It really is rocket science...

[IndependentlyPoor]

Caution: Über geek stuff

This is way cool. Watch how the rocket nozzle swivels delicately and precisely to keep the craft upright. Figuring out how to do this was one of the big stumbling blocks of making a successful rocket. (The other was keeping it from blowing up.) I believe the first to get it right were Werner von Braun and the German rocket scientists who developed the V-2 during WWII.

Armadillo Aerospace Claim Level 2 NGLLC Prize | International Space Fellowship

This is a classic problem in control theory (caution, following this link may cause your head to explode). It is what you do when you balance a pencil in your palm, but solving the equations so that you can make a machine do it stumped scientists and engineers for years.

It turns out that knowing the angle of the pencil (how far it is leaning) is not enough, you also have to know the rate of change of the angle (how fast it is falling over). In college we actually had this as a lab exercise. To simplify it for us, they made it one-dimensional: the "pencil" was hinged at the bottom and sat on a little "car" that ran along a track driven by electric motors. The mechanical apparatus was already set up for us. The problem was to design and build the a control system for the motors that would balance the "pencil". When we finally got it working it was amazing to watch. You could tap the pencil to send it rocking off balance and the "car" would go zooming off back and forth to rebalance it. Here is a video of a two dimensional one at work:

YouTube - Pencil Balancer on Changing Background

It turns out that Armadillo Aerospace is just a bunch of rich computer game geeks, playing with techno-toys. Well done guys!

[REWahoo]

Really cool!

[Nords]

Awesome.

I wonder how much of these advances comes from years of research, and how much comes from cheaper/advanced processing power. Doing this with a 386 chip would have quickly turned into an exercise in figuring out how to get enough interrupts to even start the system, let alone go 2D.

[IndependentlyPoor]

Quote:

Originally Posted by Nords I wonder how much of these advances comes from years of research, and how much comes from cheaper/advanced processing power. Doing this with a 386 chip would have quickly turned into an exercise in figuring out how to get enough interrupts to even start the system, let alone go 2D.

Good observation. Digital control systems have revolutionized the field, but they aren't the only way. It is possible to build a control system that is entirely analog. The pencil balancer lab we did in college was all analog. Not a micro-processor in sight.

[Nords]

Quote:

Originally Posted by IndependentlyPoor Good observation. Digital control systems have revolutionized the field, but they aren't the only way. It is possible to build a control system that is entirely analog. The pencil balancer lab we did in college was all analog. Not a micro-processor in sight.

I always felt that was a PITA, and I think that digital systems have made it a lot easier to automate the basics and get to the really advanced analysis & design.

I really enjoyed learning how to cook food in an imu, but once through that process was enough to understand why the ancient Hawaiians invented microwave ovens.

However it's fun to talk about biasing magnetic amplifiers so that the young whippersnappers look at you as if you're a T. rex.

[Ed_The_Gypsy]

The V-2 was stabilized using movable graphite vanes in the rocket exhaust. I do not anything about the control loop but it had to be simple and mechanical.

[JOHNNIE36]

IndependentlyPoor, this device had me really interested for about 60 seconds and then my mind wandered to the goofy planter and palm trees. Is the planter really skewed or am I seeing things? I'm at the point where I believe half of what I hear, nothing of which I read and maybe now it's 25% of what I see. I thought my eyes were deceiving me, but no, that ugly planter is really skewed. Please tell me I'm right. The planter is very interesting and I guess beauty is in the eyes of the beholder.
Sorry to call the vase

[IndependentlyPoor]

Quote:

Originally Posted by Nords I think that digital systems have made it a lot easier to automate the basics and get to the really advanced analysis & design.

Yep. The micro-electronic revolution in a nutshell. Engineers can now think on the system level instead of the transistor level. Engineering productivity has increased astronomically during our lifetimes. When I was in college, integrated circuits were literally drawn by hand and photo-reduced. Companies measured a design team's productivity in transistors per day. I have been out of the game for a while now, but now that number could easily be pushing a million a day.

Analogous advances have been made in software. We used to write assembly code (we are talking 1's and 0's here), now software engineers wield libraries of object oriented widgets. If I remember correctly, software productivity was about 7 lines a code a day. It probably still is, but that 7 lines of code now does a million times as much.

We see the fruits of this all around us. For me, the most impressive is digital audio and digital video. We studied the theory of digital audio in college, but doing it in real time was unthinkable. Now you can run your iPod Nano through the washer by mistake because you forgot it in your pocket, but they cost so little, who cares? The first time I heard of real-time digital audio was when a friend of mine commandeered his company's Sperry Univac mainfram one weekend to experiment with. A whole room full of computer (millions of dollars and tons of equipment, incuding chilled water cooling) and it couldn't come close to what a Nano can do.

I was lucky enough to have a ringside seat. It was very exciting.

T. Rex reminiscing over. Your eyes can start to un-glaze now.

[M Paquette]

Armadillo Aerospace was founded by John Carmack, a really smart guy who also started 'id Software' back in 1991. 'id' was the company that produced Commander Keen, Castle Wolfenstein, Doom and Quake.

Don't say nothing good ever came out of video games. They funded Armadillo.

[Nords]

Excellent book: "Masters of Doom".

[HFWR]

IIRC, state-of-the-art in 1983, when I started in the chip bidness, was 256k DRAMs, with 64k being the commodity. Still remember celebrating the first 1M DRAM in 1986.

Of course, most computers still had 10 or 20M HDs. Why would anyone ever need more than that...