Couplin Analysisa And Internal Model Control Of Multivariable System

With the rapid development of science and technology, the process of industrial production is also more efficient, more secure. At the same time, the quality requirements of industrial products also increase. Therefore, advanced control technology become very important under the background of industrial control. And the multivariable systems abound in the actual industrial process. Hence, Study control technology of multivariable system and study the application of advanced control technology in multivariable system become extremely important. Internal Model Control, IMC for short, due to its good features like simple structure, good robustness and less parameters adjusted, has wide attention in the control group. Therefore, study of the IMC control of multivariable system has very important significance. In this paper, for multivariable systems, coupling analysis method is put forward firstly. And combined with the interaction analysis method of multivariate system, the IMC is designed. Simulation validation is finally processed. This paper main works are as follows:(1)In this paper, the basic knowledge of the internal model control is introduced, including internal model control principle, nature of IMC and design procedures. Then basic knowledge of the multivariable system is introduced, including several classic loop pairing method and The design method of equivalent transfer function.(2)Aiming at the shortcomings of the previous proposed interaction analysis method, a new method of interaction analysis is proposed in this paper, interaction analysis method based on the proportion. The method use the ratio of the closed-loop response and open-loop response to determine the coupling of the system under the unit step response. The closed-loop response is obtained by improved equivalent transfer function. After definition is given, The calculation formula of the method is given. At the same time, according to the different special case of the system, that is, mainly based on difference of open loop time lag and the closed loop time lag, including simplified algorithm under the circumstances of unit step response of open-loop system equaling closed-loop step response originally, as well as the circumstances that the unit open loop step response equaling zero, The processing method to calculate the index is given in the paper. And then the calculation flow chart is given. And the simulation of the method is tested.(3)The equivalent transfer function method is tranfered the reduced-order model. Then the internal model controller is designed according to the model. In order to ensure the elimination of The system error in the process of calculating the equivalent function or reducing system order. adding the gain eliminate the error which causes on the basis of the original internal model controller. And then combined with the above proposed interaction analysis method for simulation, the result shows that this method obtain good control effect.