Design of robust multivariable PID controllers via IMC

We obtain a general form for the parameters of multivariable PID controllers by Maclaurin series expansion of the simple feedback form of a multivariable IMC controller. The IMC controller is designed to provide decoupled control, and is tuned either to accommodate modeling uncertainties using multivariable Mp tuning, or to get the best possible PID responses. Application of the multivariable PID controllers to simulations of three distillation models found in the literature indicates that the controllers perform as well or better than those obtained using existing methods.