POS MV V5 Installation and Operation Guide
Installation
Copyright © Applanix Corporation, 2017
2-31
Figure 13: Right-Hand Orthogonal System
The mounting angles describe the relative angles between one frame and another, for example between
your reference frame and the IMU frame. The following examples use the mounting angles between your
chosen reference frame and the IMU frame to illustrate how to measure and apply these parameters.
The examples use the following assumptions:
•
The IMU is installed so that it has a permanent roll angle of -5° relative to your reference frame.
That is, if you consider your reference frame as level, then the port edge of the IMU is lower than
the starboard edge.
•
The IMU is installed so that it has a permanent pitch angle of +2° relative to your reference frame.
That is, if you consider your reference frame as level, then the bow edge of the IMU is higher than
the stern edge.
The circular label on the top of the IMU identifies the directions of the IMU x and y-axis.
Example 1 -
The IMU x-axis nominally points towards the x-axis of the chosen reference frame, but with a
small yaw offset so that the IMU has a 3° clockwise rotation relative to your reference frame. Record the
following:
•
+3° for the IMU with respect to reference frame z mounting angle
•
+2° for the IMU with respect to reference frame y mounting angle
•
-5° for the IMU with respect to reference frame x mounting angle
Example 2 -
The IMU x-axis nominally points towards the starboard side of the chosen reference frame,
but with a small yaw offset so that the IMU has a 3° clockwise rotation relative to the y-axis of your
reference frame. Record the following:
•
+93° for the IMU with respect to reference frame z mounting angle
•
+2° for the IMU with respect to reference frame y mounting angle
y = Horizonral
(port-stbd line)
x = Horizonral
(fore-aft line)
z = Vertical
Centre of
vessel
y
T
z
T
x
T