Vibration control of a single-link flexible manipulator using command shaping techniques

This paper presents experimental investigations into the development of feed-forward control strategies for vibration control of a flexible manipulator using command shaping techniques based on input shaping and low-pass and band-stop filtering. A laboratory-scale single-link flexible manipulator is used and various system responses are obtained. Initially, an unshaped bang-bang torque input is used to determine the dynamic response parameters of the system for design and evaluation of the control techniques. Feed-forward controllers are then designed based on the natural frequencies and damping ratios of the system. Experimental results of the response of the manipulator to the shaped and filtered inputs are presented in time and frequency domains. Performances of the techniques are assessed in terms of level of vibration reduction at the natural frequencies, time response specifications, robustness to natural frequency variation and processing time. The effects of the number Of impulses and filter order on the performance of the system are investigated. Finally, a comparative assessment of input shaping and filtering techniques is presented.