Patents by Inventor Robert F. Higgins
Robert F. Higgins has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11797127Abstract: An apparatus and method for implementing a technique for performing calibration of an electromagnetic tracking apparatus on-the-fly while operating the apparatus. The apparatus and method uses a non-magnetic tracking device to determine position and orientation of a tracked object that is not subject to magnetic distortion or interference, and store calibration data for future measurements by the electromagnetic tracking apparatus based on the measurements made by the non-magnetic tracking device.Type: GrantFiled: November 15, 2022Date of Patent: October 24, 2023Assignee: ALKEN Inc.Inventors: Robert F. Higgins, Henry E. Himberg, Allan G. Rodgers, Jr.
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Patent number: 11675030Abstract: An apparatus and method for determining position and orientation (PnO) of an object within an environment and for automatically determining a hemisphere of the object relative to a source location using an electromagnetic tracking system and a non-magnetic tracking device. The method involves seeding two candidate PnO solutions, one in each hemisphere, based on initial data from the magnetic tracker. Then, as the sensor moves within the tracking volume, both the magnetic tracker and the non-magnetic tracking device are used to track changes in each of the candidate PnO solutions and to determine a correct one of the candidate PnO solutions.Type: GrantFiled: July 18, 2022Date of Patent: June 13, 2023Assignee: ALKEN Inc.Inventors: Robert F. Higgins, Henry E. Himberg, Allan G. Rodgers, Jr.
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Patent number: 11585680Abstract: A system and method for implementing a technique for dynamically switching between or mixing position and orientation determinations in a hybrid tracking system using both electromagnetic and non-electromagnetic tracking, and having a transmitter coil array for generating a magnetic field, a receiver circuit for sensing the magnetic field, and at least one non-magnetic sensor.Type: GrantFiled: May 5, 2022Date of Patent: February 21, 2023Assignee: ALKEN Inc.Inventors: Henry E. Himberg, Allan G. Rodgers, Jr., Robert F. Higgins
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Publication number: 20230036210Abstract: An apparatus and method for determining position and orientation (PnO) of an object within an environment and for automatically determining a hemisphere of the object relative to a source location using an electromagnetic tracking system and a non-magnetic tracking device. The method involves seeding two candidate PnO solutions, one in each hemisphere, based on initial data from the magnetic tracker. Then, as the sensor moves within the tracking volume, both the magnetic tracker and the non-magnetic tracking device are used to track changes in each of the candidate PnO solutions and to determine a correct one of the candidate PnO solutions.Type: ApplicationFiled: July 18, 2022Publication date: February 2, 2023Applicant: ALKEN Inc., dba PolhemusInventors: Robert F. Higgins, Henry E. Himberg, Allan G. Rodgers, JR.
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Patent number: 11543529Abstract: An apparatus and method for implementing a technique for adaptively assigning weighting factors to position and orientation determinations in an electromagnetic or hybrid tracking system having multiple transmitters or multiple receivers. The apparatus may reduce the impact of eddy current distortion to the position and orientation determinations.Type: GrantFiled: January 27, 2020Date of Patent: January 3, 2023Assignee: ALKEN Inc.Inventors: Robert F. Higgins, Keith M. Hanf, Allan G. Rodgers, Jr., Allan G. Rodgers
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Patent number: 11326905Abstract: A system and method for implementing a technique for dynamically switching between or mixing position and orientation determinations in a hybrid tracking system using both electromagnetic and non-electromagnetic tracking, and having a transmitter coil array for generating a magnetic field, a receiver circuit for sensing the magnetic field, and at least one non-magnetic sensor.Type: GrantFiled: January 27, 2020Date of Patent: May 10, 2022Assignee: ALKEN Inc.Inventors: Henry E. Himberg, Allan G. Rodgers, Jr., Robert F. Higgins
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Patent number: 11050197Abstract: An apparatus and method for implementing a reversible connector for receiving coil-based sensor signals in an electromagnetic or hybrid tracking system. The apparatus is designed to reduce the number of connector pins assigned to the coil-based sensor signals while maintaining signal quality.Type: GrantFiled: January 27, 2020Date of Patent: June 29, 2021Assignee: ALKEN Inc.Inventors: Robert F. Higgins, Henry E. Himberg, Keith M. Hanf
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Patent number: 11029369Abstract: A method for calibrating a magnetic source of an electromagnetic tracking system for tracking a position and orientation of an object using an inertial motion unit (IMU) mounted to the magnetic source and aligned with the coil array of magnetic source. Pitch and rolls angles of the coil array are calibrated using the IMU.Type: GrantFiled: January 27, 2020Date of Patent: June 8, 2021Assignee: ALKEN Inc.Inventors: Robert F. Higgins, Allan G. Rodgers, Jr.
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Patent number: 8121812Abstract: A method and system for magnetic locating resolves phase ambiguity. The system uses time-division multiplexed magnetic fields emitted from plural transmit coils. The magnetic fields are alternating fields at a carrier frequency, and the fields emitted from different coils in different transmit intervals have known phase relationship with one another as, for example where the alternating fields are coherent with one another. A receiver uses a plurality of sensor coils and derives plural components using the common phase reference or plural phase reference times having a known relationship. If the determinant of a matrix of the components has a first value, the phase information in the components is correct, and position and orientation are derived from the components. If the determinant has a second value, the phase information in the components is incorrect.Type: GrantFiled: September 10, 2008Date of Patent: February 21, 2012Assignee: ALKEN Inc.Inventor: Robert F. Higgins
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Patent number: 8013595Abstract: Plural transmitter coils of a magnetic locating system are driven with widely-separated main frequencies. One of the transmitter coils is also driven with a marker frequency close to the main frequency applied to that coil. The receiver determines a phase relationship with the transmitter based on the main and marker frequencies, so that the receiver does not suffer from phase ambiguity. The main and marker frequencies may interfere with one another, and the receiver may correct for such interference based on known characteristics of the signals at the main and marker frequencies.Type: GrantFiled: June 12, 2008Date of Patent: September 6, 2011Assignee: ALKEN Inc.Inventors: Herbert R. Jones, Robert F. Higgins, Henry E. Himberg
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Patent number: 7873491Abstract: In an AC magnetic tracker one or more multi-axis field sources, each operating at a different frequency, or frequency set, are detected and tracked in three-dimensional space, even when wireless or otherwise not physically connected to the tracking system. Multiple sources can be tracked simultaneously as they each operate with their own unique detectable set of parameters. The invention not only provides the ability to uniquely identify one or more sources by their frequencies, but also to synchronize with these frequencies in order to measure signals that then allow tracking the position and orientation (P&O) of the source(s). Further, these sources need not be present at the time of system start-up but can come and go while being detected, discriminated and tracked. It also should be noted that application of such systems in multiples with more sensors not synchronized to a source or sources also could be employed to give the reverse appearance of a known source phase and incoherency with the sensors.Type: GrantFiled: January 22, 2008Date of Patent: January 18, 2011Assignee: Alken, Inc.Inventors: Robert F. Higgins, Herbert R. Jones, Jr., Allan G. Rodgers
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Patent number: 7710395Abstract: A magnetic tracker system for use on an operator's head makes “mouse”/cursor movements on a screen similar to that of the classic computer “mouse”/track ball/touchpad/joystick. Only head movements are used as opposed to lifting a hand from the keyboard for making such moves. The new “mouse” avoids interrupting the hands from their position on the keyboard and has no moving mechanical parts that become clogged and that need a special surface (mouse pad) or special surface measurements (optical mouse).Type: GrantFiled: July 6, 2005Date of Patent: May 4, 2010Assignee: Alken, Inc.Inventors: Allan G. Rodgers, Robert F. Higgins, Suzanne T. Gagnon, James C. Farr
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Publication number: 20090076746Abstract: A method and system for magnetic locating resolves phase ambiguity. The system uses time-division multiplexed magnetic fields emitted from plural transmit coils. The magnetic fields are alternating fields at a carrier frequency, and the fields emitted from different coils in different transmit intervals have known phase relationship with one another as, for example where the alternating fields are coherent with one another. A receiver uses a plurality of sensor coils and derives plural components using the common phase reference or plural phase reference times having a known relationship. If the determinant of a matrix of the components has a first value, the phase information in the components is correct, and position and orientation are derived from the components. If the determinant has a second value, the phase information in the components is incorrect.Type: ApplicationFiled: September 10, 2008Publication date: March 19, 2009Applicant: ALKEN Inc., dba PolhemusInventor: Robert F. Higgins
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Publication number: 20090030646Abstract: Plural transmitter coils of a magnetic locating system are driven with widely-separated main frequencies. One of the transmitter coils is also driven with a marker frequency close to the main frequency applied to that coil. The receiver determines a phase relationship with the transmitter based on the main and marker frequencies, so that the receiver does not suffer from phase ambiguity. The main and marker frequencies may interfere with one another, and the receiver may correct for such interference based on known characteristics of the signals at the main and marker frequencies.Type: ApplicationFiled: June 12, 2008Publication date: January 29, 2009Applicant: ALKEN Inc., dba PolhemusInventors: Herbert R. Jones, Robert F. Higgins, Henry E. Himberg
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Patent number: 7292948Abstract: Techniques for removing distortion in an AC magnetic tracker identify a characteristic frequency in the distortion environment which is then utilized to extract distortion components from the tracker receiver signals so that the corrected position and orientation can be calculated. A multiplicity of alternative techniques for determining this characteristic frequency are disclosed, several of which can be done during operation without interrupting system operation while others can be done off-line. The invention also allows the use of a tuned tracker transmitter since it does not need to operate at multiple frequencies. The invention differs from the prior art by treating an extended conductor characteristic as just another unknown. The position and orientation algorithm solves the 6 unknown coordinates of position and orientation plus the one more unknown—the extended conductor characteristic frequency.Type: GrantFiled: April 22, 2005Date of Patent: November 6, 2007Assignee: Alken Inc.Inventors: Herbert R. Jones, Jr., Robert F. Higgins, Henry E. Himberg