Research And Application On Intelligent Temperature Control System Of Furnace Based On EPLC

The research on the furnace temperature control system in China started relatively late,the majority of the furnace temperature control systems mainly used the temperaturecontroller device, a small part used PLC(Programming Logic Controller),both exist poorsystem scalability, low ratio of defects. In2011, Zhejiang Province Key Laboratory ofEmbedded System of Hangzhou Dianzi University proposed ePLC concept based CASSplatform.The biggest feature ePLC is to use PLC development method on all kinds of specialcontrollers, ePLC has the characteristics of hardware and software easy expansion, highdevelopment efficiency, high reliability, etc. Therefore, research on key technology of furnacetemperature control based on ePLC, design of the furnace temperature control system basedon ePLC, to improve the performance of the control system of furnaces and the technical level,has important practical significance.According to the characteristics of the furnaces firing technology, this paper puts forwardthe incremental PID control algorithm with dead zone to control the gas pressure. The controlalgorithm has the characteristics of small misoperation, small impact when handing switch,not easy to overflow, and no shock caused by frequent operation, it can effectively control thegas pressure, so as to realize the effect of furnace temperature control. In order to achieve theoptimal control effect, the proportional valve is optimized by genetic algorithm was proposedfor the smallest opening. Through real-time acquisition gas pressure data and build samples,optimized the minimum opening. This paper also study the multi-threads ePLC control system,for collecting data effectively via the data acquisition thread embedding in ePLC controlsystem without bringing effect to the original features of intelligent control. By studying thepreemptive priority scheduling algorithm, scanning cycle control thread and free to performdata acquisition thread mutual coordination, and studying the system’s thread synchronizationand external communication strategy, it will implement the control system of multi-threadedscheduling, eventually making data acquisition thread collect data in CPU idle time, andsending to the upper machine for celadon fire master summary analysis, in order to achievethe goal of optimization curve.The furnace temperature control system adopts hardware and software collaborativedesign scheme for layered software design and modular hardware design, it is convenient forsystem development and design of the hardware and software design. The system is realizedby using CASS platform, it provides a exploration and attempt for the application of intelligent control of ePLC. The system has been used in the practical application of a celadonfurnaces. By analyzing the experimental data, the intelligent control system is fullydemonstrated the feasibility and practicability.