Developer

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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Replies

    • You are an experienced pilot, nothing is safe and stable guarantee with this toys ;) It's as your oun risck, but if you use the stab release, be carefull to switch from stab to loiter, pos hold, etc., I try many times with beta and the issue go away, but I'm only an user, Randy go to send to stable when he consider safe but really I like this last vers, great dev work. What vers is your last one?

      • Moderator

        Hi Cala 

        Yes, I fly OK but I loaded ver3.2.1 after some repairs a few weeks ago and then put it away to work on a project then came back to this and just wanted to catch up. 

        The snow will stop me flying until the weekend so I can wait until 3.3.2 becomes the default, Thanks Randy , great work.  your ongoing development is superb. 

  • Moderator
    I been away for a while, which is the " good" version of the software? This is for a 450 size quad.
    • Copter-3.3.2-rc2 is available through the mission planner's beta firmwares link. Changes are in the release notes
      (https://github.com/diydrones/ardupilot/blob/master/ArduCopter/Relea...) but here they are along with a video
      showing the major reason this version is out.
      1) Bug fix for desired climb rate initialisation that could lead to drop when entering AltHold, Loiter, PosHold
      2) Fix to hard landings when WPNAV_SPEED_DN set high in RTL, Auto (resolved by using non-feedforward alt hold)
      3) Reduce Bad AHRS by filtering innovations
      4) Allow arming without GPS if using Optical Flow
      5) Smoother throttle output in Guided mode's velocity control (z-axis now 400hz)

    • Hello Dw: the best vers is beta 3.3.2 rc1, read Randy red notes upside, there is explained, stable has an unconfortable bug,

  • Hi Leonard,

    My final post on this. I'm puzzled by the lack of response since it seems to me that my setup has revealed some problems with autotune.

    I took my autotune of last week which was flying quite well and setup Roll_P on channel 6. I was then able to increase Roll_P by nearly 300% and the copter flew a lot better, much more locked-in - less overshoot on roll. This confirms my earlier manual tune where a high Roll_P gave good performance but could not be accompanied by a high Roll_I which led to massive instability.

    Since this only happens on roll, my guess is that its something to do with the relatively high CG coupled with the active breaking of BLHeli. I attached a pic of my setup for reference.

    (Incidentally the RCTimer SN16A ESCs are flying fine - no issues with temps, athough I have ordered a set of RG20's given all the hullabaloo).

    IMG_5395.JPG

    IMG_5394.JPG

    • Developer

      Hi Andy,

      Sorry, I have distracted for the last week or so. The main problem with your autotune is the active breaking tends to need a low rate D but your  AUTOTUNE_MIN_D is set to 0.004 when it needs to be set to 0.001 for a small quad like this.

      As you have already discovered, you will need to manually set ATC_ACCEL parameters if you tune manually. Autotune does this for you during a tune based on measurements it makes.

      It also looks like you may not be tuning in very calm conditions. This can mess up autotune on small quads quite badly.

      I have to do some back to back testing of active braking vs non-active braking on my quad to see how much it improves things when using autotune.

      • Hi Leonard,

        So the 0.004 value was set by autotune both in roll and pitch. If I do a manual tune on roll then a value of 0.003 seems pretty stable, 0.004 is borderline. So I'm interested in the 0.001 value - that seems way below any setting that would lead to fast oscillations. Is it worth me trying this? Like I said n my previous post the main issue seems to be not having a high I value - that leads to a lot of problems. Also what determines a good stab roll value? In the Dave C method he recommends a value of about 3. Autotune selected 9 in my case - what does this affect and how can I tune it? There doesn't seem to be any way to map it to channel 6.

        I attached a log with me manually tuning Roll P from the autotuned values.

        108.BIN

        • Developer

          Hi Andy,

          The low D term is so Autotune can tune it properly. It would be great if you could give it a go. Autotune needs to be able to go lower than the optimal value to find it that is why it needs to be so low.

          Based on your issue we are reducing it by default.

          If you could take the time to do Autotune in some good conditions I would appreciate it!!

          Thanks!!

          • Hi Leonard,

            No problem - gale force here, so won't be today!

            So just so I get this right - reduce D and leave everything else the same and then run autotune?

            Just roll, or roll and pitch? If roll and pitch do I need to reduce D in both before running autotune?

            I've just bought some 2200mAh batteries so am hoping I have enough power now to get good tunes everytime.

            Thanks!

This reply was deleted.

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