Copter-3.3 beta testing

Warning #1: an issue has been found with Tower's Pause button which can cause the vehicle to fly to an old position if the vehicle has not sent a position update to Tower in some time.

Warning #2: Copter-3.3.2 fixes a bug found in Copter-3.3.1's desired climb rate initialisation which could lead to a sudden momentary drop when switching from Stabilize or Acro to AltHold, Loiter or PosHold.

Warning #3: Copter-3.3.2 fixes an issue found in Copter-3.3.1 which could lead to hard landings in RTL or AUTO if the WPNAV_SPEED_DN was set too high (i.e. >400 or 4m/s) and/or the WPNAV_ACCEL_Z was set too low (i.e. <100 or 1m/s/s).

Warning #4: a bug was found in Copter-3.3 which could cause a sudden crash if you abort a Take-off initiated from a ground station.  Video description is here.  The bug is fixed in Copter-3.3.1 so we recommend upgrading.

Note #1: AC3.3-rc8 corrected a long standing bug in the HDOP reporting.  HDOP values will appear about 40% lower than previously but this does not actually mean the GPS position is better than before.
Note #2: if upgrading from AC3.2.1 the vehicle's accelerometer calibration needs to be done again.
Note #3: set SERIAL2_PROTOCOL to "3" and reboot the board to enable FrSky telemetry like in previous versions.
Note #4: the wiki will be updated over the next few weeks to explain how to use the new features

Copter-3.3.1 is available through the mission planner.  The full list of changes vs AC3.2.1 can be see in the ReleaseNotes and below are the most recent changes since AC3.3.

Sadly this version (and all future versions) will not run on the APM2.x boards due to CPU speed, flash and RAM restrictions.

Changes from 3.3:

1) Bug fix to prevent potential crash if Follow-Me is used after an aborted takeoff

2) compiler upgraded to 4.9.3 (runs slightly faster than 4.7.2 which was used previously)

Changes from 3.3-rc11:

1) EKF recovers from pre-arm "Compass variance" failure if compasses are consistent

Changes from 3.3-rc10:

1) PreArm "Need 3D Fix" message replaced with detailed reason from EKF

Changes from 3.3-rc9
1) EKF improvements:
    a) simpler optical flow takeoff check
2) Bug Fixes/Minor enhancements:
    a) fix INS3_USE parameter eeprom location
    b) fix SToRM32 serial protocol driver to work with recent versions
    c) increase motor pwm->thrust conversion (aka MOT_THST_EXPO) to 0.65 (was 0.50)
    d) Firmware version sent to GCS in AUTOPILOT_VERSION message
3) Safety:
    a) pre-arm check of compass variance if arming in Loiter, PosHold, Guided
    b) always check GPS before arming in Loiter (previously could be disabled if ARMING_CHECK=0)
    c) sanity check locations received from GCS for follow-me, do-set-home, do-set-ROI
    d) fix optical flow failsafe (was not always triggering LAND when optical flow failed)
    e) failsafe RTL vs LAND decision based on hardcoded 5m from home check (previously used WPNAV_RADIUS parameter)

Thanks for your testing!

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    • Developer

      Hi Nate,

      If your props don't spin up when on a slope then you haven't set your THR_MIN parameter high enough or have not calibrated your ESC's. So I would start from there.

      Start with default pids and do a bit of manual tuning to get a copter you can fly in Alt hold that is stable.

      If you are getting oscillations after auto tune it is often because your frame is too flexible or you have got a large flexible gimbal installed. If it is the gimble then try an auto tune without the gimbal installed. Then do an Auto Tune and see how it flies without the gimbal installed. If it flies well then attach the gimbal and fly again. If you have oscillations with the gimbal, back off the roll and pitch rate values by the same amount say 0.75 x and fly again. Repeat that until your copter stops oscillating and you have your tune.

      If you have a flexible copter or a copter or some other issue, sometimes you have to manually tune.

      • (attached below)

      • Calibrated my esc's a few times,with no differences. However when adjusting the D rate, there are changes, the 'props not spinning on a slight slope' issue lessens or worsens.

        I do have a gimbal attached, semi-popular GLB storm 32 3 axis gimbal 

        Frame is really rigid, doubt, flex is an issue here.

        It flies ok in alt hold, but as i said is either like a feather or super twitchy no matter.

        Will try the tune again with out the gimbal and report back

        Also, thanks to you and everyone else who replied

        oh and here are my logs and param file in one link

    • We've got the same copters with 15" props, but mine's an X8 with sunny sky 4108s 14 480kv motors.  Tuning maybe similar though.  Give this a try.


      • still wayyy too twitchy with these settings. :(

        • This is a pain, but it seems to work.  I do three sets autotune's three times:

          aggr .1, .075 and .05 at each setting.  That's 9 total lol!  Save each full para listing and dl each log.  Look at the recoded PID's and your mec failure graph to see with one worked best.  Then load and fly : )

          • Lowered aggr to 0.05, this is what a roll and pitch axis tune gave me 0_o No more twitchiness, but still very weird that roll and pitch pids varied sooo much. Flew very well. Not as locked in as I would like, but very useable still. May increase to .075 and see what thats like. Thanks a lot guys


            • Well, I find with the H frame layout and my payload in the front and batteries at the back the PID's for pitch are higher than the roll.  But not that much difference as seen in your screen shot.  I'm no expert on analyzing autotune's, but I've found with the D value is still at the default (.004), that axis failed.  Try that axis again while leaving your pitch.  If it works, do both axis again and see if it improves.  You should get better results from each iteration.  I know it bites, nothing more boring than going through autotune.  I've got a new 960mm HEX I have to do today, like watching paint dry.

          • I redid auto tune without my gimbal attached, seems like a slight improvement, but still twitchy, never thought about lowering the aggr, will charge tonight batts tonight and try early in the morning, Thanks a lot.

      • I use sunnysky v3508 580kv on 4s, will try out these settings tomorrow after work.

This reply was deleted.


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