Steering mode control method of multi-wheel steering system

Abstract

The invention provides a steering mode control method of a multi-wheel steering system, the system comprises a multi-wheel steering controller, the multi-wheel steering controller collects a hard wire input signal of a steering mode switch, and receives a vehicle speed signal and a generator state signal sent by a vehicle body controller through a CAN bus; the steering mode is judged according to a certain strategy by combining fault information of the steering sensor and the driving electromagnetic valves, a suitable steering mode required by the current working condition is given, and finally, the multi-wheel steering controller controls and outputs driving signals to the driving electromagnetic valves to achieve steering in different modes. In addition, in the process, the multi-wheel steering controller can send signals such as the steering mode state and the overspeed alarm prompt sign flag bit to the combination instrument through the CAN bus so that a driver can check the signals. A fault mode and a non-action mode are introduced and form a set of complete multi-wheel steering working mode control mechanism together with a front-group mode and a multi-group mode, so that the safety and the reliability of a multi-wheel steering system are improved.

Description

Technical Field

[0001] The present invention relates to a steering mode control method for a multi-wheel steering system, and belongs to the technical field of multi-wheel steering control. Background Technique

[0002] A multi-wheel steering system usually has a front group and multiple groups of steering modes. The front group mode only has the front wheels participating in steering, which can meet the basic steering needs of the vehicle and is commonly used in scenarios with a large turning radius. The multiple groups of steering modes mean that both the front wheels and the rear wheels participate in steering, which can achieve rapid transfer and passage of the vehicle in a narrow space, and has the characteristics of a small turning radius, strong passability, and flexibility.

[0003] However, in actual operation, vehicles equipped with a multi-wheel steering system often cannot achieve multi-wheel steering due to specific working conditions. For example, when the vehicle is traveling at high speed, the multi-wheel steering system may experience a dangerous situation of tail swing, and it is necessary to forcibly close the multiple groups of modes and switch to a safer front group steering mode. However, in actual working conditions, there may be a situation of electronic control system failure (sensor or solenoid valve failure). At this time, the multi-wheel steering will fail. To ensure the basic steering needs and driving safety, the vehicle needs to be forcibly switched to the front group mode, and the prior art does not consider such special working conditions. Summary of the Invention

[0004] To solve the above technical problems, the present invention proposes a steering mode control method for a multi-wheel steering system, which realizes the switching between the front group and multiple groups of modes through a steering mode switch. When the switch is closed, the front group mode is entered, and when the switch is opened, the multiple groups of modes are entered. At the same time, in specific working conditions such as vehicle overspeed, system failure, or the vehicle not starting, a failure and no-action mode is also introduced, which together with the front group and multiple groups of modes constitutes a complete multi-wheel steering working mode control mechanism to improve the safety and reliability of the multi-wheel steering system. The specific technical solution is as follows:

[0005] A steering mode control method for a multi-wheel steering system includes the following steps:

[0006] S1: When the system is powered on, the multi-wheel steering controller judges the generator status signal sent by the body controller. If the generator status is 0, that is, the engine is not started and there is no hydraulic power source, the steering system enters the no-action mode; if the generator status is 1, that is, the engine is started, step S2 is entered;

[0007] S2: The multi-wheel steering controller judges whether there is a fault in the steering sensor or the drive solenoid valve. If there is a fault, the steering system enters the fault mode; if there is no fault, step S3 is entered;

[0008] S3: The multi-wheel steering controller judges whether the steering mode switch is open. If the steering mode switch is closed, the steering system enters the front group mode; if the steering mode switch is open, step S4 is entered;

[0009] S4: The multi-wheel steering controller determines whether the vehicle speed signal sent by the body controller exceeds the threshold. If the vehicle speed exceeds the threshold, the steering system enters the front group mode and the overspeed flag is set to 1; if the vehicle speed is lower than the threshold, step S5 is entered.

[0010] S5: The multi-wheel steering controller determines whether the overspeed flag is 1. If the overspeed flag is 1, the steering system continues to maintain the front group mode and the overspeed flag is set to 0; if the overspeed flag is 0, the steering system enters the multi-group mode.

[0011] Preferably, in S1, the no-action mode means that when the steering mode switch is switched arbitrarily, the signal output by the multi-wheel steering controller to the drive solenoid valve is 0, and when the steering mode switch is turned on, the steering mode state is set to 1, and when the steering mode switch is turned off, the steering mode state is set to 0. At this time, the steering mode state only represents the switch state, and at the same time the overspeed flag is set to 0.

[0012] Preferably, in S2, the fault mode means that when the steering mode switch is switched arbitrarily, the multi-wheel steering system enters the forced centering mode, that is, the signal output by the multi-wheel steering controller to the drive solenoid valve is 0. At this time, the rear axle automatically returns to the centered position, and at the same time the steering mode state is set to 0, the overspeed flag is set to 0, and the fault flag is set to 1.

[0013] Preferably, in S3, the front group mode means that the steering system gradually pulls the rear axle back to the middle position. After the rear axle returns to the centered position, the drive signal from the multi-wheel steering controller to the drive solenoid valve is 0, and at the same time the steering mode state is set to 0.

[0014] Preferably, in S5, the multi-group mode means that the drive signals from the multi-wheel steering controller to the drive solenoid valves are all 1, and the steering mode state is set to 1.

[0015] Preferably, when the overspeed flag is 1, a T-second delay is synchronously started. At this time, the overspeed alarm prompt flag is set to 1, and the combination instrument gives a sound and text prompt to remind the driver that the current vehicle speed exceeds the threshold and the steering system enters the front group mode; when the delay time of T seconds ends, the overspeed alarm prompt flag is reset to 0, and the sound and text prompt given by the combination instrument ends; when the overspeed flag is 0, the overspeed alarm prompt flag is also 0, and the combination instrument has no sound and text prompt.

[0016] A multi-wheel steering system for a multi-wheel steering system steering mode control method, including a multi-wheel steering controller. The multi-wheel steering controller is connected to the body controller and the combination instrument through the CAN bus. The multi-wheel steering gear is electrically connected to the steering mode switch, the steering sensor and the drive solenoid valve.

[0017] Further, the multi-wheel steering controller is used to collect the input signal of the steering mode switch, and at the same time receive the vehicle speed signal and the generator status signal sent by the body controller through the CAN bus, and receive the fault information of the steering sensor and the drive solenoid valve, and output a drive signal to the drive solenoid valve to achieve front group mode or multi-group mode steering.

[0018] Further, the multi-wheel steering controller sends the steering mode status and the overspeed alarm prompt flag signal to the combination instrument through the CAN bus for the driver to view.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] First, on the basis of ensuring the basic functions of the front group mode and the multi-group mode, the multi-wheel steering mode control method proposed by the present invention also has the control of the steering system under specific working conditions such as overspeed, failure, and the vehicle not starting (the hydraulic system has no power source), forming a complete set of steering mode control mechanisms, improving the safety and reliability of the system.

[0021] Second, in the multi-wheel steering mode control method proposed by the present invention, an overspeed alarm prompt is added, which can timely remind the driver of the steering system status in case of overspeed in the multi-wheel mode, improving driving safety.

[0022] Third, in the multi-wheel steering mode control method proposed by the present invention, since the multi-wheel steering system needs the engine to start to drive the hydraulic pump to provide a power source when working, considering the electrical safety of the system, when the engine is not started, regardless of how the steering mode switch is switched, the multi-wheel steering controller will forcibly turn off all power drive load outputs to save unnecessary power output and improve system safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a flowchart of a steering mode control method for a multi-wheel steering system of the present invention.

[0024] Figure 2 is a framework diagram of a multi-wheel steering system of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] Such as Figure 2As shown in the figure, a multi-wheel steering system includes a multi-wheel steering controller 1. The multi-wheel steering controller 1 is connected to a body controller 3 and a combination instrument 4 through a CAN bus. The multi-wheel steering controller 1 is electrically connected to a steering mode switch 2, a steering sensor 5, and a drive solenoid valve 6.

[0027] The multi-wheel steering controller 1 collects the hard-wired input signal of the steering mode switch 2, and at the same time receives the vehicle speed signal and the generator status signal (indicating whether the engine is started) sent by the body controller 3 through the CAN bus. Combining the fault information of the steering sensor 5 and the drive solenoid valve 6, it makes a steering mode determination according to a certain strategy, gives a suitable steering mode required by the current working condition, and finally the multi-wheel steering controller 1 controls and outputs a drive signal to each drive solenoid valve 6 to achieve steering in different modes. In addition, during this process, the multi-wheel steering controller 1 will send signals such as the steering mode status and the overspeed alarm prompt flag bit to the combination instrument 4 through the CAN bus for the driver to view.

[0028] As another implementation, as Figure 1 shown in the figure, the present invention provides a method for controlling the steering mode of a multi-wheel steering system, including the following steps:

[0029] S1: When the system is powered on, the multi-wheel steering controller 1 judges the generator status signal sent by the body controller 3. If the generator status is 0, that is, the engine is not started and there is no hydraulic power source, the steering system enters the no-action mode and the steering system does not work. At this time, no matter how the steering mode switch 2 is switched, the signal output by the multi-wheel steering controller 1 to the drive solenoid valve 6 is 0, and when the steering mode switch 2 is turned on, the steering mode status is set to 1, and when the steering mode switch 2 is turned off, the steering mode status is set to 0. At this time, the steering mode status only represents the switch status, and at the same time the overspeed flag is set to 0; if the generator status is 1, that is, the engine is started, go to step S2.

[0030] S2: If the generator status is 1 (that is, the engine is started), the multi-wheel steering controller 1 judges whether there is a fault in the steering sensor 5 or the drive solenoid valve 6. If any steering sensor 5 or any drive solenoid valve 6 has a fault, the steering system enters the fault mode, and the system fault flag is set to 1, otherwise it is set to 0. When the fault flag is 1, the steering system enters the fault mode. At this time, no matter how the steering mode switch 2 is switched, the multi-wheel steering system enters the forced centering mode, that is, the signal output by the multi-wheel steering controller 1 to the drive solenoid valve 6 is 0. At this time, the rear axle automatically returns to the center to ensure that the front axle steering meets the basic functions. At the same time, the steering mode status is set to 0, and the overspeed flag is set to 0. If the fault flag is 0, it means that the electronic control system is normal and there is no fault, and the next steering mode determination can be entered, and go to step S3.

[0031] S3: The multi-wheel steering controller 1 determines whether the steering mode switch is turned on. If the steering mode switch is turned off, the steering system enters the front group mode. At this time, the steering system will gradually pull the rear axle back to the middle position according to a certain strategy, so that the final state of the rear axle is straight and centered. During this process, the drive signal from the multi-wheel steering controller 1 to the drive solenoid valve 6 is 1 or 0, and the final state is 0. At the same time, the steering mode status is set to 0, and the overspeed flag position is set to 0. If the steering mode switch is turned on, go to step S4;

[0032] S4: The multi-wheel steering controller 1 determines whether the vehicle speed signal sent by the body controller 3 exceeds the threshold value. If the vehicle speed exceeds the threshold value V0, to ensure driving safety and prevent the risk of tail whipping when the rear wheels follow the front wheels during high-speed driving, the system needs to forcefully enter the front group mode. The steering system will gradually pull the rear axle back to the middle position according to a certain strategy, so that the final state of the rear axle is straight and centered. During this process, the drive signal from the multi-wheel steering controller 1 to the drive solenoid valve 6 is 1 or 0, and the final state is 0. At the same time, the steering mode status is set to 0, and the overspeed flag position is set to 1. If the vehicle speed is lower than the threshold value (or drops below the threshold value V0 again), go to step S5.

[0033] S5: The multi-wheel steering controller 1 determines whether the overspeed flag bit is 1. If the overspeed flag bit is 1, it means that there has been at least one overspeed situation. At this time, the steering system still maintains the front group mode. During this process, the drive signal from the multi-wheel steering controller 1 to the drive solenoid valve 6 is 1 or 0, and the final state is 0. At the same time, the steering mode status is set to 0. If the overspeed flag bit is 0, the steering system enters the multi-group mode. At this time, the drive signals from the multi-wheel steering controller 1 to the drive solenoid valves 6 are all 1, and the steering mode status is set to 1.

[0034] When the overspeed flag bit is 1, a T-second delay is synchronously started. At this time, the overspeed alarm prompt language flag position is set to 1, and the combination instrument 4 gives a sound and text prompt to remind the driver that the current vehicle speed exceeds the threshold value V0 and the steering system enters the front group mode. When the delay time of T seconds ends, the overspeed alarm prompt language flag bit is reset to 0, and the sound and text prompt given by the combination instrument ends. When the overspeed flag bit is 0, the overspeed alarm prompt language flag bit is also 0, and the combination instrument has no sound and text prompt.

[0035] The present invention can realize the switching between the front group and multi-group modes through the steering mode switch. When the switch is turned off, it enters the front group mode, and when the switch is turned on, it enters the multi-group mode. At the same time, in specific working conditions such as vehicle overspeed, system failure, or the vehicle not starting, fault and no-action modes are also introduced, and the mode status and overspeed information are fed back, together with the front group and multi-group modes, to form a complete multi-wheel steering working mode control mechanism to improve the safety and reliability of the multi-wheel steering system.

[0036] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A control method for the steering mode of a multi-wheel steering system, characterized in that, It includes the following steps: S1: When the system is powered on, the multi-wheel steering controller judges the generator status signal sent by the body controller. If the generator status is 0, that is, the engine is not started and there is no hydraulic power source, the steering system enters the no-action mode; if the generator status is 1, that is, the engine is started, go to step S2; S2: The multi-wheel steering controller judges whether there is a fault in the steering sensor or the drive solenoid valve. If there is a fault, the steering system enters the fault mode; if there is no fault, go to step S3; S3: The multi-wheel steering controller judges whether the steering mode switch is turned on. If the steering mode switch is turned off, the steering system enters the front group mode; if the steering mode switch is turned on, go to step S4; S4: The multi-wheel steering controller judges whether the vehicle speed signal sent by the body controller exceeds the threshold. If the vehicle speed exceeds the threshold, the steering system enters the front group mode and the overspeed flag is set to 1; if the vehicle speed is lower than the threshold, go to step S5; S5: The multi-wheel steering controller judges whether the overspeed flag bit is 1. If the overspeed flag bit is 1, the steering system continues to maintain the front group mode and the overspeed flag is set to 0; if the overspeed flag bit is 0, the steering system enters the multi-group mode.

2. The steering mode control method of a multi-wheel steering system according to claim 1, characterized in that In S1, the no-action mode means that when the steering mode switch is switched arbitrarily, the signal output by the multi-wheel steering controller to the drive solenoid valve is 0, and when the steering mode switch is turned on, the steering mode status is set to 1, and when the steering mode switch is turned off, the steering mode status is set to 0. At this time, the steering mode status only represents the switch status, and the overspeed flag is set to 0.

3. The steering mode control method of a multi-wheel steering system according to claim 1, characterized in that, In S2, the fault mode means that when the steering mode switch is switched arbitrarily, the multi-wheel steering system enters the forced centering mode, that is, the signal output by the multi-wheel steering controller to the drive solenoid valve is 0. At this time, the rear axle automatically returns to the center and aligns, and at the same time the steering mode status is set to 0, the overspeed flag is set to 0, and the fault flag is set to 1.

4. A steering mode control method for a multi-wheel steering system according to claim 1, characterized in that, In S3, the front group mode means that the steering system gradually pulls the rear axle back to the middle position. After the rear axle returns to the center and aligns, the drive signal from the multi-wheel steering controller to the drive solenoid valve is 0, and at the same time the steering mode status is set to 0.

5. A steering mode control method for a multi-wheel steering system according to claim 1, characterized in that In S5, the multi-group mode means that the drive signals from the multi-wheel steering controller to the drive solenoid valves are all 1, and the steering mode status is set to 1.

6. A steering mode control method for a multi-wheel steering system according to claim 1, characterized in that, When the overspeed flag bit is 1, a T-second delay is synchronously started. At this time, the overspeed alarm prompt flag bit is set to 1, and the combination instrument gives a sound and text prompt to remind the driver that the current vehicle speed exceeds the threshold and the steering system enters the front group mode; when the delay time of T seconds ends, the overspeed alarm prompt flag bit is reset to 0, and the sound and text prompt issued by the combination instrument ends; when the overspeed flag bit is 0, the overspeed alarm prompt flag bit is also 0, and the combination instrument has no sound and text prompt.

7. A multi-wheel steering system for the steering mode control method of the multi-wheel steering system according to any one of claims 1-6, characterized in that, It includes a multi-wheel steering controller. The multi-wheel steering controller is connected to the body controller and the combination instrument through the CAN bus. The multi-wheel steering gear is electrically connected to the steering mode switch, the steering sensor and the drive solenoid valve.

8. A multi-wheel steering system according to claim 7, characterized in that, The multi-wheel steering controller is used to collect the input signal of the steering mode switch, and at the same time receive the vehicle speed signal and the generator status signal sent by the body controller through the CAN bus, and receive the fault information of the steering sensor and the drive solenoid valve, and output a drive signal to the drive solenoid valve to achieve front group mode or multi-group mode steering.

9. A multi-wheel steering system according to claim 8, wherein, The multi-wheel steering controller sends the steering mode status and the overspeed alarm prompt flag signal to the combination instrument through the CAN bus for the driver to view.

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