Comparison of Pose Estimation Methods for a 3D Laser Tracking System using Triangulation and Programmetry Techniques*

In this paper, we compare the accuracy and resolution of a 3D-laser scanner prototype that tracks in real-time and computes the relative pose of objects in a 3D space. This 3D-laser scanner prototype was specifically developed to study the use of such a sensor for space applications. The main objective of this project is to provide a robust sensor to assist in the assembly of the International Space Station where high tolerance to ambient illumination is paramount. The laser scanner uses triangulation based range data and photogrammetry methods (spatial resection), to calculate the relative pose of objects. Range information is used to increase the accuracy of the sensing system and to remove erroneous measurements. Two high-speed galvanometers and a collimated laser beam address individual targets mounted on an object to a resolution corresponding to an equivalent imager of 10000×10000 pixels. Knowing the position coordinates of predefined targets on the objects, their relative poses can be computed using either the scanner calibrated 3D coordinates or spatial resection methods.