On the second-order sliding mode control of nonlinear systems with uncertain control direction

• Published in: Automatica (Oxford) Vol. 45; no. 12; pp. 2982 - 2985
• Main Authors: Bartolini, Giorgio, Pisano, Alessandro, Usai, Elio
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.12.2009; Elsevier
• Subjects: Applied sciences; Computer science; control theory; systems; Control theory. Systems; Exact sciences and technology; Second-order sliding modes; Unknown control direction; Unknown control direction; Second-order sliding modes; Uncertain system; Variable structure control; Sliding mode; Non linear control; High frequency; Non linear system
• ISSN: 0005-1098; 1873-2836
• DOI: 10.1016/j.automatica.2009.09.018

This note deals with the implementation of a second-order sliding mode control algorithm for a class of nonlinear systems in which the sign of the high-frequency gain, though constant, is unknown. A specific second-order sliding mode control algorithm, the “Suboptimal” algorithm, is properly modified in order to face the uncertainty in the control direction. It is shown that after a finite time the uncertain sign is identified and the standard finite time convergence takes place from that time on. Simulation results are provided.