Acromaster as UAVDevBoard platform

Hi,

here are some experiences with Bill Premerlani amazing UAVDevBoard on a Multiplex Acromaster.

Here is a video that shows the impressive ability of this device with Ben Levitt pattern stabilization firmware:

UAVDevBoard stabilized Acromaster from Riccardo Kuebler on Vimeo.

The plane, base components:

Acromaster with Apache 30/14T AR
ESC Castle Creation Phoenix 45
Lipo 4S 3600mAh
Propeller APC 12x6
Servos 4x Hitec HS81MG
ACT S3D 2.4GHz 4+2 RC rx

IMU upgrade:

UAVDevBoard
Oilpan
Ublox
Xbee Pro
A123 2S 1300mAh

Here is the options.h file with my actual settings:

options.h

Here is a spreadsheet with the commented history of the settings:

Logbook Acromaster.xls

This is a great work from all the developers and programmers (hardware: Bill Premerlani, Tom Posey; firmware:Bill Premerlani, Adam Barrow, Adam Bellchambers, Pete Holland, Ben Levitt; Aerobatics stabilization firmware: Ben Levitt; and all the fantastic rest of the team).

Best regards,

Ric

1st edit 7.2.10:
link added for autopilot devices, video embedded

Thanks Ric! Well, my current strategy (works in the sim! Does that count?) is to have a feedback loop on throttle to hold an airspeed just over stall. I approach at a -20 pitch angle... normally that accelerates me to 50 mph. But I have a trick: Reverse thrust! So the FB loop can command negative thrust to keep the speed low. I've tested a car speed controller and it looks like this idea might actually work.

Doesn't seem as elegant as some of the maneuvers in the video for this devboard though!

P.S. - The EZSTAR has tiny control surfaces (I do have ailerons) and the propwash misses the tail completely. So between what you mention and this, I don't think this is viable on that airframe. What happens is that you pull the nose up, and it starts to drop as airspeed drops. Then you add throttle, but you can never quite keep the nose high enough to enter that slow hoover realm.

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Comments

Tj Bordelon February 5, 2010 at 12:48pm

Thanks Ric! Well, my current strategy (works in the sim! Does that count?) is to have a feedback loop on throttle to hold an airspeed just over stall. I approach at a -20 pitch angle... normally that accelerates me to 50 mph. But I have a trick: Reverse thrust! So the FB loop can command negative thrust to keep the speed low. I've tested a car speed controller and it looks like this idea might actually work.

Doesn't seem as elegant as some of the maneuvers in the video for this devboard though!

P.S. - The EZSTAR has tiny control surfaces (I do have ailerons) and the propwash misses the tail completely. So between what you mention and this, I don't think this is viable on that airframe. What happens is that you pull the nose up, and it starts to drop as airspeed drops. Then you add throttle, but you can never quite keep the nose high enough to enter that slow hoover realm.
Riccardo Kuebler February 5, 2010 at 8:46am

Hi Rana,

how are you?

The Oilpan is a great idea from Tom Posey. He made few examples. Ask him about availability.

TJ, to keep nose up you do have a big elevator, with high rate and CG positioned the rear you can. As a result you get a very unstable plane (say an aerobatic devoted one). You need then big ailerons and big rudder too, because at low speed they become less responsive. I already read your performances and am very curious to see how you handle this.

Best regards,

Ric
Tj Bordelon February 5, 2010 at 7:46am

The "harrier" manuver looks perfect for coming down in a small landing zone. Awsome project!!

I've spent at least 6 months trying various ways to autoland and usually wind up coming in too fast and taking too much of a runway (and ending up in the trees) or I come in too slow and stall.

I'm using an EZSTAR, so maybe the "harrier" won't work because I don't have propwash over my tail. I've tried the high alpha landings with full throttle and they don't seem to work... I just can't hold the nose up. what's the trick?
Rana February 5, 2010 at 2:02am

Hey Ric, I loved you video and I am still loving it !
Billu Bhaiya & Ben Levitt are really great guys & man u 2 !

Rana
Paul Bizard February 5, 2010 at 1:36am

Nice. Now we must find a way to hide the board inside the fuselage !

Paul
Rana February 5, 2010 at 12:10am

Hey Ric, thats really great !
Did you etch the Oilpan PCB your self or you ordered it.
Where is the source if ordered ?

Rana
Marv2097 February 4, 2010 at 4:20pm

Nice work Ric! good to see what the UAV Dev board is capable of.

Marv
OlivierD. February 4, 2010 at 3:31pm

OMG! What a video! This is simply amazing. Bill, you have created a monster! Congratulations to Adam Barrow, Adam Bellchambers, Pete Holland, Ben Levitt for fine tuning the code, this is the biggest breakthrough in DIY IMUs I have seen so far. I am speechless.
Riccardo Kuebler February 4, 2010 at 12:49pm

Bill,

I am honored.

This all started from you.

I am deeply grateful!

Ric
T3

William Premerlani February 4, 2010 at 12:43pm

Ric,

Bravo.

Bill

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