การพัฒนาตัวควบคุมกระบวนการฟัซซีแบบฐานแบบจำลองสำหรับเครื่องปฏิกรณ์เคมีแบบถังกวนต่อเนื่อง / ทัศนีย์ วัฒนเชาวน์พิสุทธิ์ = Development of model-based fuzzy controller for a continuous stirred tank reactor / Tasanee Watanachaopisut
Presently, the controlling chemical process has a trend to use “Model-based control” approach. However, mostly mathematics models of the chemical process are non-linear which consist of the complicated mathematics equations and sometimes unable to be written. Setting up many hypothesis may result in the impreciseness of model and even time-consuming. Fuzzy relational model is an alternative that is used in building up the model. Fuzzy relational models are identified by the use of an input-output process data and the selection of an appropriate fuzzy model structure. The process of a continuous stirred tank reactors (CSTR) is one of the process in a chemical industry whose characteristic is usually non-linear so that the more effective development control is necessary. In the research, the fuzzy relational model is selected as the internal model for an internal model controller (IMC). MATLAB program is used to simulate the process and the controller in order to investigate the control performance. The controller tests are performed in 2 categories i.e. step change in setpoint and step change in disturbance. The simulation results are clearly shown that the fuzzy controller can be used to control the process with a higher performance than the conventional control. In addition, the model-based controller can be used without using mathematics model both in the level control of non-linear flow tank and the temperature control of CSTR which is the more difficult process. To be concluded, the application of the fuzzy model in the control is found profoundly impressive to use in the non-linear process particularly whose mathematics model is unable to be defined.
