Robotics

Scientists give robots a sense of touch – by knitting them a sweater

Scientists give robots a sense of touch – by knitting them a sweater
A RobotSweater-wearing robot could immediately cease movement upon accidentally making contact with an adjacent human worker
A RobotSweater-wearing robot could immediately cease movement upon accidentally making contact with an adjacent human worker
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A diagram of the RobotSweater material
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A diagram of the RobotSweater material
A RobotSweater-wearing robot could immediately cease movement upon accidentally making contact with an adjacent human worker
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A RobotSweater-wearing robot could immediately cease movement upon accidentally making contact with an adjacent human worker

In order to keep from accidentally hurting their human coworkers, many industrial robots have sensors that detect physical contact with people or other objects. Scientists have now devised a high-tech sweater which brings this functionality to robots that don't have it already.

Known as RobotSweater, the technology is being developed by a Carnegie Mellon University team led by assistant professors James McCann and Changliu Liu. The "garment" – which is wrapped around a robotic arm or other device, and connected to a power source – is made up of three stacked layers of material.

The top and bottom layers consist of regular nylon yarn, with spaced stripes of a metallic-fiber conductive yarn running through them. Those stripes are arranged in rows on one layer and in columns on the other, so they combine to form a grid when viewed from above. Sandwiched between those two layers is an insulating layer of non-conductive mesh.

A diagram of the RobotSweater material
A diagram of the RobotSweater material

As long as no external pressure is applied to the RobotSweater, the two conductive-stripe layers are separated from one another. When pressure is applied, however, some of the stripes on those layers connect with one another through the holes in the mesh layer.

This closes a circuit, producing an electrical signal. By analyzing where that signal originated within the conductive-stripe grid, it's possible to determine where pressure is being applied on the robot's sweater-clad body.

In a real-world scenario, the robot could then react by immediately ceasing movement. The technology might also allow people to train robots to perform certain actions by touching them and physically guiding them. Additionally, the researchers are now exploring the possibility of using finger-swipe and pinch commands on the sweater, as if it were a touchscreen.

And as an added bonus, because the RobotSweater is made of soft and flexible material, it can be applied over awkwardly shaped or moving parts of robots that can't accommodate conventional rigid sensors.

There's more information in the following video.

RobotSweater : Fabric Tactile Sensor "Skin"

Source: Carnegie Mellon University

2 comments
2 comments
Bob Flint
If this is meant to be a safety thing, as the robot collides by touch, it's already too late, damage done. Not a single demo showed the arm stop or change course.
Light based lasers interrupted by other things can be typically set at a safe distance from potential motion. One reason these things are in enclosed cages, to keep dumb humans out of harms way...
Karmudjun
Fascinating Ben - nice synopsis. So designers have the potential to set "touch zones" on their objects by covering those areas with this material. If the sound wave sensors and infrared don't pick up a potential contact - this would be the final "touch a hot stove" reaction sensor. A bit much for industrial robots but when this technology gets to the point of a skin like material, I see the beginnings of real "personal" robot technology. How to create fingertip sensations in a durable skin layer - or at least rudimentary pressure monitors that don't look like a steam-punk assortment of an Edward Scissorhands. GREAT SAFETY DEVELOPMENT!