Robotic 'Pack Mule'

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View the impressive Video Clip (28MB Windows media file)

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.

“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.

Robotic pack mule

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.

Kerb climbing

“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.

 

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The Most Advanced Quadruped Robot on Earth
BigDog is the alpha male of the Boston Dynamics family of robots. It is a quadruped robot that walks, runs, and climbs on rough terrain and carries heavy loads. BigDog is powered by a gasoline engine that drives a hydraulic actuation system. BigDog's legs are articulated like an animal’s, and have compliant elements that absorb shock and recycle energy from one step to the next. BigDog is the size of a large dog or small mule, measuring 1 meter long, 0.7 meters tall and 75 kg weight.

BigDog has an on-board computer that controls locomotion, servos the legs and handles a wide variety of sensors. BigDog’s control system manages the dynamics of its behavior to keep it balanced, steer, navigate, and regulate energetics as conditions vary. Sensors for locomotion include joint position, joint force, ground contact, ground load, a laser gyroscope, and a stereo vision system. Other sensors focus on the internal state of BigDog, monitoring the hydraulic pressure, oil temperature, engine temperature, rpm, battery charge and others.

So far, BigDog has trotted at 3.3 mph, climbed a 35 degree slope and carried a 120 lb load.

BigDog is being developed by Boston Dynamics with help from Foster Miller, the Jet Propulsion Laboratory, and the Harvard University Concord Field Station.Development is funded by the DARPA Defense Sciences Office.

 

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Weird man I never heard of this. I wonder about the applications and if the military will actually ever use it.

 

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From a pure robotics viewpoint, I'm amazed by it's balance. As time passes they'll become smaller, faster and yet more dextrous.

Practically, I can't seeing it doing much at this stage that a couple of guys couldn't manage. There could be some hazardous terrain that it'd be worth sending one across but unless the thing is standard issue then they have to call in a request for one by which time someone would have likely thought of some better solution. Maybe they could use one to walk a bomb into an enemy camp.

 

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Hell yeah. Dress it up like a pink mule and rig it with explosives. They be so dumbfounded you could walk it right into their camp.

 

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You could make a large one, fill it with soldiers and leave it outside the gates to their camp.