Adaptive vibration control by using magnetostrictive actuator

In the paper an experimental study on vibration attenuation by using magnetostrictive actuator with Terfenol-D rod is presented. A magnetostrictive actuator is used to provide a negating force to an external excitation for suppressing vibrational response of the disturbed system. A simple and easy-to-implement adaptive plant disturbance canceling scheme is developed and applied for vibration attenuation, when the system is subjected to a sinusoidal disturbance. The plant disturbance canceler consists of an actuation emulator and an inverse actuator (acts as a controller), which are in the forms of linear finite impulse response (FIR) filters. Impulse response of the actuation system and inverse property of the inverse actuator are utilized for obtaining the FIR filters for the actuation emulator and inverse actuator. A signed-f LMS algorithm is developed and employed for on-line adaptive tuning of the inverse actuator. Experimental results indicate that over 96.6% (or 29.3 dB) of the vibrational displacement amplitude of the disturbed system is attenuated in a tested frequency range of 50-70 Hz, thus demonstrating the validity and effectiveness of the plant disturbance canceler.