Rovers localization by using 3D-to-3D and 3D-to-2D visual odometry

Space robotic systems have been playing a crucial role in planetary exploration missions, expanding our access to harsh and hostile environments in the Solar System. Rovers' activities are still mainly controlled through ground operations, and our goal is to develop autonomous systems for navigation and path planning. The position estimates obtained by processing Wheel Odometry (WO) data induce significant errors because of wheels' loss of traction that is caused by, for example, high-slippage terrains (e.g., sandy-loose soils, steep slopes). Our work is focused on the implementation of a localization software based on Visual Odometry (VO). This is a technique developed for the estimation of rovers' position and attitude by using stereo images captured during the vehicle's motion. To determine the attainable accuracy of our software, we carried out a set of numerical simulations through a digitally-reproduced Martian-like environment. The results show that the algorithm allows reconstructing the rover's trajectory with higher accuracies compared to the localization system requirements of the NASA Mars Exploration Rovers (i.e., 10% error over a 100-m traverse).