Ins Seed / Fast Ins Initialization - Novatel SMART7 Installation And Operation Manual

SMART7 with SPAN Operation
has a a large 'crab angle' and the course-over ground trajectory will not match the direction the
IMU is pointing.)
The rotation from the IMU Body frame to the Vehicle frame (RBV) must be set to enable kin-
ematic alignment. In order to simplify this configuration it is strongly suggested that you mount
the IMU in parallel to the vehicle frame. The SMART7 should be oriented as shown in SMART7
Orientation on page 23.
The kinematic alignment begins when the receiver has a good GNSS position, fine time is
solved, the Body to Vehicle frame rotation is known and a GNSS velocity of at least 5 m/s (~ 18
km/h) is observed. During kinematic alignment, keep the vehicle roll at less then 10°.
5 m/s is the default alignment velocity. If a different alignment velocity is
required, it can be changed using the SETALIGNMENTVEL command. Refer to the
Agriculture Commands and Logs Reference Manual
While it is possible to lower the minimum speed required for kinematic alignment
to take place, the higher the value, the more closely the course-over-ground
estimate will match the vehicle heading.
The accuracy of the initial attitude of the system following the kinematic alignment varies and
depends on the dynamics of the vehicle. The attitude accuracy will converge to within spe-
cifications once some motion is observed by the system. This transition can be observed by mon-
itoring the INS Status field in the INS logs.
Dual Antenna Alignment
SPAN can also use heading information available from a NovAtel Dual Antenna ALIGN solution to
rapidly perform an alignment.
NVM Seeded Alignment
SPAN can use the alignment information from a previous power up to quickly perform an align-
ment. For information about enabling and using an NVM Seeded Alignment, refer to INS Seed /
Fast INS Initialization below.
Manual Alignment
If the initial azimuth of the system is known, it can be entered manually using the
SETINITAZIMUTH command. Refer to the
for more information about this command.
A manual alignment should be used only if the azimuth is accurately known.
4.5.2 INS Seed / Fast INS Initialization
The INS Seed functionality is an alignment method whereby INS alignment information from a
previous powerup can be injected into the system at startup to achieve an INS alignment very
quickly. This is especially useful for systems that previously required a kinematic alignment.
When INS Seed is enabled, alignment data is automatically saved when appropriate, with no spe-
cific action required from the user. During subsequent power ups, the saved solution is com-
SMART7 Installation and Operation User Manual 0C
for more information.
Agriculture Commands and Logs Reference Manual
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