Disturbance observer-based L1 robust tracking control for single-link flexible-joint manipulator systems

In this study, a novel disturbance observer-based (DOB) L-1 robust anti-disturbance tracking control problem is discussed for a kind of single-link flexible-joint manipulator with separate types of disturbances. On the one hand, a disturbance observer is imported to estimate the modelable disturbances. On the other hand, the introduction of L-1 performance index optimises the impact of unmodelled disturbances on the system. A DOB proportional-integral control input is proposed such that the stability of single-link flexible-joint manipulator can be ensured. Furthermore, the satisfactory disturbance rejection and attenuation performance with L-1 index can be obtained simultaneously. Finally, the simulation results verify this feasibility and effectiveness of the proposed control method.