The High Precision Of Internal Model Control Based On Disturbance Compensation Research And Application

Internal Model Control (IMC) is an essentially robust control strategy basedon the model of plant, which has the advantages of simple structure, easy to tuneand adjust online the parameter, disturbance rejection performance in structure.So it is widely used in industrial process. Due to the implementation of IMC andthe requirements for robust stability of closed-loop system the filter need to beintroduced in the design process. IMC with filter can effectively reject a class ofconstant disturbances. There exist slowly tracking rate, phase lag of interferencesuppression and overshoot when the desired closed-loop dynamics issignificantly faster than the open-loop dynamics, the input disturbances ofsinusoidal signals and integrating process with time delay. That is difficult forthe existence method. The main contents are concluded as follows:(1) A control method combined a time domain disturbance observer (DO)and IMC was proposed. The disturbance observer is used to estimate andcompensate the sinusoidal in disturbances on the condition that the state variableis observable. The disturbances compensated by disturbance observer convergeasymptotically on a constant. IMC can reject the input composite disturbanceeffectively and track asymptotically reference trajectory. The simulation forsingle manipulator demonstrates the effectiveness of the method.(2) The output of integral delay process is difficult to automaticallystabilize and smooth using conventional IMC when system suffers inputdisturbance. A control strategy combined a disturbance observer and IMC isapplied to integral delay process, which IMC is to track the set-point, thedisturbance observer to suppress disturbances. Adjusting the parameters of thedisturbance observer can improve disturbance observer on the condition that donot affect the track of system. There are two adjustable filter parameters in IMCand disturbance observer. A guideline is also proposed for two process models.(3) Real-time control platform of DC speed control system is built on the QStudioRP scheme of Quanser company. Designed IMC algorithm based ondisturbance observer subjected to disturbances in the DC motor. The simulationof the DC motor indicates the algorithm can effectively suppress the inputdisturbance and is robust.