Chapter 4 SMART7 with SPAN Operation
SMART7 Installation and Operation User Manual v6
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1. Remain static while initializing.
2. Wait for the system to receive a valid position from GNSS.
3. If valid, alignment data will be injected.
System Indicators
The
INSSEEDSTATUS
log reports the seed injection status for the current power up and information on current
seed validity. Refer the
OEM7 Commands and Logs Reference Manual
for more information about the
INSSEEDSTATUS
log.
The Extended Solution Status field has bits that indicate the Alignment type that occurred and NVM seed injec-
tion status.
Alignment Type: Bits 26-28
These bits indicate how the INS system reached INS_ALIGNMENT_COMPLETE. When the INS system aligns
using saved INS solution data from NVM, bits 26-28 will be set to 101
NVM Seed Status: Bits 29-31
These bits indicate the current status of the seeding process at start-up, as described in the table below:
Bit 29-31
Values
Hex Value
NVM Seed Type
000
0x00
NVM Seed Inactive
001
0x01
Seed stored in NVM is invalid
010
0x02
NVM Seed failed validation check
011
0x03
NVM Seed is pending validation (awaiting GNSS)
100
0x04
NVM Seed Injected (includes error model data)
101
0x05
NVM Seed data ignored due to a user-commanded filter reset or configuration change
110
0x06
NVM Seed error model data injected
Table 12: NVM Seed Indication
4.5.3 Navigation Mode
Once the alignment routine has successfully completed, SPAN enters navigation mode.
SPAN computes the solution by accumulating velocity and rotation increments from the IMU to generate pos-
ition, velocity and attitude. SPAN models system errors by using a filter. The GNSS solution, phase obser-
vations and automatic zero velocity updates (ZUPTs) provide updates to the filter. Peripheral updates can also
be supplied; an external receiver for heading updates.
Following the alignment, the attitude is coarsely defined, especially in heading. Vehicle dynamics, specifically
turns, stops and starts, allow the system to observe the heading error and allows the heading accuracy to con-
verge. The amount of dynamics required for filter convergence vary by the alignment quality, IMU quality, and
maneuvers performed. The INS Status field changes to INS_SOLUTION_GOOD once convergence is com-
plete. If the filter decreases in its system accuracy, the INS Status field changes to INS_HIGH_VARIANCE.
When the accuracy converges again, the INS status continues as INS_SOLUTION_GOOD.
