Runout Table Cooling Process Control Based On Fuzzy Logic

Runout table cooling process is an important step that determines quality of the steel product. Control of Runout table cooling process is difficult because of its complex nature (e.g., highly nonlinear, time varying), and the difficulty of establishing accurate mathematical model. As a result it is difficult to apply conventional control methods with good results. To overcome the control problems of runout table cooling process, this thesis designs the control strategy of the runout table cooling process based on fuzzy logic and expert knowledge for the control task. The main work of this thesis includes the following aspects:Firstly, this thesis designs controller for runout table cooling process based on the fuzzy logic. The thesis details runout table cooling process and fuzzy control theory, and proposes runout table cooling process fuzzy control system of master-slave structure. Through the real data analysis the fuzzy control rule set is obtained. During design process of master fuzzy controller, this thesis realizes that the too many fuzzy controller inputs not only increase the complexity of the controller design, but also greatly increase the number of control rules by taking into consideration that runout table cooling process is a multi-input high-dimensional system. Therefore, the variable structure fuzzy controller is designed, that is, according to the different strip thickness and speed, several fuzzy subcontrollers are designed, in accordance with the controller input thickness and the speed, the system switches to a corresponding fuzzy controller.Secondly, the thesis develops runout table cooling process simulation software by using MATLAB language. To verify the effect of the fuzzy controller the thesis uses the software to simulate the runout table cooling process in typical conditions. Simulation results show that the fuzzy control method can control the strip coiling temperature to within the range 15℃of the desired temparature, and can meet runout table cooling process technological requirements.