Stereo infrared cameras - motion capture

Qualisys is a motion capture system that has been developed in Sweden since 1989. It is a turnkey system, and acknowledged as an industry leader for its simplicity and reliability.

The principle is based on the use of infrared cameras that detect all reflecting objects. The system assimilates these objects with targets to be tracked. At least two cameras are needed in order to track movements with six degrees of freedom.

Measuring the movements of floating structures | Artelia Hydraulics
Measuring the movements of floating structures

 

Acquisition of wave-induced movements of a ship | Artelia Hydraulics
Acquisition of wave-induced movements of a ship

 

A calibration phase is required to synchronise the cameras with each other and interpret the distances between the different markers in an optimal manner. The sampling frequency can be up to 500Hz.

We use the Qualisys system for our studies to analyse the behaviour of moored floating structures.