Tj Bordelon's Page
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There is no fuselage on a flying wing :) And EPP is all but "airproof", so static reading in the payload compartement are all over the place. Plus, by regulating airspeed of 9 m/s instead of 11 m/s (both of which looking perfectly fine for this type…
@abey - I've got a bit of cheating going on in that my static port is simply ambient, in fuselage. I had originally made a nice brass dual ported tube that stuck out the nose, but it lasted exactly 1 flight. But surprisingly the difference in two id…
http://www.ntps.edu/Files/tas_fnl3.pdf
This is useful if you don't have the equipment to output pressures! And looks like you have the data to pull this off. Good luck
Unfortunately (for the static reading), I deal with an EPP flying wing (a swift II), so i don't have has much flexibility in term of picking up static port around the fuselage (or lack thereof).
@abey - you can get close to "purely" static, but it requires some plumbing. On my (full scale) sailplane I have 4 static ports, two on each side of the fuselage. They are at points behind the wing where there is little disruption of flow. The 4 por…
Actually, its not that simple in my case, because the static pressure reading is never "purely" static. Close to cruise speed, the static pressure is contaminated by dynamic flow, which requires inflight offset and gain estimation. I do this by taki…
Right abey: I do take out the offset. That's the easy part.. Just plug the pitot and take a reading.
That's pretty much exactly what we do for wind estimation and pitot calibration. However, a simple scaling from the pressure sensor ADC reading to the dynamic pressure value will not do. At least an offset and a scaling is necessary, and this wont p…
Clever! Useful both for calibrating the pitot and for biasing navigation algorithms to tighten your tracking when going crosswind.
OH-- the nice thing about the pitot method is that you don't need the constant airspeed, which seems to be difficult on my ezstar for some reason. Heck, the data wasn't even taken with a constant turn. It was flying a triangle of waypoints and ascen…
You're right- GPS alone can tell you the wind. That's a good solution for wind estimation.
The reason I got into plotting this data was to see if my pitot was calibrated. It seemed obvious that you could instantaneously determine wind in a given di…
Hi Tj
I haven't worked on the wind problem yet, but I think your data makes the problem look fairly tractable. I am a fan of forming a wind estimate in the air because I know that in my local environment we VERY commonly have low level wind shear,…
I just added a pitot to my ezstar (http://bordelon.net/ezstar) and did a flight. Naturally the plots of the airspeed sensor and GPS velocity (projected onto the X axis... straight thru the nose) did not seem to match. But should they? I figured any…
Hi Bordelon !
Nice work and nice setup !
Which AP you used ?
Very impressive! Enjoyed your website, very innovative.
Thanks!!
Profile Information
- About Me:
- Made my own autopilot system from scratch... Fully automatic takeoff, flight, and landing. NO laptop required... fully inertial.
- Website:
- http://bordelon.net/ezstar.html
- Hometown:
- Natick, MA
Tj Bordelon's Blog
Best way to calibrate a pitot / Good way to estimate wind?
I just added a pitot to my ezstar (http://bordelon.net/ezstar) and did a flight. Naturally the plots of the airspeed sensor and GPS velocity (projected onto the X axis... straight thru the nose) did not seem to match. But should they? I figured any wind would skew the results, so how do you know you're calibrated?
I first tried to make a "manometer" with a tube of water but that seemed to just make a mess and was off by 50% in the end.
I finally just flew with the manometer guess, and made 10… Continue
I first tried to make a "manometer" with a tube of water but that seemed to just make a mess and was off by 50% in the end.
I finally just flew with the manometer guess, and made 10… Continue
Posted on October 17, 2009 at 4:06pm — 12 Comments
A good video of my system in action...
This Saturday I had 15 mph winds gusting to 25 mph.. Still landed without issue. Wind is coming from the top of the image towards the bottom. You can see the aircraft try to land down the runway (right to left) but fighting the wind made the path a bit weird. But impressive given that the wind was something I wouldn't have flown in myself. Here's the plot:
I have to say that windy flights are far more impressive. I had a nice crowd watching the airplane land in the crazy winds. One guy complime… Continue
I have to say that windy flights are far more impressive. I had a nice crowd watching the airplane land in the crazy winds. One guy complime… Continue
Posted on October 12, 2009 at 9:09pm — 7 Comments
Finally, my autopilot is "finished"....
But is is ever? I define finished as in it works every time I go fly now. I go to the field, turn on my plane and it takes off, flies to waypoints, and lands with no user intervention. It's done this now for the last 4 times I've been to the field! So it feels more "finished" than ever.
I didn't use any kits or open source stuff, and built everything from scratch. Except the EZ-Star of course! I also use my own sensor fusion algorithm, which is to be featured in Circuit Cellar early next year.… Continue
I didn't use any kits or open source stuff, and built everything from scratch. Except the EZ-Star of course! I also use my own sensor fusion algorithm, which is to be featured in Circuit Cellar early next year.… Continue
Posted on September 24, 2009 at 6:05pm — 13 Comments
Comment Wall (1 comment)
- At 7:57am on September 28, 2009,
Sgt Ric said… - Sounds great, but aren't you the same TJ Bordlon who worked for NASA and has sent balloons to the edge of space?
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