"Long before it's in the papers"
June 04, 2013


New robot is “on the ball”

Aug. 11, 2006
Courtesy Carnegie-Mellon University
and World Science staff

Researchers have made a robot that balances and moves on a metal ball instead of legs or wheels. 

Ballbot co-developer George Kantor watches as the device roams about the office. (Courtesy Carnegie-Mellon University)

The battery-operated “Ball­bot” weighs 95 pounds (43 kg) and is about as tall and wide as a per­son. Its long, thin shape and abil­i­ty to ma­neu­ver in tight spaces gives it po­ten­tial to work around peo­ple bet­ter than tra­di­tion­al robots, its de­vel­op­ers claim.

Ralph Hol­lis of Carnegie-Mellon uni­ver­si­ty in Pitts­burgh, Penn., who said he orig­i­nat­ed Ball­bot in his home work­shop, pre­dicts such ma­chines could one day aid the eld­er­ly or dis­a­bled, or pro­vide of­fice help. 

Sta­ble, mo­bile robots tra­di­tion­ally move on three or more wheels, but their bas­es are gen­er­al­ly too wide to move eas­i­ly among peo­ple and fur­ni­ture, Hol­lis said. They can al­so tip over if they move too fast or on a slope. 

Robots with legs, on the oth­er hand, are com­plex and ex­pen­sive.

“We wanted to create a robot that can maneuver easily and is tall enough to look you in the eye,” Hollis said. Ballbot “can move easily in any direction without having to turn first.” 

Ballbot has an onboard computer that reads balance information from internal sensors, activating rollers that mobilize the ball on which it moves. The system is basically a mouse-ball drive in reverse, Hollis said. When Ballbot is still, it stands on three retractable legs. 

Hollis and a team of colleagues and graduate students presented research findings last October at the International Symposium for Robotics Research in San Francisco, and in mid-May at the International Conference on Robotics and Automation in Orlando, Fla. 

Future plans, Hollis said, include giving
Ballbot a head and arms, whose swinging would help rotate and balance the body. 

“We want to make Ballbot much faster, more dynamic and graceful,” he said. “But there are many hurdles to overcome, like responding to unplanned contact with its surroundings, planning motion in cluttered spaces and safety issues.” 

Hollis said he started creating robots as a hobby in the 1950s. “When I started building robots, the field didn’t even exist,” said Hollis. “Now the field has grown up around me and I’m in the middle of it. It’s like a dream come true.”

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The battery-operated “Ballbot” weighs 95 pounds (43 kg) and is about as tall and wide as a person. Its long, thin shape and ability to maneuver in tight spaces gives it potential to work around people better than traditional robots, its developers claim. Ralph Hollis of Carnegie-Mellon University in Pittsburgh, Penn., who said he originated Ballbot in his home workshop, predicts such machines could one day aid the elderly or disabled, or provide office help.  Stable, mobile robots traditionally move on three or more wheels, but their bases are generally too wide to move easily among people and furniture, Hollis said. They can also tip over if they move too fast or on a slope.  Robots with legs, on the other hand, are complex and expensive.