Patent attributes
A method for confirming entry and/or exit state of a mobile object relative to all entrance of an underground passageway by utilizing Radio Frequency Identification (RFID) technology. At least one RFID tag is physically attached to the mobile object. At least a first RFID reader and a second RFID reader, each having a monitoring range and being in communication with the RFID tag, are disposed at the entrance and a relatively inner position of the passageway respectively. The method comprises generating a first entering-state data if the RFID tag enters the monitoring range of the first RFID reader and a first exiting-state data if the RFID tag exits the monitoring range of the first RFID reader, generating a second entering-state data if the RFID tag enters the monitoring range of the second RFID reader and a second exiting-state data if the RFID tag exits the monitoring range of the second RFID reader, and processing the first entering-state and exiting-state data and the second entering-state and exiting-state data to generate an output data indicating the entry and/or exit state of the mobile object relative to the entrance of the passageway.
