Disney Conducts Interaction Research With UHF RFID Tags
Disney has been using RFID tags that are battery free in order to conduct research about how people interact with everyday objects, providing the possibility for new kinds of interactive play and developments in work and home environments, as well as providing insight into consumer behavior.
RFID tags are intended to give an identification report when scanned by a reader, but the team at Disney Research has demonstrated that the radio frequencies the tags emit can be used to find out if an item has been moved or touched, by analyzing it’s unique Radio Frequency (RF) signature.
They have pioneered a system they call “IDSense,” which can track 20 items in the same room, and break down their movements into four categories. Their findings will be presented at CHI 2015, which takes place from the 18th to the 23rd of April in Seoul, the capital city of South Korea.
This type of research has been conducted preciously using wireless sensors, but their size and the higher costs of replacing their batteries mean that they have not been as effective as some had hoped. RFID tags are a great solution because they are cheap and easily applicable to a variety of everyday objects.
The UHF RFID tags emit signals that can be read from up to 10 meters, and researchers found that in observing variations in the signals, including the Doppler shift, received signal strength indicator (RSSI) and RF phase, they gained insight into the movements of the object which had a specific tag attached.
RSSI is used to measure the power of a signal at the receiver, and usually demonstrates how far the reader is from the tag. RF phase is a measure of the angle of a signal between the tag and reader, and will show up minute changes in distance. The Doppler shift is a variation in radio frequency that is caused by the velocity of the object as it moves.
The researchers then employ algorithms to enable machine learning of data patterns, and were thus able to make sense of the variety of readings in relation to changes in the state of the object, including whether it had been moved, or if it was being held.
The team demonstrated that the technology could be used in stuffed toys, as part of interactive storytelling that depended upon the actions of the user.