Re: [Paparazzi-devel] StratoBlimp, a challenging UAV project

[P.J.S. Danneels]

Hi Guys,

GPS:
Thank you for the replies, we are not that concerned with the GPS we're confident that we can find modules that work above the 60k ft limit and our design will probably not be able to survive the speed limit of 999knots anyways. But we know about the limitations and we are taking it into account.

GPSboomerang:
Yes, the GPS boomerang is a very nice example, but we can't find any evidence that it went above 20km altitude.
So we basically want to make a more advanced GPSboomerang.

Questions to the community:
- Long range communications, our biggest unknown at the moment. We're looking at the Digi XBee Pro 868 module, with high gain antenna's and a directional ground station with auto tracking. This could be enough for most missions but occasionally the drift can be a lot bigger. Do any of you have experience with this module, these kind of antenna's and tracking setup? Or are we overlooking other types of communication. We've also come across the radio amateur bands for example the 70cm or the 2m band but then you have to do with licenses again. Any input on the communication problem is much appreciated.
- Is there any data available in how much cpu power is generally used by paparazzi on the STM32 and LPC2148 models? So do we have a lot of spare cpu power to do some fancy route calculations. or is it close to its limitations already?
- digital HD camera's. It's off course possible to strap a GoPro camera on the craft but that's not very weight/volume efficient in my opinion. Have you guys successfully implemented tiny HD camera's?

Best regards,
Pieter


On 20/11/2012 12:42, Hector Garcia de Marina wrote:

On Tue, Nov 20, 2012 at 12:04 PM, Tilman Baumann <address@hidden> wrote:

On 20/11/12 08:55, Hector Garcia de Marina wrote:

Also remember that the air density is low at those altitudes, therefore the "free fall period" (or lets say the control over your vehicle is minimum) must be designed for do not let the UAV spins at high velocities. Also you will reach a really high speed, the fuselage must be really well made for preventing fluttering, probably staying only at 3Kg as maximum could be an issue to solve.

This guy gets away with it on the cheap with simple foam wings.
http://www.gpsboomerang.com/content/view/34/42/

Perhaps spaceship one style feathering would make sense.
Not necessarily as a hinged wing. Maybe just with a piece of foam or a drogue chute that can be detached once lower speeds are reached.

Looks great Tilman, thanks for the link.

 

--
Héctor

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