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The US Army spent millions developing giant, six-legged walking trucks in 1980s

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Re: The US Army spent millions developing giant, six-legged walking trucks in 1980s

#41
post #23

Oh, that thing. Back when I was into legged locomotion, I found out more about that machine than I ever wanted to know. The designer was really into four-bar linkages. The leg mechanism is set up so that one actuator moves the leg in X, one in Y, and one in Z, with a four-bar linkage encoding that into the leg position. This simplifies the control problem, while complicating the mechanics. I suspect they wanted to be…

Oh I want one of those "Timberjack" machines. (well without the timber cutting stuff). Based on some of the papers I found on the OSU project it seems like you could replace the entire computing infrastructure it was carrying around with about one pound (1/2 kg) of computers.

I don't suppose you have a pointer to an IK paper on the 4-bar linkages do you? Looks like something that might be fun to cons up with servos.

Re: The US Army spent millions developing giant, six-legged walking trucks in 1980s

#42

I have many books on on robotics and AI from Stanford and MIT from that era, back when I started to get deeply involved in the field. My son is about a year away from graduating with degrees in CS and Robotics. He was quite surprised to realize that much of what he is learning today isn't new at all. Tremendous work was done decades ago in both domains. Put simply, you can only get so far with neural networks when yo…

It's under-appreciated just how brilliant the initial set of AI and Robotics pioneers were. Our future lies in the past.

Would you be open to digitizing these books via the Internet Archive, or something similar?

If they're sufficiently technical, you may have the only copy in the world for some of them.

Re: The US Army spent millions developing giant, six-legged walking trucks in 1980s

#43
post #16

Earlier quoted context omitted.

yeah, a single M1 Abrams tank costs over $4 million, and we have 9000 of them. DARPA R&D money always feels like money better spent than a lot of other military spending. We get future dividends, often civilian.

What are you talking about? Everyone is poor and miserable, families arent making rent. My uncle was just dumpster diving to feed his family two months ago. They're wasting the people's money over at DARPA.

If your uncle is dumpster diving for food I doubt he pays any taxes after refunds.

Re: The US Army spent millions developing giant, six-legged walking trucks in 1980s

#45
post #23

Oh, that thing. Back when I was into legged locomotion, I found out more about that machine than I ever wanted to know. The designer was really into four-bar linkages. The leg mechanism is set up so that one actuator moves the leg in X, one in Y, and one in Z, with a four-bar linkage encoding that into the leg position. This simplifies the control problem, while complicating the mechanics. I suspect they wanted to be…

Oh I want one of those "Timberjack" machines. (well without the timber cutting stuff). Based on some of the papers I found on the OSU project it seems like you could replace the entire computing infrastructure it was carrying around with about one pound (1/2 kg) of computers. I don't suppose you have a pointer to an IK paper on the 4-bar linkages do you? Looks like something that might be fun to cons up with servos.

There are quite a few quadruped robots that use them for legs: https://youtu.be/2k5lOUGenkE

Re: The US Army spent millions developing giant, six-legged walking trucks in 1980s

#46
> Between the engine and the 18 variable displacement pumps [...] was a 100-pound flywheel. It spun up to 12,000 rpm and could store .25 kWh of energy. > The flywheel also allowed the vehicle to recuperate some energy from the pumps when the ASV came to a stop […] and ensured a smooth shutdown in case of a sudden loss of power.

Re: The US Army spent millions developing giant, six-legged walking trucks in 1980s

#48

Earlier quoted context omitted.

>>DARPA R&D money always feels like money better spent than a lot of other military spending. I think "better spent than a lot of other military spending" was the point of the post you responded to. The military may be wasting The People's Money, but DARPA seems to have low costs / high return comparatively, and often has high returns for civilians/society.

What return? Dead people? Pollution? Fear?

Lasers, fusion research, GPS, the internet...

Re: The US Army spent millions developing giant, six-legged walking trucks in 1980s

#49
post #30

Earlier quoted context omitted.

What are you talking about? Everyone is poor and miserable, families arent making rent. My uncle was just dumpster diving to feed his family two months ago. They're wasting the people's money over at DARPA.

That's the choice of your fellow citizens who'd rather spend money on weapons than feed people, and will come up with elaborate stories about why your uncle deserves to be in that position. :(

The other side of this is we spend a lot of money feeding people in the US. Unfortunately, it’s not an efficient system consisting of farm subsidies, food stamps, school lunch programs etc. If the goal was simply adequate nutrition for every American we could easily have that with current budgets. But, instead money must also end up in the correct people’s pockets while also feeding people.

Re: The US Army spent millions developing giant, six-legged walking trucks in 1980s

#50
post #23

Oh, that thing. Back when I was into legged locomotion, I found out more about that machine than I ever wanted to know. The designer was really into four-bar linkages. The leg mechanism is set up so that one actuator moves the leg in X, one in Y, and one in Z, with a four-bar linkage encoding that into the leg position. This simplifies the control problem, while complicating the mechanics. I suspect they wanted to be…

Oh I want one of those "Timberjack" machines. (well without the timber cutting stuff). Based on some of the papers I found on the OSU project it seems like you could replace the entire computing infrastructure it was carrying around with about one pound (1/2 kg) of computers. I don't suppose you have a pointer to an IK paper on the 4-bar linkages do you? Looks like something that might be fun to cons up with servos.

There's an MIT Press book.[1] Chapter 6, "Leg Design by Four Bar Linkage Synthesis" covers the four-bar linkage. They were struggling to get enough working volume for the foot out of the four bar linkage without the mechanism becoming too bulky. They wanted to be able to move horizontally using only one actuator per leg, which allowed manual backup control.

It's an interesting piece of history, but there's no need to do it that way today.

[1] https://www.amazon.com/Machines-That-Walk-Adaptive-Suspensio...

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