Reserch On Integrated Intelligent Control System Of Continuous-flow Grain Driers

Food security has always been a major issue of people’s livelihood. It is the foundation of national security strategy, and it is a prerequisite for ensuring economic development and social stability. Grain drying automation is very important to reduce the loss of postpartum grain and ensure food security.Continuous-flow grain driers are widely used in the United States, Brazil,Argentina and other major grain producing countries for their advantages of large output, high automation, low energy consumption,etc. In our country, they also play a more and more significant role. According to the characteristics of continuous-flow grain driers, the author designed and studied a high-performance, integrated,intelligent grain drying control system taking STM32 as the MCU and touch screen as the control platform. This system can monitor the temperature and moisture of grain as well as the temperature of hot air and outlet grain in real time, and it is added with automatic grain inputting and discharging functions as well as multi-parameter warning function. So it is easy for people to control the running of this system intuitively and effectively. The thesis includes the following main contents:(1) This thesis introduces the the development situation of grain driers at home and abroad, and puts forward the significance of this research as well as the content of this research based on the existing problems in the control system of grain driers.(2) This thesis makes the system requirement analysis by researching the working principles and components of continuous-flow grain driers, and designs the main structure of the integrated intelligent control system of continuous-flow grain driers according to the functions and features of STM32 microprocessor, TFT-LCD, touchscreen and other integrated chips. It also plans the hardware and software of the system.(3) Hardware design of the system: choosing the microprocessor; integrating the minimum system circuit of STM32, external memory circuit, data acquisition circuit as well as data displaying and controlling circuit; designing the hardware of the integrated intelligent control system; analyzing the components and working principles of each circuit; finishing making the PCB which is the core of the system.(4) Software design of the system: introducing the software briefly; modularizing the software according to hardware; dividing the overall function incrementally and determining three modules including data acquisition, data displaying and system controlling. For each module, there are different drivers in it. This part also introduces the basic method of developing human-computer interface with u C/GUI library and the application of task creation, task scheduling, task synchronization mechanism of real-time operating system, etc.The debugging results of this system show that the integrated intelligent control system can satisfy the control requirements of continuous-flow grain driers, achieving the expected goals basically. Finally, this thesis concludes some problems occurred in the processing of system research and development, and prospects the development direction of the integrated intelligent control system of continuous-flow grain driers.