Magneto-inductive positioning using a rotating magnetic field
AssigneeUltra Electronics Maritime Systems Inc.
InventorsGraham Mark McIntyre, Sebastien Bourdage, Olivier Beslin, Jean Pierre Quirion
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Abstract
A method and system for locating the position of a source that emits a rotating magnetic field. Three or more receivers are deployed or positioned in known position relative to each other, which may be along a common axis in some cases. Phase differences between the magnetic fields measured by the receivers are detected. The phase shifts are used to determine the location of the source. With three receivers, a range and bearing angle relative to a middle receiver may be determined. With five or more receivers, a range and two bearing angles may be determined, thereby providing a three-dimensional position.
Claims22
A position locating system for determining a location of a source, the system comprising:
- the source to emit a rotating magnetic field;
- three or more receivers, each to detect the rotating magnetic field, and wherein the three or more receivers are spaced apart and a second of the three of more receivers is positioned between a first of the three or more receivers and a third of the three or more receivers;
- and
- a signal processor to determine a distance of the source from the second receiver based upon a first phase difference between a detected magnetic field at the first receiver and a detected magnetic field at the second receiver, and a second phase difference between the detected magnetic field at the second receiver and a detected magnetic field at the third receiver.
A method of determining a location of a source when the source emits a rotating magnetic field, the method comprising:
- positioning three or more receivers in spaced apart relation wherein a second of the three or more receivers is positioned between a first of the three or more receivers and a third of the three or more receivers;
- at each receiver, generating a detected signal based on the rotating magnetic field;
- and
- determining a distance of the source from the second receiver based upon a first phase difference between the detected signal at the first receiver and the detected signal at the second receiver, and a second phase difference between the detected signal at the second receiver and the detected signal at the third receiver.
Dependencies are inferred from the claim text.