Position and orientation measuring system having anti-distortion source configuration
First Claim
1. A source for a position and orientation measuring system having a driver which applies signals to said source to generate a plurality of electromagnetic fields which are distinguishable from one another, a remote sensor which senses the generated electromagnetic fields and a processor which processes an output of said sensor into remote object position and orientation relative to a reference coordinate frame of said source, comprising:
- an electrically conducting sheet; and
a planar coil including a plurality of substantially coplanar concentric rings above said sheet, said planar coil being adapted for coupling to the driver for receiving signals from the driver to generate a low-distortion electromagnetic field that may be sensed by said sensor.
2 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for determining the position and orientation of a remote object relative to a reference coordinate frame includes providing a source having a plurality of field-generating elements, wherein the field-generating elements generate electromagnetic fields and have spatially independent components defining a source reference coordinate frame. A driver applies signals to the source to generate a plurality of electromagnetic fields which are distinguishable from one another and a remote sensor has a plurality of field-sensing elements which sense each of the generated electromagnetic fields. A processor processes the output of the sensor in a remote object position and orientation relative to the source reference coordinate frame. At least one of the field-generating elements of the source has at least one electrically conductive sheet and a planar coil including a plurality of coplanar concentric rings above the conductive sheet. The planar coil is configured in a manner that a signal applied to that coil will cause a current density at each ring that is inversely proportional to the square of the radius of that ring. The planar coil may be made from a conductor formed as a simple or foliated spiral. The planar coil and the electrically conductive sheet may be formed from printed circuit board stock. A dihedral source may be made from a pair of orthogonal electrically conductive sheets each having a planar coil above the sheet. A trihedral source may be made from three electrically conducting sheets each having a planar coil above the sheet.
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Citations
33 Claims
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1. A source for a position and orientation measuring system having a driver which applies signals to said source to generate a plurality of electromagnetic fields which are distinguishable from one another, a remote sensor which senses the generated electromagnetic fields and a processor which processes an output of said sensor into remote object position and orientation relative to a reference coordinate frame of said source, comprising:
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an electrically conducting sheet; and a planar coil including a plurality of substantially coplanar concentric rings above said sheet, said planar coil being adapted for coupling to the driver for receiving signals from the driver to generate a low-distortion electromagnetic field that may be sensed by said sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of determining the position and orientation of a remote object located on one side of a plane relative to the reference coordinate system of said plane in a manner that is substantially unaffected by eddy current-induced field distortion on an opposite side of said plane, including:
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positioning a conductive sheet relative to said plane; producing an electromagnetic field on said one side of said conductive sheet, said electromagnetic field having a dipole moment substantially normal to said conductive sheet; sensing said electromagnetic field with a remote sensor; and processing the output of said remote sensor into remote position and orientation relative to said plane. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A source for a position and orientation measuring system having a driver which applies signals to said source to generate a plurality of electromagnetic fields which are distinguishable from one another, a remote sensor which senses the generated electromagnetic fields and a processor which processes an output of said sensor into remote object position and orientation relative to a reference coordinate frame of said source, comprising:
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at least two mutually orthogonal electrically conducting sheets; and a planar coil above each of said sheets, each said coil including a plurality of substantially coplanar concentric rings and being adapted for coupling to the driver for receiving signals from the driver to generate a low-distortion electromagnetic field that may be sensed by said sensor. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
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25. An apparatus for determining the position and orientation of a remote object relative to a reference coordinate frame, comprising:
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a source having a plurality of field-generating elements, wherein said field-generating elements generate electromagnetic fields and have spatially independent components defining a source reference coordinate frame, at least one of said field-generating elements having at least one electrically conducting sheet and a planar coil including a plurality of substantially coplanar concentric rings above said at least one conductive sheet configured in a manner that a signal applied to that coil will cause a current density at each ring inversely proportional to the square of the radius of that ring; a driver which applies signals to said source to generate a plurality of electromagnetic fields which are distinguishable from one another; a remote sensor having a plurality of field sensing elements, wherein said field sensing elements sense each of said generated electromagnetic fields and have spatially independent components; and a processor which processes the output of said sensor into remote object position and orientation relative to said source reference coordinate frame. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32)
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33. A source for a position and orientation measuring system having a driver which applies signals to said source to generate a plurality of electromagnetic fields which are distinguishable from one another, a remote sensor which senses the generated electromagnetic fields and a processor which processes an output of said sensor into remote object position and orientation relative to a reference coordinate frame of said source, comprising:
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an electrically conducting sheet; a planar coil including a plurality of substantially coplanar concentric rings above said sheet; and second and third mutually orthogonal coils at the center of said concentric rings and both orthogonal to said planar coil.
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Specification