Powering Humanoid Robots

[Brian-M]

Reading about humanoid robots, I noticed that they're power-hungry gadgets. Most of them can only store enough power in their batteries for an hour or two of running time.

For example, the Asimo has a 13 pound (6kg) lithium ion battery, but even a battery this huge only lasts an hour.

I assume that most of the power is being consumed by the internal computer. As the robots get smarter, it's most likely that the power demands will become even greater.

This kind of puts a damper on the whole science-fiction depiction of humanoid robots.... I don't recall a single story where the robots had to plug themselves in every single hour to avoid going flat.

Imagine commander Data having to plug himself into a cigarette lighter socket on the bridge of the Enterprize, or R2D2 dragging a portable generator behind him after escaping the Skywalker ranch so that he'd have enough power to make his way to Kenobi.

Is there any practical and plausible way to provide hypothetical domestically owned humanoid robots with enough power to last them a day or two of continuous use without needing to recharge?

(Preferably without generating huge amounts of waste heat.)

 

[catsmate]

Well actual humans use about 8-11MJ of energy per day. That 6kg lithium battery probably stores about 3.6MJ.
More advanced batteries, currently in development, will store 5-6 times as much and there are possibilities in the area of alcohol fuel cells.

 

[Mark6]

Well actual humans use about 8-11MJ of energy per day. That 6kg lithium battery probably stores about 3.6MJ.

Humans recharge 3 times a day, and take about 30 minutes for each recharge. Sounds about right!

 

[Brown]

Powering with miniaturized fuel cells is a possibility, but one of the by-products of a fuel cell is water. It may not be convenient to vent the water into the environment, so the water may be temporarily stored for elimination at a convenient site.

What I'm getting to is this: It is possible that, in the future, your robot may periodically urinate.

 

[Crossbow]

Developing batteries that have a large storage capacity coupled with low weight, small volume, and affordabilty has been a serious challange since the batteries were first developed.

 

[casebro]

I assume that most of the power is being consumed by the internal computer. As the robots get smarter, it's most likely that the power demands will become even greater.

Motors use tons more power than brains. A more efficient body is requisite. Exoskeleton, or endoskeleton? Mix? Midget, rather than Hercules?

But get to the basics, is a universal robot with short battery life better than a specialized robot with endurance?

And you are forgetting that those sci-fi stories also have powered transmitted. So the question is, how big of an antenna array will a humanoid robot need? Ears like the photo voltaic cells on satellites?

 

[TX50]

What I'm getting to is this: It is possible that, in the future, your robot may periodically urinate.

Then they'd urinate fresh water. World's coming water shortage crisis solved!

 

[aggle-rithm]

Imagine commander Data having to plug himself into a cigarette lighter socket on the bridge of the Enterprize, or R2D2 dragging a portable generator behind him after escaping the Skywalker ranch so that he'd have enough power to make his way to Kenobi.

Both Data and the Terminator had power cells with enough juice to make handy weapons-o-mass-destruction in a pinch.

 

[Brown]

Then they'd urinate fresh water. World's coming water shortage crisis solved!

Fuel cells were what supplied electrical power to the ships on the lunar missions. The service modules had tanks of oxygen and hydrogen. On Apollo 13, one of the cryo tanks burst, and the first sign of a problem was a loud noise, followed by a power failure.

Anyway, on those missions that DIDN'T explode, management of the liquid water by-product was easy enough: the crew drank it. And when they were "done" with it, they ejected it into space.

 

[aggle-rithm]

The most accurate depiction of robot power is in Futurama. Bender is powered by alcohol, and is seen constantly drinking it.

 

[TX50]

...[M]anagement of the liquid water by-product was easy enough: the crew drank it. And when they were "done" with it, they ejected it into space.

The constellation Urine.

 

[IXP]

Batteries do not provide a great power / weight ratio. Just look at electric vs. gasoline powered cars.

IXP

 

[Brian-M]

The most accurate depiction of robot power is in Futurama. Bender is powered by alcohol, and is seen constantly drinking it.

It'd have to be stronger (purer) stuff than Bender is seen drinking.

It's an interesting idea, as the robots would need to "breathe" to live, constantly inhaling fresh air and exhaling exhaust.

But looking it up, I'm not sure if alcohol would be the answer, not unless they come up with a practical alternative to platinum for the catalyst. Not just because platinum is incredibly expensive, but because alcohol contains lots of carbon, and the carbon-monoxide produced by running an alcohol-powered fuel-cell can "poison" the platinum.

Maybe hydrogen fuel-cells could be the answer?

 

[Jimbo07]

or R2D2 dragging a portable generator behind him after escaping the Skywalker ranch so that he'd have enough power to make his way to Kenobi.

So you haven't made it to Empire Strikes Back, where Luke plugs R2 in to a portable generator on Dagobah, then? It's the scene after they land and they're having lunch.



In fairness, R2D2 was always the most competent character (I'm looking at you, Han "I've got a bad feeling about this" Solo), but it was only in the new movies where he (she, it?) was given super powers

 

[aggle-rithm]

In fairness, R2D2 was always the most competent character (I'm looking at you, Han "I've got a bad feeling about this" Solo), but it was only in the new movies where he (she, it?) was given super powers

That's because super powers degrade over time in the Star Wars universe. Look at how pathetic the light sabre battles were in the later stories compared to the earlier ones.

In the new Star Wars movies, R2D2 will have to be carried around in a wheelbarrow, and the Jedi Knights will fight evil with Bic lighters.

 

[The Fallen Serpent]

It'd have to be stronger (purer) stuff than Bender is seen drinking.

It's an interesting idea, as the robots would need to "breathe" to live, constantly inhaling fresh air and exhaling exhaust.

But looking it up, I'm not sure if alcohol would be the answer, not unless they come up with a practical alternative to platinum for the catalyst. Not just because platinum is incredibly expensive, but because alcohol contains lots of carbon, and the carbon-monoxide produced by running an alcohol-powered fuel-cell can "poison" the platinum.

Maybe hydrogen fuel-cells could be the answer?

The robots drink quite large amounts of alcohol! Fry even mentions that some of the explicitly robot brands make him sick. They can also burn petroleum products, but prefer to act like ******** and the alcohol is a convenient excuse.

I don't recall the platinum issue ever coming up. Bender is probably 40% platinum though.

The carbon burning and the resulting exhaust is even a stated problem. One of the episodes they had to solve robot caused global warming, which up to that point had been contained using ice from Haley's Comet.

 

[elgarak]

Developing batteries that have a large storage capacity coupled with low weight, small volume, and affordabilty has been a serious challange since the batteries were first developed.

High power, low size (weight/volume), low price.

Pick two.

Seems to apply all over the place.

 

[Sockor]

Atomic batteries would offer long lifetime and they are portable enough. On the downside they are quite expensive, they produce waste heat, and squeamish people might find slightly unnerving the fact that their robotic butler carries around a lump of plutonium in it's tummy.
Could imagine RTG's being used in battlefield robots on long missions. Even if captured by the enemy, they'd better use it to brew coffee rather than try to put together some doomed-to-fail dirty bomb.

 

[catsmate]

The most accurate depiction of robot power is in Futurama. Bender is powered by alcohol, and is seen constantly drinking it.

Well using current/near-future tech he'd have to drink fairly pure methanol.

Batteries do not provide a great power / weight ratio. Just look at electric vs. gasoline powered cars.

But electric motors are more efficient than heat engines and battery efficiency is improving. Older NiCd batteries stored ~150J/g, while curent best poly-Li store 1080J/g.

Atomic batteries would offer long lifetime and they are portable enough. On the downside they are quite expensive, they produce waste heat, and squeamish people might find slightly unnerving the fact that their robotic butler carries around a lump of plutonium in it's tummy.
Could imagine RTG's being used in battlefield robots on long missions. Even if captured by the enemy, they'd better use it to brew coffee rather than try to put together some doomed-to-fail dirty bomb.

Probably the best radio-isotope is 238Pu which produces ~500W/kg but has a half life of ~88 years and requires little shielding.

 

[Natan]

Batteries do not provide a great power / weight ratio. Just look at electric vs. gasoline powered cars.

Nonsense. Batteries can easily have a power to weight ratio that is higher than your average gasoline engine (500 W/kg). Just look at the battery specs on the Prius, and that is not even one of those lithium batteries with fancy nanochemistries. The problem is instead energy / weight ratio as evidenced in electric vs. gasoline powered cars.

http://www.eaa-phev.org/wiki/Toyota_Prius_Battery_Specs