Ever since Roomba robot vacuums starting sucking up dust bunnies in 2002, engineers at iRobot have been fielding the question, “So, when are you going to mow my lawn?” Turns out, teaching a machine to navigate a yard is harder than it seems.
“Honestly, this robot drove me insane,” says iRobot CEO Colin Angle after announcing Terra, the company’s long-awaited yard device. “It has been an obsession.”
For more than a decade, iRobot has been struggling with robotic lawnmowers. The first problem was helping the robot identify its location so it wouldn’t get lost and miss spots—or destroy flowerbeds. Satellite-based GPS technology was too “finicky” because trees and houses interfere with the signal.
The cutting-edge computer vision—the kind on the latest Roombas—was useless too. The technology didn’t work well outside. That’s because camera lenses get blocked by leaves and dirt. Not only that, all that bumping up and down over hill and dale confuses the mower.
“We had given up,” Angle said of the lawn-bot project. “We probably gave up twice.”
Finally, though, financial pressure and a little healthy competition from overseas pushed the iRobot engineers toward success.
Robotic lawnmowers started booming in Europe. But it’s not a seamless effort. Homeowners there must set up boundary wires to confine the robo-mowers to a specific area.
That works in Germany, where backyards are usually small, flat, and rectangular. But it doesn’t work so well in the sprawling, meandering lawns of the United States. American lawn culture also sets a higher bar for how a good cut should look. (Straight, back-and-forth lines only, please!)
Finally, iRobot found an answer. The company combined radio technology using beacons placed around the lawn with the map-making memory already in its Roomba vacuums.
The quiet, electric Terra mower sports twin mulching blades. Terra maneuvers slowly around a lawn daily or a few times a week. It returns to its station when the job is complete—or when it’s low on battery.
There was just one more setback: The radio frequency idea annoyed astronomers. They claimed Terra’s radio signals could interfere with their studies of interstellar chemistry.
Huh? Over the objections of the stargazers, iRobot won permission from the Federal Communication Commission. It was allowed to use a certain kind of bandwidth (frequency for transmitting a signal) for the wireless lawnbots.
But don’t throw out your lawnmower and weed wacker yet. These much-anticipated robo-mowers won’t be sold in the United States until at least 2020.
