Field Comparison of MPU6000 vs VN100T

The U of MN UAV Lab has flown a variety of sensors in aircraft, ranging from the lowly MPU-6000 (such as is found on an atmel based APM2 board) all the way up to an expensive temperature calibrated VectorNAV VN-100T.  I wish to present a quick field comparison of these two sensors.

[disclaimers: there are many dimensions to any comparison, there are many individual use cases, the vn100 has many features not found on a cheap MPU-6000, the conditions of this test are not perfectly comparable: two different aircraft flown on two different days.   These tests are performed with a …
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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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Zombie Door

Run!!!

Zombies are pretty cool.  This post describes something a little less cool, but uses zombies to explain the concept (in a shallow, transparent attempt to capture your attention!)

Zombie Door Method

Imagine we want to generate a uniformly distributed random sampling in some complex space that our random number generator does not directly support.

Let me start with an simple example.  Imagine we have a random number generator that produces a random integer between 1 and 100.  However, we actually want to generate random numbers between 41 and 50.  (I know there are better ways to do this, but …
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Failure is not fatal

This post is penned during a moment of extreme frustration, beware!

Kobayashi Maru

https://en.wikipedia.org/wiki/Kobayashi_Maru

One of the reasons I loved the original Star Trek series is because no matter what the odds, no matter how hopeless the circumstances, no matter how impossible the foe, Captain Kirk always found a way to think his way out of the mess.  He never ultimately failed or lost to an opponent, not once, not ever.  That makes a great hero and fun TV!  Fictional super heroes do things that normal human beings could never possibly do … like fly, or be stronger than steel, …
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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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