New internal model control method for multivariable coupling system with time delays

There are many internal model control methods for the system with non-minimum phase zeros and time delays, but the decoupling result is not satisfied and the controller design is complicated. In order to solve these problems, a new decoupling IMC method is proposed. Non-minimum phase zero problem can be solved easily and if there are several different time delays in the system, the model of the system needn't to be converted to approximated model. As to parameter optimization of filter, the improved ISE index and NLJ algorithm were adopted to optimize the parameter of the filter. The simulation results have illustrated that this new internal model control method and parameter optimization method are simple and effective, and the decoupling result of two input-two output system is satisfied and has good tracking characteristics and robustness.