The Kitchen Tongs That Teach Robots
Imagine trying to teach a giant mechanical arm how to pick up a Lego brick. Usually, it’s a total nightmare.
You either have to grab the heavy robot arm and drag it around—which is like kinesthetic guidance, or trying to dance while wearing a suit made of lead—or you use a remote control that feels like playing a video game with your toes.
Scientists just found a better way: a pair of fancy, high-tech kitchen tongs.
The Unexpected Winner
In a new study, 24 people were asked to stack blocks using different tools to teach a robot. The "clumsy" tongs actually beat out the fancy remote controls in almost every way.
Pragathi
Praveena
No existing method provides the combination of good demonstration quality, good demonstrator experience, good correspondence with the robot, and good instrumentability, as provided by tongs.
The Power of a Metaphor
The Core Idea
The secret is what scientists call a "metaphor." Because a robot gripper only has two "fingers," it can't move like a human hand. When we use our bare hands to show a robot what to do, we move too fast and do things a robot can't copy.
The tongs act like a mechanical constraint, which is like putting training wheels on a bike so you don't accidentally try to do a backflip the bike can't handle. It forces the human to move just like the robot.
The Mind-Blowing Results
Time
When using the tongs, it took people only 73.2s to finish the task. When they used a remote control, it took a whopping 715s.
Smoothness
The "jerk"—which is like the shaky vibration of a car driving over a bumpy dirt road—was only 0.04 with the tongs, compared to 0.25 when people had to drag the robot arm by hand.
Mental Load
On a "brain power" test called the NASA-TLX, the tongs scored a low 24.0, while the remote control scored a stressful 64.2.
Accuracy
The "path length"—the total distance your hand travels from start to finish—was only 247cm with the tongs, while bare hands wandered for 284cm.
The Unsolved Puzzles
Current Limitations
There are still some puzzles to solve. The current tongs are connected to expensive, heavy cables, and they wouldn't work for robots that have five fingers like a human.
Key Takeaway: Even though the tongs were slightly slower than using bare hands, they were more accurate. For now, the humblest tool in your kitchen might be the key to teaching the robots of the future.
Reference: "Characterizing Input Methods for Human-to-robot Demonstrations," Pragathi Praveena, Guru Subramani, Bilge Mutlu, and Michael Gleicher. Proceedings of the 2019 ACM/IEEE International Conference on Human-Robot Interaction (HRI).