Hi everyone,

I am running out of ideas for tuning my Ansley Peace Drone, a canard design with elevons. It flies fine in MANUAL, and control deflections in FBWA look normal on the bench, but I am getting almost no response in either pitch or roll in FBWA or AUTOTUNE while airborne. You can see 'roll' vs 'nav_roll' in the first screenshot below. 'roll' never rises beyond about 15 degrees.

I have done all radio calibration, accel checks, magnetometer checks, etc. I am not using an airspeed sensor. I have tried both autotuning, and working through Method 1 for roll in the tuning guide (increasing roll P in 0.1 increments). I have taken roll P all the way to 1 with no discernible difference in roll response.

Does anyone have ideas? If nothing else, I'm wondering if anybody could shed light on what inputs the APM uses to calculate control deflection, to help me troubleshoot. I'm assuming that speed would have to be taken into account somewhere, which is why I inquired in a previous thread about how ArduPlane calculates speed with no airspeed sensor installed. I was getting erroneous high airspeed readings earlier, but have that fixed now, and the plane still flies the same. My GPS also apparently went bad yesterday so I have been flying without a GPS fix and thus no groundspeed reading, but the plane continues to fly just like it did when the GPS still worked.

Any help welcome! My most recent tuning settings are also attached (autotune-generated, with a manually input 0.8 roll P).


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I think you just haven't finished tuning. My Skywalkee's P's are above 2. Just keep cranking up the numbers until it gets responsive. When it is reasonable, then try autotune.
Also try increasing your max bank to 55 deg.
Your NAV L1 is much too high, but you having got to auto missions yet.

That was apparently it... thank you!

This is embarrassing, but I'll fess up for the benefit of others who might encounter this thread: from the beginning, I was under the assumption that P values ranged from 0 to 1. I had the idea that they represented percentages of maximum sensitivity, and it never occurred to me that might not be the case. I've spent the past week's test flights trying to tune within that range. This morning I test flew with gains in the 1.5 to 2 range, and had much better roll response.

There's nothing like learning APM to keep you humble!


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