Two Dimensional Positions Control of the Pneumatic Cylinder Using Fuzzy PWM Control Law.

• Main Authors: Chuen-Guey Hwang, 黃春貴
• Other Authors: Ming-Chang Shih
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/24829831996655400299

碩士 === 國立成功大學 === 機械工程研究所 === 83 === Because of the high compressibility of air and time-varying parameters, it is very difficult to get a precise mathematical model of pneumatic control system. The nonlinearities also lead to the traditional controllers, such as PID and states feedback controllers, attaining considerpurpose of this paper is to design the "fuzzy PWM control law," which combined fuzzy logic control and pulse width modulation (PWM) method. Instead of using servo valves, the fuzzy PWM controller drives high speed ON/OFF solenoid valves directly. The most advantages of this method are easy designed, good accuracy, and economic for industrial applications. In this study, the modified differential PWM method was proposed to eliminate the dead zone and improving the nonlinearity near by the high differential duty ratio, which due to the ON/OFF mechanical delay and the spool half-opening. The fuzzy PWM controller is applied on a robot cylinder to confirm the availability of this method. The experimental results appear the performance of ON/OFF valves is as good as servo valves. The proposed strategy provides a good accuracy and low cost method without using servo valves.