Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.