Payload Support for Planetary Exploration
Autonomous planetary exploration will play an important role in future space missions. Therefore we have studied the feasibility of robotised planetary exploration in several ESA contracts (ROBUST, PSPE, ROSA-M). Within the European Payload Support for Planetary Exploration (PSPE) project, we have proposed a Lander spacecraft configuration and control concept, which should allow to perform geo-science operations on Mars, but with higher local autonomy than, e.g., the pathfinder’s sojourner rover.
The proposed on-orbit system consists of the following components:
For the feasibility study we have proposed and realised a vision-based approach for precise Rover localisation and guidance. The image processing and 3D-localisation system of the mentioned imaging head detects significant features of the rover in the stereo images, determines the current position of the rover with respect to a reference system, and controls the rover motion to reach the desired goal position. To alleviate the feature detection job, 4 LED’s are mounted on top of the rover’s payload cabin. Using a straight-forward blob finding algorithm, applied to the difference images (LED switched off/on), the 2D-coordinates of the LED’s in the image plane can be calculated. To determine the pose of the rover, first a stereo reconstruction algorithm generates 3D-points corresponding to the given pairs of 2D image coordinates, second an algorithm is applied, which matches these “measured” 3D-points with the “modelled” ones to get the transformation between the rover and the camera system. Successful verification was not only demonstrated at ESA´s planetary test bed, but also on a specially developed Mars surface model in the institute.
Originally developed for space missions, the system can be easily adapted to applications on Earth, e.g., for controlling mobile robots in harsh and dangerous environments.
Related article: A micro-rover navigation and control system for autonomous planetary exploration (see Downloads)