Design Of Tobacco Humid Control System Based On Fuzzy PID

Tobacco baking is a production process that by control the temperature and humidity in tobacco humid according to certain baking technology, make tobacco heated to dehydrate, and make the tobacco happens inside a series of physiological and biochemical reactions, eventually obtaining the tobacco finished product which has a certain color, aroma, and chemicals quality. In the production of cigarette, tobacco baking is the essential material that determined the quality of cigarette.There have been being some research on the automation control of intensive tobacco humid at home and abroad, and appeared some commercial control system. But these control systems are mostly based on the traditional PID control algorithm that can hardly solve the problems of the dynamicity of the baking process and the coupling of temperature and humidity, so the control effect is not ideal; Besides the degree of automation of these systems is low and the distribution management sys is not perfect, there still need for further research and improvement.In this paper, to solve the existing problems of tobacco baking temperature and humidity control system, improvements were made on system design, control algorithm, hardware design and software design.In system design, a wireless local area network was built and introducing system integration management software into the system, realized the distribution management of multiple humid. Establishing distribution management system makes it possible to observe the working status of each tobacco humid, to record the data of the production process, and make it easy to management and analysis the whole production process scientifically. Presented and realized a new communication mode based on task list, solved the problem of the delay of operating instruction sending and improved the system's response speed In the control methods, the factors that influencing the control effect, dynamicity of the system and the coupling of temperature and humidity, were found by analyzing the system's characteristics and the production process. Fuzzy technology was introduced into the control system, combined with the PID control algorithm, established fuzzy self-adaptive PID control algorithm, improved the robustness of the system. The coupling of temperature and humidity in the system was analyzed, and this problem has been solved by introducing the decoupling link based on feed forward decoupling algorithm into system. Through the MATLAB simulation and analysis we can see that the system improved by fuzzy self-adaptive PID control algorithm and decoupling link have better control effect than the original system, and the qualified proportion and excellent proportion of tobacco have a sharp leap.On the hardware design, besides completing the basic functions such as the thermocouple temperature acquisition, heating control output, keyboard and display and so on.On the software design, planning and completed the single-chip microcomputer control software and system distributed management software, the former mainly includes temperature gathering, keyboard display, fuzzy adaptive PID control, feed forward decoupling, serial communication etc subprograms, while the later includes serial communication, data graphic display, documents management, historical data query etc multiple program modules.The production practice shows that the improved system are obviously better than the original system in the control accuracy, automation degree and integration degree, tobacco production quality and production efficiency has improved, labor intensity got lower.