(here's a re-post with proper text-wrapping. Sorry, all!)

Hi, all!
I'm looking for a fairly cheap (preferably <$100) way to build a tilt sensor
for use in dynamic situations. In other words, I'd like it to be able to
tell me what angle relative to the horizon it is, even in a situation where
it is experiencing lateral and vertical g-loading. I don't need terribly
great accuracy or stability: +-5degrees is good enough, and it only needs to
accurately track tilt for 1 minute or so.

There are two things I'm currently considering:
1) Two accelerometers mounted @ 45 degrees to each other (maybe one two-axis
gyro mounted on end?), to be able to sense the angle of earth's gravity in a
static situation, combined with one more accelerometer  which is used with a
micro to keep track of tilt rates and times. The third accelerometer should
be able to provide reasonably accurate dynamic tilt and can be re-calibrated
periodically with the information from the static tilt sensor.

2) I've heard of people using low frequency IR to sense the difference
between the sky and earth to get a general idea of angle to the horizon. I'm
not sure how accurate this would be, and I'm not sure exactly how to
implement it, so I'm a little reluctant to try this.

Any ideas, comments, suggestions, flames, etc.?

Thanx!

- Robert
www.geocities.com/uavbob

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