Rotational Offsets - Novatel SMART7 Installation And Operation Manual

SMART7 with SPAN Operation

4.3.2 Rotational Offsets

The differences in orientation between the SMART7 and other SPAN components are called rota-
tional offsets. Rotational offsets are given as the rotation from the IMU Body frame to the frame
of interest.
The order of rotations is Z-X-Y and all rotations are right handed.
Generally, frames of reference are defined as Z up, with Y forward, and X completing the right-
handed system. An example is the Vehicle frame, where Z is always considered to be upwards,
Y forward through the direction of travel, and X to the right.
If the SMART7 is installed with the front of the SMART7 facing the direction of forward motion for
the vehicle (as shown in Figure 7: SMART7 Orientation on page 23), an IMU Body frame to
Vehicle frame rotation is not required. The necessary rotations are configured at the factory.
An IMU Body frame to Vehicle frame calibration routine should be run to on all SMART7
installations, whether an IMU Body frame to Vehicle frame rotation is required or not.
See Body to Vehicle Frame Rotation Calibration Routine on page 71 or Multi-Line Body to
Vehicle Frame Rotation Calibration Routine on page 72 for more information. This cal-
ibration routine should be done each time the SMART7 is remounted.
Non-Standard Installation
The SMART7 is intended to be installed with the front of the SMART7 facing the direction of
vehicle travel. If the installation location does not allow this orientation, the SETINSROTATION
RBV command must be used to align the SMART7 IMU Body frame with the Vehicle frame.
The IMU Body frame of the SMART7-S is shown in Figure 19: SMART7-S IMU Body Frame on the
next page.
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