A linear extended state observer combined with differential signals: Application to a flexible rectilinear system

An improved linear extended state observer (iLESO)‐based trajectory tracking control scheme is proposed and applied to a flexible rectilinear system. By introducing differential signals into the traditional LESO, the number of correction variables of observer is increased. Frequency‐domain analysis demonstrates that the observation error of the iLESO and the tracking error of the improved active disturbance rejection control (iADRC) are bounded. Experimental tests show that LESO including differential signals can significantly improve the ability of observer and suppress peaking phenomena caused by nonzero initial states. The proposed strategy significantly outperforms traditional linear ADRC in control performance.