How-to QINSy Sign Conventions

Within QINSy certain sign conventions are used for object reference frame offsets and attitude angles and rotation offsets.

Sign Conventions:

XYZ Coordinate Offsets

Coordinate Offsets in the Ship Geometry

  

The following symbol is used in the picture above:

This mark signifies the Centre of Gravity (CoG), Centre of Rotation (CR) or the Central Reference Point (RP) of the vessel.
This point has the coordinates X=0, Y=0 and Z=0 in the Ship Geometry.

QINSy computations assume this is the point where there is minimum vertical displacement due to vessel rolling and pitching.


HPR Attitude Angles

Attitude Angles in the Ship Geometry

  

The following abbreviations are used in the picture above:

H

Heading. Drawn is the Positive Rotation to Starboard convention.
All system heading offsets and heading computations in QINSy use the Positive Rotation to Starboard convention.

P

Pitch. Drawn is the Positive Bow Up convention for motion sensors.
Other system pitch offsets and all pitch angle computations in QINSy use the Positive Bow Up convention.

R

Roll. Drawn is the Positive Heeling to Starboard convention for motion sensors.
Other system roll offsets and roll angle computations in QINSy use the Positive Heeling to Starboard convention.

Hve

Heave. Drawn is the Positive Heave Up convention for motion sensors.
Other systems and all height offset computations in QINSy use the Positive Height Up convention.