Semi-passivity and practical stability for switched discrete-time nonlinear systems

Abstract

This paper concerns semi-passivity and practical stability of a switched discrete-time nonlinear system. First, semi-passivity concept is proposed to achieve broader application. It means that each subsystem is passive outside a ball on its active time interval. Then, practical stability of switched nonlinear system is obtained by investigating the energy changing of the inactive subsystem. Second, semipassivity conditions are given. Based on these conditions, a more general switching law than ‘min’ switching law is designed to achieve semi-passivity. Third, the feedback semipassification problem for such a system is solved by designing a set of controllers and a switching law dependent on state. Finally, the validity of the obtained result is verified by its application to a thermal system.

Keywords

• Practical stability
• Switched discrete-time nonlinear systems
• Semipassivity
• Inactive subsystem