Observerbased Sliding Mode Control for System with Mismatched Unknown Input

Abstract:

An investigation was made into the sliding mode control design method for a class of linear system with unmatched timevarying unknown inputs. A reducedorder observer was developed to be independent of the control inputs and able to overcome the influence of the unknown inputs. Moreover, an algebraic unknown input reconstruction method based on state estimation was developed. Besides, an estimation method of the firstorder derivatives of the unknown inputs was proposed by means of a highgain sliding mode observer. Finally, based on the estimation of the system states, the reconstruction of the unknown input and the first derivative estimation, a novel sliding mode controller was constructed，and a simulation analysis validated the effectiveness of the proposed method.