Experimental Validation of a New Measurement Metric for Radio-Frequency Identification-Based Shock-Sensor Systems

This paper presents a radio-frequency identification (RFID)-based shock-sensor system. The impedance characteristics of tilt/vibration sensors incorporated in the RFID tag change when the electrodes and the internal conducting bolls inside the tilt/vibration sensors change between the short-circuit and open-circuit states. Thus, the antenna input impedance characteristics are also changed. Software was developed for the proposed system to measure the read-interval times between consecutive reads by the RFID reader, and to visualize the measurement metric in graphs. The validity of the proposed shock-sensor system was demonstrated experimentally using a cart and an obstacle placed on the floor. The shocks caused by the front and rear tires of the cart crossing the obstacle were clearly observed, confirming the validity of the proposed measurement metric.