Next-Generation Robots Will Lend Astronauts a Hand

The scientists behind NASA’s newest robot have outfitted their creation with an ancient tool that’s still a giant leap forward: hands.

And who can blame them? Look what hands did for human evolution.

Robonaut, the space agency’s latest-generation robot, has a hand that no other machine of its kind has ever had. Where other robots could simply pick up objects with grippers, Robonaut has four fingers, a thumb and a handshake to make a politician envious.

Robonaut’s hands are nimble enough to pick up a small metal washer with tweezers or squeeze the trigger on a variable-speed drill. One noted roboticist calls Robonaut’s hand “a masterwork development.”

“It is a big leap for robotkind,” said Red Whittaker, the founder of the Field Robotics Center at Carnegie Mellon University’s Robotics Institute. Designed as a remote-controlled space helper, Robonaut was built to work with the same tools a spacewalking astronaut would use.

“The idea was essentially to create a surrogate for the astronaut,” said NASA engineer Chris Lovchik, who designed Robonaut’s hands. “We’re putting the astronaut’s training into the robot and putting the robot out to perform the drudgery in the hazardous conditions of space.”

Hands alone aren’t enough for that kind of work.

So Robonaut’s designers at NASA Dexterous Robotics Laboratory have given their creation an arm, a torso, a head and video-camera eyes. When the full prototype is completed later this year, Robonaut will have a second arm and hand and a single leg to provide hands-free support.

That’s all downhill work after the challenge of building the hand and arm, said project director Robert Ambrose.

“We’ve gone after the hardest part first,” Ambrose said.

Though its grip is only about half that of a human and the arm can lift only 21 pounds, that’s more than enough strength to work in the weightlessness of space.

Robonaut’s controls are straight out of popular science fiction. The controller wears a pair of stereoscopic goggles that display whatever Robonaut’s camera eyes see, and wears a sensor-filled glove to control the hand and arm.

Just moving the glove tells Robonaut how far to extend its arms or twist its wrist. Once the technology is refined, the glove will provide a sense of touch to the operator, Ambrose said.

From Muscle and Bone to Metal and Plastic

So far, operators have only their eyes to guide a hand that has about half the dexterity of a human hand. Engineers measure dexterity by degrees of freedom. While Robonaut has 12 degrees in its hand, humans have 22, Lovchik said.

The onetime watchmaker dissected several human hands at area medical schools to learn how to translate the mechanics of flesh and blood into a metal-and-plastic machine.

“The reason the human-like form is so important is because we are the ones who have contrived the world,” said Whittaker, who developed a robot to facilitate cleanup of the failed Three Mile Island nuclear plant and another one to search for meteorite fragments in Antarctica. “Robonaut is well suited since we have spacecraft for people, tools for people and all of the devices we take for granted in everyday life, like doorknobs.”

The three-year, $3-million project was funded only to see if the lab could produce a robot that can work with astronaut tools with the dexterity of a suited astronaut, Ambrose said.

Though it was built with parts already rated to withstand the rigors of space travel, Robonaut won’t see orbit for at least five years, Ambrose said.

In space, Robonaut could prepare exterior work sites for astronauts, saving valuable spacewalk time for more important tasks. But if early success is any indicator, Robonaut’s future applications are fairly limitless, Ambrose said.

“Wouldn’t it be great if every spacecraft had a robot that could go out and perform repair work while it’s in flight?” Ambrose said.

Ambrose envisions such an application for future planetary exploration missions. The same Robonaut could be mounted on a land rover to explore an unknown planet’s surface in a configuration Ambrose likens to the Centaur, the half-man, half-horse of Greek mythology.

On Earth, Robonaut could be used in the hazardous conditions found in nuclear plants or petroleum refineries, and NASA says prosthetic makers have expressed interest in the hand.

But Ambrose’s goal is less specific. He simply wants Robonaut to perform human tasks with high fidelity. Then the technology’s reach would be limited only by its human operators and their imaginations.

“At the point when you stop thinking about it as a Robonaut and think of it as an extension of a person, we’ve succeeded,” Ambrose said.

On the Net:

https://vesuvius.jsc.nasa.gov/erer/html/robonaut/robonaut.html.