Apart from being four-legged animals, what do a cheetah and a pack mule have in common? They’ve both inspired what may be the next generation of war machines.
DARPA, a military research group based in Arlington, Virginia, showed off two new robots this month, one inspired by the world’s fastest land mammal and the other based on the body plan of a familiar sturdy beast of burden.
DARPA “is attempting to understand and engineer into robots certain core capabilities that living organisms have refined over millennia of evolution: efficient locomotion, manipulation of objects and adaptability to environments,” says Program Manager Gill Pratt on the DARPA website.
“Cheetahs happen to be beautiful examples of how natural engineering has created speed and agility across rough terrain,” Pratt explained. “Our Cheetah bot borrows ideas from nature’s design to inform stride patterns, flexing and unflexing of parts like the back, placement of limbs and stability. What we gain through Cheetah and related research efforts are technological building blocks that create possibilities for a whole range of robots suited to future Department of Defense missions.”
DARPA announced last week that its Cheetah robot broke its own land speed record of 18 miles per hour. “In the process, Cheetah also surpassed another very fast mover: Usain Bolt,” DARPA said on its website. “According to the International Association of Athletics Federations, Bolt set the world speed record for a human in 2009 when he reached a peak speed of 27.78 mph for a 20-meter split during the 100-meter sprint. Cheetah was recently clocked at 28.3 mph for a 20-meter split.”
Cheetah “had a slight advantage over Bolt as it ran on a treadmill, the equivalent of a 28.3 mph tail wind,” DARPA allowed. Most of the power Cheetah used was “to swing and lift its legs fast enough, not to propel itself forward.”
DARPA is working to create legged robots like Cheetah that don’t sacrifice speed for mobility on rough terrain. For now, Cheetah runs on a treadmill in a lab to allow researchers to monitor its progress, refine algorithms and maintain its moving parts.
Robotic Pack Mule
The first of two robotic LS3 pack mule prototypes “underwent its initial outdoor test earlier this year and has matured through continual testing and improvements to the point that two functioning platforms have started to run through the paces similar to what they could one day experience carrying gear for a squad of Marines or Soldiers,” DARPA said this week.
The goal of the program is to “demonstrate that a legged robot can unburden dismounted squad members by carrying their gear, autonomously following them through rugged terrain, and interpreting verbal and visual commands.”
Improvements to the mule robot include the ability to go from a 1- to 3-mph walk and trot over rough, rocky terrain, easily transition to a 5-mph jog and, eventually, a 7-mph run over flat surfaces, showing the versatility needed to accompany dismounted units in various terrains, Hitt said.
“The LS3 has demonstrated it is very stable on its legs, but if it should tip over for some reason, it can automatically right itself, stand up and carry on. LS3 also has the ability to follow a human leader and track members of a squad in forested terrain and high brush,” Hitt added.