On trajectory tracking control for nonholonomic mobile manipulators with dynamic uncertainties and external torque disturbances

This paper studies the trajectory tracking control problem of mobile manipulators subject to nonholonomic constraints, operating in task space, with the presence of external torque disturbances and dynamic uncertainties. The proposed controls are robust to external torque disturbances and can overcome the effects of the unknown dynamic parameters. The stability of the closed-loop system and the asymptotic convergences of tracking errors are proved using Lyapunov synthesis. The proposed control strategies have been designed to drive the system motion converges to the desired manifold and, at the same time, guarantees the boundedness of all the closed-loop signals. Simulation results validate that the system trajectory converge to the desired one.

► We present an adaptive controller for mobile manipulators operating in task space.
► Uncertain parameters and external disturbances are estimated and then used in the control law.
► External disturbance estimation is realized using only the information about the actual positions.
► Measurement of the joint accelerations is not required.
► The scheme can be implemented for any type of mobile manipulators.