Method for determining the position and/or speed of a guided vehicle and associated system
First Claim
1. A method for calculating, at a present moment, a kinematic state of a guided vehicle from signals emitted by a set of satellites from a constellation of localisation satellites, the method being performed by a programmed calculator on board the guided vehicle, the method comprising:
- selecting a set of usable visible satellites from among a set of visible satellites of a constellation of localisation satellites comprising, for each satellite of the set of visible satellites;
calculating an instantaneous measured value for a quantity between a Doppler coefficient and a pseudo-range, from the signal received from said visible satellite;
determining an instantaneous estimated value for the quantity, based on a dynamic model of the guided vehicle that uses only a kinematic state of the guided vehicle determined at a past moment to estimate an estimated kinematic state at the present moment and that uses a map of the track on which the guided vehicle moves;
comparing the instantaneous measured and estimated values according to a criterion, and in case of noncompliance with the criterion; and
deleting the satellite from a set of usable visible satellites; and
calculating the kinematic state of the guided vehicle at the present moment only from the signals received from the satellites of the set of usable visible satellites.
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Accused Products
Abstract
A method for selecting usable satellites from among the satellites of a localization constellation, to determine an instantaneous kinematic state of a train, is provided. The method includes determining a measured value and an estimated value of a Doppler coefficient and/or a pseudo-range, then comparing the measured and estimated values and, in case of divergence, deleting the satellite from the usable satellites. The estimated value results from a dynamic model of the train, which uses only a kinematic state at a past moment to calculate an estimated instantaneous kinematic state and that uses a mapping of the track on which the guided vehicle moves.
6 Citations
4 Claims
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1. A method for calculating, at a present moment, a kinematic state of a guided vehicle from signals emitted by a set of satellites from a constellation of localisation satellites, the method being performed by a programmed calculator on board the guided vehicle, the method comprising:
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selecting a set of usable visible satellites from among a set of visible satellites of a constellation of localisation satellites comprising, for each satellite of the set of visible satellites; calculating an instantaneous measured value for a quantity between a Doppler coefficient and a pseudo-range, from the signal received from said visible satellite; determining an instantaneous estimated value for the quantity, based on a dynamic model of the guided vehicle that uses only a kinematic state of the guided vehicle determined at a past moment to estimate an estimated kinematic state at the present moment and that uses a map of the track on which the guided vehicle moves; comparing the instantaneous measured and estimated values according to a criterion, and in case of noncompliance with the criterion; and deleting the satellite from a set of usable visible satellites; and calculating the kinematic state of the guided vehicle at the present moment only from the signals received from the satellites of the set of usable visible satellites. - View Dependent Claims (2, 3, 4)
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Specification