Magnetoquasistatic Position and Orientation Tracking

Project Members

Matthew Trotter (Disney Research Pittsburgh)
Joshua Griffin (Disney Research Pittsburgh)
Dan Stancil (North Carolina State University)
David Ricketts (North Carolina State University)
Darmindra Arumugam (Jet Propopulsion Laboratory)
Michael Sibley (Tait Towers)
Daniel Kotovsky (University of Florida)

The goal of this project is to determine the position and orientation of a light-weight, low-frequency transmitter using quasistatic magnetic fields in environments where line-of-sight occlusions and multipath propagation reduce the accuracy of conventional optical and high-frequency wireless tracking systems. This technology could be used in many applications including athlete tracking, video game control, and handheld device localization; however, the current application is tracking an American football. A small transmitter integrated into the football induces a quasistatic magnetic field that is sensed by receivers stationed around the field. With at least five unique measurements of the magnetic field, the three-dimensional (3D) position and orientation of the ball can be determined using complex image theory to account for ground effects. This system has several advantages including immunity to multipath propagation, unaffected by line-of-sight occlusions caused by groups of people, and minimum complexity on the person/object to be tracked.

An instrumented American football with the outer leather covering removed. A class-E oscillator (transmitter) and loop antenna are shown.

A cutaway of an American football showing the proposed location of the embedded loop antenna, transmitter circuit, and battery. These components are placed between the inner air bladder and the outer leather covering and are held in place by the pressure of the air bladder.

Eight loop antennas are positioned around one end of an American football field.

Selected frames from a run play are shown to compare the true path of the ball (yellow line) to the estimated path of the ball (orange line). The true position of the ball was visually estimated by the position of the player’s feet.

The final frame from a run play comparing the true path of the ball (yellow line) to the estimated path of the ball (orange line). The true position of the ball was visually estimated by the position of the player’s feet.

Publications

Enhanced Accuracy for a Complex Image Theory Position Estimator using Frequency Diversity-Thumbnail

Enhanced Accuracy for a Complex Image Theory Position Estimator using Frequency Diversity
January 20, 2014
IEEE Radio and Wireless Week (RWW) 2014
Paper File [pdf, 1.83 MB]

Experimental Demonstration of Complex Image Theory for Vertical Magnetic Dipoles with Applications to Remote Sensing and Position Tracking-Thumbnail

Experimental Demonstration of Complex Image Theory for Vertical Magnetic Dipoles with Applications to Remote Sensing and Position Tracking
September 9, 2013
International Conference on Electromagnetics in Advanced Applications (ICEAA) 2013
Paper File [pdf, 2.95 MB]

An Active Position Sensing Tag for Sports Visualization in American Football-Thumbnail

An Active Position Sensing Tag for Sports Visualization in American Football
April 30, 2013
IEEE International Conference on RFID 2013
Paper File [pdf, 5.17 MB]

Magnetoquasistatic Tracking of an American Football- A Goal Line Measurement-Thumbnail

Magnetoquasistatic Tracking of an American Football: A Goal Line Measurement
February 1, 2013
IEEE Antennas and Propagation Magazine 2013
Paper File [pdf, 3.49 MB]

Error Reduction in Magnetoquasistatic Positioning using Orthogonal Emitter Measurements-Thumbnail

Error Reduction in Magnetoquasistatic Positioning using Orthogonal Emitter Measurements
November 27, 2012
IEEE Antennas and Wireless Propagation Letters 2012
Paper File [pdf, 690.60 kB]

Experimental Study on the Effects of Groups of People on Magnetoquasistatic Positioning Accuracy-Thumbnail

Experimental Study on the Effects of Groups of People on Magnetoquasistatic Positioning Accuracy
July 8, 2012
IEEE Antennas and Propagation Symposium 2012
Paper File [pdf, 1.41 MB]

Wireless Orientation Sensing Using Magnetoquasistatic Fields and Complex Image Theory-Thumbnail

Wireless Orientation Sensing Using Magnetoquasistatic Fields and Complex Image Theory
January 15, 2012
IEEE Radio and Wireless Week (RWW) 2012
Paper File [pdf, 936.48 kB]

A Wireless Orientation Sensor Using Magnetoquasistatic Fields and Complex Image Theory
January 1, 2012
2012 IEEE Radio and Wireless Symposium (RWS), pp.251-254, January 2012
Paper File [pdf, 936.48 kB]

Two-Dimensional Position Measurement using Magnetoquasistatic Fields-Thumbnail

Two-dimensional Position Measurement using Magnetoquasistatic Fields
September 12, 2011
IEEE Topical Conference on Antennas and Propagation in Wireless Communications (APWC) 2011
Paper File [pdf, 1.66 MB]

Higher Order Loop Corrections for Short Range Magnetoquasistatic Position Tracking-Thumbnail

Higher Order Loop Corrections for Short Range Magnetoquasistatic Position Tracking
July 3, 2011
IEEE Antennas and Propagation Symposium 2011
Paper File [pdf, 316.71 kB]

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