Experimental study on coal rock recognition based on infrared thermal imaging and vibration signals

In response to the difficulties in practical application, susceptibility to signal interference, high cost, and complex implementation of existing coal rock recognition technologies, this paper theoretically analyzes the relationship between coal rock cutting heat production and coal rock hardness. The paper proves the rationality of using infrared thermal imaging to obtain cutting temperature changes for coal rock recognition. A coal rock cutting test bench is built for roadheader. Long-term cutting tests are conducted on ordinary coal seams, coal rock interfaces, and sandstone layers with different hardness. The cutting temperature and vibration signals of the cutting head are obtained through infrared thermal imaging and vibration sensors, and their change patterns are analyzed. The research results indicate the following points. ① As the cutting time increases, the cutting temperature gradually increases. The higher the hardness of coal rock, the higher the cutting temperature, and the faster the rate of increase in cutting temperature. At the initial stage of cutting, coal and rock cannot be recognized by cutting temperature, but during stable cutting, coal and rock can be recognized based on cutting temperature features. ② The vibration intensity of the cutting head increases with the increase of coal rock hardness, but does not show a significant change with the increase of cutting time. Therefore, it can compensate for the lack of recognition of coal rock through cutting temperature at the beginning stage of cutting.③ Accurate recognition of coal and rock cannot be achieved through a single cutting temperature or vibration intensity. Therefore, coal and rock can be recognized through vibration intensity during the initial cutting stage and frequent flash temperatures. In the stable cutting stage, coal and rock can be recognized through temperature obtained from infrared thermal imaging.