ELECTRO-HYDRAULIC SERVO STEERING SYSTEM AND STEERING CONTORL METHOD FOR MULTI-AXLE VEHICLE AND MULTI-AXLE VEHICLE

摘要

An electro-hydraulic servo steering system and steering control method for a multi-axle vehicle and a multi-axle vehicle with the steering system are disclosed. The electro-hydraulic servo steering system includes a hydraulic steering system and an electronic control system. The hydraulic steering system includes a variable pump (4), power steering cylinders (6) mounted on each rear steering axle (7), and servo proportional valves (5) for the oil path control and the flow regulation. The electronic control system includes a lower controller (3) which is communicated with the servo proportional valve (5) of each rear steering axle (7) and forms a closed loop control, and an upper controller (2) which calculates the target steering angle of each rear steering axle (7) based on the first axle steering angle and the steering mode. The electronic control system has a two-level controller, which forms a small closed loop between the servo proportional valve (5) and the lower controller (3). The lower controller (3) having high frequency response cooperates with the servo proportional valve (5) to ensure the precision. The programmable logic controller (2) calculates and then sends a steering angle command to each lower controller (3). The steering system is simple in structure, safe and reliable, and the operation stability is good.