Pole-placement Control of a Smart Vibrating Beam

摘要

Balancing the exacting performance objectives of modern structures such as superior strength and minimal weight introduces a dynamic component that needs to be considered. Depending on the application, low structural damping can lead to problems such as measurement inaccuracy of attached equipment, transmission of acoustic noise or structural failure. This paper proposes an approach to the design of an effective pole-placement controller for vibration suppression of a simple cantilever beam. Control is applied to the beam by means of a pair of parallel connected piezoceramic patches bonded to the surface of the beam. Sensing is implemented by means of a full bridge strain gauge circuit. A simple second order model associated with an effective method of identifying the modal parameters is presented. The generated plant model is shown to generate results that are particularly close to experimental data. Necessary control signal saturation leads to an unstable condition resulting in a limit cycle state. The addition of saturation compensation within the designed pole-placement controller is shown to be highly effective in reducing the decay time of the induced vibration.