Moderator

This seems very DIYD

tempestdrop.jpg

Not sure if this is in the military category or not...

WASHINGTON, Dec 05, 2011 The Naval Research Laboratory Vehicle Research Section has successfully completed flight tests for the Autonomous Deployment Demonstration (ADD) program. The final demonstration took place Sept. 1 at the Yuma Proving Grounds, Yuma, Ariz., and consisted of a series of eight balloon-drops at altitudes of up to 57,000 ft, delivering sensor-emplacement Close-In Covert Autonomous Disposable Aircraft (CICADA) vehicles within 15 feet of their intended landing locations.

The ADD concept is to enable small unmanned air vehicles (UAV) equipped with sensor payloads to be launched from aircraft (manned or unmanned)

cicadamk3.jpg?width=200


A custom autopilot for the CICADA, both hardware and software, was developed by the Vehicle Research Section to be both inexpensive and robust. The only flight sensors are a 5Hz GPS receiver and a two-axis gyroscope. Although
having minimal sensors, the navigation solution and the flight controller proved to be quite robust during in-flight testing, routinely recovering from tumbling launches. The flight controller also included a custom NRL algorithm that accurately estimated wind speed and magnitude, despite having no air data sensors onboard.

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  • Moderator

    Cool, how 'bout a small ArduPilot(L) project being dropped by a bigger APM2 project...

  • Moderator

    Well this is the father of most of these projects and I think the point here is the first aircraft dropping the second, that's lots going on! 

    Shaw Communications
  • @Alex: About the control. I gues they are using GPS as primary sensor for navigation and control with some rate damping on roll and pitch with the gyros... If you design an inherently stable aircraft it even works without gyros, look at this example (also to show this stuff here isn´t really a first :-) http://www.gpsboomerang.com

    @Gerry: I don´t think bslloon launching will replace propulsion. The mission profile is totally different. For things like weather probing or deploying sensors it could be ok.

  • This is very exciting. I think balloon launched sailplanes are underrepresented in the UAS field right now. Their cost/performance ratio seems to offer great potential. As gps & sensors become more affordable the cost of a propulsion system will likely become an increasingly large portion of the total vehicle/platform cost.

    With a good glide ratio, I can easily see this system as achieving longer mission ranges with reduced ground support logistics.

    Programming the autopilot to respect VNE and execute a dive recovery which doesn't rip off the wings has always intimidated me though. Now that I know it's been done I'm more tempted to give it a shot.

    Some relevant reading I found:

    http://en.wikipedia.org/wiki/V_speeds

    http://www.pprune.org/archive/index.php/t-254943.html

  • Moderator

    @Davey The CICADA bit caught my eye as they are hatching everywhere here at the minute, Christmas beetles is the local term!

    http://en.wikipedia.org/wiki/Cicada

    Great gif from that wiki page

    170px-Cicada_molting_animated-2.gif

  • @Ken. The Tempest is nice plane on its own. It's interesting that it was designed to operate from 0 to 3000 feet but in this application, it starts operating at 57000 feet and pulls up from there. Nice bird.

  • @Ken. I had assumed from its appearance and that since it was being dropped from a balloon that it WAS a glider and that somehow it was using thermals/updrafts in order to do its pull up maneuver.  Thanks for clearing that up.

  • A and AA,

    Yes, the CICADA are the little things being dropped from the big thing, but the big thing is not a glider.

    This is mamma: http://uasusa.com/tempest.php

  • I think that they are dropped from the glider and they glide to the designated location.

  • Moderator

    Is the CICADA the two small things on the wings of the glider?  that is pretty cool stuff though

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