Novel Higher Order Sliding Mode Observer for Output Noise Attenuation

Abstract

Sensor or measurement noise is an immanent disturbance in all closed loop control systems. State observers are not robust to sensor noise. Higher Order Sliding Mode Observer (HOSMO) attenuates the estimation error to a small bound in presence of output noise. A strategy is proposed in this paper for HOSM observer design which provides a further attenuation of the estimation error. A recursively designed HOSM observer with integral surface is the proposed approach. The designed observer is also shown to comply continuity condition as required by super twisting controller. Simulation results are presented to validate the proposed method.