A non-contact vibration measurement and control system for a piezoelectric-patched flexible cantilever plate is presented, using laser displacement sensors. Two laser displacement sensors are utilized to detect the deflection information of the two corners of the end of the flexible board, due to its high measurement accuracy for the small amplitude residual vibration. The vibrations of the first bending and torsional mode of the flexible plate can be extracted from the combined information. To achieve a desirable performance for the active vibration control, a kind of sliding mode predictive control strategy is developed to damp the vibration quickly. Simulation of the controller on bending and torsional vibration is conducted, based on the model built with finite element method. Furthermore, a piezoelectric flexible cantilever plate experimental setup is constructed. Experiments are conducted. The results of simulation and experiment both demonstrate the effectiveness of presented control scheme, compared with proportional and derivative control; the sliding mode predictive control can attenuate the vibration more quickly, particularly for the small amplitude residual vibration.
Residual vibration control for robotic 3D scanning with application to inspection of marine propellers
