Intelligent fuzzy immune PID controller design for multivariable process control system

Based on biological immune principle and fuzzy theory, this paper presents an intelligent fuzzy immune PID control scheme to solve the control difficulties of industry process with multi-variables. The least square algorithm was used for offline optimization to form immune feedback control system. The application on cement rotary kiln control was discussed in detail as an example. The rotary kiln calcination is the most important part of cement production including complicated physical and chemical reaction processes with large inertia, pure hysteresis, nonlinearity and strong coupling characteristics and multivariables. The main control system structure includes three control loops as the pressure control loop, the burning zone control loop and the back-end of kiln temperature control loop. The simulation results of typical step responses of three control variables using the presented control scheme show the effectiveness of the control scheme with better response time and tracking performance compared to traditional PID control.