Application Research Of PSO And BP-PID Algorithm In Double-tank Liquid Level System

With the development of industrial processes, the accurate control of liquid level has been the important aspects in order to ensure the quality of products. For example,in chemical production, liquid filtration, beverage and cosmetic industries, the precise control strategies for liquid level is necessary. At the industrial site, for a complex level system, conventional PID control method control is ineffective so that the quality of products is substandard, which seriously affects the economic efficiency of enterprises. Double tank system can simulate liquid level control object for complex industrial system well and has the certain characteristics of nonlinear, time-varying and big lag. So this topic use the current resources,namely EFAT/P- Ⅱ B process control system, to study the accurate liquid level control of double-tank.Generally, the EFAT/P-ⅡB process control experimental device is introduced simply and the hardware components of the double tank liquid level control system are described. Then the configuration software MCGS is used to configure the system and the mathematical model of double-tank is obtained by the liquid level test properties. The principles of digital PID algorithms and commonly used parameters tuning method of PID controller is illustrated. Then a model is built in Simulink to get the simulation curve of the conventional PID algorithm. The PID algorithm designing process using BP neural network is described. network initial weights to determine the flaws, advances the theory of it optimization using PSO algorithm. In order to make the flaw of hard to determine the network initial weights, the optimization using PSO algorithm is proposed. Then the PSO-BP-PID controller designing process is described in detail and the PSO-BP-PID is used in double-tank liquid level control systems by the m-file programming. So the simulation curve is obtained. At last, the double capacity level constant value control experiment with the algorithm of PID and PSO-BP-PID and observed the results. The experimentalresults show that the PSO-BP-PID algorithm are superior to conventional PID control algorithm, PSO-BP-PID is more suitable for precise liquid level control of complex system.