OPTIMIZATION OF TERMINAL SLIDING CONTROL FOR 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 is decomposed into two parts by input-output linearization, namely, an input-output subsystem and the zero dynamics respectively. A terminal sliding mode control strategy is designed to make the input-output subsystem converge to their equilibrium points in finite time. The relationship between the eigenvalues of the zero dynamics and the parameters of the redefined output is obtained. The parameters of the controller are optimized using a chaos based genetic algorithm to guarantee the zero dynamics to be asymptotically stable at equilibrium points, and thus guarantee that the entire flexible manipulator system is asymptotically stable. Simulation results are presented to validate the design.