a North China Electric Power University, Department of Automation, Zhuxinzhuang, Dewai, Beijing 102206, China;b University of Alberta, Department of Electrical and Computer Engineering, Edmonton, Alberta, Canada, T6G 2V4
Abstract:
A modified IMC structure is proposed for unstable processes with time delays. The structure extends the standard IMC structure for stable processes to unstable processes and controllers do not have to be converted to conventional ones for implementation. An advantage of the structure is that setpoint tracking and disturbance rejection can be designed separately. A method is proposed to tune the modified IMC structure with an emphasis on the robustness of the structure. Design for some typical delayed unstable processes shows that the control structure can be tuned easily and achieve good tradeoff between time-domain performance and robustness.