The PID Flow Control System Based on PLC

According to the time-varying and nonlinear characteristics of fluid, this paper puts forward a design scheme of real-time and accurate control of the liquid flow. The control system which taking the programmable logic controller (PLC) as the platform and using the PID control algorithm is composed with the touch screen, electromagnetic flow meter, temperature sensor, electric regulating valve system and so on. And the PID algorithm based on PLC design has carried on the analysis, simulation and optimization. The results show that PID algorithm is designed using this method with a strong and more precise control of the scheme. It is not only suitable for the flow control, changes in action after the equipment is also applicable to analog volume control temperature, liquid level, velocity, height etc.