RFID (radio frequency identification) technology is both controversial and amazing in its possibilities. In the field of sports, researchers are extending the precision of RFID to allow for accurate monitoring of performance. A new system attached to skis can provide feedback to a coach that is much more nuanced than an old fashioned video. The system has also the potential to improve safety for those who risk their lives on the giant slopes.
In the future, transponders – radio transmitters and receivers – will support coaches in their work. They can be attached to an athlete’s skis and transmit radio waves in every direction through small antennas one thousand times per second. The antennas are located to the front and the back of the skis. Receiving stations placed alongside a slope in regular intervals pick up the signals and analyze the time a signal needs to travel from the antenna to a station, thus accurately determining an antenna’s position within three centimeters. The underlying technology is radio frequency identification or RFID. A computer calculates the position of the skis every millisecond and displays their exact path on a monitor. “A coach recognizes whether both skis were parallel,” explains Richter, “whether the skier has drifted from her path in a curve and whether she is able to carve properly.” Carving involves taking the turns entirely on the edge of one’s skis.
The Austrian firm Abatec developed the system. Together with colleagues from the university in Magdeburg, the researchers at the Fraunhofer IFF are testing its systematic implementation in sports: What adhesive bonds the antennas to the skis so they do not loosen during a downhill run but can be detached when no longer needed? How can the radio signals be evaluated so a coach is able to draw conclusions about technique? Another challenge: Many skis contain metal layers of varying thicknesses, which shift a transmitter’s frequency. Depending on the skis’ design, the antennas transmit on another frequency and the base station no longer detects the signal. The solution: An additional metal plate under the antennas alters the signal so intensely and predictably that the slight differences between different skis are of no consequence: The antennas always transmit with the same controlled frequency. The technology performed well in initial tests in Bottrop ski hall and the system is now ready for use.
Press release: Signal opportunities on the slopes – with RFID