Controller Design for Constant Water Pressure

Water supply is very important in chemical works, but it is difficult to maintain proper pressure for reason of non-linear and large time-delay of water supply system. A hybrid controller combined Fuzzy-PID and Smith predictive model is proposed after careful analysis, the controller can compensate large delay time and change the big delay time into small one, can adjust PID parameters online by Fuzzy logic. simulation indicates that its tracking precision and converging speed are high, ability of fitting model mismatch is strong, practical results demonstrate that it works better than segment PID, Variation of water pressure is limited into a range of±400Pa.