Design and implementation of a constant selling oil automatic system based on fuzzy PID algorithm

In this paper, we propose a novel strategy to design a reliable and practical constant selling oil automatic system,through the use of S7-226PLC, flow meter, inverter and other hardware devices. A kind of fuzzy PID control algorithm was researched to guarantee the system accuracy. The fuzzy PID controller can control the inverter output frequency by changing the voltage of the inverter and self-tuning PID parameters (Kp, Ki, Kd), and thus it controls the pump speed to achieve the demanded accuracy of the constant selling oil. Finally, the paper adopted C#.NET technology to design the management software. The software can accomplish system functions such as communication with PLC, realization remote control, data management and others. Experimental results and field running shows that the system achieves the accuracy,security and energy saving demands of the constant selling oil automatic system, also obtains a satisfactory control effect.