Application of Internal Model Based Controller to Active Vibration Suppression System

More and more attention has been attracted to active vibration control with intelligent materials such as piezoelectric materials, etc. This paper deals with the problem of active vibration control of mechanisms. An internal model based controller is suited for regulation problems with periodic disturbance or tracking problems with periodic input. It has the ability to reject periodic disturbances, at the same time it is robust to parameter perturbation. In this paper an internal model principle is introduced, and simulations are carried out to show its features. In addition, the control strategy is implemented for active vibration suppression of a flexible four bar linkage bonded with piezoelectric materials as sensors and actuators. When the mechanism rotates, periodic inertial forces serve as a disturbance to induce vibration along the flexible coupler. The purpose of the experiment is to suppress this vibration using a piezoelectric actuator. The experimental system is built up with computer, A/D and D/A converter, piezoelectric sensor and actuator, low-pass filter, voltage amplifier and charge amplifier. Encouraging results are gained when the strategy is implemented in the experiments.