Networked control systems: Time delays and robust control design issues

Networked control system (NCS) has received considerable attention in the last 15 years. The interest is stimulated by the fast development of communication in computer based control system technologies that offers many benefits in integrating production planning and control. Unfortunately, the network induces imperfections and constraints in control system implementation. One of these limitations which affects the NCS is varying communication delays. The paper shows the occurrence of varying time delays in wireline or wireless network and considers robust control design methods to handle the delay uncertainties.