Offers hope to paraplegics, amputees, and rescue workers

Jessy Grizzle with MABEL. (Photo: Martin Vloet, Michigan Photography.)

For making a robot that walks with the agility of a human and runs at a nine-minute-mile pace, University of Michigan professor Jessy Grizzle recently won a Popular Mechanics’ Breakthrough Award.

Grizzle, a professor of electrical engineering and computer science, is a co-investigator on MABEL, the fastest two-legged robot with knees. He and his colleague Jonathan Hurst, assistant professor of robotics and mechanical design at Oregon State University, share the honor. They are listed in the national magazine’s November edition among “10 World-Changing Innovators for 2012.”

“I would say it was a dream come true, except I never dreamed of our work on MABEL reaching so deeply into the mainstream consciousness,” says Grizzle, the Jerry W. and Carol L. Levin Professor of Engineering. “This is an honor I will treasure for a lifetime.”

The work of Grizzle, Hurst, and their students has pushed forward the field of bipedal robotics, which could one day lead to powered prosthetic limbs that behave like their biological counterparts and exoskeletons that let wheelchair-bound people walk again. The technology could even give rescuers super-human abilities, the researchers say. Two-legged robots could potentially respond to disasters and conduct dangerous missions on uneven terrain, whether in a burning building or a war zone.

http://www.youtube.com/watch?v=xlOwk6_xpWo

Walk the Line

In their six years with MABEL, Grizzle’s lab programmed the robot to walk and recover from obstacles in its path, to run, to step up and down, and even to walk backwards. MABEL, which was retired earlier this year, did all these tricks essentially blindfolded. Without a camera to detect what was ahead, it relied on specially programmed feedback control algorithms that enabled it to react quickly to what its legs encountered. MABEL could recover from a stumble better than a person could.

“This collaboration has been fantastic. It takes more than one area of expertise to make a robot do what MABEL has done,” Hurst says. “I am extremely excited about this award, because it will help us to keep the momentum moving forward. There is so much yet to discover about walking and running.”

Sprinting for Science

Grizzle and Hurst, along with Hartmut Geyer, assistant professor at Carnegie Mellon University, have spent the last two years creating MABEL’s successor, ATRIAS. They’ve built three identical copies—one for each institution. U-M’s, which the researchers have named MARLO, recently arrived in Grizzle’s lab. The ATRIAS robots, including MARLO, should be able to run 50 percent faster than MABEL, about half the speed of an Olympic sprinter. Researchers will work to get them walking untethered inside and outside, using far less battery power than other robots with similar agility. This work is expected to move the field closer to machines that can be deployed beyond the lab. One key advancement: MABEL was always connected to a boom because its hips could not move side to side. MARLO’s hips can.

MABEL was largely funded by the National Science Foundation. The ATRIAS robots are funded by the Defense Advanced Research Projects Agency (DARPA), an agency of the United States Department of Defense.