A sliding-mode control strategy for objects with a stable finite zero

This paper describes a new method, proposed for the control of objects with a stable finite zero, using sliding mode control strategies. The method is a combination of the conventional linear control and the sliding mode approach with an observer structure. The proposed structure looks like a reference model control system. The object control signal has two components: the first one is integral of the sliding mode controller output signal, and the second is a linear combination of observer error signal and its derivative. Such a control signal has not switching nature, i.e. the process control is chattering-free. The stability of the proposed control structure is analyzed and some recommendations for controller synthesis are given. The effectiveness of the proposed control strategy is demonstrated by simulation on an example.