The Design Of Electronic Belt Weighing Instrument In Coal Mine Based On STM32

At present, with enhance of government management in coal production and safety, electronic belt weighing in coal mine has become an indispensable component in production monitoring system. Electronic belt weighting control instrument existing is generally placed in the control room and measurement unit is placed in mine roadway. It increases workload because they have to contact with staff in the roadway while zeroing or calibration to the instrument.According to existing problems, a belt weighting instrument of intrinsic safety is designed in the paper. The explosion-proof technology of intrinsic safety applied in the control instrument make the instrument safety in mine roadway since circuit energy is limited. It also set up expected technical indicators in performance according to the needs for production safety in coal mine. The hardware platform based on STM32 with Cortex-M3 core was designed in the paper for data acquisition and processing, liquid crystal display, infrared remote control, RS485 remote transmission. The function of instrument designed also includes zeroing, calibration, anti-misuse, remote transmission, communication view and parameter modifying.The overall design mainly includes three parts:In the first part structure, principle, composition and classification of the coal mine electronic belt weighting system are described. It focused on the application of intrinsic safety explosion-proof technology for electronic belt weighting in coal mine. We introduce the basic theory of industrial explosion-proof and the basic principles of intrinsic safety based on safety requirements of explosion-proof products. To intrinsic safety technology, it discusses the features comprehensive and some key problems about design of intrinsic safety circuit. What's more, classification of intrinsic safety instrument, explosion-proof signs and safety parameters are illustrated.The hardware circuit of intrinsic safety instrument is designed in the paper to meet the need of measurement for materials production in coal mines, verification easily and Preventing Improper. The hardware modules are designed, including MCU peripheral circuits, data acquisition circuit, infrared remote control circuit, LCD display circuit and remote communication circuit. The system software code are designed and compiled according to the functional requirements of instrument and hardware design. Not design methods and processes of subroutine are described but also program flow and source code are listed.The third part mainly introduces methods of testing performance of the instrument. The test result is concluded and analyzed according to relevant requirements in GB/T7724《Weighing Display Controller》and MT209-90《Mine communications, monitoring, controlling electrical and electronic General requirements for products》. Meanwhile we analyses the deficiency and error about system and propose some solutions.