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


      I'll answer this over on the drones-discuss or gitter threads 'cuz you've posted there as well and it's really more of a developer question,

      • Randy,, We are experiencing same rc3 issue. Lawnmower mode. :) Looked at drone discuss and gitter, cannot find the discussion. Note we are using Lidar Lite but not flow, we did not do the Lidar prearm because we thought it only applied to flow. Any hints? Thanks!
  • Parachute function test results 1:

    I uploaded latest 3.3 RC3 to Pixhawk and setup parachute to use servo and altitude check is disabled.

    Sometimes I receive "altitude: too low" message and sometimes parachute is ejected. I noticed that if throttle is carefully raised, altitude too low message appears. But if throttle is raised fast, is parachute ejected. Throttle position doesn't seem to do any difference, only how aggressively throttle is raised matters. On another test attempt I received only too low messages and couldn't eject.

    Any idea why eject altitude check is inconsistent?

    I have a video to be uploaded if it helps. Terminal doesn't want to connect Pixhawk and therefore logs are not available. MP is 1.3.25.

    • In mission planner, on the "flight data" screen, below the hud, there are some tabs. The 7th one is "DataFlash Logs" on that tab is a button "Download DataFLash Logs Via MavLink".

      You should be able to download logs by clicking it.

      • Parachute testing:

        Ok flight data screen - route worked, thanks. Always used terminal but that is easier.

        I made now some new tests and found that copter needs to be shaken (take off just a little off the table) before eject works. I got "parachute released" when copter throttle was above half and copter lifted from table. Lower throttle didn't activate possibility to eject, ie. gave too low message.

        Is there some rules for checking take off even altitude check is disabled?

        If so, that is good to add to Wiki at "testing the chute" section. In general I use every now and then eject with my camera workhorse copter on the ground with throttle raised only a little. This is just random check that motor shut down works and nothing is changed on mixing or settings. I'd prefer to have a change to eject manually what ever the flight situation is. Automatic eject should have strict conditions.

        Logs are here, check latest one (uploading slowly):

        Another note: eject ON PWM is active only short time, perhaps a second or so. It's good to be adjustable, or few seconds longer. This might be now too short for servo, or for our Fuse blow if parachute battery is too optimized and really flat.

        Third note: Angle detector doesn't react if lean happens quite slowly.

        This our test parachute test copter has major vibrations for sure and it may affect. But I think that could be the case on motor failure with any copter.

        I keep testing more later. If there is something you developers or anyone wants me to try, please advice me. This copter is made for risk scenarios and have dual parachute triggers (Pixhawk / direct radio) just in case. Dual parachutes is possible if needed.


        Shared with Dropbox
        • Developer

          Henri, I'll reply at the latest part of this thread rather than back here on page 42.

  • Has something changed in relation to GPS locks? I was out today for a test flight. Telemetry was telling me I had a GPS 3d lock but if I tried to arm in poshold it failed with a GPS lock required warning. Similarly if I took off in stabilise and tried to switch to poshold it wouldn't let me. Logs from one of the flights are here.

    • I had similar problem and received the following reply yesterday:

      in essence: 

      EKF check gives the same pre-arm messages (need 3D lock) but it refers a different, newly introduced pre-arm check.

    • Did you power and an wait for a GPS lock tone before arming and lifting off?  That is something new to version 3.3.

This reply was deleted.


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