Nonlinear Stabilizing Controller for a Special Class of Single Link Flexible Joint Robots

Joint flexibility is a very important factor to consider in the controller design for robot manipulators if high performance is expected. Most of the research works on control of flexible-joint robots in literature have ignored the actuator dynamics to avoid complexity in controller design. The problem of designing nonlinear controller for a class of single-link flexible-joint robot manipulators whose model incorporates the effect of the electrical actuator is considered in this paper. The main control purpose followed in this research is stabilization of the system states and backstepping approach is employed to achieve this goal and find control law. The global asymptotic stabilization of the closed-loop system is achieved in the sense of Lyapunov. Finally, to demonstrate the efficiency of the designed controller in stabilization the system states, the simulation results for system dynamics and closed-loop system, are compared in different initial conditions without and in the presence of external disturbances.