MABEL is constructed to walk like a human, not only to make the form more relatable, but potentially more helpful in future application. The EECS team was challenged to develop a gait for MABEL that closely resembles our own. MABEL's knees allow the robot to move its legs in a fluid-like motion. Also, because there are springs powering the legs, like tendons, MABEL can spend 40 percent of its stride in the air while running.
Not only is MABEL one of the few robots in the world that can run, it holds the record for fastest bipedal robot with knees, clocking in at a peak pace of 6.8 mph. What makes MABEL so fast? It's not just the design.
The EECS team spends much of its time programming and tweaking MABEL. The trickiest part is creating the feedback algorithms. MABEL's balance is entirely dependent on how the robot interprets physical feedback gathered from sensors at the end of its legs. The team develops algorithms designed to keep MABEL's balance stable. Too much stability can result in slow speeds, whereas too much speed can result is low stability. It's all about making small adjustments to find the perfect balance.
There are many possible uses for a dynamically stable, two-legged robot like MABEL. "We envision some extraordinary potential applications for legged robot research: exoskeletons that enable wheelchair-bound people to walk again or that give rescuers super-human abilities, and powered prosthetic limbs that behave like their biological counterparts," said Jonathan Hurst, one of MABEL's developers.
Even further down the line, Grizzle imagines robots like MABEL being able to go places that humans are unable to go. "If you would like to send in robots to search for people when a house is on fire, it probably needs to be able to go up and down stairs, step over the baby's toys on the floor, and maneuver in an environment where wheels and tracks may not be appropriate," said Grizzle. A MABEL-like robot could perform these task because its balance is all based on physical feedback--not visual sensors that could be obstructed by lack of light or smoke. In other words, a dark, smoke filled room is the same to MABEL as a bright, clear room.
The MABEL project is funded by government agencies like DARPA and NSF. There are certainly interests from a defense point of view, but even further beyond that, MABLE's legwork could set up a big paradigm shift in the future. God speed, MABEL; break a leg.