H ∞ switched adaptive control for a class of robot manipulators

This paper investigates the H ∞ adaptive tracking control problem for a class of robot manipulators with alternating unknown loads. Since each load produces its corresponding parameter of the manipulator, a switched system is established to model the parameter-jumping manipulator, where each subsystem represents the manipulator carrying the corresponding load. An individual adaptive controller is designed for each subsystem. Under arbitrary load changings, asymptotic tracking is achieved in the absence of disturbance. Meanwhile, for non-zero disturbance, a sufficient condition is proposed to guarantee the solvability of the H ∞ tracking control problem of the closed-loop system. The provided method is validated by a two-degree-of-freedom robot manipulator.