ACM Loiter (GPS) Hold Traditional Helicopter



Firstly thanks to Jason for his New Alpha code. 2.0.40. Randy for all the help and Martin who keeps supplying tea

The new control laws that he has implemented work really well. The oscillations have virtually disappeared in stabilise, and Loiter held for over 8 mins with only very slow drift, had to bring the heli back to the start point twice.

I think i need to adjust the I value to get a few more degree's to fight the wind.

Also needed to wait until the GPS got as many sats as possible for the most stable hold.


I set the APM_config.h file so that Loiter had a manual throttle (collective Pitch on trad heli). I added this as well to lessen the lean of the heli. Although i might be wrong and it could be for something completely different.


//////////////////////////////////////////////////////////////////////////////// Autopilot control limits////

how much to we pitch towards the target

#ifndef PITCH_MAX

# define PITCH_MAX 22 changed to 10// degrees



changed this too as the Trad Heli would not fly well in this mode



Next is to try Loiter and ALT_HOLD together.


WE also shot some video of martin flying after a rebuild that took us 2 hrs, we decided to close the throttle. One motor didnt fire and we it hit the floor hard. This video is the rebuilt quad really impressed with how quick it was. we had another problem. Watch the vid :)



Views: 1331

Comment by Randy on September 3, 2011 at 5:07pm

nice.  I agree it looks like you need more I on the heli loiter.


pretty aggressive take off on the quad!  You've gotta love have you can throw those things around.

Comment by Jonathan Diaz on September 3, 2011 at 8:59pm

great flight! hmm did you use an external gyro for yaw? or did you just use the apm?

Comment by Randy on September 3, 2011 at 10:02pm


     Malcolm's using an external tail gyro in heading lock mode.

Comment by Jonathan Diaz on September 4, 2011 at 12:19am

aw I see! Thanks randy!

Comment by Martint on September 4, 2011 at 1:29am

@ Malcolm,

I could not get over how stable the 600 was yesterday, if we can just get the "drift" under control now, that would take it from being great to outstanding! It has come on so much from the first hops we did! I hope we have good weather for testing again later!



Randy, thank you for your time and effort on the project. I have to say the Quad flys so well and it's such great fun, I did build one for a customer using the 880Kv motors and 12" props a week back, and that was super fast and made my Quad feel very slow! I would not recommend one with the larger motors and props if you are a first time user..... you might not ever see it again!


The Crashing Quad:

We did not manage to catch the first "landing" on video, which by all accounts was far more spectacular! and completely our (my) fault!  I did not feel bad after the crash, when you push the limits you have to expect a few failures along the way...

In short we were busy pushing the quad to the limits and it would appear a little beyond, the ArduCopter was sent in to the ground from at least 50 feet up and done two arms, one prop and a motor mount and a host male / female spacers which supports the APM. My Quad tips the scales at just over 1KG with the battery (3s 4000 mah) on board, so it came down with some force! I have to give credit here to Jani on an excellent choice of build materials, in my opinion had the arms not folded and the spacers not snapped the electronics would have been given a death blow by the force of the impact! The second crash was just very unlucky / stupid choice of front arm marking using a length of tape which fouled a prop as you can see in the video, damage done....... one prop snapped on the "landing", now ready to fly again, lesson learnt! :)





Comment by Christoph on October 13, 2011 at 12:41pm


You are using an external gyro as Randy wrote.

Did you connect the gyro rudder in directly to your RX or is the rudder signal going through the ACM?


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