A Study on Servo Control of Motor-pump Controlled Hydraulic Steering System for Autonomous-rail Rapid Tram

Abstract

As a core component of autonomous-rail rapid tram, the steering system is primarily used for the coordinated multi-axle steering of the trams, enabling trackless guidance and track following. To achieve rapid response, accuracy, and stability, among other dynamic feature requirements of the autonomous-rail rapid tram steering system, this paper proposes a sliding mode variable structure-fuzzy adaptive hybrid servo control method for the autonomous-rail rapid tram's motor-pump controlled hydraulic steering system. This method establishes a simulation model for the motor-pump controlled hydraulic steering system of the autonomous-rail rapid tram, investigates the three closed-loop control strategy of the permanent magnet synchronous motor (PMSM) current loop, speed loop, and position loop based on space vector pulse width modulation (SVPWM) technology. To improve control performance, it suggests sliding mode control for the current loop, addressing the issue of current susceptibility to interference. Simultaneously, it also proposes fuzzy adaptive control for speed loop and position loop to deal with the variation in motor-pump steering external load that affects system response performance. Simulation results demonstrate that the utilization of three closed-loop sliding mode variable structure-fuzzy adaptive hybrid servo control method yields an improvement in the autonomous-rail rapid tram motor-pump controlled steering system response time less than 1.5 s, with steering accuracy less than 0.2°, showcasing superior dynamic response characteristics.

Keywords

• autonomous-rail rapid tram
• motor-pump
• hydraulic steering
• servo control
• sliding mode control
• fuzzy control