Drosophila-nator (Prototype)

This is a joint Entomology / Aerospace project to look for evidence that Spotted Wing Drosophila (an invasive species to North America) may be migrating at higher altitudes where wind currents can carry them further and faster than otherwise expected.

Skywalker Flight #69

Altitude: 200′ AGL
Airspeed: 20 kts
Weather:  10 kts wind, 22C
Mission: Circle fruit fields with insect traps.

Skywalker Flight #70

Altitude: 300′ AGL
Airspeed: 20 kts
Weather:  12 kts wind, 20C
Mission: Circle fruit fields with insect traps.

Skywalker Flight #71

Altitude: 400′ AGL
Airspeed: 20 kts
Weather:  13-14 kts wind, 20C
Mission: Circle fruit fields …
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Flying on the Edge of a Storm

This is a follow up to my eclipse post.  I was forced to end my eclipse flight 10 minutes before the peak because a line of rain was just starting to roll over the top of me.  I waited about 20-30 minutes for the rain to clear and launched a post-eclipse flight that lasted just over an hour of flight time.

Here are some interesting things in this set of flight videos:

  • You will see the same augmented reality heads up display and flight track rendering.  This shows every little blemish in the sensors, EKF, flight control system, and airplane!  

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Flying on the Edge of an Eclipse (2017)

On August 21, 2017 a full solar eclipse sliced a shadowy swath across the entire continental USA.  The totality area missed Minnesota by a few hundred miles so we only saw about 85% obscuration at our peak.

I thought it could be interesting to put a UAV in the sky during our partial eclipse and record the flight.  I didn’t expect too much, but you never know.  In the end we had a line of rain move through a few minutes before the peak and it was really hard to say if the temperature drop and less light was due …
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Adventures in Aerial Image Stitching Episode #5

Aerial Deer

Last Friday I flew an aerial photography test flight using a Skywalker 1900 and a Sony A6000 camera (with 20mm lens.)  On final approach we noticed a pair of deer crossing under the airplane.  I went back through the image set to see if I could spot the deer in any of the pictures.  I found at least one deer in 5 different shots.  Here are the zoom/crops:






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Continuously Self Calibrating UAV Compass

Manual UAV sensor calibration is dead!

I know the above statement isn’t exactly true, but it could be true if everyone who develops UAVs would read this article. 🙂

In this article I propose a system that continuously and dynamically self calibrates the magnetometers on a flying UAV so that manual calibration is no longer ever needed.

With traditional UAVs, one the most important steps before launching your UAV is calibrating the magnetometers.  However, magnetometers are also one of the most unpredictable and troublesome sensors on your UAV.  Electric motors, environmental factors, and many other things can significantly interfere with …
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Autopilot Visualization: Flight Track

 

Augmented reality

Everything in this post shows real imagery taken from a real camera from a real uav which is really in flight.  Hopefully that is obvious, but I just want to point out I’m not cheating.  However, with a bit of math and a bit of camera calibration work, and a fairly accurate EKF, we can start drawing the locations of things on top of our real camera view.  These artificial objects appear to stay attached to the real world as we fly around and through them.  This process isn’t perfected, but it is fun to share what …
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Synthetic Air Data (an afternoon hack)

Motivation

On June 1, 2009 Air France flight #447 disappeared over the Atlantic Ocean.  The subsequent investigation concluded “that the aircraft crashed after temporary inconsistencies between the airspeed measurements – likely due to the aircraft’s pitot tubes being obstructed by ice crystals – caused the autopilot to disconnect, after which the crew reacted incorrectly and ultimately caused the aircraft to enter an aerodynamic stall from which it did not recover.”  https://en.wikipedia.org/wiki/Air_France_Flight_447

This incident along with a wide variety of in-flight pitot tube problems across the aviation world have led the industry to be interested in so called “synthetic airspeed” sensors.  …
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Howto: Action Cam HUD overlay

NOTICE: This is a draft document and in the process of being written.  It is incomplete and subject to change at any time without notice.  

In this post I share my process and tools for creating HUD overlays on a flight video.  Here is a quick overview of the process: (1) Calibrate your camera, (2) Extract the roll rate information from the flight video, (3) Automatically and perfectly time correlate the video with the flight data, (4) Render a new video with the HUD overlay.

Source Code

Please be aware that this code has not yet gone through a v1.0 …
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Autopilot Visualization

Blending real video with synthetic data yields a powerful and cool! way to visualize your kalman filter (attitude estimate) as well as your autopilot flight controller.

screenshot-from-2016-11-30-14-31-14

Conformal HUD Elements

Conformal definition: of, relating to, or noting a map or transformation in which angles and scale are preserved.  For a HUD, this means the synthetic element is drawn in a way that visually aligns with the real world.  For example: the horizon line is conformal if it aligns with the real horizon line in the video.

  • Horizon line annotated with compass points.
  • Pitch ladder.
  • Location of nearby airports.
  • Location of sun,

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Mistakes!

dj-mistakes-homer-dohmistake-pano_13891

I make thousands of mistakes a day, mistakes typing, mistakes coding software, mistakes driving, mistakes walking, forgetting to order my sandwich without mayo, etc.  Most of the time they are immediately obvious — a red squiggly line under a word I mistyped, a compiler spewing an error message on line #42, a stubbed toe, my gps suggesting a u-turn at the next intersection, etc.

mistakes

But what happens when the mistake isn’t obvious, isn’t noticed immediately, and doesn’t cause everything around me to immediately fail?  Often these mistakes can have a long lifespan.  Often we discover them when we are looking …
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