Optimal H2 - IMC based PID Controller Design for Multivariable Unstable Processes

IMC based PID controller with lead-lag filter is designed for multivariable unstable processes. The design is based on H2 optimal closed loop transfer function for set point changes and step input disturbances. The individual controllers are designed based on the corresponding equivalent transfer function (ETF) model. Simplified decouplers are designed based on the ETF model. Two examples are considered to show the closed loop responses. The proposed method provides significantly improved closed loop performances when compared to the methods in the literature.