APM Copter 2.9.1.b has been released


APM Copter 2.9.1.b has been released to the Mission Planner and is also posted in the downloads area.
2.9.1b is a maintenance release incorporating changes to 4 default parameters that have been optimized since 2.9.1 was released.  There are also 4 minor bug fixes.  There are no code function changes or additional features.
The changes are:
1) reduce default INS_MPU6K_FILTER to 20hz
2) reduce InertialNav Z-axis time constant to 5 (was 7)
3) increased max InertialNav accel correction to 3 m/s (was 1m/s)
4) reduce yaw_rate P default to 0.20 (was 0.25)
5) bug fix for alt_hold being passed as int16_t to get_throttle_althold_with_slew which might have caused problems if you climbed over 320m.
6) bug fix for throttle after acro flip (was being kept at min throttle if pilot switched out of ACRO mode while inverted)
7) bug fix to acro trainer to do with roll correction 
8) prevent cli from being entered more than 20seconds after reboot.
Users are recommended to:
    Update Mission Planner to 1.2.41 and
    Update their flight code to 2.9.1b from the Firmware tab on Mission Planner. There is no need to go through a new configuration process in the Mission Planner.


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  • I've been testing version V3.0.0-rc1 and quite pleased so far. However, I did find a rare but nasty bug which causes the copter to tear off to the southwest at high velocity and fast decent rate until it crashes into the ground or you switch back to manual mode. It is triggered by having two successive waypoints that are the same, for example if you mistakenly put two waypoints in the same place in Mission Planner, or if FollowMe sends two successive waypoints that are the same location.

    I think perhaps the offending code is line #250 of AC_WPNav.cpp:

    _pos_delta_unit = pos_delta/_track_length;

    I think this would be a division by zero if successive waypoints are the same, and that could be what's causing the out of control flying southwest into the ground. In the logs, right where the copter goes crazy, you also start seeing a lot of nan's.

    Hopefully this should be an easy fix in the code.

  • Hello,

    My question just why Crash?

    I Fly 2x Times high, after this slowly fly down and switch to ROTH ( Lose Video Signal) but the Ardupilot don't give throttle...

     This is the Second Crash in RTH Mode! Many Times i test the RTH Mode and it works!

    But always if i need this function, it doesn't works!


    2013-05-04 18-41 69.log

    2013-05-04 18-41 69.log.gpx

    2013-05-04 18-41 69.kmz

  • Here are the log files...

    2013-05-05 09-16 34.log

    2013-05-05 09-16 34.log.gpx

  • The crash of unknown cause.
    After 3 minutes flying it cut power suddenly on all engines. The hexa flips around and fall to the ground upside down.
    I've attached logs and video. Lipo detector beeps for approx. 1 min. and flips machine after 3 min. in the video. The Gopro3 is placed on side of landing gear facing to the right.

    S800 with APM 2.5 and 2.91b
    2 x 6S 8000mAh in parallel.
    Batteries measured 23.8 volts after the crash, realize that lipo detector beeps during takeoff with large power consumption, by this time it alerts no more.

    Have checked the logs and can not find similarities with the video. Need some help here.

    The injury was a broken arm, carbon tube on the landing gear and four props.

  • Small demo of my TBS like with APM1 and Mediatek GPS
    Quite windy conditions today.

    To remove the vibration I used the O-ring solution in combination with the Kyosho Zeal tape.
    Took me some time to get it all tuned in but now it is flying quite well.
    Loiter and alt hold are working as well (taking into account that it is a mediatek GPS and the BMP085 sensor)

  • If found the Error:

    If Sonar is turned on, but is disabled by CH7, it remains active and interferes ALT_HOLD.

    Sonar makes Spikes on attitude every few seconds.

    Now it works with default Parameters.

    ALT_HOLD now is very good.

    Greeting Peter

  • Thanks for your great work Randy and Co.
    I've flown in the past few weeks every day with a new version from the trunk.

    ALT_HOLD no longer works for a long time. The copter always shoots a few feets into the air and falls back a few feets.

    With INAV_TC_Z  = 1.8 and  THR_ALT_P  = 0.14 it looks better, but is not stable..

    Vibrations are very low.

    Greeting Peter

  • Woohoo. And we even have a good weather forecast for the weekend!
  • Developer

    ArduCopter 3.0-rc1 (release candidate #1) is now available in the new downloads area.  Alternatively you can download the zip from the github site here or finally click on the Mission Planner's Firmware screen and click the "Beta firmwares" link which will temporarily change the versions that are downloaded for each frame type.

    ArduCopter 3.0.0-rc1 improvements over 2.9.1b:
    1) Inertial navigation for X & Y axis (Randy/Leonard/Jonathan)
    2) 3D waypoint navigation library (Leonard/Randy)
        WPNAV_SPEED, WPNAV_SPEED_UP, WPNAV_SPEED_DN control target speeds during missions and RTL
        WP_YAW_BEHAVIOR to allow disabling yaw during missions and RTL
    3) PX4 support (some features still not available) (Tridge/Pat/PX4Dev Team)
    4) Safety improvements:
        Tin-can shaped fence (set FENCE_ENABLED to 1 and copter will RTL if alt > 150m or horizontal distance from home > 300m) (Randy/Tridge/Leonard)
        GCS failsafe (set FS_GCS_ENABLED to 1 and if you are using a tablet to fly your copter it will RTL and return control to the radio 3 seconds after losing telemetry) (Randy)
        pre-arm checks to ensure accelerometer and radio calibration has been performed before arming (Randy)
    5) motor interference compensation for compass (Jonathan/Randy)
    6) Circle mode improvements:
        set CIRCLE_RADIUS to zero to do panorama shots in circle mode (copter does not move in a circle but instead slowly rotates)
        CIRCLE_RATE parameter allows controlling direction and speed of rotation in CIRCLE mode and LOITER_TURNS (can also be adjusted in flight from CH6 knob)
    7) SONAR_GAIN parameter add to allow reducing the response to objects sensed by sonar (Randy)
    8) support for trapezoidal quads (aka V shaped or FPV quads) (Leonard/Craig)
    9) performance improvements to dataflash logging (Tridge)
    10) bug-fix to analog read which could cause bad sonar reads when using voltage or current monitor (Tridge)
    11) bug-fix to motors going to minimum when throttle is low while switching into Loiter, AUTO, RTL, ALT_HOLD (Jason/Randy)
    12) bug-fix for auto disarm sometimes disarming shortly after arming (Jason/SirAlex)

    There are already a number of known issues that have been added to the issues list:

        a) sometimes the copter jerks severely when first entering loiter, RTL or reaching a waypoint.

        b) spiraling around a waypoint normally caused by your compass heading not agreeing with true north

        c) too many nearly empty log files produced

        d) climb and descent speeds during RTL or missions can be very slow

        e) accelerometer calibration through mission planner can required multiple clicks of the button

    A couple of warnings -- it's only release candidate #1 (there will be at least 1 more before the official release) so it's still a work in progress.  I won't be able to analyse every log posted because I also need to spend time on fixing up the known issues.  Still, all feedback both positive and negative (so we can get the issues resolved) would be greatly appreciated.

  • Any idea's when a stable version will be released that sorts out the loiter and alt hold issues?

    I use these features a lot and haven't been able to sort them out since 2.9.1 was released, my quad just goes nuts when in either of these two modes. Works brilliantly in stabilised or auto modes.

    I went through the vibration testing when 2.9.1 was released but was told by Randy that the loiter and alt hold will be skittish until 2.9.2 is released even though my posted vib results were very good.

    Might have to go back to 2.8 as that was really stable in loiter until this issue is fixed!

This reply was deleted.


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