A hydraulically interconnected articulation system for improving high-speed stability of virtual rail train with consideration for curve negotiability

Abstract

As a type of multi-car modular system, Virtual Rail Train (VRT) is prone to lateral instability at high speeds. To improve the high-speed stability and critical speed of VRT, this paper proposes a Hydraulically Interconnected Articulation System (HIAS), which enhances stability by providing articulation stiffness while mitigating its adverse effects on yaw motion during steering. First, a five-degree-of-freedom planar model of a six-axle VRT with three carriages is established and linearized around the equilibrium point. Eigenvalue analysis shows that articulation stiffness improves stability more than does damping. A Hydraulic Interconnected Articulation System (HIAS) is designed to primarily enhance articulation stiffness, a function that traditional dampers cannot provide sufficient stiffness. Next, to mitigate the impact of articulation stiffness on curve negotiation, a pair of check valves and solenoid valves are incorporated for adaptive mode switching, thereby reducing yaw resistance torque during steering. Finally, the system is validated through co-simulation using AMESim, MATLAB/Simulink, and SIMPACK. The simulation results demonstrate that the HIAS improves the high-speed stability of the VRT while minimizing the impact on curve negotiation performance. The proposed method offers an effective solution for integrating articulation stiffness into the VRT.