Multirate Output Feedback Based Discrete-Time Sliding Mode Control for Fractional Delay Compensation in NCSs

This paper addresses the time delay problem in Networked Control Systems (NCSs) occuring due to the presence of communication medium. To compensate the time delay multirate output feedback based sliding mode controller is designed in which the control input is computed based on the system outputs and past control signals by taking full advantage of network transmission. A Thiran Approximation technique is used to compensate the networked delays. The sensor to controller delay is compensated at the sliding surface, while sliding mode controller (SMC) is utilized to compute the control sequences. The stability of the closed loop NCSs is derived using Lyapunov approach. Simulations results are given to demonstrate the effectiveness of the proposed approach.