A stereovision system for a planetary rover: calibration, correlation, registration, and fusion

This paper describes a complete stereovision system, which was originally developed for planetary applications, but can be used for other applications such as object modeling. A new effective on-site calibration technique has been developed, which can make use of the information from the surrounding environment as well as the information from the calibration apparatus. A correlation-based stereo algorithm is used, which can produce sufficient dense range maps with an algorithmic structure for fast implementations. A technique based on iterative closest-point matching has been developed for registration of successive depth maps and computation of the displacements between successive positions. A statistical method based on the distance distribution is integrated into this registration technique, which allows us to deal with such important problems as outliers, occlusion, appearance, and disappearance. Finally, the registered maps are expressed in the same coordinate system and are fused, erroneous data are eliminated through consistency checking, and a global digital elevation map is built incrementally.