Timeline for How much energy would this robot need?
Current License: CC BY-SA 4.0
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| Feb 7 at 15:08 | history | edited | Nosajimiki | CC BY-SA 4.0 |
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| Feb 6 at 21:30 | history | edited | Nosajimiki | CC BY-SA 4.0 |
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| Jan 26 at 19:26 | history | edited | Nosajimiki | CC BY-SA 4.0 |
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| Jan 25 at 22:21 | history | edited | Nosajimiki | CC BY-SA 4.0 |
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| Jan 25 at 17:02 | comment | added | Nosajimiki | @DKNguyen Muscles are bad at doing motor things, and motors are bad at doing muscle things, you lose efficiency either way when you try to use one to do the other's job. Also, horsepower is a bit of a misnomer. It is the linear power of a walking horse. most horses max out at 10-14 horse power iirc. | |
| Jan 25 at 16:51 | history | edited | Nosajimiki | CC BY-SA 4.0 |
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| Jan 25 at 16:20 | comment | added | DKNguyen | @Nosajimiki Well, your hand is a bad example of that because it also does not contain enough room either which is why all your finger muscles are in your forearm. | |
| Jan 25 at 16:18 | comment | added | DKNguyen | @MatijaNalis The stages of mechanical transmission part and weight of structural materials makes sense. The weight of the motor though, not so much. Someone recently on here was arguing saying that motors and cars have better power to weight than muscle. I was working off a Stephen Vogel reference saying that the power-weight of motor and muscle were about the same. But then they brought up how a 700HP car weighs much less than 700 horses, even after you account for extraneous mass of the horse. | |
| Jan 25 at 16:06 | history | edited | Nosajimiki | CC BY-SA 4.0 |
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| Jan 25 at 15:56 | history | edited | Nosajimiki | CC BY-SA 4.0 |
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| Jan 25 at 15:51 | comment | added | Nosajimiki | @MatijaNalis Batteries on modern androids are comparatively much lighter than the power systems used by humans. This is mostly because of the inefficiencies of the mechanical systems that you've described leaving so little room for the power system. But, since the OP describes wanting to use human like efficiencies, then once you free up mass from the mechanical systems, you can reinvest it into a much larger battery. | |
| Jan 25 at 15:46 | comment | added | Nosajimiki | @DKNguyen MN is correct about the mechanical systems. I coach my daughter's robotics team, and the amount of power loss the kids see for every gear, belt, and axel they add to thier designs is very significant, and engineering something as complex as a hand can not be done with a bunch of direct motor connections because they would not all fit where you need them to fit. I've expanded on my answer to cover this. | |
| Jan 25 at 15:39 | history | edited | Nosajimiki | CC BY-SA 4.0 |
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| Jan 25 at 4:41 | comment | added | Matija Nalis | @DKNguyen also, electric motors are heavy, due to being mostly metal. Just because they have relatively good mechanical_motion/heating ratio (i.e. efficiency), does not mean their mechanical_motion/mass ratio fares as good - they are made mostly of metals, and metals are heavy... Also while you can use more of human-alike sugar/fat burning and energy transport mechanisms to avoid bulky and heavy rechargeable Li-ion batteries, but then your robots becomes being more like human replicants with few prosthesis enhancements than "real" robots... | |
| Jan 25 at 4:31 | comment | added | Matija Nalis |
Because batteries are dead-weight with bad [specific energy/energy density], and even worse, it is constant regardless if your battery is full or empty (compare to human stomach). E.g. you typical lithium-ion battery might have specific energy of 0.8 MJ/kg, while body fat has 38 MJ/kg. Of course you could make it run on gasoline (46 MJ/kg) or even liquid hydrogen (120 MJ/kg!), but those require bulky, heavy and needy combustion engines (cooling), so don't work well for human-sized robots (but truck-sizes robots are much better match).
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| Jan 25 at 4:04 | comment | added | DKNguyen | How does this work out? Because motors can be 90%+ efficient. So where is the 7x reduction in power consumption coming from? | |
| Jan 24 at 20:33 | history | edited | Nosajimiki | CC BY-SA 4.0 |
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| Jan 24 at 20:10 | history | answered | Nosajimiki | CC BY-SA 4.0 |