dc.contributor.author | Fourie, Dehann | |
dc.date.accessioned | 2022-09-01T18:03:04Z | |
dc.date.available | 2022-09-01T18:03:04Z | |
dc.date.issued | 2017-08-31 | |
dc.identifier.uri | https://hdl.handle.net/1721.1/145253 | |
dc.description.abstract | This thesis presents a sum-product inference algorithm for platform navigation called Multi-modal iSAM (incremental smoothing and mapping). Common Gaussian only likelihoods are restrictive and require a complex front-end processes to deal with non-Gaussian measurements. Instead, our approach allows the front-end to defer ambiguities with non-Gaussian measurement models. We retain the acyclic Bayes tree (and incremental update strategy) from the predecessor iSAM2 max-product algorithm [Kaess et al., IJRR 2012]. The approach propagates continuous beliefs on the Bayes (Junction) tree, which is an efficient symbolic refactorization
of the nonparametric factor graph, and asymptotically approximates the underlying Chapman-Kolmogorov equations. Our method tracks dominant modes in the marginal posteriors of all variables with minimal approximation error, while suppressing almost all low likelihood modes (in a non-permanent manner). Keeping with existing inertial navigation, we present a novel, continuous-time, retroactively calibrating inertial odometry residual function, using preintegration to seamlessly incorporate pure inertial sensor measurements into a factor graph. We centralize around a factor graph (with starved graph databases) to separate elements of the navigation into an ecosystem of processes. Practical examples are included, such as how to infer multi-modal marginal posterior belief estimates for ambiguous loop closures; raw beam-formed acoustic measurements; or conventional parametric likelihoods, and others. | en_US |
dc.description.sponsorship | NSF, ONR, DARPA | en_US |
dc.language.iso | en_US | en_US |
dc.publisher | MIT | en_US |
dc.rights | CC0 1.0 Universal | * |
dc.rights.uri | http://creativecommons.org/publicdomain/zero/1.0/ | * |
dc.subject | SLAM, robotics, navigation, mapping, localization, factor graph, Bayes tree, non-Gaussian, multi-modal, junction tree, inertial odometry, preintegration, IMU, radar, acoustic, Chapman-Kolmogorov transit integral | en_US |
dc.title | Multi-modal and Inertial sensor Solutions for Navigation-type Factor Graphs | en_US |
dc.type | Thesis | en_US |
dc.identifier.citation | Fourie, D., 2017. Multi-modal and inertial sensor solutions for navigation-type factor graphs (Doctoral dissertation, Massachusetts Institute of Technology and Woods Hole Oceanographic Institution). | en_US |