A new tracking technique proposed by researchers from Disney, Carnegie Mellon, and MIT could boost the number of low-tech devices with which computers interact. Using only RFID tags—no batteries or other electronics required—the team demonstrated how a computer could track the real-time location of any non-conductive object, such as a piece of wood.

RFID, which stands for Radio Frequency Identification, has long been used to track objects like library books. It's an alternative to barcodes, which require a line of sight. But RFID's latency issues and sensor limitations make the tags impractical for tracking speed and location in real time.

Until now. The researchers found a way to enable "low-level uncertainty to be handled in a high-level fashion," according to their report. That is, they created software that enables the computer to accurately estimate where the RFID tag is even when it doesn't receive a signal.

To demonstrate their findings, the team created a few sample applications. One is a controller for a Pong-like game. To keep the ball afloat, you move physical RFID-enabled wooden blocks, which correspond to the on-screen paddles.

Another is a music controller made up of individual pieces. It might not meet the needs of club DJs, but the movements of several wooden blocks can activate different music loops and control their volume. The controller has 17 tags, and produces about 490 reads per second, resulting in an approximately 28Hz per-tag update rate.

One of the biggest advantages of RFID tracking is that the tags require no batteries; they draw their power from the receivers. So solving the latency problem using probabilistic software is a big step in making RFID a viable option for connected device manufacturers.

As for why Disney is interested, the company has been experimenting with RFID in its theme parks for a little over a year. Its MagicBands are durable, waterproof plastic bracelets that replace guests' room keys, park tickets, and credit card for room charges.