关键词: 多轴车辆, 线控液压转向系统, 滑模控制, 转向磨损

Abstract: The angle of the third axle steering wheel under the cargo box and the front steering wheel under the cab of multi-axle vehicles were required to conform to Ackerman principle for reducing rear steering wheel wear. The steering-by-wire hydraulic system was designed and the dynamics model was established based on a certain 8×2 four-axle heavy truck for controlling the steering angle of the third axle steering wheel. The sliding mode controller based on the exponential approach law was simulated in the typical operating conditions, and vehicle experiments were carried out. The experimental results show that the sliding mode controller based on the exponential approach law has faster response, shorter approaching time and overshoot duration, and smaller steady-state difference, compared with the sliding mode controller based on the proportional switching function and open-loop controller. Installation of the steering-by-wire hydraulic system based on the controller may significantly improve the steering wear resistance of the third axle tire, and improve the steering performance of the vehicles, compared with the mechanical hydraulic steering systems.

Key words: multi-axle vehicle, steering-by-wire hydraulic system, sliding mode control, steering wear