I've recently tried to setup APM for my new flying wing and discovered that it is not safe to fly in other than Manual modes =( The reason is servo throws for most flying wings must be limited, but APM limits them only in Manual, in all other modes servos goes to endpoints.

After some googling I've found 2 bugs submitted to issue logger on google code of arduplane:

1)

Issue 647:

Elevon control throw for manual mode does not match control throw for other modes

2)

Issue 686:Servo limits (maximum throw) is not working in stabilize, fbw and other modes.

Another helpful user - Vladimir Popov commented:

Comment by Vladimir Popov yesterday

I just investigated firmware sourses... Stick deflections are added to servo output a bit tricky - automatic output signal is scaled down to leave place for manual signal. It seems Ok, but the algorithm is internally limited - manual signal must not exceed +-400 ms from trimmed value. I do not know why. So, don't move sticks too much...

I think you can ask developers about this limitation. Function stabilize() in Attitude.pde.

In RTL mode sticks are not mixed at all.

So what should we change in order to make it work? Thanks for the help!

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

Join diydrones

Email me when people reply –

Replies

  • Developer

    Hi Yure,

    If you are using APM:Plane 2.74 then you should have a look at the docs on the ELEVON_OUTPUT and MIXING_GAIN parameters. These allow you to setup a virtual elevon mixer in the plane, and set your transmitter to normal aileron/elevator (ie. no elevon mixing). That allows you to get rid of the weird artifacts of the old elevon handling system.

    Cheers, Tridge

  • I upload the newest ArduplaneNG software (from here:http://megapirateng.googlecode.com/svn/branches/arduplane/ ), and I think problem is solved. But didn't fly too much, because I changed the board to HK Pilot 2.5, and working very well!!!

    Use http://downloadsvn.codeplex.com then. Just copy paste the above URL for the arduplane branch and you are good to go.

  • Investigated code myself. So if I change '500' to '225' in lines 369,370 (attitude.pde)

    g.channel_roll.radio_out = elevon1_trim + (BOOL_TO_SIGN(g.reverse_ch1_elevon) * (ch1 * 500.0/ SERVO_MAX));
    g.channel_pitch.radio_out = elevon2_trim + (BOOL_TO_SIGN(g.reverse_ch2_elevon) * (ch2 * 500.0/ SERVO_MAX));

    I got somewhat good servo throws. Don't know if it is the correct way of doing it. I'll fly it today.

    Warning! Do NOT try this yourself - this is not checked at all. Stay tuned for further notice.

This reply was deleted.

Activity

DIY Robocars via Twitter
20 hours ago
DIY Robocars via Twitter
RT @NVIDIADRIVE: Season Beta has arrived! Check out the first race of the @roborace season, livestreaming from Anglesey Circuit Sept. 24-26…
yesterday
DIY Robocars via Twitter
RT @IndyAChallenge: Here is the ROS-based small-scale vehicle platform showing the ROS Visualization (Rviz) screen with multiple ROS nodes…
yesterday
DIY Robocars via Twitter
RT @IndyAChallenge: Here is Black & Gold Autonomous Racing's simulated racecar running a lap @IMS and showing the team's code overtaking ot…
yesterday
DIY Robocars via Twitter
yesterday
DIY Robocars via Twitter
RT @donkey_car: New Maintainers! Donkey Car 4.0 and more! Here is our September Newsletter! https://donkeycar.substack.com/p/september-donkey-newsletter?r=2ji2t&utm_campaign=post&utm_medium=web&utm_source=copy
yesterday
DIY Robocars via Twitter
RT @chr1sa: Kinda cool that we just hit 2,500 members of our Bay Area self-driving car racing league. More than 10k globally. Fast, cheap…
yesterday
DIY Robocars via Twitter
RT @chr1sa: Our next @DIYRobocars virtual AI car race is next Saturday. Compete from home using the @donkey_car simulator -- no physical ca…
Sunday
DIY Robocars via Twitter
RT @RoboticMasters: Students from @Sydney_Uni working hard on improvements and changes to @donkey_car simulator. @diyrobocars @adafruit…
Sunday
DIY Robocars via Twitter
Practice virtual race this Saturday; the real thing will be on Oct 3 https://www.meetup.com/DIYRobocars/
Sep 23
DIY Robocars via Twitter
Sep 23
Derrick Davies liked lisa TDrones's profile
Sep 23
DIY Robocars via Twitter
Sep 21
DIY Robocars via Twitter
RT @SahikaGenc: AWS DeepRacer & Hot Wheels Track https://youtu.be/4H0Ei07RdR4 via @YouTube
Sep 14
DIY Robocars via Twitter
Sep 8
DIY Robocars via Twitter
RT @davsca1: We are releasing the code of our Fisher Information Field, the first dedicated map for perception-aware planning that is >10x…
Sep 8
More…