Author Topic: Armadillo Test Flies New Vehicle (w/video) (Read 18614 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.