Nonlinear Output Feedback Trajectory Tracking Control for Harmonic Drive Systems

Based on a class of nonlinear saturated functions with the characteristics of "enlargement of small error and saturated in large error", a nonlinear proportional plus linear derivative and system dynamics (NP-D+) control algorithm is designed. Compared with traditional output feedback tracking control algorithms, the algorithm gives a faster response ignoring flexibility effects, and it can compensate for the kinematic error effectively. The semi-global asymptotic stability of the closed-loop system is proved based on Lyapunov theory. Simulation examples verify the effectiveness of the proposed NP-D+ output feedback tracking control algorithm.