A nimble, four-legged robot is so surefooted it can recover its balance even after being given a hefty kick. The machine, which moves like a cross between a goat and a pantomime horse, is being developed as a robotic pack mule for the US military.
BigDog is described by its developers Boston Dynamics as “the most advanced quadruped robot on Earth”. The company have released a new video of the robot negotiating steep slopes, crossing rocky ground and dealing with the sharp kick. View the impressive clip here (28MB Windows media file).
“Internal force sensors detect the ground variations and compensate for them,” says company president and project manager Marc Raibert. “And BigDog's active balance allows it to maintain stability when we disturb it."
This active balance is maintained by four legs, each with three joints powered by actuators and a fourth "springy" joint. All the joints are controlled by an onboard PC processor.
The project is sponsored by the US Defense Advanced Research Projects Agency (DARPA), who want the robotic pack mule to assist soldiers in terrain too tough for vehicles. Ground-based soldiers often need to carry 40 kilograms of equipment.
Raibert says the latest version of BigDog can handle slopes of 35° – a steeper gradient than one in two. The hydraulics are driven by a two-stroke single-cylinder petrol engine, and it can carry over 40 kg, about 30% of its bodyweight. The robot can follow a simple path on its own, or can be remotely controlled.
“They seem to have done a good job with adaptive dynamics and fast reflexes to deal with terrain variation and disturbances,” says Barbara Webb, at Edinburgh University's Mobile Robotics Research Group in the UK. “These are hard problems.” But she notes BigDog is not shown negotiating higher obstacles such as kerbs, which may pose difficulties.
Roboticist Darwin Caldwell, at the University of Salford, UK, adds: "It certainly looks very impressive - fast moving, highly reactive, autonomous both in power and possible intelligence and looking fairly robust. I have seen none that would be better. But there must always be a certain caution from videos."
The legs on the next version of BigDog, V3, will each have an additional powered joint and will be able to take on even steeper slopes and rougher terrain at higher speed, its makers say.
By Jerry Shown
Thu Nov 01 16:52:24 GMT 2007
Imagine this machine, wide enough to sling a chair in the middle to carry one person along with camping equipment. Guided by joystick and upgraded hydraulics with the ability to kneel for mounting. This would make a great machine for disabled persons to be able to tour parks and walking trails in national forests and to go where wheelchairs or scooters can't.By Chuck R.
Fri Mar 21 01:11:56 GMT 2008
As soon as it can run you just replace "pack mule" with "guns and armor" and tell it to take that hill. What could the enemy do? Imagine 20 dog-like robots running towards you shooting with marksman-like accuracy. Following you into a building with no worry of being shot. Every visual detail collected and shared without a word. War is going to change.All comments should respect the New Scientist House Rules. If you think a particular comment breaks these rules then please use the "Report" link in that comment to report it to us.
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