By Jason Maderer
Today’s robots usually see the world with cameras and lasers, which can miss objects hidden in clutter. Mobile robots could be more useful in homes if they could locate people, places, and objects.
A complementary way robots can sense what is around them is through the use of small ultra-high frequency radio-frequency identification (RFID) tags. Inexpensive self-adhesive tags can be attached to objects, allowing an RFID-equipped robot to search a room for a tag’s signal, even when the object is hidden. Once the tag is detected, the robot knows the object it’s trying to find isn’t far away.
“But RFID doesn’t tell the robot where it is,” said Charlie Kemp, an associate professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. “To actually find the object and get close to it, the robot has to be more clever.”
That’s why Kemp, former Georgia Tech student Travis Deyle, and University of Washington Professor Matthew Reynolds developed a new search algorithm that improves a robot’s ability to find and navigate to tagged objects. The team implemented the system on a PR2 robot, allowing it to travel through a home and locate tagged objects, including a medication bottle, TV remote, phone, and hairbrush.
The researchers equipped the robot with articulated, directionally sensitive antennas and a new algorithm that allows the robot to find and navigate to the desired object. By moving the antennas on its shoulders and driving around the room, the PR2 can figure out the direction it should move to get a stronger signal from a tag and get closer to a tagged object. In essence, the robot plays the classic childhood game of Hotter-Colder, with the tag telling the PR2 when it’s getting closer to the object.
Related video: Finding and navigating to household objects with UHF RFID tags by optimizing RF signal strength
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