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


      As you say, this is the AC3.3 testing thread but I'll respond here in any case.  Probably best to start a new discussion and send me a link if we discuss this flight further.

      It's very clear the heading goes bad (see ATT's ErrYaw field which goes to 1.0 which means it's lost it's heading estimate) which must be caused by either a bad gyro bias estimate (i.e. gyro calibration) or bad compass.  I think it's the gyro calibration just before take-off.

      The heading begins to go bad as early as 1.5min into the flight but it gets very bad just past 3 minutes.  This leads to all the EKF check errors and failure to enter Loiter.  The only way to recover the vehicle in these cases is to switch to Stabilize or AltHold.

      3702587097?profile=originalI don't see any sensor failures in the log.  Magnetic interference is slightly high (30%) but that's the bottom end of the "grey zone" where it's normally ok.

      Sorry I don't have a really good answer on this one yet.  I'll ask Tridge and perhaps Paul Riseborough to have a look to see if they more clearly see the cause.

    • His.rar

    This video was taken after I landed, barely, and while the quad was not moving or armed.

    I am not sure my problems are really 3.3 related, but 3.3r8 is loaded...

    I am having major Yaw problems! I took off in alt hold and every thing looked good so I raced around the sky for about 15 secs then the quad started Yawing on its own. Giving enough rudder to counter the Yaw causes the quad to bobble and would not stop the yawing.

    The problem was present in 3.2, but the problem has gotten worse to the point of being unflyable since I reloaded 3.3r8 and calibrated every thing. 

    I am thinking I might have a hardware issue, motor, esc, FC.

    How do I deduce the source of the problem?

    2015-08-12 17-13-06 9.bin

    2015-08-12 17-13-56 10.bin

    2015-08-12 17-14-27 8.bin

    • Developer


      I think the vehicle has a very bad motor imbalance.  Maybe some ESCs need calibrating or there's a weak motor or it's leaning or something to that effect.  The vehicle is spinning counter-clockwise (CCW), to counteract this the CCW motors (1&2) are increasing to maximum, the CW motors are going to minimum. The motors have hit their limits and can't provide any more rotational force but still the vehicle continues to rotate.  Motor problem!


      • Thank You!

        So it is likely that one of my ccw motors is failing, (motor 1 or 2).

        I might try tying this quad down and running the motors up 70% or so and see if one motor is getting hotter than the others. The hot motor might be the bad one, unless it is an esc issue...

        What is still a mystery unrelated to a possible motor issue is the video I posted, with the aircraft on the ground after landing from this bad yaw problem, Mission Planner's artificial horizon is going crazy rolling around all over the place displaying compass variant error, GPS error and so on.
        • I tested the motors with motor test and watched the amps on the OSD, all motors are with in about 1/2 an amp of each other.

          I did an esc calibration just to be sure, and the results were still with in about 1/2 amp. Highest 11.9 and lowest 11.4.

          I ran the motors at 70% for about 10mins with no notable difference in motor temps.

          To me this rules out motors or esc's as the cause of the problem.
          • Wes,

            That graph looks all too familiar.

            I don't know what your frame looks like, but I strongly suspect that the motors are not level.  One or more motors which are tilted by as little as 2 or 3 degrees can cause a persistant tendency to yaw in a partitular direction.  The controller will have to compensate by slowing down two motors and speading up the other two.  Check each motor with a level or a square against a common surface.  It can be difficult to see, but if the controller is not in the way you may be able to sight along the arm and see that a motor is not exactly parallel to the motor on the oposite side.  If your frame has round tubes, rotate the motors into alignment.  If not, place a paper or light cardboard washer or a few layers of masking tape on the low side of the motor between it and the mount to level it out.

            • The motors pulling same amps when run individually doesn't mean they're not fighting each other in flight due to the motor levels being off.

            • I will check the motors to be sure they are level.

              I swapped FC's tonight and flew again, all is good, smooth steady heading hold until I made a few yaw movements and there it is again- unstoppable yaw.

              The aircraft has power to spare, all motors are pulling nearly the same amps at full throttle, it can't be the FC as that has also been swapped.

              I must be missing some thing,

              In the morning I will check for level motors.
              • Developer


                I totally agree with Brad, GlennM that it's a most likely a motor leaning.  Not to get too picky but I'd prefer if we could take the problem off to another discussion at this point *except* if you find it doesn't happen if the vehicle's put back on AC3.2.1.  That would indicate that we're more sensitive to motor imbalances than the previous version and I'd be happy to review of log of AC3.2.1 running on this vehicle.

This reply was deleted.


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