A control method for automatically navigating cross-axle off-road conditions

Abstract

This invention provides a control method for automatically navigating off-road cross-axle conditions, comprising the following steps: responding to a cross-axle mode activation request, determining whether the preconditions for activating the cross-axle mode are met; if the preconditions are met, controlling the vehicle to enter cross-axle mode operation; when the vehicle enters cross-axle mode operation: applying braking pressure to the wheel ends while utilizing maximum wheel-end torque; limiting the vehicle speed to a low speed; raising the vehicle suspension height to its maximum; automatically locking the rear axle differential lock; capturing images of the vehicle's surroundings via a camera and displaying them to the user; and distributing torque between the front and rear axles by determining whether the front or rear wheels are slipping or spinning, and accelerating the braking pressure and increasing the braking speed for slipping or spinning wheels. This invention enhances the vehicle's off-road capability and lowers the barrier to vehicle use for consumers.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and in particular to a control method for automatically navigating off-road cross-axle conditions. Background Technology

[0002] As electric vehicle technology matures, consumer demand for electric vehicles is becoming increasingly diversified. Therefore, in addition to meeting standard driving conditions, more and more users want electric and hybrid vehicles to be able to handle off-road scenarios. When a vehicle reaches a pothole, one or any two diagonal wheels may lose traction (driving force), preventing the vehicle from moving forward. This condition is known as a "cross-axle situation." Traditional vehicles lack control strategies designed for cross-axle situations, requiring drivers to rely entirely on their experience to navigate them. Conventional off-road crawling logic often results in significant torque fluctuations when traversing cross-axles, leading to speed spikes or complete stops. Therefore, developing off-road functionality for cross-axle situations, enhancing actual vehicle traction, and lowering the barrier to entry for consumers has become a pressing issue. Summary of the Invention

[0003] The purpose of this invention is to provide a control method for automatically navigating off-road cross-axle conditions, thereby enhancing the vehicle's off-road extrication performance and lowering the barrier to vehicle use for consumers.

[0004] The technical solution adopted by this invention to solve its technical problem is:

[0005] A control method for automatically navigating off-road cross-axle conditions includes the following steps:

[0006] In response to the request to activate the cross-axle mode, determine whether the preconditions for activating the cross-axle mode are met; if the preconditions for activating the cross-axle mode are met, control the vehicle to enter the cross-axle operating condition.

[0007] When the vehicle enters cross-axle mode:

[0008] It can apply braking pressure to the wheel end while simultaneously activating the maximum torque at the wheel end;

[0009] Lock the gear in low gear;

[0010] Raise the vehicle's suspension height to its maximum.

[0011] Automatic locking of the rear axle differential lock;

[0012] The camera captures images of the area around the vehicle and displays them to the user.

[0013] It also distributes torque between the front and rear axles by determining whether the front or rear wheels of the vehicle are slipping or spinning, and accelerates the braking speed and increases the braking pressure on the slipping or spinning wheels.

[0014] Preferably, in conjunction with the above scheme, the preconditions for activation include:

[0015] Determine if the driver's door is closed;

[0016] Check if the driver's seatbelt is fastened;

[0017] Determine if the vehicle speed is zero;

[0018] Determine if the brake pedal has been depressed;

[0019] Determine if EPB is in a released state;

[0020] Determine if the current gear is D;

[0021] Determine if the steep slope descent control function is turned off;

[0022] If all judgment results are yes, then the prerequisite for enabling the cross axis mode is met; if any judgment result is no, then the prerequisite for enabling the cross axis mode is not met.

[0023] Preferably, in conjunction with the above scheme, when the vehicle is in cross-axle mode, the vehicle speed is limited to 1-2 kPH.

[0024] Preferably, in conjunction with the above scheme, when the vehicle is in cross-axle mode, the cross-axle mode will automatically exit when the driver presses the accelerator pedal and the vehicle speed exceeds the limit speed value and remains there for a limit time.

[0025] Preferably, in conjunction with the above scheme, after the vehicle exits the cross-axle mode, the vehicle automatically switches back to the previous driving mode.

[0026] Preferably, in conjunction with the above scheme, when the vehicle is in cross-axle mode, the driver presses the accelerator pedal or the brake pedal, and the vehicle performs corresponding acceleration or braking control.

[0027] Preferably, in conjunction with the above scheme, when the vehicle is in cross-axle mode, the user can manually choose whether to lock the front axle differential lock.

[0028] Preferably, in conjunction with the above scheme, when the vehicle is in cross-axle mode, the creep and coasting energy recovery functions are automatically turned off.

[0029] Preferably, in conjunction with the above scheme, when the vehicle is in cross-axle mode, the car's large screen displays the AVM interface to show the environment around the vehicle.

[0030] Preferably, in conjunction with the above scheme, when the vehicle is in cross-axle mode, the vehicle instrument panel and large screen display vehicle function fault reminders and prompts on how to operate in cross-axle mode.

[0031] Preferably, in conjunction with the above scheme, when the vehicle is in cross-axle mode, if it is determined that the front wheel is slipping or spinning, the torque of the front axle is reduced and the torque of the rear axle is increased; if it is determined that the rear wheel is slipping or spinning, the torque of the front axle is increased and the torque of the rear axle is reduced.

[0032] The beneficial effects of this invention are as follows: The automatic control method for cross-axle off-road conditions allows the driver to easily experience cross-axle or steep inclines by simply clicking the cross-axle mode option on the large screen while controlling the steering wheel. The driver does not need to control the vehicle speed using the accelerator or brake pedals; the system automatically maintains stable control at extremely low speeds in cross-axle and similar conditions. This allows the driver to focus entirely on the road ahead, greatly enhancing the off-road experience and sense of safety. For users with limited off-road experience, this function helps them experience cross-axle or steep inclines more safely and smoothly.

[0033] The present invention will now be described in more detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0034] Figure 1 This is a strategy diagram of a control method for automatically navigating off-road cross-axle conditions according to the present invention.

[0035] Figure 2 This is a system structure diagram for implementing the control method of the present invention. Detailed Implementation

[0036] like Figure 1 The control method shown includes the following steps for automatically navigating off-road cross-axle conditions:

[0037] In response to the cross-axle mode activation request, determine whether the preconditions for activating cross-axle mode are met; if the preconditions are met, control the vehicle to enter cross-axle operation mode; when the vehicle is in cross-axle mode:

[0038] Apply braking pressure to the wheel end while simultaneously utilizing the maximum torque available at the wheel end;

[0039] Lock the gear in a low gear (e.g., first gear or L gear). The torque is high in low gears, and ESC is responsible for the stable control of the target speed after the cross axle has been opened. Use a very low speed to slowly pass through the cross axle road condition, ensuring sufficient power while making the vehicle posture more stable and reducing the driver's panic during the dynamic process.

[0040] Raising the vehicle's suspension height to its maximum can effectively improve the vehicle's passability;

[0041] Automatic locking of the rear axle differential lock to prevent power transmission loss in cross-axle conditions;

[0042] The camera captures images of the area around the vehicle and displays them to the user on a large screen, enabling the user to make timely and appropriate maneuvers to avoid obstacles while the vehicle is in motion.

[0043] It also determines whether the front or rear wheels of the vehicle are slipping or spinning, and distributes the torque between the front and rear axles, and accelerates the braking speed and increases the braking pressure on the slipping or spinning wheels.

[0044] To ensure the proper functioning of the cross-axis mode, the prerequisites for enabling it include:

[0045] It can determine whether the driver's door is closed and whether the driver's seat belt is fastened. When the driver's door is closed and the driver's seat belt is fastened, it can ensure the driver's personal safety when off-roading.

[0046] To determine if the vehicle speed is zero and if the brake pedal is depressed; the vehicle is stationary when the brake pedal is depressed, so that the driver can prepare off-road driving equipment and ensure driving safety.

[0047] Determine whether the EPB electronic parking brake is in the released state. The vehicle can only be unlocked and driven forward when the EPB electronic parking brake is in the released state.

[0048] Determine if the current gear is D. The vehicle will only move forward normally when it is in D gear.

[0049] Determine if the Hill Descent Control function is turned off; the Hill Descent Control function allows the driver to smoothly pass through steep downhill sections without pressing the brake pedal. This function conflicts with the Cross Axle Mode, so it needs to be turned off.

[0050] The HCU controller, acting as the upper-level arbitrator, is responsible for arbitrating the conditions for enabling, interrupting, and exiting the cross-axis mode. After arbitrating whether the above conditions are met, the HCU provides textual alerts via the ICM instrument. If all the above judgment results are yes, then the preconditions for enabling the cross-axis mode are met; if any judgment result is no, then the preconditions for enabling the cross-axis mode are determined not to be met.

[0051] When the vehicle is in cross-axle mode, the speed is limited to a low speed of 1-2 km / h, which can provide stronger power output while ensuring driving safety.

[0052] When the vehicle is in cross-axle mode, it will automatically exit cross-axle mode when the driver presses the accelerator pedal and the vehicle speed exceeds the limit for a specified time. When the vehicle speed exceeds the limit (e.g., 40 km / h) and continues to travel for a specified time (e.g., 10 seconds), it indicates that the vehicle has escaped the cross-axle situation or left the cross-axle condition, and the vehicle will automatically exit cross-axle mode.

[0053] After exiting cross-axle mode, the vehicle automatically switches back to the previous driving mode. For example, if the driver was in snow mode before entering cross-axle mode, the vehicle will return to snow mode after exiting cross-axle mode. This increases the vehicle's ease of handling and intelligence.

[0054] When the vehicle is in cross-axle mode, the driver presses the accelerator or brake pedal, and the vehicle accelerates or brakes accordingly. In cross-axle mode automatic control, the driver can actively control the vehicle's acceleration and deceleration. If no subjective input from the driver is detected (no accelerator or brake pedal is pressed), a torque request is sent to the HCU according to the target gear and speed to increase and maintain vehicle driving force, while simultaneously using ESC to actively boost pressure and brake to stabilize speed. If a subjective input from the driver is detected (pressing the accelerator or brake pedal), the HCU responds to the driver's request and controls the vehicle speed.

[0055] When the vehicle is in cross-axle mode, the user can manually choose whether to lock the front axle differential lock. When cross-axle mode is activated, the rear axle differential lock automatically locks to ensure the vehicle's passability, while the front axle differential lock locking option is displayed on the large screen and can be manually locked by the driver to ensure steering stability and increase the vehicle's passability.

[0056] When the vehicle is in cross-axle mode, creep and coasting energy recovery functions are automatically disabled. When creep is enabled, the torque interface of cross-axle mode will conflict with the creep torque interface, affecting the final torque response of the vehicle. Furthermore, if coasting energy recovery is not disabled, when the driver accelerates by pressing the accelerator and then releases it, coasting energy recovery will be triggered, affecting speed control and the performance of cross-axle mode.

[0057] When the vehicle is in cross-axle mode, the car's large screen displays the AVM interface to show the surrounding environment. The driver can view the surrounding environment through the 360-degree panoramic view on the car's large screen, so that they can make appropriate maneuvers in time to avoid obstacles, reduce vehicle scratches, and reduce off-road difficulty.

[0058] To provide drivers with more intuitive information, when the vehicle is in cross-axle mode, the instrument cluster and large screen display vehicle function fault warnings and instructions on how to operate in cross-axle mode. For example, the system prompts the driver to choose whether to lock the front axle differential and indicates which conditions for activating cross-axle mode must not be met. The cross-axle mode function switch is located on the large screen. When the user taps the switch on the large screen to activate cross-axle mode, the ESC (Electronic Stability Control) responds and activates the cross-axle function. The HCU (Hydraulic Control Unit), acting as the upper-level arbitrator controller, is responsible for arbitrating the conditions for activating, interrupting, and deactivating the cross-axle function. After arbitrating whether the following conditions are met, the HCU provides text prompts via the ICM (Information Management System). Corresponding voice prompts can also be provided through the IHU (Information Controller Unit).

[0059] To avoid wasted power output and improve vehicle traction, when the vehicle is in cross-axle mode, the system first determines whether the wheels are slipping or spinning (e.g., using existing technology to determine this by whether the speed difference between the front and rear axles exceeds a certain threshold, or whether the speed difference between the left and right wheels exceeds a certain threshold). The ESC (Electronic Stability Control) system then requests torque from the HCU (Hardware Control Unit) through a specific torque interface. When the system determines that the front wheels are slipping or spinning, the front axle drive motor reduces torque, while the rear axle motor increases drive torque to suppress front wheel slippage or spinning. Conversely, when the system determines that the rear wheels are slipping or spinning, the front axle drive motor increases torque, while the rear axle motor reduces drive torque to suppress rear wheel slippage. Torque can be distributed proportionally; for example, in standard mode, the front-to-rear axle torque distribution ratio is 5:5. When the rear wheels slip, the maximum front-to-rear axle torque distribution ratio can be set to 9:1; when the front wheels slip, the maximum front-to-rear axle torque distribution ratio can be set to 1:9.

[0060] In the standard mode of this embodiment, to protect vehicle hardware and ensure driving safety, the maximum available wheel-end torque is limited to 5600 Nm. However, in the cross-axle mode of this embodiment, the maximum available wheel-end torque is increased to 7300 Nm, almost without limiting the vehicle's power output. Furthermore, braking control is more aggressive, quickly and actively intervening in the slipping wheel, with faster braking pressure and stronger braking force than in the standard mode. In the standard mode, only 5 MPa of braking pressure can be applied to the slipping wheel within 0.3 seconds; while in the cross-axle mode, 10 MPa-16 MPa of braking pressure can be applied to the slipping wheel within 0.3 seconds, preventing wheel spin and providing stronger power to the wheel at the contact point, thus increasing traction.

[0061] like Figure 2As shown, the vehicle in this embodiment of the invention is equipped with a CGW central gateway controller, wheel speed sensors, an ESC electronic stability control system controller, an HCU hybrid vehicle controller, a brake pedal switch, an accelerator pedal position sensor, an FLZCU left domain controller, a prompt unit (including an ICM instrument cluster and an IHU infotainment audio head unit), and an ADAS driver assistance system controller (the camera is a component in ADAS).

[0062] The CGW central gateway controller communicates with the prompting unit; wheel speed sensors detect vehicle speed and send it to the CGW central gateway controller via the ESC electronic stability control system controller; the HCU hybrid vehicle controller sends output torque to the CGW central gateway controller and the controllers of each module on the same CAN line, while controllers on different CAN lines forward the information to their corresponding CAN lines via the CGW central gateway controller; the brake pedal switch detects whether the brake pedal is depressed; the accelerator pedal position sensor detects the accelerator pedal opening; the FLZCU left domain controller sends signals for the driver's seatbelt and driver's door for the cross-axle mode operating logic judgment; the prompting unit issues human-machine interaction text prompts for cross-axle mode; the ADAS driver assistance system controller works with the AVM to display the vehicle's surrounding environment, etc.

[0063] The present invention has been described above with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made using the inventive concept and technical solution of the present invention, or direct application to other situations without modification, fall within the protection scope of the present invention.

Claims

1. A control method for automatically navigating off-road cross-axle conditions, characterized in that, Includes the following steps: In response to the request to activate the cross-axle mode, determine whether the preconditions for activating the cross-axle mode are met; if the preconditions for activating the cross-axle mode are met, control the vehicle to enter the cross-axle operating condition. When the vehicle enters cross-axle mode: It can apply braking pressure to the wheel end while simultaneously activating the maximum torque at the wheel end; Lock the gear in low gear; Raise the vehicle's suspension height to its maximum. Automatic locking of the rear axle differential lock; The camera captures images of the area around the vehicle and displays them to the user. It also distributes torque between the front and rear axles by determining whether the front or rear wheels of the vehicle are slipping or spinning, and accelerates the braking speed and increases the braking pressure on the slipping or spinning wheels. The aforementioned preconditions for activation include: Determine if the driver's door is closed; Check if the driver's seatbelt is fastened; Determine if the vehicle speed is zero; Determine if the brake pedal has been depressed; Determine if EPB is in a released state; Determine if the current gear is D; Determine if the steep slope descent control function is turned off; If all judgment results are yes, then the prerequisite for enabling the cross axis mode is met; if any judgment result is no, then the prerequisite for enabling the cross axis mode is not met.

2. The control method for automatically traversing off-road cross-axle conditions according to claim 1, characterized in that, When the vehicle is in cross-axle mode, the speed is limited to 1-2 km / h.

3. The control method for automatically traversing off-road cross-axle conditions according to claim 1, characterized in that, When the vehicle is in cross-axle mode, it will automatically exit cross-axle mode after the driver presses the accelerator pedal and the vehicle speed exceeds the limit for a limited time.

4. The control method for automatically traversing off-road cross-axle conditions according to claim 3, characterized in that, After the vehicle exits cross-axle mode, it automatically switches back to the previous driving mode.

5. The control method for automatically navigating off-road cross-axle conditions according to claim 1, characterized in that, When the vehicle is in cross-axle mode, the driver can press the accelerator or brake pedal, and the vehicle will then accelerate or brake accordingly.

6. The control method for automatically traversing off-road cross-axle conditions according to claim 1, characterized in that, When the vehicle is in cross-axle mode, the user can manually choose whether to lock the front axle differential lock.

7. The control method for automatically traversing off-road cross-axle conditions according to claim 1, characterized in that, When the vehicle is in cross-axle mode, the crawl and coasting energy recovery functions are automatically turned off.

8. The control method for automatically traversing off-road cross-axle conditions according to claim 1, characterized in that, When the vehicle is in cross-axle mode, the car's large screen displays the AVM interface to show the environment around the vehicle.

9. The control method for automatically traversing off-road cross-axle conditions according to claim 1, characterized in that, When the vehicle is in cross-axle mode, the vehicle's instrument panel and large screen will display vehicle function fault reminders and instructions on how to operate in cross-axle mode.

10. The control method for automatically traversing off-road cross-axle conditions according to claim 1, characterized in that, When the vehicle is in cross-axle mode, if the front wheel is detected to be slipping or spinning, the front axle reduces torque and the rear axle increases torque; if the rear wheel is detected to be slipping or spinning, the front axle increases torque and the rear axle reduces torque.

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