Compensation of delay time uncertainties on industrial control ethernet networks using LMI based robust H∞ PID controller

Industrial Ethernet and wireless network become a common platform to implement industrial control in industries. Network control systems are subjected to delay time uncertainties due to the load traffic in the networks. As the PID controller is a major control algorithm in industries, this paper proposes a LMI based robust H_infin PID controller using robust integral backstepping method to compensate the delay time uncertainties. To design using robust integral backstepping method, the plant and the PID controller are represented as a full state feedback control system in state space representation. The obtained parameters can then be used in the installed PID controller in the network based industrial control systems.