Adaptive Motion/Force Control of Mobile Under-Actuated Manipulators With Dynamics Uncertainties by Dynamic Coupling and Output Feedback

In this paper, adaptive motion/force control by dynamic coupling and output feedback is considered for nonholonomic mobile manipulators with an under-actuated joint, in the presence of parametric and functional uncertainties. It is obvious that the constraints of the system consist of kinematic constraints for the mobile platform and dynamic constraints for the under-actuated joint. Through using dynamic coupling property of nonholonomic mobile under-actuated manipulators, adaptive output feedback control is investigated for the system by using a high gain observer to reconstruct the system states, whose states and time derivatives of the output are unavailable. Moreover, the nonholonomic constraint force between the wheels and the ground is also considered in the control design such that the slipping or slippage is avoided during the motion. It is shown that output tracking errors of motion and force converge to adjustable neighborhoods of the origin for the output feedback control.