Mi-Ching Tsai

National Cheng Kung University, Taiwan

Title: Active vibration control of piezoelectric self-sensing actuators based on velocity observer


Mi-Ching Tsai has completed his PhD in Engineering Science from the University of Oxford UK in 1990. He is currently a Chair Professor at the Department of Mechanical Engineering, National Cheng Kung University, Taiwan. He has authored or coauthored more than 117 journal papers and holds more than 100 patents. His research interests include robust control, servo control, motor design, and applications of advanced control technologies using DSPs. He is a Fellow of the Institution of Engineering and Technology, UK and previously served as an Associate Editor of the IEEE/ASME Transactions on Mechatronics from 2003 to 2007 and the Deputy Minister of the Ministry of Science and Technology, Taiwan from 2016 to 2017.


Piezoelectric self-sensing actuators (SSAs) have been extensively used in vibration control of fl exible structures over the last three decades. Compared to separated sensor/actuator systems, the SSA is simple, robust, and cost-eff ective. According to the literature, the specially designed electric circuit, referred to as a bridge circuit, is required to realize the concept. A method of achieving self-sensing capability without a bridge circuit is proposed by utilizing a velocity observer, and then the vibration velocity of a SSA can be estimated by the measured voltage and current signals. Th us, the SSA active vibration control can be implemented without using a physical velocity sensor to achieve the required vibration suppression based on feedback control design. Th e SSA vibration suppression performance is highly dependent on the equivalent mechanical admittance, which consists of equivalent mass, stiff ness, and damping. Furthermore, the equivalent stiff ness and damping will be directly influenced by the controller parameters. Th us, the SSA vibration suppression performance can be adjusted by the control design. The experimental results show that the proposed method can eff ectively reduce the structural resonance phenomenon when the controller parameters of the SSA are properly designed with a required mechanical admittance.