New generation of robots hopping in

Rover-hopper hybrids can leap buildings, but landing is rough

Sue Vorenberg | The New Mexican

7/17/2008 - 6/27/08

You might wonder what the shoebox-sized rover is doing when it nears the 8-foot wall, pops a pen-sized eyeball out of its midsection and has a look around.

But that's just the start of its weird behavior.

Soon after, the eyeball lowers back in place, the vehicle sits patiently for a moment, like a cat about to jump up on a counter, and then pop, its internal combustion chamber hurls the rover 9 feet in the air, then drops it on the other side of the wall to continue its journey.

This robot, called an unmanned ground vehicle, is more commonly referred to as a "hopper" by the scientists and engineers who invented it at Sandia National Laboratories.

And after about 10 years of research, a new generation of the devices are almost ready to hop out of the lab's door and into the real world, said Bary Spletzer, a senior scientist at Sandia.

"We're within a year, I'd say, of having this completely ready," Spletzer said.

The ability to hop might sound odd for a robot, but it's actually extremely useful in a wide range of situations, said Jon Salton, who is currently leading the project.

"You could use these for planetary exploration, for search and rescue applications," Salton said. "In the last few years, we've had a lot of news about people getting trapped in mines. With this you could get to them in a place where it might not yet be safe for rescuers to go."

Remote operators of the hoppers can control the height and direction of each hop. So in a collapsed building, for instance, you could perhaps strap some water or supplies to one and hop it over fallen debris into a place where people are trapped, he said.

There are also military applications, where a hopper could go in and investigate an enemy base, going over walls and other barricades that might be set up.

"The whole idea for hoppers came out of the concept that in small-scale robotics, mobility is a problem," Spletzer said. "You can't even get most small robots over a curb."

Spletzer and Gary Fischer, another Sandia scientist, came up with the original idea of making robots hop to get around that problem in the late 1990s.

"The first hoppers we came up with were pure hoppers — they didn't roll, they just hopped," Spletzer said. "It took a while for us to figure out how to combine that into a wheeled vehicle."

Still, the program did get a badge of honor well before it turned to the rover-hopper hybrid design. In 2001, during the early years of the research, the team got a hopper into the Guinness Book of World Records with a jump of 30 feet.

"Of course, it's not like there was a second-place contender for that category," Spletzer said with a laugh. "We've had some jump higher than that. One jumped into a tree. We've jumped them over three-story buildings, too."

The wheeled variety adds a lot of mobility, so you can drive the hopper where you want it to go, rather than hopping it in a general direction, which is possible with the nonwheeled varieties.

And the biggest challenge actually isn't the hopping part, Salton said.

"Going up isn't the hard part of the problem; the really hard part is landing from that height," he said.

The rovers weigh about 6 and a half pounds. If you picture throwing a 5-pound hand weight 30 feet in the air and having it drop on the floor, you can see how landing a hopper might be a problem, he said.

"It can get over and onto things that a larger vehicle can't, but you have to cushion its landing," Salton said.

Scientists and engineers on the team have been looking at various tire designs to make it land more softly on concrete, sand, grass and other surfaces, he said.

When it's ready, the base vehicle with nothing attached to it will probably cost less than $10,000. The team envisions the devices being geared for a number of purposes and attachments, though, which could make prices vary significantly, Salton said.

"It's a pretty fun, exciting, challenging area to work in," Salton said. "Everyone working on it is eager to see what sort of applications evolve for it."

Contact Sue Vorenberg at 986-3072 or svorenberg@sfnewmexican.com.