Crack Monitoring System for Soft Rock Mining Conveyor Belt Using UHF RFID Sensors

In general, crack monitoring of coal mining conveyor belt is carried out by simple visual inspections that are found to be inefficient due to being quite labor-intensive and for providing inaccurate health conditions of the conveyor belt. In this article, we propose a robust and low-cost passive ultrahigh-frequency (UHF)-based radio frequency identification (RFID) crack sensing system, which allows the processing and detection of the presence of crack from the sensors' data in real time. A graphical user interface (GUI) is developed and integrated into a UHF RFID commercial reader to collect and process the received signal strength indicator (RSSI) from the sensors. A theoretical model of RSSI in the presence of a crack in the conveyor belt is introduced here. The investigation on RSSI measurement has been carried out for both scenarios when the belt is static and in motion. The moving belt RSSI measurement depicts two different cases. The first case involves the interrogation of embedded sensors by using a single reader antenna, whereas multiple antennas are used for the second case. Experimental results demonstrate that the proposed monitoring system can offer highly accurate early detection of a crack having a width of as little as 0.5 mm. Moreover, the proposed GUI can enhance the system performance in processing the sensors' data using multiple reader antennas when the belt is in high motion. The experimental results have revealed promising opportunities to adapt the proposed system in a realistic scenario for monitoring the health of soft rock conveyor belts.