I think dave was thinking more along the lines of home made FOG'S? In
which case it might make sense to use a few given that they likely wouldn't
be anywhere near as good as a commercial unit...
Andrew
On 19/01/2016 6:40 pm, "Ben Brockert" <wikkit@xxxxxxxxx> wrote:
I talked with a guy who had done this with MEMS IMUs at the suborbital
conference and the general take is that you get a signal that is
sqrt(number of sensors) times as good as a single sensor.
It's a bit silly doing it with FOGs though, they are some of the best
gyros on the market. Making orbit with FOGs is certainly possible, and I'd
be surprised if SpaceX isn't doing that.
On Monday, January 18, 2016, David Weinshenker <daze39@xxxxxxxxxxxxx>
wrote:
On 01/17/2016 08:55 PM, Henry Spencer wrote:
For example, maybe there's
some cross-coupling between gyro axes that you can take out by combining
all three gyro channels together into a vector and multiplying by a
correction matrix to give three synthetic channel values.
Thinking about this - AIUI, the hard part of making a "good" FOG isn't
the optical system itself, but subtleties in the winding geometry of
the fiber, required to ensure that the gyro responds only to rotation
about one axis and ignores all rotation about other axes.
If one had three "not quite perfect" (but perhaps cheaper to build) FOG
units, each of which only roughly approximated this condition, could one
generate a "good" 3-axis output from a set of them, processed through
this sort of correction matrix algorithm?
-dave w
