Research on Electric Hydraulic Power Steering Motor Control Strategies

In order to reduce energy consumption during the steering process of the electric hydraulic power steering system, employing a permanent magnet synchronous motor based on sensorless control technology as the steering assist motor is a feasible solution. This paper first analyzes the structure of the electric hydraulic power steering assembly, determines the speed regulation characteristics of the steering assist motor based on the load characteristics of the steering pump at different speeds. Based on this, a sensorless control strategy is proposed, utilizing a high-order sliding mode observer instead of the traditional sliding mode observer to mitigate the system chattering issues caused by the traditional observer. Through the establishment of a simulation model, the proposed control strategy is verified to possess strong robustness and disturbance rejection capabilities. Furthermore, the strategy is validated with actual steering conditions, demonstrating its favorable speed tracking performance.