Servers by jDrones

MicroArduCopter, 3" props, Omnibus Nano, Success!


(S) #1

I finished my micro arducopter build. Everything is working!
Omnibus nano v6 fc.
Crossfire radio and telemetry.
GPS/Compass

It flew great from the start in stabilize. (I have experience w/ 250 size quads and know the general tuning requirements for a small copter, and they all worked well).
I really struggled w/ alt-hold. But, the issue was the usual… Needed more foam and wind protection, and less vibrations. I also adjusted the EKF alt setting that controls how much it relies on the baro vs the other sensors. I set it to 2 from 3, which means rely on the baro more. I had to majorly decrease the PID’s related to alt-hold. Throttle Accel is .2 for p, and .4 for i. I lowered the other couple of related settings, too.

I was going to include a few more technical details, but my 3 year old is screaming in my face…
If anyone has questions about getting a small copter together, I’m happy to answer.

One other thing, I knew from the start I’d have electronic interference on this small build, so just about every board in my stack has a layer of copper foil tape on it, all star grounded to the battery. I have no noticeable issues! GPS gets a solid lock w/ my camera and everything running.

-also, have low esr caps on both the ESC terminals, and the 5v output on the FC.


Sky Viper Journey Pro Video GPS Drone V2700 -It's HERE!
(Joel Ben) #2

Trying to get a fluent tutorial in flashing to ardupilot. Have a board http://www.readytoflyquads.com/flip32-f4. Any help would be greatly appreciated if you have time.


(S) #3

http://ardupilot.org/copter/docs/common-loading-firmware-onto-chibios-only-boards.html
The official wiki has detailed instructions for loading ardupilot onto the boards.

I’m not positive if that board is supported, though… Only specific boards are. A lot of betaflight boards are technically the same, but I don’t know enough about it… There’s a good chance that one is the same as the omnibus or another supported f4 board, but I don’t know for sure.
I’d stick to the omnibus f4 pro, or other definitely supported board.
Here are all the supported ones:
http://firmware.ardupilot.org/Copter/beta/


(Peter Hall) #4

Great build! What gps compass unit are you using? I have a 180 with a mini revo, the internal compass is unusable due to interference, this locks out loiter and auto. I couldn’t find a small gps and compass so I have this one to fit once I have finished messing about with boats.


(S) #5

I started with a csg shop micro gps, which was expensive! That’s what’s in the picture. But I completely destroyed it and my relatively expensive crossfire micro receiver while tuning the copter! :(. Like I said, I really struggled w/ altitude hold!
Now I’ve got an old rtfq mini gps on it, which is bigger, but actually the same weight. (and, I think it works better… I didn’t get a lot of use out of the csg shop one, but in MP the copter track was moving all over the place while the copter was still)
Next, I’m waiting for stock to arrive of a new matek mini GPS/Compass, which is about the same size as the csg shop one, but 1/3 the cost.

As for the interference, you can’t see it in the pic, but the copper foil I mentioned is what mitigates the interference in my case. My camera and camera cables, and ESC are covered in it. And, the low esr oscon caps I have on the ESC and the 5v output of the FC help.


(MartinKeilloh) #6

Ive got the Matek GPS/compass and it appears good,im watching this with great interest did you get loiter and rtl working well,many thank’s,Marty


(S) #7

I’m getting inconsistent results w/ loiter tuning.
I’m not sure if the settings are applied w/out rebooting… It was working well enough from the start… It ‘held’ its position w/in about a 1 meter area. But I thought maybe I could get it to hold position a little better. So, I was tuning the PSC settings last night. Thought I had it dialed in very well. Then my battery died and I put on a new battery, booted up, and then loiter was out of control! It was moving quickly all over a 5 meter area. Then the sun went down.
SO, I’m going back out to work on that today.

I’ve never had consistent results w/ loiter, though, on any of my arducopters… One day it works well, the next it drifts all over. Regardless of satellite/hdop. I’ve asked for help tuning it several times, but never get any responses. Maybe it’s a mystery for everyone.


(MartinKeilloh) #8

Thank you wicked1,but you are nice1 to me,yea will play with it and see if I get good loiter etc,will keep you up to speed,I allways had RTL work good does it on the omnibus board


(S) #9

About loiter tuning…
I’ve been finding that generally, the psc xy velocity settings need to be lower on these small copters. And, the psc xy position p setting needs to be higher.
At this point my velocity are 1/2… From p=2, i=1, d=.5 to p=1, i=.5, d=.25.
And, I doubled the position p setting from 1 to 2.

I confirmed similar settings on my 250 size copter w/ logs… It was easy to see as I changed settings that it didn’t wobble as much and matched its position better.
I don’t have logs on this little one, but it seems to be working well.

At this point I think I’m done w/ my basic tuning, and am ready for my goggles.
It’s easier to notice the little twitches and wobbles in goggles, so I’m sure I’ll have a lot of fine tuning to do in the future. It’s working just as well as my other bigger copters, though. I honestly expected more trouble w/ this little guy.

Thanks to everyone involved in ArduPilot! This has basically been my dream copter for a couple years now, and thanks to ChibiOS and all the hard working developers, I’ve got it!
(Well, my dream copter would be this small w/ a tiny gimbal, but we’re not there yet :slight_smile: )


(MartinKeilloh) #10

thank you so much for sharing maybe get my one up and running tomorror or wednesday for testing,its great the work the devs do for us they are real stars,thank every one so so much


(vosair ) #11

Super cool build! What was the inspiration? Any particular purpose other than fun?


(S) #12

I don’t have a lot of room to fly… So, small is more fun for the area I’m in.

And, it’s much less scary and less expensive testing settings and beta software on a small copter than a big one…
I started off in this hobby w/ a 16" prop drone about 5 years ago, and that thing was expensive and dangerous when things went wrong. Then I built 250 size drones, and they aren’t much better… Still do some damage if they crash into something. These micro copters are relatively safe… Usually don’t break when they crash.

The big drone has a gimbal and all the advantages that come w/ that. But I’ve done photogrammetry (made 3d models of construction sites and buildings) w/ my 250 size copter and a down facing camera. This microcopter would be able to do that, too.


(MartinKeilloh) #13

Hi wicked1,could you please share your pid’s,im down to .08 and 07 on pitch and roll ans still massive vibes,many thank’s


(S) #14

I started w/ p=.03, i=.03, d-.0005
Auto-tune increased them to about p,i=.04 and d=.0009

Start w/ the lower numbers… You probably have to set them in the full parameter list, as the extended tuning screen might not let you go that low.

You should also change your filter settings…
Change these too:
INS_GYRO_FILTER = 80
INS_ACCEL_FILTER = 10 (Some people have trouble w/ this one this low… Maybe leave it at 20, or some have put it up to 40 to fix issues w/ altitude hold)
MOT_THST_EXPO = 0.5
ATC_RAT_RLL_FILT = 40
ATC_RAT_PIT_FILT = 40

SCHED_LOOP_RATE=800
(This last one is sort of experimental at this point)


(S) #15

I should also mention, I have relatively weak 1103 motors and 2s batteries.
A more powerful setup would need even lower PID’s.

Generally bigger copters need larger PID’s because there’s more mass to move, and more powerful batteries/motors need lower PID’s.


(Andy Kwong) #16

Amazing thread here wicked1. Congrats on the slick build!

I’ve been trying to get a 3" ‘MicroArducopter’ (also with an Omnibus Nano) to work in Drift mode for a couple weeks now with little success. I got it tuned well enough to fly around confidently in Acro, but it would pitch, roll, and lose altitude all over the place in Drift. I was in dire need of help when I came across this thread.

Thank you for sharing your settings, there are a few that I didn’t even know of. I will tune accordingly and be sure to report back!

Here is my 3" setup:
Omnibus Nano V6
Airbot Ori32 4-in-1
Taoglas GPS
1306 Emax red bottoms
Runcam Split
TBS Unify Race
Axii Stubby
FlySky-A8S

Best,
Andy


(MartinKeilloh) #17

I am so greatfull to you wicked1,will put them in and try again,you are a pure star in my eye’s,cheers im owe you a whiskey or 2


(Guglie) #18

Cool work @wicked1! I’m trying to tune the position controller of my small copter (~250). Surely I’ll test your parameters, but can you check my logs and video here?
(I’m using motion capture to have precise localization and tune the parameters as smooth as possibile)


(MartinKeilloh) #19

Just been out with my one flying very nice in stabilized but like a jack in a jumping box in loiter or position hold have xy velocity and increased xy position in extended tuning any other advice please

https://www.flickr.com/photos/153418808@N03/44511851681/in/dateposted-public/ https://www.flickr.com/photos/153418808@N03/43794044694/in/dateposted-public/


(S) #20

Is it smooth in altitude hold?
First tune stabilize. (Sounds like that is ok)
Next, tune Alt_hold.
Then last, tune Loiter.

So, let me know if alt_hold is ok, and then we’ll know if it needs Z tuning or XY tuning.

-That looks like a much more powerful copter than mine, so you might need some very low PID’s.