Comment by itissid | Hacker News Reader

Comment by itissid | Hacker News Reader

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Is it true that a walking system only to operate its legs and limbs would still consume more power than a rocker bogie — with all the innovations in battery tech?

Ofc Yes.

On Mars would any other mobility system today achieve better performance for it's purportedly stated(neigh most ridiculous stated but to be fair difficult engineering) goals i.e. colonization? Also no.

I am surprised after watching this that there is so much of the Boston dynamic stuff man/dog walking out there, given that mobility is so well accomplished. Do you need — to invest — an anthropomorphized man to scale walls and be stable after getting kicked around?? I know one thing here on earth all large scale semi(think agro machines) and almost fully(delivery bots) autonomous look nothing like anthropomorphics or canines.

Maybe I have the dunning Kruger effect, because I am not a robotics engineer, but why is building an anthropomorphic _mobility_ platform so important to solve _pragmatic_ problems?

I'm also wondering why people are so enamored with these humanoid robot - what they've accomplished is impressive, but from the perspective of replacing humans, I'm sure we are many years away from the versatility required to replace skilled tradespeople.

A humanoid robot shambling along a factory floor to pick up a plastic cover and deposit it onto a shelf does not look like a trillion dollar industry. I'm sure there are much more straightforward ways of accomplishing the same stuff.

Imo the biggest advantage of reproducing humanoid forms, is that then the robot can be teleoperated with full body harnesses that track the human operator. One such system I like really much, is what the Japanese use for fixing overhead power wires - it looks like a humanoid robot torso mated to a mobile crane.

Altough the technology behind that could be done in the 80s, with electromechanical analog controls.

Isaac Asimov answered that - the world is already built for humans so if robots are going to be generally useful replacing and operating alongside humans, they'll have to be human-shaped.

It’s a benchmark that people can understand. And of course humans evolved along with our environments. There are many places where a wheeled contraption can’t go without clearing a path for itself.

Likewise for intelligence. Is human-style intelligence the best benchmark for intelligent machines?

Most factories, including the one I work in, are already designed for wheeled robots, in a sense, because anything heavier than a certain amount is moved around on wheeled carts.

Legged robots can be more efficient, in theory.

Whenever you drive/walk in soft terrain, the wheel/leg is constantly climbing the ramp created by it sinking into the terrain. In a perfect system, this determines how much power you need to move. This is why trains are so efficient. A hard wheel on a hard rail has very little deflection -- so excellent efficiency.

Wheels have to climb that ramp for every inch of travel. Legs get to step forward and only take that penalty for each step. If everything else is the same, the legs win on soft terrain.

But everything else is never the same :-). The early legged vehicles used linear motions, which means you have these very long sliding surfaces. This is heavy and the drive system efficiency dominates over the terrain interaction efficiency. Add in the fact that you have multiple axis to drive and the weight and drive losses really add up.

Modern dog and human style walking robots are MUCH better on efficiency than those early designs. However, they require enough sensing and compute to dynamically balance. Legs can do things that wheels can't, but you have to have smart enough software to take advantage of that. The compute available for a high radiation environment is a fraction of what is in your smartwatch. Wheels are still winning on energy efficiency, but at least it's getting closer.

I worked on Dante at CMU and Marsokhod at NASA Ames; and was in the same group that developed Ambler.

I’d say a lack of imagination.

Lose mobility for a few weeks or months, like breaking both legs (or just try wheelchair access) and see how much of even the paved first world is inaccessible.

Nevermind less refined places like well-maintained hiking trails.

And you can forget about actual trail-blazing.

Then appreciate just how flexible and robust animal and human mobility really is!

The usual reasoning is that 2 legged robots will be able to use the same affordances that two legges humans do.

Legs look cooler, and so get the investment dollars.

There isn't enough money atm to be gained by solving realistic problems, so Tesla et al have to convince investors that it's going to be an incredible leap forward. Which means impressing investors, not focusing on solving problems.

Building a robot and building a robot to operate on Mars are eye-wateringly different challenges.

a bicycle is more efficient than walking, it's not hard to see why - moving a mass up and down is wasted energy

> why is building an anthropomorphic _mobility_ platform so important to solve _pragmatic_ problems

because something rolling along isn't as visually impressive as a complex system to walk, and these companies require hype

To answer my own last question I would also think probably not that important.

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