordinated steering of the four wheels, the vehicle can achieve a smaller turning radius and easily complete a U-turn or turn.

[0042] 3. Parallel parking: Parallel parking is a common parking method in urban parking scenarios. However, due to vehicle size, driver skills, etc., it sometimes takes multiple adjustments to successfully park. Crab mode can help drivers complete parallel parking more easily and reduce unnecessary adjustments.

[0043] 4. Crossing obstacles: In the jungle or complex terrain, the vehicle may encounter obstacles such as trees and rocks. Crab mode allows the vehicle to move sideways like a crab, easily crossing these obstacles and avoiding damage to the vehicle.

[0044] The above supplementary information is only an example, and the actual implementation may be different. The key to the present invention is to provide a crab mode control method based on rear-wheel steering. The crab mode provides the driver with a more flexible, convenient and safe driving experience by improving the maneuverability of the vehicle, reducing the turning radius, coping with special road conditions and enhancing the driving experience.

[0045] Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, they are all within the protection scope of the present invention.

Claims

1. A crab mode control method based on rear wheel steering, characterized in that: After the driver enters the start command through voice or the in-vehicle large screen, it is determined whether the conditions for starting the crab mode are met. If so, the crab mode is entered and the in-vehicle large screen displays the front and rear wheel angle information in real time.

2. A crab mode control method based on rear wheel steering as claimed in claim 1, characterized in that: After entering the crab mode, the steering angle of the front wheels is collected in real time, and the rear wheels are controlled to rotate in the same direction and angle as the front wheels.

3. The crab mode control method based on rear wheel steering according to claim 1 or 2, characterized in that: After entering the crab mode, if it is detected that the vehicle has turned on the intelligent assisted driving function, the rear-wheel steering system acts as an actuator, receives the rear-wheel steering command sent by the intelligent assisted driving system in real time and executes the corresponding target turning angle.

4. A crab mode control method based on rear wheel steering as claimed in claim 1 or 2, characterized in that: Determining whether the crab mode activation conditions are met includes: collecting the current vehicle speed signal and steering wheel angle signal. Only when the vehicle speed signal is less than a set threshold and the steering wheel angle is less than a set angle threshold, is it determined that the crab mode activation conditions are met. Otherwise, it is determined that the crab mode activation conditions are not met.

5. A crab mode control method based on rear wheel steering as claimed in claim 1 or 2, characterized in that: The rear-wheel steering system responds to the steering wheel angle signal to deflect the rear wheel angle or responds to the intelligent driving assistance system command to execute angle deflection. At the same time, the vehicle-mounted large screen will receive the rear wheel angle in real time for display, predict the trajectory of the rear wheel and display the rear wheel angle trajectory.

6. A crab mode control method based on rear wheel steering as claimed in claim 1 or 2, characterized in that: After the Crab Mode is activated, the vehicle's operating status is monitored in real time, and a determination is made based on the operating status whether the safe operating conditions of the Crab Mode have been exceeded. If the safe operating conditions have been exceeded, the Crab Mode is exited.

7. A crab mode control method based on rear wheel steering as claimed in claim 6, characterized in that: The safe operating conditions of the crab mode are that the vehicle speed is ≤ the safety threshold speed and the steering wheel angle is less than the safety angle threshold.

8. A crab mode control method based on rear wheel steering according to any one of claims 1 to 7, characterized in that: In Crab Mode, if the automatic assisted driving function is turned on, the intelligent assisted driving system will send a speed limit instruction to the vehicle power system. In Crab Mode, the vehicle power system will control the vehicle power output and limit the vehicle speed to the set speed threshold.

9. A crab mode control method based on rear wheel steering according to any one of claims 1 to 7, characterized in that: After determining that the safe operating conditions of the Crab Mode have been exceeded, the Crab Mode is exited. At this time, an exit reminder is issued through the on-board large screen and the vehicle brakes are controlled at the same time. After the vehicle brakes, the rear wheel angle is adjusted to the initial state through the rear-wheel drive system to complete the exit from the Crab Mode.

10. An automobile, characterized in that: The automobile has a built-in crab mode, and the crab mode is controlled by the crab mode control method based on rear wheel steering as described in any one of claims 1-9.

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