author = "Waldmann, Jacques and Silva, Raul Ikeda Gomes da and Chagas, Ronan 
                         Arraes Jardim",
          affiliation = "{Instituto Tecnol{\'o}gico de Aeron{\'a}utica (ITA)} and {INSPER 
                         Instituto de Ensino e Pesquisa} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)}",
                title = "Observability analysis of inertial navigation errors from optical 
                         flow subspace constraint",
              journal = "Information Sciences",
                 year = "2016",
               volume = "327",
                pages = "300--326",
                month = "Jan.",
             keywords = "Inertial navigation, GPS outage, Optical flow, Subspace 
                         constraint, Sensor fusion, Observability analysis.",
             abstract = "Fusion of inertial and vision sensors is an effective aid to 
                         inertial navigation systems (INS) during GPS outage. Optical 
                         flow-aided inertial navigation circumvents feature tracking, 
                         landmark mapping, and state vector augmentation typical of 
                         simultaneous localization and mapping (SLAM). This paper focuses 
                         on the observability analysis of INS errors from implicit 
                         measurements of the optical flow subspace constraint, and derives 
                         how observable and unobservable directions are affected by the 
                         motion of a camera rigidly coupled to an inertial measurement unit 
                         (IMU). Straight motion and piecewise constant (PWC) attitude 
                         segments yield the random constant IMU errors observable. The 
                         unobservable directions are the three-dimensional (3D) position 
                         error, the velocity error along the ground velocity, and the 
                         combination of angular misalignment about the local vertical and 
                         the velocity error along the horizontal direction orthogonal to 
                         the ground velocity. The velocity error along the ground velocity 
                         becomes observable with horizontal maneuvering. A Monte Carlo 
                         simulation validates the observability analysis, and reveals the 
                         feasibility of IMU calibration and the mitigation of navigation 
                         error growth with the aid of the optical flow subspace constraint 
                         compared with the unaided INS.",
                  doi = "10.1016/j.ins.2015.08.017",
                  url = "http://dx.doi.org/10.1016/j.ins.2015.08.017",
                 issn = "0020-0255",
                label = "lattes: 5964335207790589 3 WaldmannSilvChag:2015:ObAnIn",
             language = "pt",
           targetfile = "2015_waldmann.pdf",
        urlaccessdate = "29 nov. 2020"