Mapping and positioning for a prototype lunar rover
In this paper, we describe practical, effective approaches to outdoor mapping and positioning, and present results from systems implemented for a prototype lunar rover. For mapping, we have developed a binocular head and mounted it on a motion-averaging mast. This head provides images to a normalized correlation matcher, that intelligently selects what part of the image to process (saving time), and subsamples the images (again saving time) without subsampling disparities (which would reduce accuracy). The mapping system has operated successfully during long-duration field exercises, processing streams of thousands of images. The positioning system employs encoders, inclinometers, a compass, and a turn-rate sensor to maintain the position and orientation of the rover as it traverses. The system succeeds in the face of significant sensor noise by virtue of sensor modelling, plus extensive filtering and data screening.