The Design of Terminal Sliding Controller of Two-Link Flexible Manipulators

A terminal sliding mode controller is proposed for a two-link flexible manipulator to address its non-minimum phase characteristics using the output redefinition method. The manipulator system is decomposed into two parts by input-output linearization, namely an input-output subsystem and the zero dynamics respectively. Then a terminal sliding mode control strategy is designed to make the input-output subsystem converge to zeros in finite time. The relationship between the eigenvalues of the zero dynamics and the parameters of the redefined output is obtained. Moreover, the zero dynamics can be asymptotical stable at equilibrium point by choosing suitable controller´ parameters. The whole original two-link flexible manipulator control system is guaranteed to be asymptotically stable and the control design procedure is simple and easy to implement. Simulation results are presented to validate the design.