WiSee You! WiFi Gizmo Detects Your Movements Even Through Walls
If you thought the Clapper was cool (and let’s be honest, who didn’t?), get a load of the WiSee, a wireless recognition system that does a lot more than turn the lights on and off. The system recognizes an individual’s specific gestures to perform a host of tasks, including turning up the temperature while lounging in bed or changing the song if someone else in the house has terrible taste in music. With this system, it doesn’t matter where in the house the user is — one could be cooking, showering, or vacuuming the stairs.
Unlike its predecessors, such as the Xbox Kinect, WiSee doesn’t rely on cameras or gadgets, thus solving the problem of inadvertently moving out of the motion-sensing zone. Instead, the WiSee uses WiFi. Brilliant deduction, Watson! And because WiFi isn’t limited to line of sight or to one particular room, the WiSee will work throughout the whole house — even through walls!
By recognizing the frequency change of a wave caused by movement, otherwise known as a Doppler shift, the WiSee can recognize nine gestures, including kicking, punching, and waving (I don’t know about you, but I definitely like to kick things when I don’t like the music). This is particularly impressive given that a human hand performing one of these gestures creates only a minute Doppler shift.
In tests performed by the developers at the University of Washington, the WiSee correctly classified these gestures 94% of the time using a four-antenna receiver and two single-antenna receivers (fewer receivers reduces the accuracy). The tests also measured false triggers, which happen fairly rarely because of a start-up sequence users are required to perform. The start-up sequence reduces the number of false positives, as it identifies users’ specific gestures. Thus, if one exaggerates the gestures in the start-up sequence, false triggers are less likely to occur (and the user gets to execute manic waves and wild punches in the air to control the system).
The tricky part is when you have different people in the house who use the WiSee (and who don’t appreciate the same music). It would seem difficult for the system not to get confused by multiple users. Here’s where the ubiquity of MIMOs (multiple-input and multiple-output) technology comes in handy. To improve performance, wireless devices use multiple antennas. The WiSee or a Wisee-enabled receiver could use these antennas to focus on one specific user.
The future of the WiSee includes adding up to 50 recognizable gestures, as well as password protection, which is likely to also be gesture-based. I also hope that the future of WiSee includes some entirely gesture-based fights over control of the house.