Multivariable Internal Model Control Pid Within Air-conditioned Room Temperature And Relative Humidity Control System

Central air-conditioning system as an indispensable part of the modernarchitecture has very important significance to improve working conditions, quality oflife, to ensure that labor productivity and the maintenance of human health. Currently,most of the central air-conditioning system only controls the temperature for thesupply air or the air-conditioned room. In recent years, in order to meet people’scomfort and requirements of industrial production, the relative humidity ofair-conditioned room has gradually become one of the main objects of study. On theother hand, more and more buildings began to use the enclosed indoor mode to solvethe urban dust pollution problems. How to deal with polluted indoor air has becomean urgent problem. However, at this stage both domestic and foreign study ofcontrolling the temperature and relative humidity of air-conditioned rooms isrelatively less. Therefore, the study of this type of air-conditioning system hasenormous economic value and significance.This paper first briefly introduces the research background and the developmentof central air-conditioning control strategies. By determining the basic situation andbackground of the practical project, analyzing the current problems of the centralair-conditioning system, this paper determines the research purpose and researchcontents of this article.Then, the structure of the central air-conditioning system has been designedbased on analyzing the characteristics of traditional system. Aiming at the problemthat central air-conditioning system can’t operation stably with the large hysteresisand the circuit coupling of temperature and relative humidity, this paper presents amethod for controlling the temperature and relative humidity of air-conditioned roomswith IMC-PID controller for the multivariable system. Air-conditioned room is theresearch object of this paper. First, get the temperature and relative humidity stepresponse curve of air-conditioned room, in order to establish the system transferfunction matrix. Then design a multivariable decoupling IMC controller of thissystem. To make the controller easy to use in central air-conditioning system, thispaper integrates the IMC controller and object model as an IMC-PID controller.Finally, the system control architecture is designed according to the characteristics of the system. And then this article introduces the PC monitoringsoftware and controller software features.