Disturbance observer based tracking control

A disturbance observer based tracking control algorithm is presented in thi s paper. The key idea of the proposed method is that the plant nonlineariti es nad parameter variations can be lumped into a disturbance term. The lump ed disturbance signal is estimated based on a plant dynamic observer. A sta te observer then corrects the disturbance estimation in a two-step design. First, a Lyapunav-based feedback estimation law is used. The estimation is then improved by using a feedforward correction term. The control of a tele scopic robot are is used as an example system for the proposed algorithm. S imulation results comparing the proposed algorithm against a standard adapt ive control scheme and a sliding mode control algorithm show that the propo sed scheme achieves performance, especially when large external disturbance s are present.