Toward construction of a mobile system with long-range RFID sensors

A simple mobile system is described for humans and robots with a radio-frequency identification (RFID) tag sensor. In this paper, the system assumes to be used in a hospital to identify the location of patients and recognize their state. At first we use one positive RFID sensor. The range of this directional antenna is long (about 5 meters, 2 meters) and an RIFD antenna is set on a rotating pan-tilt platform we made, making the best use of the directional sensor. It is difficult to recognize a person with an ID tag because the microwave output from the antenna attenuates by human's moisture. However, we confirm the effectiveness of this RFID system against the people who have a tag by experiments. Experimental results show that this system is available for identifying a person. At last we were able to make the extended system, using three RFID sensors without the rotating platform