Tuning issues with plane, successful auto t/o and land maiden - now not so much

Hello there, I deleted my initial post as it wasn’t really clear about what I was trying to get after, I’m hoping to get some help interpreting my bin files and specifically the PID values. My
project is an electric motorised glider utilising an RFD900x telemetry radio that I use for telemetry as well as control inputs in manual or autotune modes.

Ardupilot 4.3.4 running on Matek H743 Wing. RFD900x. Matek 4525 ASI. Matek 3901 Optical flow sensor. 4S 3500mah LiIon battery. Heron Multiplex airframe.

Unfortunately, I don’t have any RC experience, although I do have flying experience and reasonable understanding of aerodynamic theory. This lack of RC experience has led to a bias towards auto missions that is further biased by what was a very successful first sortie with the auto take-off and land working flawlessly and a sense that even if there are some oscillations, ultimately it will land ok.

There has been a total of 4 flights so far, and the issue that I am experiencing every time is increasing pitch and roll oscillations during part or all of the flight, on flights 2 and 3 resulted in an ugly landing just short of the landing point with no damage, and on flight 4 a
departure early on final and a crash into a lake. I attempted an autotune on the first flight however I was unable to have many inputs as oscillations started and I hit the RTL. In viewing the bin files I believe that the PID settings need to be amended but I am hesitant to fly again without some improvement.

A number of issues have been resolved along the way. These include:

  1.     Compass calibration on the first flight wasn’t completed correctly which resulted in a 180 deg turn just after take-off that the FC handled well. When I experienced some oscillations on this flight I mistakenly assumed that a bad calibration was the cause.
  2. Airspeed indicator. A large discrepancy between G/S and A/S, auto calibration was set, and again I thought it might have been the cause of the oscillations. Sortie 3 set to only recognise airspeed with zero throttle, Sortie 4 turned ASI off (this caused me to have to set throttle settings for cruise and auto land which may have created another issue).
  3. I have increased speed on final for auto mission however same issues.
  4. I don’t believe that there is asymmetric flap deployment however I may reduce F2 settings in future as it probably isn’t the priority to short land distance right now.

I will upload the .bin and telemetry files below for each flight with notes.

I would be very interested if anyone could confirm, that it is the PID settings that are causing the
issue, and if there is a particular event that is causing an RTL (potentially voltage drop on take off). I think the answer will be to get after the auto tune and take over as required but it would be great to have some PID values I can put in.

Maiden Flight.

Plan was to launch switch to auto tune, complete the auto tune and then auto land.

Launched with compass calibration error message which I ignored as I had incorrectly calibrated my compass the night before. A couple of auto tune inputs, followed by oscillations and me hitting the RTL. Bin file and landing vid (apologies for the quality) below.

Sortie 2 and 3.

Returned with a correctly calibrated compass. Hoping that all issues were resolved. Noting that there was a large discrepancy between a/s and g/s and at one point during the maiden the airspeed ignored message was received, sortie 2 had read a/s only when throttle zero, sortie 3 had disregard ASI.

Auto Take-off went well on each occasion.

Significant oscillations on each sortie. I believe that I hit RTL on sortie 2, and my laptop died with the cold weather on sortie 3 and it went straight to land RTL.

Final approach was untidy on both occasions with a no damage crash.

4th Sortie.

Upgraded to 4.4 beta. Airspeed indicator input disregarded. Long 5% final to try and ensure a stable approach.

Auto takeoff, I input some rudder followed by aileron just to visually see the effect. Shortly after the oscillations started. At some point RTL was triggered by voltage drop on take off or perhaps the oscillations.

In auto for entirety of the sortie, got it self onto final then pitch up and down with some wing drop and ended up in the lake a long way short of the landing point. I did not take over as it previously got back close to the planned landing point, and I backed the FC in over myself.

Looking at the pitch and roll graphs there is almost an 180 degree phase shift in the roll by the end. I am sure that the autotune will be able to sort most of this out but a closer starting point or anything else people might feel important or helpful would be much appreciated.

After drying everything out, and unfortunately having to replace the FC, I will be going ahead with the following changes:

Autoland to default settings as per first, and largely successful maiden flight.

Cruise speed increased to 14 m/s from 12.5 IOT allow a wider margin.

Decrease F2 from 100% to 20%, short landings can be got after stable landings.

Reenabling ASI, after further reading here it looks like 1-2m/s fluctations when stationary are normal and reduce as speed increases.

Next mission will be shorter, flown at lower alt requiring a shorter final, with the sole aim of completing autotune process.