RESEARCH ARTICLE
Continuous-Time Tracking Filters for the Coordinated Turn Model
Bertil Ekstrand*
Article Information
Identifiers and Pagination:
Year: 2009Volume: 2
First Page: 1
Last Page: 9
Publisher Id: TOAEJ-2-1
DOI: 10.2174/1874146000902010001
Article History:
Received Date: 10/03/2008Revision Received Date: 18/12/2008
Acceptance Date: 18/12/2008
Electronic publication date: 11/2/2009
Collection year: 2009
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Continuous-time tracking filters based on the coordinated turn model are discussed. By a coordinate transformation, the four-state filter design is reduced to design of two-state filters. An observer approach is applied, including pole placement and transfer function analysis. Deterministic steady-state errors for a circular turn are obtained as analytical expressions in target acceleration, filter bandwidth, and the actual and assumed turn rates. It is seen that no errors are obtained if the turn rate is known. If it is unknown, performance could still be better than with independent filters, if the assumed turn rate is not too erroneous. Even a first order transfer function can be formulated from which the steady-state errors are easily obtained. An interpretation in terms basic two-state filters is given of filters based on the coordinate turn model. Furthermore, the Kalman filter for a stochastic coordinated turn model is given in closed form and compared to the observers.
