HN Theater @HNTheaterMonth

#Softwarish - I'm biased a bit more towards interface development:

greg wilson - What We Actually Know About Software Development, and Why We Believe It’s True - https://vimeo.com/9270320#t=3450s

steve wittens - making webgl dance - the title is deceptive, it's in some ways a visual crash course in linear algebra - https://www.youtube.com/watch?v=GNO_CYUjMK8&t=84s

glenn vanderburg - software engineering doesn't work - https://www.youtube.com/watch?v=NCns726nBhQ

chris granger - in search of tomorrow - https://www.youtube.com/watch?v=VZQoAKJPbh8

alan kay - tribute to ted nelson at intertwingled fest - https://www.youtube.com/watch?v=AnrlSqtpOkw

bret victor - this is already mentioned but if I had to pick one it'd be 'the humane representation of thought' - https://vimeo.com/115154289

#Hardwarish:

saul griffith - soft, not solid: beyond traditional hardware engineering - https://www.youtube.com/watch?v=gyMowPAJwqo

deb chachra - Architectural Biology and Biological Architectures - https://vimeo.com/232544872

#Getting more meta in technology and history:

James Burke - Connections

Can anyone in robotics weigh in on whether new approaches like pneubotics / otherlab [0, 1] make Boston Dynamics' super heavy/noisy/expensive robots irrelevant or not? That's what Saul Griffith has been saying at least [2], I'd like to hear an impartial take on it

[0] http://www.pneubotics.com/

[1] https://otherlab.com/projects

[2] "[...] we're the only game in town." 21:00 onwards https://youtu.be/gyMowPAJwqo?t=1263

⬐ gene-h

In my opinion, I don't think inflatable robots are very practical.(except for niche applications)

One of the most important things in robotics is reliability, the more work your robot does before breaking down or needing maintenance the more money it makes you. In industrial robot arms the gold standard for this is a Mean Time Between Failures of more than 100,000 hours. That's more than 10 years of continuous operation!

I am skeptical that inflatable robots will be able to last this long. The fabric/elastomer combo is certainly not going to last through 10 years of continuous operation. Sure this part may be cheap, but you still need expensive valving and pneumatics to control said robot. Not to mention that maintenance costs money too. The payback period for robots is also shortening,

The other problem that pneumatic robots suffer from is that air is compressible. This means that moving it around to drive pneumatics is gonna be inefficient and that pneumatic structures aren't that rigid. Higher rigidity means higher resonant frequency which means your robot can operate faster without wobbling around. The inefficiency might be compensated for because the robot is so light, but I have yet to see any hard numbers on this.

This lack of rigidity is touted as a feature by the people who make inflatable robots. Because they are so light and aren't rigid they aren't going to hurt people if they fuck up. There are other ways to solve this problem that are currently used in the robotics industry. One of them is to put a spring on every link in the robot, which is what the Baxter robot does. Another is to make the robot as light as possible and limit speed which is what one of Kuka's human safe robots does[0]. Better control also fixes this problem, if you don't hit the human then you don't have any problem.

But there might be niche applications. Maybe they will find use in the medical field where having anything rigid touch a human is unacceptable or where you need a weird shape to grab a human on a bed. Entertainment might be another, a while back a japanese company made giant inflatable robots for parades.

[0] http://www.phriends.eu/URAI_08.pdf

⬐ jarmitage

Hey thanks for responding!

If the parts are cheap enough, might it not matter that they don't last the regular MTTF?

One of the arguments I've seen them using is that their robots can actually move faster than regular ones due to their weight advantage - currently I would guess accuracy is not as good though.

Another point I've been thinking about is that biological systems tend to combine the rigid and non-rigid per the needs of the organism, right? It seems that combining these techniques could also be interesting.

⬐ Animats

(http://www.phriends.eu/URAI_08.pdf)

That's a very good paper. There are many advantages to using two opposed springs driven by actuators to simulate muscles. You get muscle-like properties. You get energy storage and recovery. (Humans recover about 70% of energy from muscle springiness when running. Cheetahs, 90%. BigDog, 0%.)

As that paper points out, there are several ways to do this. The cleanest is a double-ended pneumatic cylinder with proportional spool valves at each end able to connect to pressure or exhaust. That was tried on a legged robot at CWRU some years ago. There are schemes with linear springs, string, two motors, and linkages, which tend to be bulky and complex.[1][2] Those work, but are more of a research design than a production mechanism. Somebody will do a better design, probably with rotational springs and no strings.

I once considered a design with two motors, rotational springs, and a differential. One motor controls impedance, the other controls position. If you don't need to change impedance rapidly, which you usually don't, the impedance motor can be much smaller and geared down.

[1] http://mech.vub.ac.be/multibody/topics/maccepa.htm [2] http://www.inacomm2013.ammindia.org/Papers/106-inacomm2013_s...

⬐ pj_mukh

Boston Dynamics' primary innovation is in the software/control design. The reason their robots are noisy is because they really haven't innovated a whole lot in the basic actuator design. That's not to say their mechanical design was easy, not by a long shot. It's super impressive stuff!

Any new inventions that would make their mechanical design steer away from loud hydraulics would no doubt be amazing. However, without Boston dynamics' delightfully ground-breaking controls software design, it'll be dead in the water!

For a little bit of proof, see who they are hiring! http://www.bostondynamics.com/bd_jobs.html

⬐ jarmitage

Thanks for your reply.

Is there much publicly available information about their software/control design innovations?

Hmm, maybe one might expect they would be hiring more mechatronics engineers to do just that? Or maybe there's still not much point for them because as you mentioned their focus is slightly different currently.

⬐ pj_mukh

A person with a core Mechatronics focus will probably be a great systems integrator. BD's core workforce are these PhD's in controls (usually from ECE departments). Source: Am a Mechatronics Engineer with a Controls focus.

check out some of the work of BD's CEO (Marc Reibert). This (http://web.unair.ac.id/admin/file/f_7773_bigdog.pdf) is the summary paper on Big Dog, but they cite a bunch of the older Reibert papers on Controls designs for legs.

⬐ PhasmaFelis

A lot (most?) of the noise comes from the engine, not the hydraulics, and the engine can't be replaced because sufficiently high-capacity batteries do not exist yet. That's not a problem that can be solved by innovative actuators.

⬐ pj_mukh

That too. Also engine design was contracted out.

⬐ KiwiCoder

This video is about the applications of soft/flexible materials in robotics and other hardware. It's not (as I mistakenly assumed) a teardown of the SOLID principles.

⬐ dsfsdfd

Yeah I was disappointed, I thought maybe I was going to see some cool new compliant software engineering principles.

⬐ xtrumanx

I assumed it wasn't about SOLID principles due to the "Hardware Engineering" bit in the title but I can see why there would be confusion due to the capitalization of SOFT and SOLID.