Adaptive Pid Controller Based On Gpc In The Extruder Temperature Control Applications

The temperature control systems in industry are usually nonlinear and have large time-delay. They are easily affected by unpredictable disturbances in the outside environment, which can bring overshoot and persistent oscillations. So it is not easy to achieve high precision in temperature control systems.This paper is on the base of temperature control in plastic extruder of B&R. Plastic extruder is the main producing equipment for plastic materials. As the needs of plastic products are increasing, the request of quality is higher and higher, so we must manage to prove the producing efficiency and the control precision of plastic extruder. The effects of temperature control in plastic extruder directly influence the quality of plastic products, the temperature can't be too high or too low and must be in a determinate range. Although the PIDXH controller used in temperature control by B&R at present can bring perfect performance, its parameters are turned off-line. When the working condition changes, the parameters must be readjusted, it is discommodious for producing. So we must manage to find a kind of self-turning PID controller to achieve satisfactory performances, which is suitable for temperature control and can adapt complicated working conditions. This paper applies the self-tuning GPC-based PID controller to the temperature control of plastic extruder, and a lot of theoretical research, simulations and experiments are done. The main works are as follows:(1) Studying the structure of barrel of plastic extruder and the process when plastic are extruded, Analyzing the present researching status of temperature control , and pointing out the route of solution.(2) Analyzing the principles of the fixed PID controller and many other self-tuning PID controllers, and comparing their advantages and defaults in practice.(3) Studying the GPC-based self-tuning PID controller introduced by Toru Yamamoto, using it to control the temperature systems with large time-delay, comparing it with the fixed PID controller in MATLAB and Automation Studio simulations and achieving perfect performances.(4) Doing experiments on the temperature control platform made up of PCC (Programming Computer Controller). The results of experiments show that the performance by using self-turning GPC-based PID controller to control temperature systems is satisfactory in system's stability, robustness, real-time tracing and so on.