On-line Tuning Fuzzy Controller Design

• Main Authors: Jian-Cheng Su, 蘇建成
• Other Authors: Shih-Hsiung Twu
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/12919916291365042918

碩士 === 中原大學 === 電機工程研究所 === 93 === Abstract Conventional PI controllers were often in widespread use owing to their capability of efficiently improvement of steady-state responses of systems; however, transient responses are often their defect. Based on the advantages of PI controllers, the thesis proposed that in the case that a PI controller is served as a host controller, a on-line tuning fuzzy controller can be used as a servant controller to improve the transient response to get better performance of the whole system. In the past, the rule base of a fuzzy controller was mostly created by professional experience or trial-and-error. This was not only wasting a lot of time but also requiring redesign for different plants so that the fuzzy controller is not wide used in industry. Therefore, in the present study, an appropriate performance index was chosen first. Then a “Simplified Gradient Method” was used to decide integral correction of the active rules to get decreasing values of the performance index. The Simplified Gradient Method can properly tune the rule bases of the fuzzy controller for different control systems, and the system performances are improved effectively. At last, by computer simulation, we compared the responses of several systems controlled by PI controller along with those accompined by on-line tuning fuzzy controller. The simulation results reveal that the on-line tunung fuzzy controller can distinctly improve (decrease) both the rise time and maximum overshoot.