Robotics

Karate-chopping Centauro robot shows that four legs are better than two

Karate-chopping Centauro robot...
Centauro is designed for disaster relief missions
Centauro is designed for disaster relief missions
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Centauro lifting a 6-kg weight
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Centauro lifting a 6-kg weight
Centauro karate chopping a plank
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Centauro karate chopping a plank
Centauro is designed for disaster relief missions
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Centauro is designed for disaster relief missions

In a remarkable two-for-one, engineers at IIT-Istituto Italiano di Tecnologia have developed a new robot centaur that is not only capable of aiding in disaster situations, but also has a mean karate chop. Called Centauro, the 1.5-meter-tall (5 ft), 93-kg (205-lb) robot combines two arms with four legs in a robust construction to give it both dexterity and stability while dealing with harsh environments.

If you look at videos of 2015's DARPA Robotics Challenge, you'll notice that the bipedal robots of just three years ago had one depressing tendency – they fell down a lot. For robots designed for disaster relief, it makes a lot a sense to base them on the human body. Not only can humans navigate a remarkable variety of terrains, but humanoid robots are better at handling architecture, machines, vehicles, and tools built for humans. However, humans do have drawbacks.

For one thing, the human is body is so unstable that walking has been described as controlled falling down. That's a problem because it implies that if things go wrong, falling down is the likely result. Though some of the latest bipedal robots show a remarkable degree of stability and agility, standing and working on two legs is still a less sturdy platform than four legs.

Centauro lifting a 6-kg weight
Centauro lifting a 6-kg weight

Working from this basis, a team led by Nikos Tsagarakis at the IIT-Istituto Italiano di Tecnologia's Humanoid and Human Centred Mechatronics Lab developed Centauro around a four-legged base and an anthropomorphic torso with two arms for lifting and manipulating objects. The robot is also designed to be on the tough side with components made out of aluminium, magnesium, and titanium alloys, as well as 3D-printed plastics to allow for rapid prototyping.

The quadrupedal design makes Centauro stable while working, yet able to navigate manmade environments with doors and narrow corridors, as well as debris-strewn areas. The legs not only let the robot walk and climb stairs, but each leg has a powered aluminium wheel shod in a high-friction elastomer material for fast travel on flat surfaces. Each leg has six-degrees of freedom with rotating and extending hips, knees, and ankles.

According to the team, this configuration allows the robot to handle power tools, while the lightweight arms with the ability to lift about 11 kg (24 lb) are designed to combine the manipulation strength of a human adult with dexterity and the ability to withstand physical shocks to the usually vulnerable actuators. The latter is particularly important because Centauro's party piece is being able to break wooden planks with a neatly executed karate chop.

Centauro karate chopping a plank
Centauro karate chopping a plank

The head contains Centauro's sensors, including imaging cameras, RGBD (red, green, blue, depth) sensors, and a lidar system for all-around coverage, while high fidelity torque sensing and thermal sensors are scattered throughout the body.

Centauro is powered by a 1.6-kWh Li-Po battery for 2.5 hours of operating time, with three on-board computers handling information processing. Control of the robot is through a combination of telepresence and predictive semi-autonomous systems. This means that a human operator directly controls the movement of the robot and its limbs, but in the event of a communications break or delay, the on-board computers can predict the intended movements and complete them without assistance.

The video below shows Centauro making some moves and breaking some boards.

Sources: Istituto Italiano di Tecnologia, Centauro Project

The Centauro

3 comments
Daishi
After 30 years of dead ends and failures in bipedal robots I'm glad people are finally considering other mobility solutions. I still think most of these teams are a representation of people with more talent and money than vision. I think entrepreneur advice of "scratch your own itch" is something being ignored by these teams. They invent an obscure imaginary problem in an imaginary environment and then build a complex and expensive solution to solve it. To make the point a human could karate chop a log but what a human lacks would be something like bolt cutters. Give the thing a utility belt with an attach mechanism for the hand so that it can swap between drills, screwdriver, bolt cutters, pliers, disk cutter, universal socket etc. Then have a human pilot it over the Internet using cameras to perform remote tasks and see if they can succeed remotely at something real and now you might have something with actual application within the next 30 years. For now just use a "skateboard" mobility platform with large wheels and a low battery that well known and easy and build the intelligence/application on top of it until you get an application that's useful. then if the wheeled platform isn't cutting it you move to some other transportation method but until that happens all the people with legged mobility platforms are tying the problem of useful application to complex mobility for no good reason and failing to deliver meaningful results (for 30 years and counting) because of it.
ljaques
Hurray, the office chair broke the tongue depressor!
warren52nz
I assume it could use its legs to climb over things or go up/down stairs. Those little wheels wouldn't be any good on rough surfaces. Or maybe that's not the application the designers had in mind. Would be a shame if hitting a 2 by 4 on the ground could stop it in its tracks.