The Research And Implement Of Predictive Control Software Package Based On OPC

The fast development of Internet and software bring us a new wave of technologyrevolution. It is very important and necessary to apply those advanced softwaretechnology into the design of advanced process control (APC) software, otherwise wewill be eliminated from the market. Our national industry of APC has dropped behindothers very much and the market is primarily hold by those big oversea companies.There are several limitations in existing APC software products as follows: (1) poorfunction and low integration; (2) appropriative driver with poor open-ability; (3)inflexible structure with poor adaptability; (4) low re-usability and poor stability. Theright way is utilizing the key software technology to design APC software and this willbring us the chance to break the monopolization. Thus this paper mainly studies thedesign and development of APC software based on OPC technique.The paper summarized and studied the distributed component technique, e.g.COM/DCOM and OPC specification, and then put forward the design mode of APCsoftware. Afterwards, the predictive control software package has been designed anddeveloped based on OPC technique. The research works can be summarized asfollows:1) The history of distributed component technique, the basic principle ofCOM/DCOM and its application in the industrial automation have been dissertated.Then, the well-known realization of applying COM/DCOM in industry automation, e.g.OPC, has been discussed about its specification, special background, communicationmode, application framework in industry automation and the running environmentconfiguration of its server and client. In conclusion, the method of using OPC todesign APC software has been brought forward. 2) Based on the predictive control and OPC technology, distributed componentpredictive control software package has been designed and developed. The totalframework of the software package has been presented. Its function modules havebeen designed in detail. This software package has good open-ability, flexibility,reliability and it can overcome the disadvantages of traditional APC software.3) For a class of nonlinear systems whose open-loop y-u curve is monotoneincreasing (or monotone decreasing), a fuzzy-logic extended DMC algorithm has beenpresented.4) The realization method of the predictive control software package wasresearched based on CENTUM CS1000 DCS system. The detail approach was usingCS1000's function block window to configure the nonlinear continuous fermentationsystem, using OPC automation interface to access process data and then depositingthem to database, applying fuzzy-logic extended DMC algorithm to calculate theoptimization manipulated variable and download it back to CS1000 by OPC interface.This software package includes three main software. They are OPC interface software,real-time database software and predictive control software. The basic functions of thethree software were realized after the experimental research.Finally, on the basis of the summarization of the research work in this dissertation,the further development about APC software is discussed.