Author Topic: Armadillo Test Flies New Vehicle (w/video) (Read 18616 times)

braddock · « **on:** 08/10/2006 12:25 pm »

Armadillo Aerospace test flew on a tether their new vehicle, which they intend to enter into the Lunar Lander Challenge at this year's X-Prize.

http://media.armadilloaerospace.com/2006_08_07/liftoff.jpg">

A new Armadillo update covering the past month is at: http://www.armadilloaerospace.com/n.x/Armadillo/Home/News?news_id=331

Video of the flights are at:
http://media.armadilloaerospace.com/2006_08_07/hop1.mpg
http://media.armadilloaerospace.com/2006_08_07/hop2.mpg
http://media.armadilloaerospace.com/2006_08_07/hop3.mpg
http://media.armadilloaerospace.com/2006_08_07/hop4.mpg <- only flight with sane control system

They had the roll-thrusters backwards in the control system that mystified them until the last flight. Damn software.

I'm not qualified for anything, but it looks damn unstable to me. The thruster is very close to the CG. Watch the nozzel swing back and forth to the stops to keep it remotely level in the last flight until the oscillations overcome it, and the tilt angle forces a shutdown.

Carmack says he can avoid the osciallations for this by doubling the control system gain - he managed to reproduce it in his simulator.

NotGncDude · « **Reply #1 on:** 08/10/2006 12:47 pm »

Definitely unstable, just look at that oscillation.

astrobrian · « **Reply #2 on:** 08/10/2006 09:33 pm »

One of the videos seemed like it was fairly stable throughout the entire burn. Great stuff

braddock · « **Reply #3 on:** 08/11/2006 12:56 am »

Quote

astrobrian - 10/8/2006 5:20 PM
One of the videos seemed like it was fairly stable throughout the entire burn. Great stuff

The fourth test was the best (it was the only one with the roll control thrusters hooked up right), but it didn't end at the planned end of burn, but instead because a tilt safety sensor forced a shutdown.

Here is Carmack's description:
Steady flight, but increasing oscillations eventually caused a tilt shutdown. Roll thrusters fired in both directions, behaving properly.

This type of divergence is usually a simple matter to fix with a gain change, and I was able to replicate the behavior in the simulator by tripling the polar moment of the simulated vehicle, which makes sense comparing the quad to last year's X-Prize Cup vehicle. Correcting the behavior in the simulator was just a matter of doubling the angular position gain (and leaving the rate gain alone).

I hope they get it working. They don't have much time left before the X Prize, and they lost their Texas test site so they have to drive all day to Oklahoma to test fly now - and they still need to get permits rushed to fly before a crowd of people, which I'm sure goes faster with a functional vehicle.

nacnud · « **Reply #4 on:** 08/11/2006 12:59 am »

Gain = speed of the actuator controlling the nozzle?

braddock · « **Reply #5 on:** 08/11/2006 01:03 am »

I think "angular position gain" must be the amount of angle the nozzle is moved for a given feedback (?), since he said the "rate gain" (speed of actuator?) would stay the same.

nacnud · « **Reply #6 on:** 08/11/2006 01:26 am »

Oh ok, the nozzel moverment did look a little like PIO but presumably the flight control logic would have a handle on that.

astrobrian · « **Reply #7 on:** 08/11/2006 02:40 am »

So is this a stand alone project or is it destined to go in a specific vehicle of thiers?

nacnud · « **Reply #8 on:** 08/11/2006 03:03 am »

It's their entry into the NASA Luna lander challange.

astrobrian · « **Reply #9 on:** 08/11/2006 03:43 am »

I just finally caught that on the very first post [DOH] Guess I need to stop gravitating to all the pretty pictures of fire

braddock · « **Reply #10 on:** 09/02/2006 02:13 am »

Armadillo apparently had a pretty successful test hover yesterday.

They are reportedly heading out to the Oklahoma space port to try a full 90 second test this weekend.

That test last night doesn't seem to have any stability problems: looks rock stable to me...

hover35 dual

mpeg format of single view

MKremer · « **Reply #11 on:** 09/02/2006 03:30 am »

That looked *much* better!

However I still haven't seen an indication they can successfully throttle down to a stable landing. Even more difficult will be a translation, then back to a stable hover.

astrobrian · « **Reply #12 on:** 09/02/2006 04:10 am »

Looks like they really stepped up to the plate on that one. I saw little to no rolling at all. One step at a time

braddock · « **Reply #13 on:** 09/02/2006 09:45 am »

Yeah, they have a long way to go. But of course they are only working on this unpaid nights and weekends...more like a model rocket club on steroids than a space company.
Armadillo is definitely one of the most fun groups to watch.

astrobrian · « **Reply #14 on:** 09/02/2006 01:49 pm »

Thats usually the best people to work for, nothing gets held back that way and anything goes

meiza · « **Reply #15 on:** 09/03/2006 12:24 pm »

Armadillo has one paid worker (after the nvidia sponsor) doing paperwork atm.

JesseD · « **Reply #16 on:** 09/05/2006 01:45 pm »

new update:
http://www.armadilloaerospace.com/n.x/Armadillo/Home/News?news_id=333

looks like they got some good performance from their cast metal injectors.

There's some good pictures there, too!

bad_astra · « **Reply #17 on:** 09/05/2006 03:38 pm »

Can't wait to see Vertical Drag Racer fly

NotGncDude · « **Reply #18 on:** 09/05/2006 05:21 pm »

This test doesn't show the oscillation that was obvious in the test from a few weeks ago.

astrobrian · « **Reply #19 on:** 09/05/2006 07:50 pm »

The daylight test shown above was also cut short by something said to be GPS in the video.

josh_simonson · « **Reply #20 on:** 09/05/2006 07:52 pm »

Stable feedback systems can be complex to design, specifically the gain at the frequency that corresponds to the loop delay time must be less than 1 or you get positive feedback that causes oscillations or sloppy settling. When dealing with instability this leaves 3 options, increase frequency compensation of the amplifier so the gain rolls off at a lower frequency, decrease the DC gain to reduce the gain over the entire frequency spectrum, or get a faster attitude sensor to push the phase inversion out.

Generally killing DC gain is the easiest of the bunch, but it comes at the cost of accuracy - which is often a firm design requirement. Generally I start a design by pegging the gain at the lowest point that will safely meet my requirements, then fiddle with compensation if needed and last consider architectural changes if compensation is intractable or prohibitive.

From the sounds of it they're either reducing their DC gain or fiddling with some AC gain parameters in digital filters that are used to compensate the system.

meiza · « **Reply #21 on:** 09/05/2006 08:12 pm »

Quote

astrobrian - 5/9/2006 8:37 PM

The daylight test shown above was also cut short by something said to be GPS in the video.

It tells all in the update: it was raining, and they couldn't get good enough GPS data (I gather the two things were related).
They might relax the terms a bit in the future...

braddock · « **Reply #22 on:** 10/05/2006 06:51 pm »

New Update, including a fairly stable 90 second tethered flight!
They also almost have the second vehicle ready to go. They want to RACE them at XPrize Cup!

http://media.armadilloaerospace.com/2006_09_30/pixelAndTexel.jpg">

http://media.armadilloaerospace.com/2006_09_30/FOFflight.jpg">

Unfortunately, they can't do any untethered tests until the actual XPrize Competition, because it requires a launch permit. Seems rather detrimental to safety if the FCC makes the launch permits so hard to get that the first real test flight will be right in front of a few thousand people.

MKremer · « **Reply #23 on:** 10/05/2006 08:25 pm »

Racing would be cool!

Interesting that they've got an nVidia sponsor logo on the tank.
(wonder who ATI/AMD could want to sponsor?

)

braddock · « **Reply #24 on:** 10/05/2006 08:39 pm »

Quote

MKremer - 5/10/2006 4:08 PM
Interesting that they've got an nVidia sponsor logo on the tank.

And of course there are the rocket's names:
Pixel and Texel....

Too bad these rocket's lack Frustums and ViewPorts, but I hope they still have Vectors!

Martin.cz · « **Reply #25 on:** 10/05/2006 09:04 pm »

They got nVidia to sponsor them

"NVIDIA is Armadillo Aerospace’s official sponsor for the X-Prize Cup events this year."
Carmack + nVidia + Rockets = best combination ever

hop · « **Reply #26 on:** 10/05/2006 10:10 pm »

There's a new update http://www.armadilloaerospace.com/n.x/Armadillo/Home/News?news_id=335

Looks like they are on track to have two flyable vehicles for the xprize cup this year.

Spirit · « **Reply #27 on:** 10/07/2006 09:56 pm »

The project is really cool! I wonder how much will it cost to build such a machine in East Europe. I would like to build something like this in my backyard in Bulgaria

Good luck to Armadillo and his/their vehicle!

meiza · « **Reply #28 on:** 10/07/2006 11:29 pm »

Quote

Spirit - 7/10/2006 10:39 PM

The project is really cool! I wonder how much will it cost to build such a machine in East Europe. I would like to build something like this in my backyard in Bulgaria

Good luck to Armadillo and his/their vehicle!

If the regulatory environment and companies are more relaxed in your country, you might get your hands on high test peroxide, which was Armadillo's first try anyway (you can read the archive posts on their site). It might be relatively easy to construct rocket engines with that, although it can be dangerous.

hop · « **Reply #29 on:** 10/08/2006 03:02 am »

Quote

Spirit - 7/10/2006 2:39 PM

The project is really cool! I wonder how much will it cost to build such a machine in East Europe. I would like to build something like this in my backyard in Bulgaria

It's not quite in your back yard, but you might want to check out http://www.arcaspace.ro/en/home.htm in Romania.

braddock · « **Reply #30 on:** 10/12/2006 11:34 am »

Here is a picture of Armadillo's would-be competition, Maston Space Systems. They haven't test flown it yet. They claim it is ready for first flight, but they didn't get their flight qualification and permit.

http://lunarlander.spaceracenews.com/wp-content/uploads/2006/10/masten.jpg">

Armadillo still hasn't gotten a permit for a flight at the X Prize. They just did another 90 second flight yesterday, and will be trying for a 180 second flight today.

Carmack: "Flying at the cup is gated on the experimental permit. I suppose we might be able to do a tethered demo flight without it, but I’m certainly not going to pay for the insurance, consumables, and transport for a non-prize flight."

http://lunarlander.spaceracenews.com/?p=99

braddock · « **Reply #31 on:** 01/04/2007 06:32 pm »

New update from Armadillo, always a must-read.
http://www.armadilloaerospace.com/n.x/Armadillo/Home/News?news_id=340

Anyone wanna to go for a ride? The saddle is installed.

http://media.armadilloaerospace.com/2007_01_03/saddle.jpg">

Also, apparently this is how you test after the police shut down testing at your shop and your neighbor shuts down testing at your farm:

http://media.armadilloaerospace.com/2007_01_03/horizontalTest.jpg">

http://media.armadilloaerospace.com/2007_01_03/horizontalCloseup.jpg">

They can't stop ya if they can't catch ya!

meiza · « **Reply #32 on:** 01/04/2007 11:04 pm »

Graphite nozzle ("saddle"), the material between the cooling methanol and the expanding hot combustion products... it sounds like asking for trouble, why not go for aluminium? Their chamber pressure is low, it shouldn't be hard, no?

jongoff · « **Reply #33 on:** 01/05/2007 05:38 am »

Meiza,

Quote

Graphite nozzle ("saddle"), the material between the cooling methanol and the expanding hot combustion products... it sounds like asking for trouble, why not go for aluminium? Their chamber pressure is low, it shouldn't be hard, no?

Aluminum might be possible, but they had a lot of issues trying to make it work previously. Copper would work fine. His pressures are much lower than ours are, and our engine is smaller, which typically makes cooling harder, but after taking the data and doing the thermo, we got our very first regen cooled engine to work no problem. In order to get aluminum to work though, he'd actually have to take a lot of data, and do the analysis right--aluminum is kind of marginal for the job.

~Jonathan Goff
Masten Space Systems

braddock · « **Reply #34 on:** 02/06/2007 06:51 pm »

New Armadillo update is posted: http://www.armadilloaerospace.com/n.x/Armadillo/Home/News?news_id=342

They are flying again, and with a regen engine no less.
http://media.armadilloaerospace.com/2007_02_05/groundLanding.wmv

Also, here is a VERY cool slowmo video of a tank burst test: http://media.armadilloaerospace.com/2007_02_05/tankBurst.mpg

"We made three good long flights with Pixel this month. There are three significant changes since the X-Prize Cup: new landing gear, regeneratively cooled engine, and new gimbal actuators."

"I’m happy to hear that a number of new teams are springing up looking to compete in the lunar lander challenge (I know of at least six prospects, outside of the 2006 entrants), but I think it is going to be a long shot for anyone to beat us to first place. "

Dem sounds like fight'n words, Jon...

ericr · « **Reply #35 on:** 02/06/2007 07:22 pm »

What fun. I want one too!

josh_simonson · « **Reply #36 on:** 02/06/2007 07:25 pm »

Quote

braddock
Also, here is a VERY cool slowmo video of a tank burst test: http://media.armadilloaerospace.com/2007_02_05/tankBurst.mpg

Looks like pac-man at a frat party!

publiusr · « **Reply #37 on:** 02/07/2007 06:06 pm »

The smaller these craft are--the faster they can get out from under you.