Active Vibration Isolation by Adaptive Control

Abstract

In this paper, an adaptive controller known as a self-tuning regulator (STR) is employed for active vibration isolation. Numerical simulation of the developed STR for active vibration isolation of a simple two- degree-of-freedom mechanical system subject to external disturbances is carried out. Experimental studies of vibration isolation using a magnetostrictive actuator with Terfenol-D rod are also presented. Both studies demonstrate the validity and effectiveness of the STR for active vibration isolation when the system is dis turbed by an unknown source. The unknown disturbance in the study includes a pure harmonic, a two-mode harmonic, a normally distributed random noise, and a band-limited random noise. In addition, a comparative study of the STR with a previously developed plant disturbance canceler (PDC) for active vibration isolation is conducted. Performance of the STR is shown to be superior to that of the PDC in both the numerical and experimental investigations.