Active Vibration Control of a 3-PRR Flexible Parallel Manipulator With PZT Actuators and Sensors
This paper presents an experimental study on active vibration control of a moving 3-PRR parallel manipulator with three flexible intermediate links, with bonded lead zirconate titanate (PZT) actuators and sensors. Experimental modal tests are conducted to identify structural vibration mode shapes and natural frequencies used. These modal tests provide guidance to design the filter and determine the location of PZT transducers. A PZT actuator controller is developed based on strain rate feedback (SRF) control. A state-space model is formulated with the control input voltage applied to PZT actuators, and output generated from PZT sensors. Then, the design of an optimal active vibration controller is presented based on SRF for the parallel manipulator with flexible links with multiple bonded PZT transducers. Active vibration control experiments are conducted to demonstrate that the proposed active vibration control strategy is effective. Power spectral density (PSD) plots of vibrations illustrate that the structural vibration of flexible links is reduced effectively when the proposed vibration control strategy is employed.