A crab mode control method based on rear wheel steering and a vehicle

Abstract

The application discloses a crab mode control method based on rear wheel steering and a car. After a driver inputs an opening instruction through voice or a vehicle-mounted large screen, it is judged whether crab mode opening conditions are met. If yes, the crab mode is entered, and the vehicle-mounted large screen displays real-time front and rear wheel angle information. After entering the crab mode, the rotation angle of the front wheel is collected in real time, and the rear wheel is controlled to rotate at the same angle in the same direction as the front wheel. The application has the advantages that the user experience, safety, and reliability of the crab mode are improved through visual interactive control and safety control logic implementation of the crab mode.

Description

Technical Field

[0001] This invention relates to the field of automotive steering control, and in particular to a crab-mode control method and an automotive based on rear-wheel steering. Background Technology

[0002] Crab mode control based on rear-wheel steering is an advanced technology in automotive steering systems, a special vehicle operating mode that mimics the lateral movement of a crab. In crab mode, the vehicle uses a specific steering system to make the rear wheels deflect in the same direction as the front wheels, thus allowing the entire vehicle to slide diagonally forward. Implementing crab mode in automobiles typically requires a four-wheel independent steering system or similar technology. Therefore, in cars without rear-wheel steering, low-speed lateral deflection is impossible, potentially limiting handling performance and the improvement of the driving experience.

[0003] With technological upgrades and improved manufacturing processes, rear-wheel steering has gradually become a feature that vehicles can carry. This provides the basis for the line of sight in the crab mode. After the crab mode is implemented, it can meet the needs of users for vehicle translation at special angles under special circumstances.

[0004] While existing technologies can meet the specific driving requirements of vehicles, they often only focus on vehicle operation in crab mode and do not address aspects such as start-up control, interaction control, and safety control. This results in deficiencies in user experience and safety in crab mode control. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a crab mode control method and vehicle based on rear wheel steering. By implementing visual interactive control and safety control logic for crab mode, the user experience, safety, and reliability of crab mode operation are improved.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a crab mode control method based on rear wheel steering. After the driver inputs the activation command via voice or in-vehicle screen, it is determined whether the conditions for activating the crab mode are met. If they are met, the crab mode is entered, and the in-vehicle screen displays the front and rear wheel angle information in real time.

[0007] After entering crab mode, the rotation 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.

[0008] After entering crab mode, if the intelligent driver assistance function is detected to be activated, the rear wheel steering system acts as the actuator, receiving the rear wheel steering command sent by the intelligent driver assistance system in real time and executing the corresponding target steering angle.

[0009] The judgment of whether the crab mode opening condition is met comprises: collecting the speed signal and the steering wheel angle signal of the current vehicle, and only when the speed signal is less than a set threshold and the steering wheel angle is less than a set angle threshold, it is judged that the crab mode opening condition is met, otherwise it is judged that the crab mode opening condition is not met.

[0010] The rear wheel steering system deflects the rear wheel angle in response to the steering wheel angle signal or in response to the intelligent driving assistance system instruction, and at the same time, the vehicle-mounted large screen displays the real-time received rear wheel angle, and the trajectory of the rear wheel is predicted and displayed.

[0011] After the crab mode is started, the vehicle operating state is monitored in real time, and it is judged whether the crab mode safety operating condition is exceeded based on the operating state, and if the safety operating condition is exceeded, the crab mode is exited.

[0012] The crab mode safety operating condition is that the vehicle speed is less than or equal to a safety threshold speed and the steering wheel angle is less than a safety angle threshold.

[0013] In the crab mode, if the automatic auxiliary driving function is started, the intelligent auxiliary driving system sends a speed limiting instruction to the vehicle power system, and the vehicle power system controls the vehicle power output and limits the vehicle speed within a set speed threshold in the crab mode.

[0014] After it is judged that the crab mode safety operating condition is exceeded, the crab mode is exited, at this time, the exit reminder is sent through the vehicle-mounted large screen and the vehicle brake is controlled, and after the vehicle brake is controlled, the rear wheel angle is adjusted to the initial state through the rear wheel driving system to complete the exit of the crab mode.

[0015] An automobile, which is built-in with a crab mode, the crab mode is controlled by a crab mode control method based on rear wheel steering.

[0016] The advantages of the present application are that the user experience, safety and reliability of the crab mode operation are improved through the visual interactive control and safety control logic implementation of the crab mode. The crab mode control method based on rear wheel steering combines the front wheel steering and rear wheel steering of the automobile to rotate in the same direction, making the parking and narrow space control more easy and efficient, and can respond to the request of the intelligent driving assistance system for vehicle cooperative control, bringing higher control and more driving experience to the driver. In some cases, the crab mode can simplify the operation of the driver. For example, when parallel parking, the driver does not need to adjust the position and angle of the vehicle multiple times, but only needs to use the crab mode to easily park the vehicle at the designated position. The crab mode improves the vehicle's maneuverability, shortens the turning radius, improves safety, enhances driving experience, and expands application scenarios, providing a more flexible and convenient driving method for the driver. BRIEF DESCRIPTION OF DRAWINGS

[0017] The following is a brief description of the content expressed in each figure of the present application and the labels in the figures:

[0018] Figure 1 The overall structure of the crab mode control method based on rear wheel steering of the present application is shown in the figure.

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

[0020] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0021] The present embodiment is aimed at the logic design of the start control of the crab mode of the prior art, the crab mode control method that improves the user experience of the crab mode by satisfying the user's participation in control or obtaining control information or reminding information, and the user experience, safety and reliability of the crab mode work are improved by the visual interactive control and safety control logic implementation of the crab mode. The specific control scheme of the present scheme is as follows:

[0022] A crab mode control method based on rear wheel steering, after the driver enters the start instruction through voice or vehicle-mounted large screen, it is judged whether the crab mode start condition is satisfied, if so, the crab mode is entered, the front and rear wheel angle information is displayed in real time on the vehicle-mounted large screen, if not, the shoe type mode is prohibited. The driver can start the crab mode through the start button on the vehicle-mounted large screen or by entering voice commands through vehicle-mounted voice interaction, the driver's intention is judged by recognizing the driver's voice command or the button start state on the vehicle-mounted large screen, thereby providing multiple start methods to meet the driver's needs and improve user experience.

[0023] After detecting the starting intention of the driver, it is judged whether the current vehicle meets the condition for starting the crab mode. Since the crab mode is actually a special mode that cannot meet the requirements of fast and large-angle driving, the vehicle state at this time needs to be judged to determine whether the crab mode can be started. The judgment of whether the crab mode starting condition is met includes: collecting the vehicle speed signal and the steering wheel angle signal of the current vehicle, and 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 judged that the crab mode starting condition is met, otherwise it is judged that the crab mode starting condition is not met, otherwise the crab mode is not started. The form of the current vehicle is judged by the crab mode starting condition, thereby avoiding the safety hazards caused by the crab mode in the case of excessive vehicle speed and / or excessive angle, and improving the safety of the crab mode. The vehicle speed threshold and the set angle threshold in the scheme can be calibrated according to the actual situation, and the general vehicle speed is 3-5km / h and the angle is 3-5°, which can be designed according to the actual situation.

[0024] After entering the crab mode, the rotation angle of the front wheel is collected in real time, and the rear wheel is controlled to rotate in the same direction and at the same angle as the front wheel, thereby meeting the requirements of the crab mode operation. After entering the crab mode, if it is detected that the vehicle starts the intelligent auxiliary driving function, the rear wheel steering system acts as an actuator, and real-time rear wheel steering instructions are received from the intelligent auxiliary driving system and the corresponding target rotation angle is executed. In the crab mode, there are generally two control methods: active control by the driver and automatic control by the automatic auxiliary driving system. When the driver actively controls, the front wheel angle is rotated by the steering wheel, and the rear wheel angle is rotated according to the same direction and the same angle, thereby realizing the control of the crab mode direction. At this time, the vehicle speed is controlled by the driver himself. When the intelligent auxiliary driving system such as the broken car into the garage is used, the control of the vehicle is realized by the auxiliary driving software. At this time, the rear wheel angle is controlled by the auxiliary driving system, and the front and rear wheel following motion is dynamically adjusted according to the control of the auxiliary driving system.

[0025] While the rear wheel steering system responds to the steering wheel angle signal to deflect the rear wheel angle or responds to the intelligent driving auxiliary system instruction to execute the angle deflection, the vehicle-mounted large screen displays the real-time rear wheel angle and predicts and displays the rear wheel angle trajectory, thereby realizing the convenience for the driver to understand the running state information of the crab mode. The rotation angle is directly displayed on the large screen, and the rear wheel motion trajectory is collected by the panoramic camera to obtain panoramic image data of the vehicle, and then the collected rear wheel angle data is predicted according to the running trajectory of the rear wheel at this angle. The rear wheel trajectory information is added by lines in the panoramic image, which is convenient for the driver to view, and the panoramic image is shot by the panoramic camera. Taking the overhead view of the vehicle around as an example, the running trajectory of the vehicle is added on the overhead view, which is convenient for the driver to view, thereby improving the user experience.

[0026] After the crab mode is started, the vehicle running state is monitored in real time, and it is judged whether the crab mode safety running condition is exceeded based on the running state. If the safety running condition is exceeded, the crab mode is exited. The crab mode safety running condition is that the vehicle speed is less than or equal to a safety threshold vehicle speed and the steering wheel angle is less than a safety angle threshold. In the crab mode, due to the special situation of the crab mode, it cannot run at a large angle and a large speed, otherwise a safety accident will occur, affecting the driving safety of the driver, so the maximum speed and the maximum angle are designed to limit the safety running of the crab mode, that is, when the vehicle speed is less than or equal to the safety threshold vehicle speed and the steering wheel angle is less than the safety angle threshold, it belongs to the safety running condition of the crab mode, and if the condition is exceeded, the crab mode is exited.

[0027] In a preferred embodiment, a short-term overrun of the safety threshold is allowed, such as a situation of getting out of trouble, which requires a large throttle, so that the vehicle may instantaneously overrun for a short time. Therefore, when it is detected that the crab mode safety running condition is exceeded, a prompt information is immediately sent through the vehicle-mounted large screen, and a delay is performed. If the duration of the crab mode running condition exceeds the delay setting time, the vehicle is braked and the crab mode is exited. The purpose of this is to remind the safety condition, which can timely remind the real-time state of the crab mode and provide basic information for the driver, facilitating the subsequent processing and prediction of the driver. After the delay, the vehicle is braked and the crab mode is exited, which can improve the safety of the crab mode running and avoid safety accidents caused by long-time overrunning and over-angling of the crab mode. The delay setting time can be a few seconds, which is to meet the needs of getting out of trouble in some extreme situations and allow a sudden overrun of 10 km per hour, and then recover within a few seconds. If the duration exceeds the set time threshold, it is judged that there is a safety hazard, and the vehicle is braked and the crab mode is exited.

[0028] After it is judged that the crab mode safety running condition is exceeded, the crab mode is exited. At this time, an exit reminder is sent through the vehicle-mounted large screen, and the vehicle is braked. After the rear wheel angle is adjusted to the initial state by the rear wheel drive system after the vehicle is braked, the crab mode is exited. Since the crab mode is exited, the rear wheel needs 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 wheel is restored to the initial state. The steering is controlled when the vehicle speed is small, which improves safety. Here, the small vehicle speed is to meet safety, and the rear wheel angle can be restored to 0 even after braking, so as to complete the crab mode exit operation.

[0029] In a preferred embodiment, in crab mode, if the automatic auxiliary driving function is turned on, the intelligent auxiliary driving system sends a speed limit instruction to the vehicle power system, which controls the vehicle power output and limits the vehicle speed within the set speed threshold in crab mode, thereby improving safety. Since the automatic auxiliary driving system can control the speed, the speed in crab mode is directly limited by the automatic driving system, ensuring that the vehicle power output does not exceed this speed, thereby improving safety in crab mode.

[0030] The present application also provides an automobile with a built-in crab mode, which uses the above-mentioned crab mode control method based on rear wheel steering to control the crab mode. Since the automobile has all the features of the crab mode control method, it has all the technical advantages of the control method in the above-mentioned embodiments.

[0031] The crab mode control method based on rear wheel steering 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. Crab mode is very useful in narrow and complex road environments, such as jungle, gully, and other off-road environments. It can help the vehicle easily cross the front tree obstacles and complete the parallel parking and other actions that conventional vehicles cannot complete.

[0032] Crab mode is a special vehicle operating mode that simulates the lateral movement of a crab to improve the maneuverability and flexibility of the vehicle in complex road environments. Although this technology is currently mainly applied to some specially designed vehicles, with the continuous progress of technology, it may be applied to more types of vehicles in the future. The present application provides a crab mode control method based on rear wheel steering, which includes the following components: vehicle driving data, rear wheel steering system, intelligent driving assistance system, large screen, steering wheel. The driver turns on the crab mode function through the large screen, 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 click the intelligent driving assistance system on the large screen to take appropriate collaborative control after turning on the crab mode.

[0033] The control logic of the crab mode is as follows: the rear wheel steering system receives the driver's click on the crab mode switch on the large screen to turn on the signal, confirms that it can enter the crab mode, and the rear wheel follows the front wheel angle in this mode to rotate in the same direction and angle, so that the vehicle can move laterally. If the intelligent driving assistance is turned on at the same time in crab mode, such as one-key parking and one-key parking, the rear wheel steering system receives the rear wheel steering angle instruction from the intelligent driving assistance and executes the target steering angle as an actuator, and cooperates with other systems to realize advanced functions.

[0034] The crab mode control method based on rear wheel steering combines the front wheel steering and rear wheel steering of the vehicle to rotate in the same direction, making the parking and operation in narrow space more easy and efficient, and can respond to the request of the intelligent driving assistance system for vehicle cooperative control, bringing the driver a more advanced control and more driving experience. In some cases, the crab mode can simplify the operation of the driver. For example, when parallel parking, the driver does not need to adjust the position and angle of the vehicle multiple times, but can easily park the vehicle in the designated position by using the crab mode. The crab mode has the advantages of improving the maneuverability of the vehicle, shortening the turning radius, improving safety, improving driving experience, and expanding application scenarios, etc., providing the driver with a more flexible and convenient driving method.

[0035] As shown in Figure 1 , 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, whole 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 instructions of the upper computer. If the driver turns the steering wheel, the front wheel turns according to the transmission ratio, and the rear wheel follows the steering wheel angle to maintain the same angle as the front wheel. The driver can control the vehicle to travel in a certain attitude by controlling the vehicle speed and steering wheel angle. If the driver turns on the intelligent driving assistance system, such as one-key out-of-warehouse and one-key parking functions, the rear wheel steering system as an actuator receives the rear wheel turning angle instruction from the intelligent driving assistance system and executes the target turning angle, and cooperates with other systems to improve the driving experience.

[0036] As shown in Figure 2 , the control flow of the crab mode based on rear wheel steering is shown. First, the driver needs to turn on the rear wheel steering, which can only be operated after the rear wheel steering function is turned on, and the crab mode needs to pass the vehicle speed <= 3kmh && steering wheel angle (absolute value) <= 3° judgment before it can be turned on. 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 instruction to execute the angle deflection, and 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 state of the vehicle will be judged, and if the vehicle speed > 10kmh or the front wheel angle (absolute value) >= 10° or the rear wheel steering is turned off, the crab mode is exited, and if the conditions are always met, the vehicle can always drive in crab mode.

[0037] Through the above-mentioned embodiments, the driver can make the vehicle walk like a crab by turning on the rear wheel steering and crab mode, and drive within the conditions of function implementation, that is, the front and rear wheels keep the same angle of movement, which is very useful in some narrow or complex road environments. For example, when off-road driving, encountering obstacles or needing to avoid other vehicles, the crab mode can help the vehicle to easily bypass them; in urban environments, the crab mode can also help the vehicle to easily park in narrow parking spaces or flexibly adjust the position on busy streets. And the crab mode can respond to both the driver's operation and the angle instruction of the intelligent driving assistance system, bringing the driver a higher level of control and more driving experience.

[0038] Figure 1 The overall structure diagram of the rear wheel steering based crab mode control method shows the connection relationship between the car large screen, rear wheel steering system, whole vehicle driving, intelligent driving assistance system and steering wheel. Figure 2 The rear wheel steering based crab mode control method flow chart shows the process of entering and exiting the crab mode under the condition of setting the rear wheel steering and crab mode function by the driver, and the rear wheel steering system responding to the steering wheel angle signal of the driver or the instruction signal of the intelligent driving assistance system.

[0039] The rear wheel steering based crab mode control method in the above-mentioned embodiments can be implemented differently according to specific needs and actual situations. Here are some specific use scenarios and effects of the crab mode according to the real-time situation of the vehicle:

[0040] 1. Off-road driving: Vehicles often need to pass through complex terrain, such as rugged mountain roads, sand dunes, and muddy areas. In these environments, the crab mode can significantly improve the vehicle's maneuverability and passability. For example, when off-road driving, the front and rear wheels need to follow the ruts. When you need to cut out the ruts, if there is no rear wheel steering, the front wheels may have already 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 to escape smoothly.

[0041] 2. Narrow road sections and sharp turns: In narrow road sections or sharp turns, traditional vehicle turning methods may be limited, while the crab mode can make the vehicle more flexible in these scenarios. Through the coordinated steering of the four wheels, the vehicle can achieve a smaller turning radius, easily completing U-turns or turns.

[0042] 3. Side parking: In urban parking scenarios, side parking is a common parking method. However, due to vehicle size, driver skills, and other reasons, sometimes multiple adjustments are needed to successfully park. The crab mode can help the driver more easily complete side parking, reducing unnecessary adjustments.

[0043] 4. Obstacle crossing: In the jungle or complex terrain, the vehicle may encounter obstacles such as trees, rocks, etc. The crab mode can make the vehicle move laterally like a crab, easily cross these obstacles, and avoid damage to the vehicle.

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

[0045] Obviously, the specific implementation of the present application is not limited by the above-mentioned manner, and various non-essential improvements made by adopting the method concept and technical solution of the present application are within the protection scope of the present application.

Claims

1. A crab-mode control method based on rear-wheel steering, characterized in that: After the driver inputs the activation command via voice or the in-vehicle screen, it is determined whether the conditions for activating the crab mode are met. If so, the crab mode is entered, and the in-vehicle screen displays the front and rear wheel angle information in real time. After entering the crab mode, the rotation 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. After entering the crab mode, if the intelligent assisted driving function is detected to be activated, the rear wheel steering system acts as an actuator, receiving the rear wheel steering command sent by the intelligent assisted driving system in real time and executing the corresponding target steering angle. Determining whether the conditions for enabling the crab mode are met includes: collecting the current vehicle speed signal and steering wheel angle signal. The conditions for enabling the crab mode are only determined to be met if the vehicle speed signal is less than a set threshold and the steering wheel angle is less than a set angle threshold; otherwise, the conditions for enabling the crab mode are not met.

2. The crab-mode control method based on rear-wheel steering as described in claim 1, characterized in that: While 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 in-vehicle screen will receive and display the rear wheel angle in real time, and predict and display the rear wheel trajectory.

3. The crab-mode control method based on rear-wheel steering as described in claim 1, characterized in that: After the crab mode is activated, the vehicle's operating status is monitored in real time. 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.

4. The crab-mode control method based on rear-wheel steering as described in claim 3, characterized in that: The safe operating conditions for Crab Mode are: vehicle speed ≤ safe threshold speed and steering wheel angle less than safe angle threshold.

5. A crab-mode control method based on rear-wheel steering as described in any one of claims 1-4, characterized in that: In Crab Mode, if the automatic driving assistance function is activated, the intelligent driving assistance system issues a speed limit command to the vehicle's power system. In Crab Mode, the vehicle's power system controls the vehicle's power output and limits the vehicle's speed to within the set speed threshold.

6. A crab-mode control method based on rear-wheel steering as described in any one of claims 1-4, characterized in that: If the conditions for safe operation of the crab mode are exceeded, exit the crab mode. At this time, an exit reminder will be issued through the vehicle's large screen and the vehicle will be braked. After the vehicle brakes, the rear wheel angle will be adjusted to the initial state through the rear wheel drive system to complete the exit from the crab mode.

7. A car, characterized in that: The vehicle is equipped with a crab mode, which is controlled by the crab mode control method based on rear wheel steering as described in any one of claims 1-6.

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