ZED-F9R - Integration manual
3.2.6.1.3 Suspended fusion mode
Sensor fusion is temporarily suspended in cases where no fused solution should/can be computed.
In this case, the receiver produces a GNSS-only solution. The receiver is considered to be
in temporarily-disabled fusion mode when the
UBX-ESF-STATUS.fusionMode
field is set to
2:SUSPENDED
.
Fusion is suspended in the following scenarios:
• If one or several sensors deliver erroneous data or no data at all. Fusion is suspended during the
sensor failure period. The receiver automatically recovers once the affected sensor or sensors
are back to normal operation.
• If the vehicle is detected to be on a ferry or other moving platform, where odometer data does
not indicate any displacement.
3.2.6.1.4 Disabled fusion mode
Sensor fusion can be permanently disabled if recurrent fusion failures occur. The receiver is
considered to be in permanently disabled fusion mode if the
UBX-ESF-STATUS.fusionMode
field
is set to
3:DISABLED
. In this case, the receiver produces a GNSS-only solution if possible.
Fusion is permanently disabled in the following cases:
• If the fusion filter was manually turned off by the user with the
CFG-SFCORE-USE_SF
key.
• If the filter diverges due to significantly wrong installation or filter parameters.
3.2.6.2 Accelerated initialization and calibration procedure
This section describes how to perform fast initialization and calibration of the HPS receiver for
evaluation purposes.
The duration of the initialization phases depends on the quality of the GNSS signals and the
dynamics encountered by the vehicle.
You can shorten the initialization time required for reaching the fused navigation mode by following
the procedure in the order described in the table below.
Phase
Procedure
Indicator of success
IMU initialization
After receiver cold start or first receiver use, turn
on car engine and stay stationary under good GNSS
signal reception conditions for at least 3 minutes.
IMU initialization status
UBX-ESF-
STATUS.imuInitStatus
shows
2:INITIALIZED
.
INS initialization
(position and velocity)
Once IMU is initialized, stay stationary under good
GNSS signal reception conditions until a reliable
GNSS fix can be achieved.
GNSS 3D fix achieved, good 3D position
accuracy (at least 5 m), high number of
used SVs (check UBX-NAV-PVT message).
IMU-mount alignment
initialization
Start driving at a minimum speed of 30 km/h and do
a series of approximately 10 left and right turns (at
least 90 degrees).
You can skip this step if automatic IMU-mount
alignment is turned off.
IMU-mount alignment status (
UBX-
ESF-STATUS.mntAlgStatus
) shows
2:INITIALIZED
, the IMU-mount
alignment status
UBX-ESF-ALG.status
shows
3:COARSE ALIGNED
.
Wheel tick sensor
initialization
Drive for at least 500 meters at a minimum speed
of 30 km/h. To shorten this calibration step, drive
the car at a higher speed (around 50 km/h) for at
least 10 seconds under good GNSS visibility.
Wheel tick sensor initialization status
UBX-ESF-STATUS.wtInitStatus
shows
2:INITIALIZED
.
INS initialization
(attitude)
Drive straight for at least 100 meters at a
minimum speed of 40 km/h.
INS initialization status
UBX-ESF-
STATUS.insInitStatus
shows
2:INITIALIZED
.
Table 9: Accelerated initialization procedure
UBX-20039643 - R01
3 Receiver functionality
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