Dynamic modeling and active vibration control of a 3-PRR flexible parallel manipulator with PZT transducers

This paper addresses the dynamic modeling and active vibration control of a 3-PRR parallel manipulator with three flexible intermediate links with multiple bonded lead zirconate titanate (PZT) actuators and sensors based on strain rate feedback (SRF). Using the assumed mode method, flexible intermediate links are modeled as Euler-Bernoulli beams with pinned-pinned boundary conditions. Experimental modal tests are conducted to verify the assumed mode shapes and boundary conditions. A PZT actuator controller is designed based on strain rate feedback control. The dynamic equations are developed by incorporating control moments from PZT actuators. A state-space model is developed to formulate the control input and output voltages applied to PZT actuators, and generated from PZT sensors. Then, the design of an optimal active vibration controller is presented for the parallel manipulator with flexible links with multiple bonded PZT transducers based on SRF. Numerical simulations and active vibration control experiments are performed and demonstrate that the proposed active vibration control strategy is effective.