Asymptotic rejection of unmatched general periodic disturbances in a class of non-minimum-phase non-linear systems

• Published in: International journal of control Vol. 82; no. 2; pp. 335 - 342
• Main Author: Ding, Zhengtao
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis Group 01.02.2009; Taylor & Francis
• Subjects: Applied sciences; Computer science; control theory; systems; Control system synthesis; Control theory. Systems; disturbance rejection; Exact sciences and technology; Modelling and identification; non-linear systems; nonminimum phase; periodic disturbance; Periodicity; Non linear control; Control synthesis; Asymptotic approximation; Input estimation; Non linear system; Non minimum phase system; Steady state; Phase feedback control; Output feedback
• ISSN: 0020-7179; 1366-5820
• DOI: 10.1080/00207170802090185

This article deals with asymptotic rejection of unmatched general periodic disturbances in nonminimum phase non-linear output feedback systems. The steady state responses are defined for unstable systems subject to general periodic disturbances, and the generalised gain and phase are defined for stable systems subject to general periodic disturbances. Based on the new definitions, new results are obtained for the equivalent input disturbance and disturbance estimation. An L p -convergent estimate of the equivalent input disturbance is incorporated in the control design to ensure the asymptotic rejection of unmatched general periodic disturbances while maintaining the stability of the non-linear system.