M
Mike
- Jan 1, 1970
- 0
Hi - I'm working on building a fairly sophisticated IMU system. It
will combine data coming from 3 axes of gyro, 3 axes of accelerometer,
3 axes of magnetometer, and a DGPS corrected GPS into an XYZ offset
and roll pitch yaw offset from initial conditions.
Anyways - right now I'm trying to identify what sort of magnetometer
to use. I care most about accuracy, precision, and bandwidth. Right
now I'm thinking I'll use some Honeywell parts:
http://www.ssec.honeywell.com/magnetic/products.html - probably the
HMC1053: http://www.ssec.honeywell.com/magnetic/datasheets/HMC105X.pdf
Good linearity (.1%), high bandwidth (5MHz), small size (LCC-16
(essentially a QFN without a ground pad)), annoying interface (lots of
external parts needed - including high voltage stuff - a complete pain
to work with).
One thing I worry about a bit - Honeywell also has some parts with 3x
the sensitivity of the HMC1053, but in unappealing packages (and only
single or dual axes). Will I lose any accuracy by having to set my
gain 3x as high on whatever instrumentation amp. I use? From my
understanding typically the non-linearity of instrumentation amps is
in the hundreths or thousandths of a percent, so it won't matter at
all.
PNI make some sensors that seem to be more bandwidth limited. Various
other companies make magnetometers with somewhat slow digital
interfaces, whereas I'm looking for an analog interface. I would like
about 1KHz bandwidth or more.
Any other parts I should be looking at?
Thanks!
-Mike
will combine data coming from 3 axes of gyro, 3 axes of accelerometer,
3 axes of magnetometer, and a DGPS corrected GPS into an XYZ offset
and roll pitch yaw offset from initial conditions.
Anyways - right now I'm trying to identify what sort of magnetometer
to use. I care most about accuracy, precision, and bandwidth. Right
now I'm thinking I'll use some Honeywell parts:
http://www.ssec.honeywell.com/magnetic/products.html - probably the
HMC1053: http://www.ssec.honeywell.com/magnetic/datasheets/HMC105X.pdf
Good linearity (.1%), high bandwidth (5MHz), small size (LCC-16
(essentially a QFN without a ground pad)), annoying interface (lots of
external parts needed - including high voltage stuff - a complete pain
to work with).
One thing I worry about a bit - Honeywell also has some parts with 3x
the sensitivity of the HMC1053, but in unappealing packages (and only
single or dual axes). Will I lose any accuracy by having to set my
gain 3x as high on whatever instrumentation amp. I use? From my
understanding typically the non-linearity of instrumentation amps is
in the hundreths or thousandths of a percent, so it won't matter at
all.
PNI make some sensors that seem to be more bandwidth limited. Various
other companies make magnetometers with somewhat slow digital
interfaces, whereas I'm looking for an analog interface. I would like
about 1KHz bandwidth or more.
Any other parts I should be looking at?
Thanks!
-Mike
