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Done flies fine in stabilized mode jerky in Loiter and RTL.

Posted by Rob Summers on July 20, 2016 at 3:24pm

 My drone  flies well in stabilized  mode but when in loiter it gets jerky and somewhat noisy. It still flies, but not like I would like. I have changed flight controllers, GPS's and motors not the Q-brain ESC. There is no issue until I go to loiter or RTL. It has to be a setting in Mission planner but I cant find the answer. when I remove the Tiger MN4110 370kv motors and put Turunigy 4425 390kv it flies perfect. The extra weight or something is making the set up not fly well.

Any suggestions are appriciated.

Rob

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Replies

  • Craig July 22, 2016 at 12:50pm

    Tilt? I keep all my craft as close to defaults as humanly possible. 45 degrees has been perfect for me since I don't fly acro or race or anything. My T960 on 320kv motors and 15x4.5 props flies perfect on stock pids and settings and even in wind holds really well. I do find though that the bigger the frame, the larger the props, the more it does get "pushed" around by the wind and tends to have to work a bit harder to hold position in loiter. 

  • Rob Summers July 22, 2016 at 12:13pm

    I reset to default and started over. I changed the THR MID to 400, calibrated everything and it seems to fly good. I am thinking after an autotune it will be correct. Thanks again for the help. I would like to get your thoughts on the tilt for windy conditions. what would be a good setting for higher winds?

    Rob Summers said:

    content://media/external/file/4849
  • Rob Summers July 22, 2016 at 9:18am
    content://media/external/file/4849
  • Rob Summers July 22, 2016 at 9:11am
    Here is the mission planner perms. I am working with. It still flies perfect in stabilized. What parameters control output to the motors in GPS assisted flight modes?
  • Rob Summers July 21, 2016 at 9:04pm


    ok ill try that in the am and let you know. thanks again....
    Craig said:

    then make sure to set THR_MID to 400

    Rob Summers said:


    I would guess 40% throttle
    Craig said:

    how "much" below 50% in stabilize? Seems Mark already answered what I was eluding to. Set your Throttle Mid Point in Mission planner to your stab hover % and it will help but also as Mark says you do need to do a full calibration and possibly a compassmot. 

    Rob Summers said:


    I was wondering if the input to the ESC has a separate parameters one from stabilize another to control Loiter or GPS assisted modes?
    Rob Summers said:

    In Stabilized mode the throttle is below 50%, in Loiter 50% holds the drone at same altitude

    Craig said:

    Initial views of the log don't turn up a lot of issues. Your vibs are a "tad" high but within specs though personally I'd work on bringing them down some. I do see some long loop issues, but that may be because of all of the excessive logging.

    When you hover using stabalize where is your throttle stick at on your radio? Above 50%, below 50%, or right @  50%?

  • Craig July 21, 2016 at 8:58pm

    then make sure to set THR_MID to 400

    Rob Summers said:


    I would guess 40% throttle
    Craig said:

    how "much" below 50% in stabilize? Seems Mark already answered what I was eluding to. Set your Throttle Mid Point in Mission planner to your stab hover % and it will help but also as Mark says you do need to do a full calibration and possibly a compassmot. 

    Rob Summers said:


    I was wondering if the input to the ESC has a separate parameters one from stabilize another to control Loiter or GPS assisted modes?
    Rob Summers said:

    In Stabilized mode the throttle is below 50%, in Loiter 50% holds the drone at same altitude

    Craig said:

    Initial views of the log don't turn up a lot of issues. Your vibs are a "tad" high but within specs though personally I'd work on bringing them down some. I do see some long loop issues, but that may be because of all of the excessive logging.

    When you hover using stabalize where is your throttle stick at on your radio? Above 50%, below 50%, or right @  50%?

  • Rob Summers July 21, 2016 at 8:26pm


    I would guess 40% throttle
    Craig said:

    how "much" below 50% in stabilize? Seems Mark already answered what I was eluding to. Set your Throttle Mid Point in Mission planner to your stab hover % and it will help but also as Mark says you do need to do a full calibration and possibly a compassmot. 

    Rob Summers said:


    I was wondering if the input to the ESC has a separate parameters one from stabilize another to control Loiter or GPS assisted modes?
    Rob Summers said:

    In Stabilized mode the throttle is below 50%, in Loiter 50% holds the drone at same altitude

    Craig said:

    Initial views of the log don't turn up a lot of issues. Your vibs are a "tad" high but within specs though personally I'd work on bringing them down some. I do see some long loop issues, but that may be because of all of the excessive logging.

    When you hover using stabalize where is your throttle stick at on your radio? Above 50%, below 50%, or right @  50%?

  • Rob Summers July 21, 2016 at 8:25pm


    That is correct but i did do and auto tune but I made no specific changes for motors.. I have built 7 or 8 of these then decided to improve my wind performance with motors. In hind sight I needed to work on tilt angle and other tuning areas.
    Mark Brummett said:

    THR_MID sets the midpoint in Stabilize.  Loiter will ALWAYS be around 50 percent because it uses the altimeter to find the hover.  Stabilize doesn't.  You need note where on the throttle throw in percentage that the craft hovers in stablize mode.  Set THR_MID to that number (I can't remember, it might be percentage * 10 - example, if it takes 30 percent throttle to hover in stabilize then set THR_MID to 300).  But the oscillation to me sounds more like you changing motors on a frame without retuning.  You noted that when you changed back to a specific motor, that behavior stopped.

  • Craig July 21, 2016 at 8:04pm

    how "much" below 50% in stabilize? Seems Mark already answered what I was eluding to. Set your Throttle Mid Point in Mission planner to your stab hover % and it will help but also as Mark says you do need to do a full calibration and possibly a compassmot. 

    Rob Summers said:


    I was wondering if the input to the ESC has a separate parameters one from stabilize another to control Loiter or GPS assisted modes?
    Rob Summers said:

    In Stabilized mode the throttle is below 50%, in Loiter 50% holds the drone at same altitude

    Craig said:

    Initial views of the log don't turn up a lot of issues. Your vibs are a "tad" high but within specs though personally I'd work on bringing them down some. I do see some long loop issues, but that may be because of all of the excessive logging.

    When you hover using stabalize where is your throttle stick at on your radio? Above 50%, below 50%, or right @  50%?

  • Mark Brummett July 21, 2016 at 8:04pm

    THR_MID sets the midpoint in Stabilize.  Loiter will ALWAYS be around 50 percent because it uses the altimeter to find the hover.  Stabilize doesn't.  You need note where on the throttle throw in percentage that the craft hovers in stablize mode.  Set THR_MID to that number (I can't remember, it might be percentage * 10 - example, if it takes 30 percent throttle to hover in stabilize then set THR_MID to 300).  But the oscillation to me sounds more like you changing motors on a frame without retuning.  You noted that when you changed back to a specific motor, that behavior stopped.

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