Optimal actuator placement for vibration control of two-link piezoelectric flexible manipulator

Flexible manipulators have the advantages of light quality, low energy consumption and high efficiency. However, its vibration seriously affect performance. The coupled dynamic model is established based on assumed modes method and Lagrange equation to describe two-link piezoelectric flexible manipulator in this paper. And the rigid-flexible-electric coupling characteristics of flexible manipulator are analyzed. The stress of surface layer of the second link is obtained through the modal function, by which optimal placement of actuator on the second link is determined. Then, the fuzzy self-tuning PID controller is established. Experimental results show that the method of optimal placement is feasible using the stress of structure surface layer. Flexible manipulator vibration can be suppressed effectively using the fuzzy self-tuning PID controller, and the optimal position for vibration suppression is obtained accurately.