Radar Speed Sensor; Magnetics - Advanced Navigation Certus OEM Reference Manual

Certus Reference Manual • Installing Certus OEM

6.9.4 Radar Speed Sensor

For applications requiring high performance in harsh conditions where aftermarket wheel speed sensors are not
feasible, a radar speed sensor is recommended. Advanced Navigation recommends radar speed sensors from
Stalker or GMH Engineering.
Figure 18: Radar Speed Sensor

6.10 Magnetics

Certus contains magnetometers which it can use to measure the Earth's magnetic field in order to determine its
heading. The principle is the same as that of a compass. When operating Certus with magnetic heading
enabled, sources of magnetic interference can degrade the Certus solution if not compensated for.
Note: Magnetic interference affects the performance of gyroscopes by causing rotation errors; it is
recommended that you mount Certus away from magnetic interference.
There are two types of magnetic interference: Static and Dynamic.
Sources of static magnetic interference are predominantly ferrous materials (e.g. steel, iron, nickel, cobalt),
high- current cables and permanent magnets located near the Certus. Static disturbances are easily
compensated for by running a magnetic calibration. A magnetic calibration should always be performed after
installation into a vehicle if accurate magnetometer heading is required. See
instructions on how to calibrate your device.
Dynamic magnetic interference is a much more complex and problematic issue due to its many variable factors
and unpredictability. Sources of dynamic magnetic interference include high current wiring, electric motors,
servos, solenoids and nearby large masses of metal that don't move with Certus. Certus should be mounted as
far as possible from these interference sources.
Certus contains a special algorithm to reduce the effects of dynamic magnetic interference. This is able to
compensate for most typical interference sources encountered, however certain types of prolonged dynamic
interference cannot be compensated for. The best way to check for dynamic magnetic interference is to use the
Raw Sensors view in the web UI or Certus Manager and watch the magnetometer outputs whilst the vehicle is
operating but stationary. See
should be constant: if the values are fluctuating there is dynamic magnetic interference present.
If dynamic magnetic interference is causing performance problems and there is no way to mount Certus away
or, where practical, magnetically shield it from these interference sources, the magnetometers should be
disabled and an alternative heading source should be used, see
v2.4
8.1 Using the Web User Interface
Page 38
7.5 Magnetic Calibration
or 8.2 Using Certus
7.5.4 Disabling Magnetometers.
for
Manager. The values
2024-12-17