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View Full Version : Discussion Helicommand Idea - for the Electronics Gurus!


furyphoto
Jan 16, 2009, 07:02 PM
So this is just an out of the blue hypothesis, and even if it were possible I would not have the skills or the gumption to pull it off.

But...

I was looking at Helicommand Units today, I have been thinking about getting one, because I live in an area that is difficult for my AP2000i. Lots of trees and mountains make it difficult not to drift if I need to turn the heli around.

I realized after a bit of reading that, since the Helicommand can hold position a few meters off the ground, using it's down pointing visual sensor, It already has "Position Hold" functionality built into the unit.

Would it not be possible to swap out the visual sensor for (and here is where it turns into a hypothesis) a GPS unit, and some sort of PIC controller that takes a sampling of GPS data, does a little math (or a lot!) and emits output that imitates that of the Helicommand's visual sensor?

I'm thinking a GPS receiver like the one in my Cell phone (which is amazingly accurate), a power supply, some sort of PIC microprocessor, some smart coding knowledge, and a bit of know how (none of which I have) would be able to emulate the signals that the visual sensor provides to the Helicommand thus giving relatively affordable GPS position hold.

Any electronic geniuses out there care to support, ponder, or utterly debunk this theory?

-A

rbeall
Jan 16, 2009, 09:32 PM
http://en.helicommand.com/index.php?option=com_content&view=article&id=46&Itemid=54

Sorry man. Great idea but knowing the ins and outs of what they are trying to accomplish with each sensor does kind of pull the curtain back a little.

They are trying to measure/hold an altitude. GPS does give you altitude but for this application it isn't accurate or fast enough to produce results adequate enough for auto-landing or hover. However the laser range finder (assuming because that's what it looks like) that they are using probably has a 200x faster capture rate as well as a 100x better resolution.

GPS: 1-10 ft @ 1-5 hz

Laser: .5-5inches @ 200-400hz

These are all guesses but what I have seen in some of my past research.
Sonar altimeters are also a very cheap method of low altitude control which is what I am experimenting with.

sonar: .7in @ 200 hz

-Ryan