Intelligent Control of Grate-kiln-cooler Process of Iron Ore Pellets Using a Combination of Expert System Approach and Takagi-Sugeno Fuzzy Model

Grate-kiln-cooler has become a major process of producing iron ore pellets in China. Due to the diversity of the raw materials used and the multi-device multi-variable characteristics, this process still encounters with control problem. An attempt was proposed to deal with this issue. The three-device-integrated feature of the process was firstly analyzed to obtain control strategy, and then an intelligent control system using a combination of expert system approach and Takagi-Sugeno (T-S) fuzzy model was developed. Expert system approach was used to diagnose and remedy the abnormal conditions, while T-S fuzzy model was used to stabilize the thermal state. In the construction of T-S fuzzy rules, antecedents were identified by fuzzy c-mean clustering algorithm incorporated with subtractive clustering algorithm, and consequent parameters were identified by recursive least square algorithm. The control system was applied in a Chinese pelletizing plant and the application results demonstrated its effectiveness of stabilizing the thermal states within three devices.