Rapid slewing and pointing of a flexible structure with embedded piezoceramics

Active control of flexible multi-body systems and structures through utilization of smart materials is considered in this paper. Specifically, utilization of piezoceramics for sensing and actuation is investigated. Experimental setups have been developed at Control/Robotics Research Laboratory (CRRL) to study modeling issues and control design approaches for flexible structures with embedded (or surface-mounted) piezoceramics. In this paper, experimental results on vibration suppression for a clamped-free beam and a rotating flexible beam with surface mounted piezoceramics are presented. We compare and contrast the analytical modeling and control design with the experimental results. It will be shown that piezoceramics substantially improve the performance of the systems under consideration. The advocated approaches for control designs are decentralized frequency shaping and self-tuning adaptive controllers. The self-tuning controller is based on identification of the system dynamics in frequency domain utilizing Fast Fourier Transform (FFT). The realtime computing power to evaluate FFTs is provided by digital signal processing boards (TMS320C30 based). Addition of a self-tuning regulator enhances the performance and the robustness of the controlled system to parameter variations.