Nonsingular terminal sliding mode control of uncertain two-link flexible manipulators

This paper proposes a nonsingular terminal sliding mode control for a two-link flexible manipulator. The flexible robotic system is decomposed into an input-output subsystem and an internal subsystem. A novel inverse dynamics nonsingular terminal sliding mode controller is designed to make the input-output subsystem converge to its equilibrium point in finite time. In order to achieve good performance of zero dynamics of the system, six parameters of the controller are optimized by a genetic algorithm. Furthermore, a bounded convergence region is obtained using Lyapunov stability theory to guarantee the stability of the zero dynamic subsystem with uncertain parameters, which leads to asymptotical stability of the whole flexible manipulator system. Simulation results are presented to validate the design.