Multiple-model navigation filter with hybrid positioning

摘要

A generalized positioning system, corresponding filter, and corresponding method, for estimating the state of motion of an object, the generalized positioning system including a measurement engine, a model selector and model bank, and a filter, which is preferably a statistical filter. The measurement engine is responsive to information provided by a source of range information, from which a measurement of the state can be determined, and provides a succession of measurements of the state, each corresponding to a different instant of time. The model selector and model bank selects at least one motion model for use in estimating the state for a segment of the motion of the object. The filter is responsive to the succession of measurements of the state, and further responsive to a model mixing parameter and to the selected motion models. It determines a succession of multiple-model state estimates, preferably according to the so-called interacting multiple-model. In a further aspect of the present invention, the generalized positioning system also includes: a weighted least squares (WLS) filter, responsive to each of the measurements in the succession of measurements of the state, for directly determining a succession of WLS state estimates; and a consistency checker, responsive to the WLS state estimates and to the multiple-model state estimates, for selecting either the WLS state estimate for an instant of time or the multiple-model state estimate, based on the multiple-model state estimate as well as on previous multiple-model state estimates.