The Research Of Coal Level Detection System Based On Laser Imaging And Image Processing Technology

In the production process of coal enterprise, there are any number of coal bunkers at the top and bottom of a shaft in order to alleviating the pressure of transportation system and convenient for work organization, coal bunkers undertake the task to store and transport raw coal of each coal mine, the normal and safe operation of coal bunkers especially for underground bunkers directly affects the production of raw coal, so it's necessary to arrange coal production and transportation rationally according to the change of coal level to realize safety in production.This paper detailedly introduced a solution of coal level detection system which is a distance measuring system both uses controllable energy and uses image based on laser active imaging and image processing technology, used range-gated laser imaging system to obtain the object image and acquired the coal level message through image processing system and the recognition algorithm. The principle of the range gated laser (RGL) imaging and the component of the RGL imaging system were illustrated in detail. The key techniques of the RGL imaging system were analyzed. The trigger signal generating circuit for the RGL imaging system was designed according to the actual requirements. On the basis of the multichannel delay pulse generator based on the complex programmable logic device (CPLD) and programmable delay line, the synchronization control circuit for the RGL imaging system was designed, and its feasibility was verified through experiment; The image processing used FPGA as the central processor, It was composed of real time image conversion module, asynchronous FIFO module, gray image acquisition module, I~2C configuration module, image frame storing control module, image preprocessing module, coal level information recognition module ,communication module and FPGA configuration circuit. Coal level image sequence from the RGL imaging system was converted into digital image which format was needed by the real time image conversion module, the FPGA image preprocessing module accomplished operations of noise removing and image binary and so on. The gray image data after preprocessing was sent to coal level information recognition module and coal level information was extracted according to the coal level detection algorithm.The system used the synchronization control circuit based on CPLD and programmable delay line to make experiment with SNV-842W/X Laser-ICCD system, and realized the gating function. The design of CPLD and FPGA was developed under the platform of QuartusII and was implemented in hardware and reached the anticipated effect. The coal level detection system of this paper is especially suitable for underground coal bunkers, the synchronization control circuit has extensity and parameter adjustment is very convenient, it can detect multiple coal bunkers at the same time; The image processing system can also be used in the circumstance that needs the image to be processed, and the real time image data from the preprocessing module can be change into preprocessing real time image by the video codec chip, which is sent to the video monitoring system to realize real-time monitoring of coal bunkers.