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IMU User Guide revision 3.1 SMC Ship Motion Control www.shipmotion.eu
3.3
ALIGNMENT
To achieve maximum performance of the motion sensor, it is important to perform an accurate
alignment of the motion sensor along the vessel longitudinal axis. The physical alignment must be as
accurate as possible using the notches on the motion sensor mounting plate for reference.
For the deck mounted standard motion sensor, the single notch is to be pointing to the fore direction
of the vessel. A misalignment in the Z axis rotation (yaw) will generate a cross axis motion, where
pitch will generate a roll reading from the motion sensor and vice versa. From the SMC IMU
Configuration Software, it is possible to fine tune the alignment errors from the installation of the
motion sensor.
Note:
The Z-axis alignment is only to be used to correct the physical misalignment and
not
to change
the yaw output reading from the motion sensor.
3.4
DECK MOUNTED - MOUNTED ON HORIZONTAL SURFACE
When the motion sensor is delivered for Deck mounting the motion sensor cannot be used for
sideways mounting without a recalibration at the factory.
Mounting of the motion sensor must be carried out with the mounting plate placed horizontally. The
notches on the plate mark the orientation points of the motion sensor. The indexes marking the Pitch
axis must be aligned to port/starboard, along the vessels center of rotation or on the axis you have
defined. The single notch is to be mounted pointing to the fore of the vessel. In the figure below the
Motion Sensor viewed from the top.
