System and method for positioning active rfid tag

A method adapted to use a plurality of RFID (Radio Frequency Identification) readers to position a target object with an active RFID tag equipped thereon, the method comprising the steps of:

• defining a geometric center of the locations of the RFID readers as a first coordinate for a positioned location of the object;
• repeating the following steps when the RFID readers continuously receive RF (Radio Frequency) signals of the active RFID tag:
• receiving the RF signals of the active RFID tag through the RFID readers to calculate a corresponding signal intensity of each of the RF signals;
• comparing corresponding signal intensity of each of the RF signals;
• calculating an approaching vector corresponding to the location of the RFID reader with the greatest signal intensity of the RF signal;
• approaching the positioned location of the target object from the first coordinate to a second coordinate according to the approaching vector;
• resetting the first coordinate as the location of the second coordinate;
• and
• outputting the reset first coordinate as the latest positioned location of the target object.

A system to use a plurality of RFID (Radio Frequency Identification) readers to position a target object with an active RFID tag equipped thereon, the positioning system comprising:

• a receiving module receiving a RF (Radio Frequency) signal of the active RFID tag received from each of the RFID readers respectively;
• a selection module randomly selecting two-by-two of the RFID readers to match a plurality of comparison pairs;
• a comparison module comparing the RF signals of the RFID readers within the comparison pairs, and determining the RFID reader with the greater signal intensity within each of the comparison pairs;
• a positioning module positioning an effective range of each of the RFID reader with the greater signal intensity within each of the comparison pairs to calculate an overlapped range of the effective ranges;
• and
• an output module outputting the overlapped range as a positioned location of the target object.