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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      • Hi Leonard,

        So I attempted to tune today my Y6B and ran out of battery as well.  So back to re-reading this post.  So if I understand you right, multiple axis tune is adding any sequence of 1, 2, or 4 to get a total for what you want the copter to tune to.


        1 + 2 = 3           So 3 is what I put into AUTOTUNE_AXES to get it to tune just Roll and Pitch

        2 + 4 = 6           Would be to tune Pitch and Yaw only

        So I tried to enter in a single axis tune such as Roll (1) but the mission planner stated not a valid number. However after entering 2 and 4 and then back to 1, the mission planner didn't balk at me for enter 1 into it.

        At this point I disconnected power to Y6B and re-powered and connected to find I could not repeat the error message.  Hmmmm.  Gremlins.

        Thanks for explaining the Autotune configuration settings.  This will help me tremendously to tune my Y6B using the 6000 mah batteries I have.

        • So cool!

          I set my Autotune_Axes to 1 and Roll was successful. Tomorrow (weather permitting) I will plan to perform Pitch test only.  Attached is my logged flight for anyone to review.

          3702782747?profile=originalOutside temp = 61F

          Humidity = 55%

          Winds = Calm


          On a separate note. I noticed on all my test flights that the GPS status indicated in the AutoAnalysis stated FAILED Satellite min 0.

          However, when I reviewed my logs, they showed both GPS units (NEO-M8N (P) and LEA-6H (S) held satisfactory number of satellites and both had low HDOPS (below 2.0) for majority of flight.  However it FAIL due to HDOP hitting above 2.0.  

          So the question is, is it truly a FAIL as most of the flight it stayed low?  I suppose if it goes up at anytime during the flight it's considered a FAIL for GPS status.  Guess I'm glad I wasn't in Auto.

          Log File C:/Users/Doug/Documents/ArduCopter/UAV Logs/HEXAROTOR/1/2015-04-15 19-31-14.log
          Size (kb) 20005.1103515625
          No of lines 269057
          Duration 3 days, 23:45:27
          Vehicletype APM:Copter
          Firmware Version V3.3-rc1
          Firmware Hash 5a4039d9
          Hardware Type
          Free Mem 0
          Skipped Lines 1

          Test: Autotune = NA -
          Test: Balance/Twist = NA -
          Test: Brownout = GOOD -
          Test: Compass = GOOD - mag_field interference within limits (16.48%)
          Max mag field length (564.60) > recommended (550.00)

          Test: Dupe Log Data = GOOD -
          Test: Empty = GOOD -
          Test: Event/Failsafe = FAIL - ERR found: FS_BATT
          Test: GPS = FAIL - Min satellites: 0, Max HDop: 2.5
          Test: IMU Mismatch = GOOD - (Mismatch: 0.36, WARN: 0.75, FAIL: 1.50)
          Test: Parameters = GOOD -
          Test: PM = NA -
          Test: Pitch/Roll = NA -
          Test: Thrust = NA -
          Test: VCC = GOOD -



  • "support do-set-home command (allows return-to-me and locked home position once GCS enhancements are completed)"

    Can somebody provide some information on this specific feature above (10.a)? Is this implemented and its currently usable? If not, then when will it be available? 



  • Simple test flight with autotune on Y6B - tuned parameters are not usable - reverted to manually tuned.

    What is changed by Autotune_aggr and Autotune_Axes? What are recommended values?



    • Developer

      Hi Hubertus,

      In exactly what way is it un usable?

      Autotune_aggr is a parameter that sort of defines the noise rejection of the autotune. It should have been 0.1. Autotune_Axes is a bit mask to define what axis will be tuned. 1 is Roll, 2 is Pitch, 4 is Yaw, 3 is Roll and Ptich ect ect.

      You have the same a similar problem I am seeing with others (but not enough to stop you getting what looks like a reasonable tune) and I hope the next release will fix this.

      • Leonardt,

        tried again flying with the autotune parameters - it´s flyable, but there is some overshoot and oscillations in roll. Rate P/I pitch is out of range according to MP - is this a problem? Response in pitch axis is quite good, so perhaps i should leave it to the tuned params.

        • Developer

          Hi Hubertus,

          Oscillations is definitely bad. But it is strange as tuned pids seem to be more conservative than your original pids.

          If you could try the autotune in the next release for me I would really appreciate it!!


  • Distributor

    wow - thank you very much to all the developers!

  • Thanks Randy. My 4 Year old Daughter is into everything. Have had to lapse a little with playing the devs builds in the park. Have a pix and am looking on adding a second GPS. Maybe the Neo 7 as a redundant backup? Humm..

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