Research On Decoupling Control Method Of Multivariable Processes With Time-delay

With the development of modern industrial technology,many production processes can be equivalent transformed into multivariable time-delay processes.Due to the characteristics of coupling and time delay,the design of multivariable process is very complicated and it is difficult to control effectively.Under this background,the research of decoupling control for multivariable time-delay processes has made great progress,especially the method combining decoupling control and internal model control has a good application prospect.However,the research and design methods of multi-variable time-delay processes are still not perfect.Based on effective design methods,how to achieve better decoupling and control and give full play to its advantages will become an important direction and theoretical problem for many scholars to study in the next step.Therefore,the controller design method for a class of multivariable time-delay processes with general significance is studied in this paper.(1)For multivariable time-delay processes,an inverse decoupling active disturbance rejection internal model control method is proposed based on the good tracking and anti-interference ability of the active disturbance rejection controller.Firstly,the system is completely decoupled by the inverse decoupling method,and then the decoupled subsystems are respectively controlled by the combination of active disturbance rejection and internal model control,and the feedback filter is added to the interference suppression loop to overcome the effect of process delay and uncertainty.Simulation results show that the proposed method not only achieves complete decoupling of multivariable time-delay processes,but also has good control effect,and improves the tracking ability and anti-interference ability of the system to a certain extent.(2)For the multivariable time delay process,a fractional control method based on internal model control with phase marginφ_m and gain cross frequencyω_g independently specified is proposed.The multi-variable system is transformed into an easy to operate univariable system by inverse decoupling method.At the same time,the feedback filter is added to the interference suppression loop,so that the system has good disturbance rejection characteristics and robustness.On the other hand,the proposed method can improve the output response of the system by independently selecting the requiredφ_m andω_g,and the experimental simulation results show its effectiveness.(3)A three-degree-of-freedom internal model control method is proposed for the multi-variable time-delay non-square system.Feedforward filter and feedback filter are introduced to enhance the robustness of the system,and the non-square process is completely decouped by inverse decoupling method without obtaining the generalized inverse of the matrix.The three degrees of freedom internal model controller is designed to adjust the tracking performance,anti-interference performance and robustness performance respectively.