Degenerate motions in multicamera cluster SLAM with non-overlapping fields of view *

•Analysis of solution degeneracy in general multicamera cluster SLAM.•Decomposition of system determines conditions for degeneracy.•Dense sub-matrix reveals geometric structure for futher analysis.•Identification of degenerate motions independent of feature constellation.•Experiments demonstrate that adding features and cameras decreases degenerate set.

An analysis of the relative motion and point feature model configurations leading to solution degeneracy is presented, for the case of a Simultaneous Localization and Mapping system using multicamera clusters with non-overlapping fields-of-view. The SLAM optimization system seeks to minimize image space reprojection error and is formulated for a cluster containing any number of component cameras, observing any number of point features over two keyframes. The measurement Jacobian is transformed to expose a reduced-dimension representation such that the degeneracy of the system can be determined by the rank of a dense submatrix. A set of relative motions sufficient for degeneracy are identified for certain cluster configurations, independent of target model geometry. Furthermore, it is shown that increasing the number of cameras within the cluster and observing features across different cameras over the two keyframes reduces the size of the degenerate motion sets significantly.