Visual Navigation for Rendezvous and Docking using PMD Camera

Kurzfassung

There is one common problem of satellites which quite widely discussed: the lifespan. An idea to extend operational lifespan of a satellite in orbit, instead of replacing it by a new one, is concluded in On-Orbit Servicing (OOS) projects. The typical scenario of OOS is safe and reliable Rendezvous and Docking (RvD) of the approaching chaser to the target and taking over attitude control. In this paper relative navigation using new product Photonic Mixer Device (PMD), as new sort of the 3D Time-of-Flight (ToF) sensor, is suggested and of great interest, because the PMD sensor has never been used in space environment before. For optical navigation based on using a PMD camera, the following tasks and challenges have to be considered: initial pose estimation with a subsequent real-time object tracking, extension of the measurement range of the PMD sensor, camera calibration, performance measurements with a RvD simulation facility like EPOS 2.0 (European Proximity Operations Simulator). This paper mainly focuses on the first objective, namely pose estimation with a PMD sensor. Before calculating the pose estimate, the problem of actually finding target must be solved. The model based matching algorithm is proposed in this paper for 3D target acquisition and estimation of 6 degrees of freedom (3D position and 3D orientation) using data measurements from PMD camera.