Semi-active vibration suppression for smart structures with sliding-mode control

A semi-active vibration suppression system is developed for flexible structures. The vibration suppression system comprises bimorph piezoelectric ceramic tiles shunted by a resistor–inductor electrical circuit with a switching component. The vibration suppression control is designed by tuning the optimal resistance and inductance parameters of the shunted resistor–inductor network. In this article, we propose a semi-active vibration control technique to improve the damping effect while maintaining the stability of the passive control system. The proposed control law is similar to a sliding-mode control that accelerates the convergence of the system using switching functions. This study shows that the resonant circuit functions as a type of dynamic damper for mechanical systems and that the sliding-mode control is very effective for damping the multi-mode responses. The results of the numerical simulations of a cantilevered beam show that a semi-active vibration control system is more effective in damping vibrations than a passive control system. A hardware demonstration based on a laboratory model has also been carried out. The preliminary results of the experiment show that the system is sensitive to the noise, and improved implementation of the switching circuit is needed for practical application.