Semi-Active Method of Motion Stabilization Applied to Mechanical System with the Constant Reaction Force Vibroisolation (CRF) – Model Study

Abstract

The use of the CRF vibration isolation system with zero natural frequency for machinery and equipment in the Earth's gravity field requires stabilization of motion because of its high susceptibility. For this purpose, an additional spring element with a low elastic coefficient “k1” and a semi-active damper “c (t, x, v, ff)”, was included in the vibration isolation system and parallel-attached to the CRF vibroisolator. Investigation of the effect of the additional element to stabilize the motion of the mechanical system was carried out by a numerical simulation of its motion. The simulation was based on a physical and mathematical model of the system including the spring and the magnetorheological damper (MR). The mathematical model was then used to develop a dynamics simulation program of the system and conduct simulations using sample data in order to study transitional processes and their stability. Simulation results indicate a substantially improved stability of motion in the system. Stability studies of motion were also combined with an analysis of power distribution in the system. The aim of this study was to determine energy efficiency of the system developed, defined as the ratio of the RMS power of the exciting force to RMS power of the elastic force. The resulting energy efficiency of CRF vibroisolation was equal to 5168 for a simulation period of 6 seconds.