On-line Collision Detection in Space Using Photonic Mixer Devices

This paper presents a collision detection system especially designed for Rendezvous and Docking (RvD) maneuvers to passive objects in space. It is based on 3D images provided by a Photonic Mixer Device (PMD) and makes use of the output of a pose estimation algorithm developed particularly for this 3D information. The algorithm on-line predicts the trajectory of the observed object and detects possible collisions along this trajectory. The intersection tests performed for that purpose consist of examining multiple oriented bounding boxes that surround target and observer spacecraft. Different scenarios including approaching, departing, rotating and by-passing were conducted in a laboratory setup with two robot manipulators holding a client mockup model and a PMD camera. By the help of these scenarios the functionality of the developed algorithm in common RvD maneuvers was evaluated and confirmed.