Active electrorheological damper for railway vehicle couplers

Abstract

This paper presents the development of an active damper for the couplers of railway vehicles using electrorheological (ER) fluid as a functional material. The purpose of design of the presented damper is to absorb the longitudinal impact from the coupler to the railway vehicle body, which is a very important design factor for the structure of the super express bullet train Sinkansen. A prototype damper is fabricated, which consists of a hydraulic cylinder, an ER bypass slit valve and a PID controller. The buffer force is developed in the ER fluid both through the bypass slit and at the piston-cylinder gap, and is controlled by adjusting the applied electric field to the ER fluid. Active control tests were carried out on the problem where the shaft reaction force is retained at a constant prescribed strength while the shaft is translating at a sinusoidally-varying velocity. A bang-bang and PID switching controller is introduced to prevent the reset-wind-up phenomenon. Results show that the coupler force of the railway vehicle can be controlled effectively by using the proposed electrorehological bypass damper.