The design, simulation, and experiment of high-accuracy multi-axle electro-hydraulic control servo steering system

Abstract

Many multi-axle applications use electro-hydraulic control systems with proportional valves. The proportional steering system can satisfy common engineering requirements, but it is likely to fail if the steering angle or load changes drastically because of poor dynamic characteristics, including dead zones, hysteresis, and frequency response. An electro-hydraulic servo steering system with servo solenoid valve is proposed to guarantee a precise dynamic response and good price–performance ratio of the closed-loop system. A co-simulation model based on ADAMS and AMESim was established to analyze the influence of the main parameters on steering performance. The mechanical model includes tire and ground parts, and the steering load can be simulated accurately. The simulation results show that dead zones, hysteresis, and frequency response of control valve have great influence on the steering performance, and the servo solenoid valve is proper for this system. The servo steering system was applied to the actual seven-axle all-terrain crane, and the system performance was extensively tested. The experiment results show that the system has good accuracy and tracking response performance in several real situations, including parking and high-speed transport.