Design of variable structure controller - From sliding mode to sliding sector

In general, a variable structure (VS) control system is designed with a sliding mode. But recently a sliding sector designed using algebraic Ricatti equation has been proposed to replace the sliding mode for chattering-free VS controllers and for discrete-time VS controllers. In this paper we design a new sliding sector based on the sliding mode and propose a VS controller with the sliding sector. The proposed VS control system is quadratically stable even if there exists parameter uncertainties and external disturbances. The experimental results on an inverted pendulum show the effectiveness of the proposed VS control algorithm with the sliding sector.