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Humanoid Robot Actuators

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Re: Humanoid Robot Actuators

#41

Post by aDyslecticCrow »

Animats wrote: post #14
Fraterkes wrote: post #13

Earlier quoted context omitted.

I can understand pre-computation making the “software” problem of locomotion easier, but how does it help with the hardware problems laid out in the article, ie repeated very high load over a very short amount of time?

BD used hydraulics for a long time. Works, but inefficient. You have to carry the actuators, the tank, probably a hydraulic accumulator, the pump, valves, and the power source for the pump. That's why BD's machines were so big. Someone at Google said "We need to have a conversation about hydraulics", and the dog robot in 2019 was the first all-electric machine.

plenty BD clips of old atlas include oil lines bursting and showing the room with oil.

it's indeed a mess.

Re: Humanoid Robot Actuators

#42

Post by AntiUSAbah »

vova_hn2 wrote: post #39

Probably a dumb question, because I know nothing about robotics, but: > The "Zero RPM" Problem > When a robot bends its knees to stand, the motor must constantly fight gravity. There is no skeletal structure to lock against. To an electric motor, holding a static load—known as stall torque—is the most punishing state possible. Why not just add some kind of brake that can fully or partially lock the joint?

You need to keep balancing fast enough. I don't think a break would give you this agility.

Re: Humanoid Robot Actuators

#43

Post by spwa4 »

TLDR: we don't have the actuators required to make humanoid locomotion work reliably.

Also: something every human actually kind of knows. You need to take impacts on muscles, not on mechanical connections. Even if we had the actuators required, you also need perfect control. The only way actuators can work this well is if they properly predict the impacts so that the power of the motor ("the magnetic field") can absorb nearly all the impact. If you try to take the impacts even on human bones (that are very solid and self-repairing) they will break surprisingly quickly.

My opinion is that the need for high reduction is only because we can't have high voltage on the motors. If we either had very small distances between the magnets and electrical wires (think micrometers), or we have voltages in the 100s to 1000s of volts, we don't have to make this poisoned choice. (in a way, VERY small distances between magnets and wires is how human and animal muscles do it. But they go all the way down to sub-10 nanometers)

Re: Humanoid Robot Actuators

#44

Post by bryanrasmussen »

Fraterkes wrote: post #13
Animats wrote: post #12

Earlier quoted context omitted.

Their approach required pre-computation and simulation before execution. If you watch their videos carefully, you can see the advance planning work on some of the screens.

I can understand pre-computation making the “software” problem of locomotion easier, but how does it help with the hardware problems laid out in the article, ie repeated very high load over a very short amount of time?

overclocking a CPU might make it seem that you solved something and gotten better performance, but sooner or later it breaks down, as I read the article I believe that pre-computation essentially allows you to "overclock" the hardware, and make it seem that you have solved the problem of locomotion when what you have actually done is made something that looks impressive for a very much shorter of time than is usually used to calculate what the hardware can bear.

on edit: apologies if my analogy is not the best.

Re: Humanoid Robot Actuators

#45

Post by bitwize »

rob74 wrote: post #21
elil17 wrote: post #17

Earlier quoted context omitted.

Right, but: 1. Asimov wrote that because he needed robots to be indistinguishable from humans for plot reasons. 2. We do 99% of our tool use with our arms and hands. We are already very good at building robot arms. We are getting better at robot hands. We can build robot legs, but they're very expensive and they pose a major safety risk for the robot itself and surrounding humans (because the robot can fall if there…

You can still have a humanoid robot that looks very different from an actual human (and most robots from Asimov's novels were of that kind, although one of the main characters wasn't - https://en.wikipedia.org/wiki/R._Daneel_Olivaw ). Ok, so maybe a robot with wheels could solve most tasks, but it would still be severely limited: couldn't climb stairs (which would make it unsuitable as a domestic robot in a house or…

Remember the Segway?

Its predecessor was a stair-climbing wheelchair: https://en.wikipedia.org/wiki/IBOT

One of the codenames for Segway was "Ginger", a reference to Ginger Rogers, because the codename for iBOT was "Fred Upstairs" (a pun on Fred Astaire).

Re: Humanoid Robot Actuators

#46

Post by thrownthatway »

vova_hn2 wrote: post #39

Probably a dumb question, because I know nothing about robotics, but: > The "Zero RPM" Problem > When a robot bends its knees to stand, the motor must constantly fight gravity. There is no skeletal structure to lock against. To an electric motor, holding a static load—known as stall torque—is the most punishing state possible. Why not just add some kind of brake that can fully or partially lock the joint?

Complexity, weight, failure modes, wear, maintenance, support burden of legacy parts.

Also the brake components are never in the same plane as the drive components, so now you have additional forces to engineer for.

Re: Humanoid Robot Actuators

#47

Post by jFriedensreich »

Its completely impossible to trust an article when half the diagrams have serious issues and headlines are worst slop indicators. I am sure the author is knowledgeable and spend some time on this. But please please, with butter, please, either spend the last 10% to get rid of these issues or just don't publish it! Keep it in your ai research gallery or if you want to publish that gallery as ai research?

Re: Humanoid Robot Actuators

#48

Post by thrownthatway »

bloak wrote: post #25
rob74 wrote: post #15

Earlier quoted context omitted.

Isaac Asimov already explained that better than I could ( https://www.reddit.com/r/asimov/comments/pm84ud/why_robots_a... ): > Besides that, our entire technology is based on the human form. An automobile, for instance, has its controls so made as to be grasped and manipulated most easily by human hands and feet of a certain size and shape, attached to the body by limbs of a certain length and joints of a certain typ…

It seems that he wrote that in a book published in 1953, but it's weird, I find, that he was imagining a robot driving a car. I would have thought he would have imagined that cars would become robots well before there would be humanoid robots wanting to drive them. So by the time you have a humanoid robot wanting to drive a car it's just one robot talking to another robot, electronically. And knives and forks are for…

I need to get on to one of the prediction markets.

I’m willing to bet we’ll have a humanoid robot that can drive a car before we have level 5 autonomous vehicles.

And by can drive a car I mean a general purpose humanoid robot that can do basic household chores like move the car and wash it with a foaming brush and a hose.

I don’t mean the robot will be capable of sitting in any regular car and doing level 5 autonomous driving.

Re: Humanoid Robot Actuators

#49

Post by olig15 »

RaSoJo wrote: post #35

How can we trust this article or the company if the writer/so-called chief engineer decides to hide himself behind an AI avatar? From what I can understand this is the Robbie Dickson in question: https://www.huffpost.com/entry/lessons-from-a-serial-ent_b_9... Nobody has a problem with companies using AI to edit articles, create images. But when even the writer is an AI persona, the trust factor gets destroyed.

I think at very least, the diagrams are AI generated too.

> https://cdn.shopify.com/s/files/1/0554/0567/4694/files/strai... The middle component has teeth on the inside half way round, should be smooth on the inside.

> https://cdn.shopify.com/s/files/1/0554/0567/4694/files/inver... 4 of the 5 orbiting threaded rollers are perpendicular to the screw thread, so wont do anything.

> https://cdn.shopify.com/s/files/1/0554/0567/4694/files/ball-... Ball doesnt fit in the screw thread, just 'squashed' to make it fit?. Screw thread isnt consistent.

> https://cdn.shopify.com/s/files/1/0554/0567/4694/files/stiff... Classic 3 interlocked gears.

> https://cdn.shopify.com/s/files/1/0554/0567/4694/files/optic... Has the elastomer been ripped when the key was inserted?

> https://cdn.shopify.com/s/files/1/0554/0567/4694/files/biolo... Another gearbox that doesnt do anything...

The rest of the website seems filled with just as much slop too...

Re: Humanoid Robot Actuators

#50

Post by conductr »

bloak wrote: post #25
rob74 wrote: post #15

Earlier quoted context omitted.

Isaac Asimov already explained that better than I could ( https://www.reddit.com/r/asimov/comments/pm84ud/why_robots_a... ): > Besides that, our entire technology is based on the human form. An automobile, for instance, has its controls so made as to be grasped and manipulated most easily by human hands and feet of a certain size and shape, attached to the body by limbs of a certain length and joints of a certain typ…

It seems that he wrote that in a book published in 1953, but it's weird, I find, that he was imagining a robot driving a car. I would have thought he would have imagined that cars would become robots well before there would be humanoid robots wanting to drive them. So by the time you have a humanoid robot wanting to drive a car it's just one robot talking to another robot, electronically. And knives and forks are for…

Perhaps the samples were chosen specifically as things the audience would have universal familiarity/understanding of thus making his point resonate.

He didn’t craft it for literal interpretation on HN 70 years in the future.

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