End Users — continued from Page 43
The BrainPort sensor that IHMC is using to reroute sight to the tongue for the blind. AUVSI photo.
Filling in the periphery Focusing in on a person’s central vision doesn’t cover the entire picture though. Raj’s work incorporates peripheral vision with what the tongue display’s camera sees to give a person a wider field of view. “If we’re reading the menu at the restaurant, we can notice when a waiter approaches us,” explains Raj. “We’re not startled when they come up, whereas with something like the BrainPort for a blind person, they would have to be zoomed in tightly enough on the menu to be able to read the text, and with that setting they wouldn’t necessarily be able to perceive that someone walked up.” To accomplish this, Raj is using a series of infrared emitters that use a frequency-modulated beam to detect a person’s surroundings, like doors and hallways. The sensors work the same way as a television remote does, only accepting a mod-
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ulated signal that doesn’t consider other light sources. Raj uses 24 pairs of these sensors in an array around the head, which through an algorithm the institute created can tell how far away objects are by measuring the echoes of infrared beams. “But our real interesting part is our software algorithm that more or less creates this streaming map of the environment via multiple sources and sensors.” The software filters out errors, like strange reflections, so it can work in nearly any environment. The algorithm also has another task because of the infrared array’s location — canceling out any head unintentional head motion. “So if you’re walking, your head is bobbing around a little bit, or if you just turn your neck around, it doesn’t really change how things are relative
to your body in the world around you. So we don’t necessarily want to reflect every single one of those changes.” To do this, Raj takes other measurements from accelerometers and gyroscopes and cancels out updates that are strictly related to head movements. “The focus is to improve the sensory interactions between robotic systems, for example, and the humans that are interacting with those systems.” This kind of focus is the essence of Raj’s work at IHMC, he says. “Robots don’t go off and do things by themselves,” he says. ” … They do what we ask them to do or what we command them to do, and what we’re working on is when we can make that level of interaction more interactive and more functional with less cognitive effort. And that goes both ways.”