The Research On MIMO Decoupling Internal Model Control

In thermal process, Internal model control can achieve better effect than PIDcontrol，particularly in the field of multivariable processes control.As one of the effective advanced control strategies, the Internal Model Control(IMC) is getting more and more attention and meanwhile. It is applied into practicemore widely. Lots of the oriental researches and practical applications have provedthat for multi-in puts and multi-out puts(MIMO), Internal model proposed strongcoupling object such as it has a good high dimension decoupling ability, quickresponse speed，easy calculation，simple design method，great robustness，nicetracking performance and stability，and has the very good compensation effect to theprocess delay. The paper focus on medium speed mill pulverizing system and hasdone in-depth research and analysis in the design of multi-variable internal modeldecoupling controller, considering to distorted and variable strong couplingcharacteristics of large delay system. Using the internal model algorithm indecoupling control, improve the suitability and controllable capacity of the system.The main work is as follows:This paper has done in-depth research and analyse the method of designingmulti-variable internal model decoupling controller, and give the proposal for thetime delay and right zeros of the plant’s transmission function in the design process.The reduction of time-delay model is processed with genetic algorithm, and thedesign process is simplified, the minimum phase and the non-minimum phase areseparated based on the model reduction, then design the internal model decouplingcontroller based on the diagonal elements of the decoupled closed-loop transferfunction and the controller should meet the requirements of the time-delay and RHPzero. And then low-pass filter is added in the feedback loop, Both the system stabilityand robustness are considered to choose the filter parameters． Based onMATLAB/SIMULINK platform, the paper proposed multi-variable internal model decoupling for medium-speed mill design to address the problem of efficient control.The simulation results prove the effectiveness our internal model based controlstrategy. Finally, using internal model decoupling control for further study of thenon-square system, the simulation results show its validity.