[Canberrauav] Thursday Recap (yes, there's still more!)
Stephen Dade stephen_dade at hotmail.com 
Thu Oct 4 22:10:51 EST 2012 

Hi all,

Today was spent packing up our equipment and searching for the dropped 
water bottle. The original plan was also to start the drive back to 
Canberra, but events overtook us and we will now being the journey back 
tomorrow morning. We should be back in Canberra by Saturday evening.

As for the bottle search:
Tridge, Jack, Chris and myself spent the morning theorising about the 
timeline and process of the bottle being ripped off the UAV.

After looking at the telemetry logs, we found 4 specific events related 
to the incident. Three of these were very sudden decreases in speed and 
one was when the bottle sensor registered a detachment of the bottle. 
All of these events were over 4 minute period. This potentially indicated 
that bottle had "hung around" the UAV for a bit (caught on the tail?) 
after being detached. Another theory is that the parachute string had 
loosely fitted around the propeller for a couple of minutes before 
becoming tight enough to rip the bottle off.

By finding the bottle we could ascertain when in the flight it really 
came away from the UAV.

We plotted the UAV's position at the times of these four events and 
went off looking around those areas for the bottle. Where possible, 
we got permission of the local landowner first. We also had the help 
of the Dickson College UAV team (~8 college students and 2 adults) in 
the search.

Chris was the one that found the bottle ~90m downwind from the point 
when the bottle sensor registered a detachment of the bottle. The location 
of the bottle was (-26.627069, 151.846367) in lat/long. The bottle was 
completely intact too (minus the parachute of course).

This tells us that the bottle remained attached to the UAV for some time 
before ripped off. I intend to write up a full report in the next couple 
of days (attempting) to explain our process and conclusions in regards to 
this.


Also - the UAV Challenge organisers have published their final assessment 
of CanberraUAV's performance:
http://t.co/KczWKA3k
In short - we detected Joe to 3m accuracy. This is within the error bounds 
of GPS. This is an awesome result :)

Thanks

Stephen

Copyright 2012 http://canberrauav.org.au/