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Two crashes and rethinking the plane

Hello from the AUVSI Student UAS competition! The 4 of us – Joe, Paul, Cindy, and Rijesh – are currently in Lexington Park, Maryland.

As you may have heard, we had some show-stopping events just before the AUVSI competition. Inconceivable, our last remaining airframe, crashed twice into the North Saskatchewan River in the days just before the AUVSI Competition.

Crash #1, with the boaters that rescued Inconceivable for us

Crash #2, when we weren’t so lucky

The causes of the crashes are as follows:

  • Crash 1: Inconceivable has flaperons that were engaged on takeoff. These were not turned off after takeoff, meaning that the aileron servos could not move enough to have the plane bank as intended. The plane went into a severe right bank, lost altitude quickly, and crashed into the river. Thanks to the boaters in the picture above, we were able to recover the plane.

  • Crash 2: When tuning a pitch control loop in AUTO2, Inconceivable went into a severe pitch down and gained a significant amount of speed. The pilot was not able to recover Inconceivable in time. Because Inconceivable was pointing north at the time this happened, it descended into the river. These crashes were due to a combination of poor planning, a limited amount of time to tune and develop our autopilot, and pilot error. As a consequence, we have no functioning system right now, and are here at the competition as observers only.

We’ve been starting to think about our next system. Because of the crashes, we are in need of a new airframe and a new camera system altogether. The EPP FPV airframe we previously had is out of stock, and we have been thinking about replacing our camera system for a while. Some ideas that have been floated for each of these include:

  • A small foam delta wing airframe. We’ve had good experiences with Murphy and Inconceivable, our two EPP FPV foam aircraft. Foam offers less weight and cheaper and easier repairs in case of a crash. We’ve seen 3 separate teams here with very similar delta wing models, and have been talking to them about their experiences.
  • Another scientific imaging camera (with a wider-angle lens that what we had).
  • A DSLR or other Canon/Nikon consumer camera running with a tethered shooting software, so that we can read live images from the camera.
  • A smartphone camera, with image processing happening on the phone.

We are going to the awards banquet tonight; there will be a post later today about some of the events of the competition, as well as the competition results.