Experimental Implementation on Vibration Mode Control of a Moving 3-PRR Flexible Parallel Manipulator with Multiple PZT Transducers

Abstract

This paper presents the experimental implementation of active vibration control applied to a moving 3-PRR parallel manipulator with three flexible links. The active vibration control is implemented using three piezoelectric (PZT) transducer pairs applied to one flexible intermediate link based on modal strain rate feedback (MSRF) control. A real-time active vibration control system is developed using two PCs with LabVIEW Real-Time. Modal analyses are conducted, and the results demonstrate that the vibration modes of the intermediate links are dynamically coupled and the vibration frequency components are complicated and closely spaced. Simplified and efficient modal filters are developed to extract modal coordinates in real time, and a second order compensator is used to filter amplified noises and unmodeled high frequency dynamics. A MSRF controller is then designed using an independent mode space control strategy, and is implemented experimentally with the first mode targeted for control. Experimental results demonstrate that the vibration amplitude of the first vibration mode of the intermediate link is significantly reduced using three PZT control pairs. The experimental results using one PZT control pair and two control pairs are provided to justify the use of three PZT control pairs.