Development of an optimized LEB filter and its application to INS/GPS test data
Abstract
An optimized linear-ellipsoidal-bounded (LEB) filter has been developed and applied to data obtained from a ground test using a combined INS/GPS configuration. In this cascaded configuration, the filter receives eight outputs from the INS (accelerations, velocity, angles, altitude) and six outputs from the GPS (velocities and positions). The GPS measurements have included the effect of SA of varying or unknown spectrum which, although likely to be estimated and compensated with some modelling techniques at the expense of including extra state variables, could also be dealt with the approach indicated in this article at much less effort. An optimized formulation for the LEB filter is presented in which the volume of the ellipsoid containing the estimation errors is minimized at every step or at selected intervals. The SA effect is modelled as an unknown-but-bounded (UBB) noise process. Comparisons with an Extended Kalman filter (KF) show that KF innovations are not white and the LEB filter estimates are one order of magnitude smaller that those produced by the KF.
- Publication:
-
AIAA Guidance, Navigation and Control Conference
- Pub Date:
- 1993
- Bibcode:
- 1993gnc..conf.1740A
- Keywords:
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- Global Positioning System;
- Inertial Navigation;
- Optimal Control;
- Optimization;
- Positioning;
- Precision;
- Accuracy;
- Air Data Systems;
- Ground Tests;
- Kalman Filters;
- Markov Processes;
- Space Communications, Spacecraft Communications, Command and Tracking