Robust hybrid observer for speed sensorless estimation of a DC motor

In this paper, the speed estimation and unknown parameter reconstruction problem is considered for a series dc motor. By combining the high gain observer with a sliding mode term, a hybrid robust observer is applied to guarantee the asymptotical stability of the estimation error. Furthermore, by attenuating the chattering phenomenon, the unknown parameter can be directly obtained without filtering effect. To demonstrate the effectiveness of the proposed algorithm, some experimental results are presented.