A Changeable Damping Strategy for the Sky-Hook Control of a Rail Vehicle Semi-active Hydraulic Damper with Parallel Orifices

Damping changeability design and evaluation is the most fundamental issue at the beginning of any new semi active hydraulic damper or its control system development. In this study, the changeable damping strategy for the sky-hook control of a rail vehicle semi-active hydraulic damper, which has three parallel orifices, is designed. Fluid formulae for the changeable damping calculation under different control modes are established. Simulation results show that the damper obtains a 1:7 wide range of changeable damping coefficients, which guarantees absorbing a wide spectrum of vibrations. Thus, the damping changing strategy put forward and fluid formulae explicitly established are significant to the damper development and its control system design.