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US 6,888,623 B2Granted
Fiber optic sensor for precision 3-D position measurement
AssigneeDynamic Technology, Inc.
InventorGregory Minot Clements
Life of this patent
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AssigneeDynamic Technology, Inc.
InventorGregory Minot Clements
Estimating the term…
The central system component of the present invention is a flexible “smart cable” which enables accurate measurement of local curvature and torsion along its length. These quantities are then used to infer the position and attitude of one end of the cable relative to the other. Sufficiently accurate measurements of the local curvature and torsion along the cable allow reconstruction of the entire cable shape, including the relative position and orientation of the end points. The smart cable for making these measurements comprises a multicore optical fiber, with individual fiber cores constructed to operate in the single mode regime, but positioned close enough to cause cross-talk (mode coupling) between cores over the length of the fiber. This cross-talk is very sensitive to the distribution of strains (curvature and torsion) along the cable.
Apparatus comprising an optical medium having curved sections, said medium including a plurality of single mode cores, said cores being closely spaced to exhibit cross-talk therebetween, said cross-talk exhibiting changed values only at bends in said medium, said apparatus including a broadband source for illuminating said cores sequentially, means for measuring the spectral intensities including the magnitude of light signals at different freguencies of the entire plurality of cores each time a core is illuminated, and means responsive to said spectral intensities for determining the positions of said curved sections.
A positioning sensor comprising an optical fiber cable having multiple, closely positioned single mode cores;
A method for measurement of the position of one end of a fiber optic cable relative to a known position of another end of the fiber optic cable, the cable having a plurality of closely-positioned single-mode cores;
Dependencies are inferred from the claim text.