Coal and rock interface identification based on active infrared excitation

Aiming at the problem of low identification accuracy of coal and rock in the intelligent cutting of shearer in a fully mechanized mining face,this paper adopts an infrared thermal imaging technology to establish an experimental platform for active excitation coal rock interface. Three kinds of test pieces of whole coal,whole rock and coal rock were respectively made by using pulverized coal,cement,sand and binder. The coal rock interface identification experi- ment was carried out under the excitation intensity of single light source 9 kLux. During the experiment,the IRBIS3 in- frared analysis software was used to extract and analyze the temperature field information at the different time points of the three test pieces,and the temperature field gradient model was established for the experiment. The results show that the temperature field characteristics of coal and rock under the same excitation are obviously different. When there is coal and rock mixing,the temperature difference range and standard deviation in the detection area will increase signif- icantly,which can be used as a prediction and identification basis for coal rock mixing. When the coal rock specimen is actively excited,the temperature rise in the first 10 minutes at the detection area is most obvious,the temperature difference range and the standard deviation increase rapidly,and the temperature rises slowly within 10-30 minutes, the temperature difference range and the standard deviation are slowly increased. After 30 minutes,the temperature is relatively stable,and the temperature difference range and standard deviation have no significant change. Although the longer the incentive time,the greater the difference in temperature field information between coal and rock,which is more conducive to improving the accuracy of coal rock identification. However,after comprehensively considering the temperature difference of the temperature field information and the active excitation energy consumption,it is reasona- ble to select the infrared image when the active excitation is 30 minutes. By extracting the temperature field information in the detection area,the temperature field gradient model can be compared. The distribution position and distribution trend of coal and rock can be visually observed. By dividing the temperature gradient model into the temperature line, dividing the coal and rock distribution,and establishing the simulated reduction image of coal and rock distribution,the transition area of coal and rock distribution can be accurately determined,and the coal can be upgraded. The accuracy of rock identification reduces the degree of shearer’s pick wear during the cutting process and effectively extends the pick service life.