Replies
Dale,
Yes, we are looking at adding "analog" tone to the Gen 1 code. We are working hard on Gen 2 now, have some more flight testing to do, and since this is a hobby project, we don't have a specific timeline
I'd be happy if we have a mature circuit design and good code by Oshkosh time next summer so we have something to brief! As soon as we validate the AOA algorithm, we'll post the design and code on GitHub.
Since the components are so inexpensive, we have added an accelerometer pad that will provide future growth capability for additional overload warning. We want to experiment with 3 dimensional G sensing to provide asymmetric over-G warning (another great McDonnell concept used in the F-15) in addition to the aural AOA tone. We are also going to experiment with wing skin sensor ports (ala AFS stand alone AOA systems) and wireless sensors as well to determine what's in the art of the doable.
Mike,
GRT is in the TWS volume (i.e., in our cross-check), but the Gen 2 box is going to be a better option if we crack that nut!
Carl,
Thanks. We'll post a similar video with the new "analog" tone as soon as we get our test airplane modified and I have some time. Interestingly, Lenny (one of our world-class, way smart engineering types) came up with a way for me to actually adjust the wave pattern in the software, so what we are using now matches the sound of my piano. I figured that's a reasonable analog place to start.
It never occurred to me when we started this project that the tone itself would be an issue (guess I had flown with it too long and was simply biased), but we'll make sure there are user definable options (including a null tone, i.e., no sound when ONSPEED, although I would argue that operationally this isn't a good idea since the pilot does not receive continuous feedback) in Gen 2.
Johnnie,
We built the tone generator. The one in the video receives an AOA signal from a Dynon EFIS through serial output. Our "box" processes that signal and generates the tone pattern for the pilot. If you go back through this thread or search ONSPEED or ON SPEED (there's no right way to spell that) it might give you some more insight. We are now working on a 2nd generation box that will measure AOA and provide the tone. Our designs and software are posted on GitHub for folks that want to build one and we are standing up our own web site (flyonspeed.org) to consolidate all of our resources. We're also going to remain active here on the safety page.
All,
Our primary objective with the Gen 2 box is to eliminate or minimize calibration tasks for the pilot. Our biggest lesson learned is how varied commercial AOA system algorithms are, what the limitations of those algorithms are and that the average pilot has a difficult time getting the Dynon AOA system "dialed in." With the Dynon EFIS AOA display, it is essentially impossible to exactly replicate a calibration twice in the same airplane, using identical technique, under identical conditions. Simultaneously calibrating two identical EFIS (DY-10A's) even produced different results for each unit.
I have to point out the Dynon system does exactly what it's designed to do: provide excellent progressive stall warning. Turns out we were simply asking too much of that system to provide accurate AOA for ONSPEED or L/Dmax conditions with every calibration.
ONSPEED and L/Dmax only come into play when you use AOA to actually fly the airplane and assist with energy management as opposed to simply avoiding the aerodynamic (stall) limit. Besides demonstrating the utility of the tone logic, our other big objective is to provide educational resources so folks can develop a better understanding of how flying AOA not only helps avoid loss of control, but can really simplify precise control (energy management) of the airplane.
Cheers,
Vac