Intelligent Water System Based On A Fuzzy Adaptive PID Controller

When water pumps work at high-speed over a long time, it can’t keep the water pressure stable. Thus, it is easy to cause the water hammer effect, so the water system should operate in a constant pressure. Therefore, the frequency conversion technology is often used in the water system. Not only does it have reduced the resistance of pipelines, but also it has saved electricity. The reason is what output power change with frequency when the water pressure is constant. The water pressure deviation and the bad anti-interference ability often exist in the traditional constant pressure water system. There are many disadvantages, such as long regulating-time, the increase in the supply line loss and the chance of tube blasting. So it is bad for reducing fuel to energy conservation.According to this, a new kind of variable frequency constant pressure water system bas-ed on intelligent control strategy is developed in this paper. The intelligent control of the fuz-zy adaptive PID control algorithm has the adaptive changing working ability. What’s more, it has strong robustness and the ability to handle the highly complexity and uncertainty system, the expert system is designed based on the fuzzy adaptive PID control theory. The basic char-acteristics of water system and the design goal of thesis is presented in the beginning of this paper. The theory analysis, the simulation model and the experimental verification are used to describe the design process of the system in the main body of this paper.The PLC (Programmable Logic Controller) experimental platform, frequency converter, motor, computer, FPGA development board and other various devices are used to build the hardware platform. This project successfully designs a new intelligent water system. LabVI-EW software is used as PC to provide friendly man-machine interface for the water system. The experiment sets0.3MPa constant water pressure as the goal. The results have proven that this system can achieve accuracy of0.1percent, which are in agreement with the Matlab soft-ware simulation results. As the contrast experiments show, the system control hydraulic don’t have overshoot. The time of adjusting and responding is very short. The water pressure chan-ges within0.1%. The anti-jamming force is strong. The system dynamic performance, stable operation has been greatly enhanced. Above all, the validity and reliability of this system has been proved.