Chapter 3 SPAN Operation
OEM7 SPAN Installation and Operation User Manual v14
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4. Perform an initial system alignment using one of the methods described in
on page 95. Ensure the system reaches Solution Good.
5. Enable calibration using the
INSCALIBRATE
command with an optional standard deviation target.
INSCALIBRATE ANT1 NEW [target_stdev]
6. To monitor the calibration, log
INSCALSTATUS
using the ONCHANGED trigger.
7. Start to move the system. The lever arm is not observable while the system is stationary. Immediately, drive
a series of maneuvers such as figure eights. The turns should alternate between directions, and you should
make an equal number of turns in each direction. Some height variation in the route is also useful for provid-
ing observability in the Z-axis.
8. When the calibration is complete, either because the accuracy requirement has been met, or the calibration
has been halted by user command, the calibrated offset value can be viewed in either the
INSCALSTATUS
log or the
INSCONFIG
log.
To save a calibrated lever arm for subsequent start ups, issue the
SAVECONFIG
command after calibration is
complete. If the IMU or GNSS antenna are re-mounted, re-run the calibration routine to compute an accurate
lever arm.
For information about the logs and commands used in this procedure, refer to the
.
3.4.6 Body to Vehicle Frame Rotation Calibration Routine
Kinematic alignment requires that the rotational offset between the vehicle and IMU Body frame (RBV) is known.
If the angles are simple (that is, a simple rotation about one axis) the values can easily be entered manually
through the
SETINSROTATION RBV
command. If the rotational offset is more complex (that is, rotation is
about 2 or 3 axis), then the calibration routine provides a more accurate estimation of the values.
The steps for the calibration routine are:
1. Apply power to the receiver and IMU.
2. Configure the SPAN system including an approximate IMU Body to Vehicle frame (RBV) rotation. See
SPAN Configuration for Receiver Cards
3. Ensure that an accurate lever arm has been entered into the system either manually or through a lever arm
calibration, see
4. Perform an initial system alignment using one of the methods described in
on page 95. Ensure the system reaches Solution Good.
5. Enable calibration using the
INSCALIBRATE
command with an optional standard deviation target.
INSCALIBRATE RBV NEW [target_stdev]
6. To monitor the calibration, log INSCALSTATUS using the ONCHANGED trigger.
7. Start to move the system. As with the lever arm calibration, movement of the system is required for the
observation of the angular offsets.
Drive a straight course on level ground (remember that most roads have a crown resulting in a constant roll
of a few degrees). Avoid driving on a surface with a constant, non-zero, slope to prevent biases in the com-
puted angles. Vehicle speed must be greater than 5 m/s (18 km/hr) for the calibration to complete.
8. When the calibration is complete, either because the accuracy requirement has been met, or the calibration
