Re: [Paparazzi-devel] Tiny on larger glow/gas aircraft

[Matthew Currie]

Daniel,


 You will likely get a wealth of information about gas engines/exhaust 
+ copilot from RC forums as they are obviously much more popular for 
non-uav applications.  When I bought my first FMA copilot several years 
ago, the manual contained numerous photos with gas planes in the 
instruction manual.  Check the support section of the FMA site for a PDF 
user manual for the Co-pilot system as a lot of questions may be 
answered in detail there.  I saw the FMA co-pilot mounted to the bottom 
of the fuselage often which keeps it outside line-of-sight of the engine 
but not from the exhaust oils.  The IR sensors have a "viewing angle" 
and it goes without saying that a hot engine should not be within this 
"cone".  This wiki image demonstrates example temperatures the IR sensor 
might be looking to see: 
http://paparazzi.enac.fr/wiki/index.php/Image:IR_example2.jpg

 The servos will operate with lower PWM voltage.  It is common in the 
RC world for large models to apply a seperate 6.0V supply to the servos.


Regards,
Matthew Currie

Daniel Kauter wrote:
> Hi everyone,
>
> Has anyone tried using paparazzi with gas or glow engined planes, and if so, 
> was it a success? If not, could anyone speculate on whether it would?
>
> My concerns with it relate to the IR sensors:
>
> 1. Would the hot exhaust (which contains oils and residues) significantly 
> affect the angle measurements? There is likely to be hot exhaust behind, and to 
> one side of the aircraft, and possibly even below. The best strategy I can see 
> to mitigate this is to mount the x,y sensor high on the tail.
>
> 2. Would the hot engine at the front of the plane affect the angle measurements 
> significantly? Hopefully the fuselage will shield most of the engine from the 
> IR sensors fov, but probably not completely.
>
> 3. Would hot oil and exhaust damage the IR sensors? Being on the outside of the 
> aircraft, I imagine it would be hard to ensure they are safe from this.
>
> My only other concern is with regard to larger aircraft. Obviously the 5V 
> supply won't be capable of supplying 5 or 6 large servos, so I am planning to 
> supply them from a 6.0V NiCd. Does anyone know if the servos will have a 
> problem detecting their 5V PWM signals from the Tiny when their supply voltage 
> is higher?
>
> Thanks in advance to those who respond. Your input may save me a lot of time 
> pursueing something that might not work!
>
> Also, thanks to everyone who has helped create paparazzi. My team and I enjoyed using it to build our MAV last year. I'm hoping we can continue using it this year with a larger aircraft for this: 
>
> http://www.uavoutbackchallenge.com.au/
>
> Maybe paparazzi can get another title under its belt!
>
> Cheers,
>
> Dan
>
>
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