Design and Implementation of a Low-cost Attitude and Heading Nonlinear Estimator

Centre Automatique et Syst`emes, Ecole des Mines de Paris, 60 boulevard Saint-Michel, 75272 Paris Cedex 06, France´philippe.martin@ensmp.fr, erwan.salaun@ensmp.frKeywords: Observers, sensor fusion, nonlinear filters, strapdown systems, invariance, inertial navigation, extendedKalman filters.Abstract: In this paper we propose a nonlinear observer (i.e. a “filter”) for estimating the orientation of a flying rigidbody, using measurements from low-cost inertial and magnetic sensors. It has by design a nice geometricalstructure appealing from an engineering viewpoint; it is easy to tune, computationally very economic, and withguaranteed (at least local) convergence around every trajectory. Moreover it behaves sensibly in the presenceof acceleration and magnetic disturbances. We illustrate its good performance on experimental comparisonswith a commercial system, and demonstrate its simplicity by implementing it on a 8-bit microcontroller.