Hybrid Control Scheme Consisting of Adaptive and Optimal Controllers for Flexible-Base Flexible-Joint Space Manipulator with Uncertain Parameters

The trajectory tracking and vibration suppression problems of a flexible-base flexible-joint space manipulator with uncertain parameters are addressed. Dynamic equations of the manipulator are described as a linear function of a series of combined inertia parameters, and then the flexibility compensation technology and singular perturbation method are introduced to obtain the revised slow and fast subsystems. Using the linear-in-combined-parameters property of system dynamics, a regressor-based adaptive control approach is proposed for the slow subsystem to handle with the parameter uncertainties, while the flexible vibration of the base and joints is dealt with by the liner quadratic optimal control which is presented for the fast subsystem. The proposed hybrid control scheme ensures that the tracking errors and velocity errors converge to zero asymptotically and the vibration of system can be suppressed effectively. Simulations on a flexible-base space manipulator with weak-stiffness joints are given to show the feasibility of the proposed controller.