Trajectory tracking control of omnidirecitonal wheeled mobile manipulators: Robust neural network based sliding mode approach

This paper focuses on developing a robust neural network (NN) based sliding mode controller (NNSMC) to solve the trajectory tracking problem of a redundantly-actuated omnidirectional mobile manipulator. The SMC is designed to be robust to disturbances assuring the stability of the system. The NN is used to identify the unstructured uncertainty of system dynamics. The stability of the closed-loop system, the convergence of the NN weight-updating process, and the boundedness of the NN weight estimation errors are all strictly guaranteed. Through theories analysis, we know the controller is also capable of disturbance-rejection in the presence of time varying disturbances. Finally, simulation results demonstrate the proposed NNSMC approach can guarantee the whole system´s convergence to the desired manifold with prescribed performance.