Advanced Navigation Spatial FOG Dual, Справочное руководство

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Spatial FOG Reference Manual
Page 38 of 144
Version 2.3
03/05/2018
Cable Type Minimum Bend Radius Signal Loss
RG-58/U Low Loss 20 mm ~0.92 dB/m
LMR240 20 mm ~0.33 dB/m
LMR300 22.2 mm ~0.26 dB/m
LMR400 25.4 mm ~0.17 dB/m
Table 16: GNSS antenna co-axial cable properties
9.7 Static Port
Spatial FOG uses atmospheric pressure to stabilise its vertical velocity. The static port
vents can be found on the sides of the Spatial FOG enclosure at the top. These are
special vents that do not allow water to enter the enclosure.
9.8 Odometer
On ground vehicles, the use of an odometer input can greatly improve Spatial FOG's
navigation and orientation solution during GNSS dropouts. With a high resolution
wheel encoder Spatial FOG can be used to navigate indoors with GNSS disabled
altogether.
There are several diferent options for odometer installation which are listed below.
9.8.1 Factory VSS Signal
Most road cars since 1980 contain a VSS (vehicle speed sensor) signal that can be
wired directly into one of Spatial FOG's GPIO pins. The vehicle should be taken to an
automotive electrician to perform the work.
To setup the odometer, the appropriate GPIO pin should be set to the odometer input
function using Spatial FOG Manager, see section 11.8.6. The odometer pulse length
must then be set either manually or automatically, please see section 10.8 for more
information.
For more information on the GPIO signals and their requirements please see section
12.4.3.
9.8.2 OBDII Odometer Interface
For applications where it is undesirable to modify the vehicle or the system needs to
be used with multiple vehicles, the OBDII odometer interface may be a better solution.
OBDII is a vehicle diagnostic port standard and most vehicles from the mid 1990s
onwards contain an OBDII port in the drivers side foot well. Advanced Navigation
produces an OBDII odometer interface that plugs into this OBDII port and feeds Spatial
FOG with odometer data over the Auxiliary RS232 port, please see Illustration 19.
These units are priced at approximately AUD 500. Please contact Advanced Navigation
sales for more information.