Fuzzy Modeling And Hybrid Control Of Rotary Kiln Calcination Temperature

Rotray kiln is the key equipment in the production of metallgury, cement and material of fire-fast. And the calcination temperature is one of the most important parameters in the rotary kiln process control. It is significative for ameliorating production quality, saving energy, reducing operating costs to improve control precision of rotary kiln.The production process of rotary kiln is a complicated physical chemistry course of reaction and has characteristics of big inertia, pure time-delay, nonlinearity and so on. So the calcination temperature model of rotary kiln is not easy to be set up by traditional methods. But the problem can be solved with data based fuzzy modeling method. Based on analying the rotary kiln's technology and control requests, using the lime rotary kiln's running data from Tianjin iron group, the model of rotary kiln's calcination temperature is established by WM fuzzy modeling method based on datas. In the modeling process, the outputs are introduced back into the "IF" parts after analyzing the model outputs. The modeling precision is improved by the advanced WM method.Because rotray kiln has the feature of complicated circumstances and varity of parameters, higher quality calcination temperature controller is needed. And it is difficult to control the calcination temperature by traditional methods. So, in this paper a hybrid control mothed is given, which is made of multi-model predictive control and fuzzy control through a fuzzy weight regulator, and the two controllers switch smoothly by using fuzzy rules. It does not only take full advantage of multi-model predictive controller's high quality, but also avoid large computation and bad real-time character because of solving quadratic programming problems repeatly. What's more, when predictive model of predictive controller does not match the plant, the fuzzy controller could work well as assistant.Finally, a simulation is given which validate that the hybrid controller does not only avoid large computation and bad real-time character, but also solved the mismatching of models. The calcination temperature of rotary kiln can be controlled well by this mothod.