On Extended State Observer Based Control for A class of Nonaffine Systems with Unknown Saturation

This paper studies the control problem for a class of nonaffine uncertain systems with unknown saturation. The system model is built to describe many physical plants satisfying generalized saturation model of control input. The inflection point of the saturation model, which is critical for conventional controller design, is assumed to be unknown in this paper. The extended state observer is constructed to not only online estimate the “total disturbance” but also identify the inflection point. The simulation results on the typical aircraft flight control module show the effectiveness of the proposed controller.