The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 08, 2020
Filed:
Nov. 24, 2014
Sagem Defense Securite, Boulogne-Billancourt, FR;
Association Pour LA Recherche Developpment Des Methodes ET Processus Industriels—a.r.m.i.n.e.s., Paris, FR;
Axel Barrau, Boulogne-Billancourt, FR;
Silvere Bonnabel, Boulogne-Billancourt, FR;
SAFRAN ELECTRONICS & DEFENSE, Boulogne-Billancourt, FR;
ASSOCIATION POUR LA RECHERCHE DEVELOPPEMENT DES METHODES ET PROCESSUS INDUSTRIELS—A.R.M.I.N.E.S., Paris, FR;
Abstract
The invention relates to an alignment method based on a simplified mode allowing processing using an invariant Kalman filter, in which each speed involved in the navigation equations is expressed in a work reference frame (Rt) translated with respect to an inertial reference frame (Ri) and for which the origin moves along a reference inertial trajectory, the carrier of which is assumed to be close (geographic origin for alignment with the sun at known position, GPS trajectory for alignment in-motion, etc.). This simplified mode comprises the repetition of the following steps to estimate a mobile carrier state (P): —propagation (PROP) determining an estimated current state from a preceding estimated state, inertial sensor measurements and theoretical information on the carrier trajectory (P) —updating (MAJ) the estimated state using theoretical information on the carrier trajectory (P). The deterministic uncertainties of the sensors (bias/drift/scale factors, etc.) are only estimated during the propagation and update steps. A perturbation step (PERT) then allows inclusion of the values ignored in the simplified mode and estimation of these values by an optimisation method.