Polhemus, Inc.

Said Sanford J. Wright, by Said Peter Anderson and Said Ralph Grimes

Peter Traneus Anderson

Sanford J Wright, Jr

Ralph S Grimes

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.

Position and orientation measuring system having anti-distortion source

A remote object position and orientation determining system employs electromagnetic coupling to sense the position and orientation of a remote object. A plurality of electromagnetic fields are generated having steady state components by applying time-division multiplexed pulsed DC signals to a plurality of field generating elements having spatially independent components defining a source reference coordinate frame. In this manner, the fields are distinguishable from one another. The generated electromagnetic fields are sensed with a remote sensor having a plurality of passive field-sensing elements having spatially independent elements in order to detect the rate-of-change of each of the generated electromagnetic fields. The output of the remote sensors are integrated in order to establish the steady state components of the generated electromagnetic fields. The steady state components are resolved into remote object position and orientation relative to the source reference coordinate frame.

Pulsed-DC position and orientation measurement system

Apparatus and method for sensing, recognizing, displaying, processing and storing motion generated symbolic information including a hand held, mark-forming writing instrument having motion sensing means and a wrist mounted display communicating with the writing instrument through character recognition circuitry to simultaneously display information formed by the writing instrument. An information control and storage circuit is included capable of operating in any one of several possible modes to receive, store and cause the display of information thereby permitting a multiplicity of functions heretofor requiring a vastly greater number of physical components. In particular, this highly portable apparatus readily and broadly compliments the kinesiology of writing instruments and composures that accompany human thinking and problem solving. The operational modes include horological display, data calculation, reminder message storage and display, and financial account storage.

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Burlington, VT, United States of America

Peter Traneus Anderson