Today I did a lot of testing and tuning with the new unreleased beta version of ArduCopter code, known as "2.9.2ß" (V3 i think for the official exit), quad with APM V2.5 and U-Blox GPS by 3DRobotics.
The inertial control developed by Leonard and Randy, with the support of Jason, is finally giving the results that for over a year all we are waiting.
To be perfectly sure I've repeated this test at least 10 times in three different flight, with the same great performance.
As you can see from this image and video the max radius in Loiter is now not over one meter in windless/gusty winds and max two meters in strong crosswind, near the position hold performance of the best commercial product, DJI Wookong-M.
We are trying to improve the waypoint navigation but now we're here, the next release will be really a milestone.
We still have to solve a few problems related to the inertial control x/y/z, but I am sure that the excellent results achieved so far are to mean that we are on the right track.
I attach the telemetry log.
DJI, here we come...


-= AC Dev Team =-

EDIT: in my video you can see the version "3" of the code, nothing secret of course, is the current master branch on GitHub called at the moment "2.9.1b-DEV".
Jason Short on the dev list has proposed to move version from 2.9.1 to 3.x for the massive changes inside the code (ap_hal, PX4 support and other), and following its proposal I have appointed as such in my videos, that's all.


E-mail me when people leave their comments –

You need to be a member of diydrones to add comments!

Join diydrones


  • Developer

    Yes, all the info are in the ArduCopter Wiki.

  • Is there a site out there with tutorials on how to do certain things like load custom firmware or get help?

  • Yesterday I was able to make test flight on my hexa with px4 on board. Alt-hold was perfect as a Loiter and RTL. I still have not good vibes on frame (bad motors) but two layers of moongel save me a little.

  • Thanks very much for your help and inputs, Marco.

    After having gone through more than a doz. fine tuning flights (lost count since yesterday), starting with your suggested setup initially, finally hit the sweet spot settings! Changes included: 

              INAV_TC_XY               6

              HLD_LAT~~LON_P      0.239

              LOITER_LAT_I             0.450

    Flight characteristics (using commit Date:   Fri Apr 26 22:57:05 2013 +0900)

           alt hold is simply solid (typically lands with alt hold).

           loiter's circular drift pattern and oscillations, gone.. though would tend to slowly drift within a 2 to 2.5 r.

    The quad now flies repeatably stable and predictable during loiter that I feel confident enough to hold and push around (like a flying dog ;-) my quad while loitering.

    I'm now trying fine tune and optimize further, tweaking same parameters, to minimize the slow drift r.  (Now can't wait for the LEA 6H's delivery to see if this will help make the diff... rem. current GPS is NEO 6M.)

    All the best.


  • I load custom firmware from from /Copter/latest/apm2-quad and do a calibration of everything with successful results but I can not get system to ARM itself.  When I reload 2.9.1 I am able to ARM the system.  What I am missing?  Is there a 'secret arming sequence for testing firmware?

  • Yeah, I'll keep at it.  I really don't care if I ruin this hexa since it's just a test platform, really want to figure out what's causing the intermittent takeoff when switching to loiter.

  • Developer

    @Peter, LOL! :-)
    Nice, i see your correct parameters now, you must tune better your Loiter parameters, try to play first reducing P and I.
    Or try with the "test version" 2.9.1b-DEV, flash and then reset the board to default and changing only the parameters that I wrote above.
    @Ben H: same suggestion for you, if you want to try the test release, but always and only if you are aware of what you do.
    There have been many fixes since version 2.9.1b and some of these relate to the stability of the Loiter and the other automatic mode.

  • Just throwing in some random feedback here.  Threw the latest dev build on it today, reset all the params and started off with marco's default parameter file as well as recalibrating everything.  Copter flies pretty well so far.  Do have a intermittent issue when I hit the switch to enter loiter, randomly the hexa will tilt to a different direction at almost 70+ish degrees and take off max throttle, switching back to Stabilize quickly and some stickdance regains control.  Usually have to switch to loiter and save it 3 or 4 times before it goes into it normally and stays locked in place.  It does battle wind pretty good when in loiter, however if it's calm in loiter and I apply quick pitch or roll, the hexa swings back into position then begins to oscilate extremely violently until I hit Stabilize again.

  • Sorry Marco that was the params file before I did the calibration. My fault forgot to upload the updated version.

    I do know what I am doing as I have built over 150 of these to date. It is just the loiter params that I am struggling with as the defaults are Loiter rate P of 1.0 but the description is from 2?

    Updated params file HERE:

  • Developer

    Hi Peter, from your parameters file i see this:


    Please don't hammer me with this kind of request, if you don't manually calibrate the compass and accelerometers how are you supposed to be able to make a Loiter? ;-)
    For users wanna try the test code: please test it only if you know what you're doing, you might fly away and crash your quad!
    There's a testers team that is trying for a long time, we always need your feedback are very important to us, but if you don't know how to proceed don't do more tests, wait for the final version.

This reply was deleted.