Improving joint PD control of single-link flexible robots by strain/tip feedback

This paper considers improving the tip motion performance of a joint-PD controlled single-link flexible robot by respectively introducing nonlinear base-strain and tip-acceleration feedback. The stability is theoretically proven directly based on the partial differential equations (PDEs) of the system. The controller is independent of system parameters and thus possesses the stability robustness to parameter uncertainties. Using base-strain/tip-acceleration feedback is motivated by the fact that strain gauge and accelerometer have been widely used in control of robots with flexible links, and are comparatively easy for engineering implementation. Simulations are provided to show that the tip motion performance are greatly improved by the two kinds of nonlinear feedback