Discrete-Time Sliding-Mode Switching Control Scheme With Disturbance Observer and Its Application to Superheated Steam Temperature Systems

In this paper, we have addressed a sliding-mode switching control scheme with disturbance observer for a class of single-input single-output (SISO) discrete switched nonlinear systems which suffer from uncertain parameters. To overcome the influences, the external disturbances, and uncertainty, an application of the boiler steam temperature control systems has been modeled as the control plant, and a disturbance compensator observer from the sliding-mode dynamics has been proposed to enhance robustness and decrease the system chattering. With the presented control scheme, using the feedback linearizable method and average dwell time technique, the closed-loop switching system is stable such that the output tracking error converges to a small neighborhood nearby zero and the sliding-mode surface can be well obtained. Experimental results of the superheated steam temperature systems have developed the better performance of the proposed control scheme over traditional sliding control strategy, which have demonstrated good accuracy of tracking error performance.