Active Vibration Control: using over-sensing and over-actuation

Abstract

The demand for faster production times and higher precisions in the industrial automation is ever-increasing. Resonance modes caused by flexural elements in these machines are limiting the maximum bandwidth. Because of this, high-precision motion systems in industrial machines are limited in the maximum operating speed and precision. To improve the performance of these machines, an active vibration control (AVC) system is needed. In present scientific literature, all AVC systems consist of an under-actuated or perfect-actuated setup. However, the damping performance of these systems could be increased by implementing an over-actuated setup. In an over-actuated setup, multiple actuators are used to control one resonance mode. In this way, control inputs for suppressing modes are provided at more efficient locations, which increases the amount of damping. In this thesis, an over-actuation and over-sensing strategy for active damping is proposed. In this new method, a large number of piezoelectric sensors and actuators are used to control the first four vibration modes of a cantilever beam. The damping performance is evaluated in an experimental setup. Finally, the performance of the new topology of sensors and actuators is compared to the state-of-the-art active damping method that uses a perfect-actuation strategy. The improvement of the new method compared to the state-of-the-art method is shown both in time and frequency domain.