The Research Of Coal Hopper Material Level Measurement And Control System Based On Strain Detection Technology

Harbor dumping system as an important material transshipment equipment, is commonly used for transferring the bulk material from rail transport to sea transport. Accurately obtaining the situation of real-time material level in the hopper of the dumping production line, plays a vital role for the whole production process and the dumping efficiency. This paper is set in the coal hopper material level measurement and control project of Qinhuangdao harbor dumping system, aims at the shortcomings of nuclear radiation formula and radar level indicator, proposes a material level measurement and control scheme which is based on the strain detection technology.The paper realizes the use of the STM32 microcontroller as the main chip in hardware design, modulates the weak strain signal to AC signal, and by amplifying, filtering processing, the AC signal enters phase-sensitive detection circuit with the reference signal which has the same frequency and phase with the AC signal, and executes correlation detection by the lock-in amplifier principle. Finally, the demodulated analog signal is digitized by the A/D converting circuit, the data is disposed and analysed under the optimization of locally weighted regression scatterplot smoothing algorithm, and encapsulated into Modbus protocol packet format. The system completes data conversion from Modbus protocol to Ethernet/IP network protocol by a network communication module, and achieves the communication between the field data collection device and PLC device of the dumping control system. In order to achieve the uninterrupted monitoring functions of the coal hopper material level, the paper extends the material level monitoring interface on the basis of the original Intouch PC interface, achieves the functions such as material level display, feed control, data logging, and so on. It raises the automation control extent of the dumping system.In the end, the paper completes the system experimental debugging and data analysis on the basis of realizing the hardware platform of material level measurement and control system, and confirms the accuracy of the coal hopper material level measurement and control system based on the strain detection technology. The system provides a strong guarantee for the efficient operation of harbor dumping systems, and achieves the expected design goals, has widespread use and popularization value in related fields.