The brainy folks at MIT have outdone themselves again. Not only did they develop a robot that can run untethered while mimicking the bounding gate of a quadruped, but now their speedy cheetah can even jump.
The groundwork for this latest feat in robotic engineering actually began last year when MIT scientists developed an algorithm that allowed cheetah to increase its running speed. The algorithm enabled the cheetah to determine the necessary forces required for high-speed running and it all starts with bounding.
"Bounding is like an entry-level high-speed gait, and galloping is the ultimate gait," says Sangbae Kim, an associate professor of mechanical engineering at MIT, in a press release last September when the new gate was introduced. "Once you get bounding, you can easily split the two legs and get galloping."
They tested the new gate on an indoor track, where the robot was able to sprint at up to 10 mph. They hope the cheetah will eventually reach speeds of up to 30 mph.
"Most robots are sluggish and heavy, and thus they cannot control force in high-speed situations," Kim says. "That's what makes the MIT cheetah so special: You can actually control the force profile for a very short period of time, followed by a hefty impact with the ground, which makes it more stable, agile, and dynamic."
And that newfound speed and agility has been put to good use, for now the cheetah is perfecting the art of jumping.
"A running jump is a truly dynamic behavior," said Kim this week when they broke the news of their jumping cheetah. "You have to manage balance and energy, and be able to handle impact after landing. Our robot is specifically designed for those highly dynamic behaviors."
Their cheetah is not only fast, it's also smart. It plans out its running path much like a human does, by detecting obstacles, estimating the obstacle's height and distance, then adjusting its stride and exerting the necessary forces to clear the hurdle.
The cheetah does all this through onboard LIDAR - a visual system that uses laser beam reflections to map the surrounding terrain. And since both the vision and mapping system are built onboard the robot, it is able to perform untethered.
The agility of the cheetah is obtained through complex algorithms, which enables it to adjust its performance based on what it encounters on the landscape.
"If you want to optimize for, say, energy efficiency, you would want the robot to barely clear the obstacle - but that's dangerous, and finding a truly optimal solution would take a lot of computing time," Kim says. "In running, we don't want to spend a lot of time to find a better solution. We just want one that's feasible."
The cheetah has been successfully tested on treadmills and indoor tracks, where it has achieved a 90% success rate in clearing its hurdles. The next step is to take it for a test drive on grassy terrain, where the cheetah should feel right at home.
