Onboard autonomous rock shape analysis for Mars rovers

In the quest to maximize the scientific return of future robotic missions, it is imperative that our rovers be capable of determining the importance of the science they collect so that they may prioritize the acquisition and relay of that data. As an important step in this process, we present an automated technique to allow a rover to classify the shape and other geological characteristics of rocks from 2D photographic images and 3D stereographically produced data. Experiments were conducted in the Matlab environment using images returned by JPL´s Mars Pathfinder mission. Our method begins by first segmenting the rocks from the background using a combination of image intensity and height data. Various metrics are then used to classify the region´s sphericity, roundness, and other geometric properties. Preliminary experiments to determine the most useful metrics were conducted by characterizing the 2D rock shape while the 3D shape was later studied with metrics derived from these 2D techniques. Seven measures were developed and implemented. The performance of each measure was characterized by analyzing images from the Pathfinder mission and ranking the rocks according to the measured properties. Combined, the measures would provide a tool by which an automated rover could discover a greater amount of information about the data it collects, leading to a more productive mission.