An Adaptive Output Feedback Proportional-Integral-Derivative Controller for n-Link Type (m, s) Electrically Driven Mobile Manipulators

The design of a trajectory tracking controller for a general class of n-link type (m, s) electrically driven wheeled mobile manipulators has been addressed in this paper. In order to achieve a high level of the tracking performance, an adaptive robust proportional-integral-derivative (PID) controller is proposed which only requires position measurements by designing a velocity observer. Integral actions are incorporated into the design of both controller and observer to reduce the steady-state error as much as possible. The dynamic surface control approach is also applied to reduce the design complexity at the actuator level. Lyapunov's direct method is used to guarantee that tracking and observation errors are semiglobally uniformly ultimately bounded. Simulation results are presented to illustrate the effectiveness of the proposed controller for a group of mobile manipulators.