Steering wheel small-angle steering control system of drive-by-wire mine wide-body dumper

Abstract

A small-angle steering control system for steering wheels of a drive-by-wire mine wide-body dumper comprises a hydraulic oil tank, a steering pump, an emergency steering pump, a priority valve, an electric control steering valve, a steering gear and a steering cylinder. The emergency steering pump is a 24V synchronous direct current motor controlled through CAN communication. The steering pump and the emergency steering pump are connected in parallel through a pipeline and then are sequentially connected with the high-pressure filter and the priority valve in series. The front end of the steering gear and the electric control steering valve connected in parallel through a pipeline is connected with the priority valve in series, and the rear end is connected with the steering cylinder in series to form a hydraulic loop. The control precision of small-angle steering is improved; adjusting times of the steering system are reduced, and energy consumption of the steering system is reduced; the difficulty of realizing small-angle steering control is reduced, and the hardware cost of an unmanned steering system is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of dump trucks, in particular to a small-angle steering control system for steering wheels of a wire-controlled wide-body mining dump truck. Background Art

[0002] During the debugging process of the steering system of the unmanned wide-body mining dump truck, it was found that when turning at a large angle (more than 3°), the steering angle control was relatively precise by turning the steering wheel or issuing steering commands to the electronic steering valve. However, when turning at a small angle, the control overshoot easily exceeded the allowable amount, especially when the steering wheel angle sensor was calibrated to zero position. It was difficult to control the steering wheel to within the allowable deviation range of the zero position.

[0003] The existing technology uses servo valves to control steering and improve steering accuracy to achieve the purpose of small angle control. However, servo valves are very expensive, more than three times the price of ordinary electric control steering valves, and there is overflow during the adjustment process, which wastes some energy.

[0004] The existing technology uses ordinary electric steering valves and optimizes the algorithm of the unmanned driving system to avoid small angle adjustments as much as possible. However, due to the dead zone of the valve when it is working, there will be flow shock when the valve is opened, making small angle adjustments impossible. Even if the algorithm is optimized, it cannot completely avoid small angle adjustments. Summary of the invention

[0005] The technical problem to be solved by the utility model is to provide a small-angle steering control system for the steering wheel of a wire-controlled wide-body mining dump truck, which improves the control accuracy of small-angle steering; reduces the number of times the steering system is adjusted, and reduces the energy consumption of the steering system; reduces the difficulty of implementing small-angle steering control, and saves the hardware cost of the unmanned steering system.

[0006] In order to solve the above technical problems, the technical solution of the utility model is: a wire-controlled mining wide-body dump truck steering wheel small-angle steering control system, including a hydraulic oil tank, a steering pump, an emergency steering pump, a priority valve, an electronically controlled steering valve, a steering gear and a steering cylinder; the emergency steering pump is a 24V synchronous DC motor controlled by CAN communication; the steering pump and the emergency steering pump are connected in parallel through pipelines and then connected in series with a high-pressure filter and a priority valve in turn; the steering gear and the electronically controlled steering valve are connected in parallel through pipelines, and the front end is connected in series with the priority valve, and the rear end is connected in series with the steering cylinder to form a hydraulic circuit. The principle of the utility model: in the process of zero position calibration of the wheel angle sensor, when the steering wheel is close to the zero position, the steering pump is turned off, and only the emergency steering pump is started, the speed of the emergency steering pump drive motor is adjusted to 300rpm, and the steering wheel is turned to adjust the steering wheel, so that the zero position deviation of the steering wheel can be controlled within ±0.25°, which greatly improves the accuracy of the zero position. During vehicle operation, when small angle adjustments are required, the unmanned driving system can shut down the steering pump drive motor in advance based on the route, vehicle, road conditions, etc., and start the emergency steering pump to supply oil to the steering system, so as to achieve the purpose of small angle steering control, reduce the number of steering system adjustments, and reduce the energy consumption of the steering system.

[0007] As an improvement, the rotation speed of the driving motor of the emergency steering pump is controlled within a range from 300 rpm to its maximum allowable rotation speed.

[0008] Compared with the prior art, the utility model has the following beneficial effects:

[0009] 1. Provides the hardware foundation for the high-precision zero-position calibration of unmanned driving wheel angle sensors;

[0010] 2. Reduce the number of steering system adjustments during unmanned driving, improve the stability of the unmanned driving system, and reduce the energy consumption of the steering system;

[0011] 3. Reduce the difficulty of implementing small-angle steering control and save the hardware cost of the unmanned steering system. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is the pipeline diagram of the utility model. DETAILED DESCRIPTION

[0013] The utility model will be further described below in conjunction with the accompanying drawings.

[0014] like Figure 1As shown in the figure, a small-angle steering control system for the steering wheels of a wire-controlled mine wide-body dump truck includes a hydraulic oil tank 1, a steering pump 3, an emergency steering pump 2, a priority valve 5, an electronically controlled steering valve 6, a steering gear 7, and a steering cylinder 8. The emergency steering pump 2 is a 24V synchronous DC motor controlled by CAN communication; the rotational speed of the drive motor of the emergency steering pump 2 is controlled between 300 rpm and its allowable maximum speed. The steering pump 3 and the emergency steering pump 2 are connected in parallel through pipelines and then connected in series with a high-pressure filter 4 and a priority valve 5 in sequence; the front end of the steering gear 7 and the electronically controlled steering valve 6 connected in parallel through pipelines is connected in series with the priority valve 5, and the rear end is connected in series with the steering cylinder 8 to form a hydraulic circuit.

[0015] When the vehicle is driving straight normally, the steering pump 3 sucks hydraulic oil from the hydraulic oil tank 1 and then pumps it out, and returns to the hydraulic oil tank through the priority valve 5 for unloading. When manually steering, the hydraulic oil pumped out by the steering pump 3 passes through the priority valve 5 and then through the steering gear 7 and flows into the steering cylinder 8 to push the wheels to rotate to achieve steering; when steering in an unmanned mode, the hydraulic oil pumped out by the steering pump 3 passes through the priority valve 5 and then through the electronically controlled steering valve 6 and flows into the steering cylinder 8 to push the wheels to rotate to achieve steering. When small-angle control is required, the steering pump 3 stops working, and the emergency steering pump 2 operates to replace the action of the steering pump 3 for pumping oil.

[0016] Without turning the steering wheel and without sending a steering command to the on-vehicle computer, the vehicle will maintain a straight drive. When the steering wheel is turned or a steering command is sent to the on-vehicle computer, the vehicle will steer according to the command. Since there are dead zones when the spool of the electronically controlled steering valve 6 and the spool of the steering gear 7 move, before the spool crosses the dead zone, the hydraulic oil will be blocked to form high pressure. After crossing the dead zone, the high-pressure hydraulic oil quickly surges into the steering cylinder, forming a flow impact, which causes an uncontrolled stroke of the oil cylinder. This is the main reason for the large deviation during small-angle steering. The dead zone of the spool is a physical property of the valve and cannot be changed. Therefore, only the flow impact during the dead zone can be reduced, and reducing the flow rate when opening the spool is an effective way to reduce this impact.

[0017] During the zero-position calibration process of the wheel angle sensor, when the steering wheel approaches the zero position, turn off the steering pump 3 and only start the emergency steering pump 2. Adjust the rotational speed of the drive motor of the emergency steering pump 2 to 300 rpm and turn the steering wheel to adjust the steering wheel, and the zero-position deviation of the steering wheel can be controlled within ±0.25°, greatly improving the zero-position accuracy. During the vehicle operation, when small-angle adjustment is required, the unmanned system can turn off the drive motor of the steering pump 3 in advance according to the route, vehicle, road conditions, etc., and start the emergency steering pump 2 to supply oil to the steering system to achieve the purpose of small-angle control steering, reduce the number of adjustments of the steering system, and reduce the energy consumption of the steering system.

Claims

1. A wire-controlled wide-body dump truck steering wheel small-angle steering control system, comprising a hydraulic oil tank, a steering pump, an emergency steering pump, a priority valve, an electronically controlled steering valve, a steering gear and a steering cylinder; characterized in that: The emergency steering pump is a 24V synchronous DC motor controlled by CAN communication; the steering pump and the emergency steering pump are connected in parallel through pipelines, and then connected in series with the high-pressure filter and the priority valve in turn; the steering gear and the electronically controlled steering valve are connected in parallel through pipelines, and the front end is connected in series with the priority valve, and the rear end is connected in series with the steering cylinder to form a hydraulic circuit.

2. The small-angle steering control system for steering wheels of a wide-body dump truck controlled by wire in a mine according to claim 1, characterized in that: The speed of the driving motor of the emergency steering pump is controlled at 300 rpm to its maximum allowable speed.

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