Research On Fuzzy Decoupling Control System Of Two-Cycle Water Temperature Based On PLC

Decoupling control is an important issue of multi-input and multi-output system, and it's also the difficult problem of modern industrial production. In industrial production project one fluctuated variable may touch other variables. We used coupling to description this phenomenon that variables interact each other, and to eliminate obnoxious interacting we called decoupling.Fuzzy control is an important application filiation of fuzzy mathematics. It's a kind of new intelligent control algorithm formed by the combination between fuzzy mathematic and automation. When the target or process which is controlled have some features such as long time lag, nonlinearity, intensive mufti-parameters coupling, stochastic noises, the complicated mechanism of process and uncertain measurement condition in the working field, the precise mathematic model of target or process can't be built. Then fuzzy control, a kind of algorithm similar to expert rules, offered a kind of ideal algorithm for these target and process.Programmable logic controller (PLC) is a kind of electronic device for digital operation which is designed for industrial application specially. It have programmable memorizes in which some operation instructions such as logic operation, sequence operation, motion control, timing, counting is saved and runs, and then it can control kinds of mechanism and process through input and output of digital or analog signal.In this paper, we have using MIMO fuzzy decoupling control to control the two-cycle water's temperature coupling system. And the engineering application and actualization of fuzzy decoupling control is researched, based on ROCKWELL PLC RSlogix 5000 software, to realize fuzzy decoupling control.Experimental results show that the fuzzy control can resolved the strong coupling and nonlinearity problems well without the precise mathematic model. When there is not much the content in fuzzy querying table, this method for programming is more compact and the response is faster. The control effect is better. So it can be used in similar field of industrial control and is a kind of better strategy for decoupling.