Time Response Model of ER Fluids for Precision Control of Motors

Abstract

The improvement of control performance or new control demands of mechatronics devices using particle type electrorheological (ER) fluids requires further investigation of the response time of the fluids. Although the response time of particle type ER fluids is commonly reported to be approximately 5 ms, the formula structure of the delay remains unclear. The present study is an attempt to develop a functional damper (attenuators) that can control its own viscous characteristics in real time using an ER fluid as the working fluid. ER dampers are useful for accomplishing both high-precision positioning and high-speed movement of the motor. In order to realize such a functional damper that can be manipulated according to a situation or task, the modeling and control of ER fluids are necessary. The present article investigates the time delay effects of ER fluids and constructs an in-depth dynamic model of the fluid through a simulation and an experiment. The mathematical model has a dead time and first-order delay of the fluid and a high-voltage amplifier for the fluid.