Compact and high performances equipment for vision-based navigation

The paper is dedicated to the presentation of the MOSS (Multi Ocular Smart Sensor) project, co-financed by the Italian Space Agency, for the design and development of compact and high performances equipment for vision- based navigation. Vision-based navigation can be considered as a major enabling technology in support of the autonomy requirements of space applications like: Exploration missions (landers, rovers, etc.), On-Orbit Servicing Applications (like Satellite Inspections, Rendezvous. Docking etc.) and Formation-Flying Missions. The project is being carried out by implementing a comprehensive path: 1) analysis of a number of possible mission scenarios, 2) identification of different imaging requirements for the different scenarios, 3) assessment of the relevant radiation environment and 4) design and development of a set of equipment capable of fulfilling the above requirements. In general systems and equipment, employed for past and also current visual navigation applications, suffer for the adoption of processing architectures not suitable for true real-time image processing. Therefore the image processing architectures for future mission have to offer much better performances than the currently available ones. The MOSS equipment under development arc: a Multi-ocular Camera, two Monocular Cameras and a High- performance Processing Unit for Visual Navigation (HPVN). The Multi-ocular camera is a three sensors camera offering 3D vision, based on two monochrome sensors, and panoramic vision, based on one color HD image sensor. Two monocular cameras adopt different image sensors and lens; the former is based on a CMOS color HD image sensor and fixed lens, while the latter is equipped with a CCD color HD sensor and motorized lens, offering auto- iris, autofocus and zoom. The different configurations of the cameras arc aimed at fulfilling a wide range of imaging and accommodation requirements, depending on the specific mission and the space platform. Three cameras can operate in stand-alone mode, thus minimizing mass, volume, and power consumption or they can take advantage of a very powerful processing electronics (HPVN) capable of supporting up to 4 HD video inputs, and performing a number of (hardware accelerated) image processing algorithms: loss-less and/or lossy compression, feature detection and tracking and real-time disparity map calculation. Main on-board resources are duplicated and can be configured in parallel to implement a single point failure architecture or in a master-slave mode, so to run in parallel to improve processing capabilities. All the above described parts arc available in two radiation tolerance levels. Copyright © (2012) by the International Astronautical Federation.