ZED-F9R-Integration manual
3.2.7.1.4 Directionless odometer mode
This feature allows the use of odometer data for which the sign bit or the wheel tick (WT) pin polarity
input is not trusted or not available. The directionless odometer support can be enabled by the
configuration item CFG-SFODO-DIS_DIR_INFO=1.
After setting this configuration item, the directional information, that is, the polarity bit of the WT
measurement and the sign of the wheel speed measurement in the UBX-ESF-MEAS message as well
as the WT polarity pin input will be ignored. In particular, the following configuration items shall have
no effect when used in combination with CFG-SFODO-DIS_DIR_INFO=1.
•
CFG-SFODO-DIR_PINPOL
•
CFG-SFODO-DIS_AUTODIRPINPOL
The performance with directionless odometer feature is expected to be worse than that of ADR with
usual directional odometer data, but better than that of the UDR fallback mode.
The odometer measurements shall be used as a velocity measurement only if the direction
of motion (forwards/backwards) can be reliably determined based on other measurements
(GNSS, IMU). Typically, this requires high enough speed.
3.2.7.1.5 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.
3.2.7.1.6 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.
3.2.7.2 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 to reach sensor fusion mode, while using the
automotive dynamic model, by following the procedure in the order described in the table below.
UBX-20039643 - R06
3 Receiver functionality Page 32 of 119
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