MRU
Demo Program Manual
Inertial Labs, Inc
TM
Address:
39959 Catoctin Ridge Street, Paeonian Springs, VA 20129 U.S.A.
Tel: +1 (703) 880-4222, Fax: +1 (703) 935-8377
Website:
www.inertiallabs.com
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The Inertial Labs MRU software allows compensation of influence of the
carrier object soft and hard iron on the heading angle calculation accuracy.
For this purpose, field calibration of the MRU-E magnetometers is provided.
This calibration does not require any additional equipment, but it requires
turns of the carries object on which the MRU-E is mounted.
The MRU-E can be calibrated using 2D, 3D or 2D-2T calibration procedure.
2D calibration
is designed for carrier objects that move with small pitch and
roll angles (not more than a few degrees). The calibration procedure
involves a few full 360 rotations in the horizon plane of the carrier object
with the installed MRU-E (see Fig.10.1). During this calibration pitch and roll
angles must be as close to zero as possible.
3D calibration
is designed for carrier objects that can operate with large
pitch and roll angles. For this calibration the carrier object is rotated in the
horizon plane (the Z-axis is up) with periodical stops about each 90 degrees
for tilting in pitch and roll (see Fig.10.1 – Fig.10.3). After full 360 rotation the
object with the MRU-E is turned over (the Z-axis is down) and the procedure
described above should be repeated. During this calibration the range of
pitch and roll angles changing must be as much as possible.
2D-2T
calibration
is designed instead of 3D calibration for carrier object that
operates with limited range of pitch and roll angles. This calibration involves
several (two or more) 2D calibration procedures but with different pitch
angles. During every 2D calibration run with set pitch angle, tilt angles must
be constant as possible. In the calibration those MRU-E readings are used
only in which pitch and roll differ from their median not more than inclination
threshold set in appropriate field Fig.4.3.
