Sensor Fusion in Head Pose Tracking for Augmented Reality Stelian-Florin Persa Sensor Fusion in Head Pose Tracking for Augmented Reality PROEFSCHRIFT Ter verkrijging van de graad van doctor aan de Technische Universiteit Delft, op gezag van de Rector Magnificus, Prof.dr.ir. J.T. Fokkema, voorzitter van het college voor promoties, in het openbaar te verdedigen op dinsdag 6 Juni om 10.00 uur door Stelian-Florin PERSA Inginer Universitatea Tehnica din Cluj-Napoca geboren te Cluj-Napoca (Roemenie) Dit proefschrift is goedgekeurd door de promotoren: Prof.dr.ir. I.T. Young Prof.dr.ir. R.L. Lagendijk Toegevoegd promotor: Dr.ir. P.P. Jonker Samenstelling promotiecommissie: Rector Magnificus Technische Universiteit Delft, voorzitter Prof.dr.ir. I.T. Young Technische Universiteit Delft, promotor Prof.dr.ir. R.L. Lagendijk Technische Universiteit Delft, promotor Dr.ir. P.P. Jonker Technische Universiteit Delft, toegevoegd promotor Prof.dr.ir. H.J. Sips Technische Universiteit Delft Prof.dr.ir. J.J.M. Braat Technische Universiteit Delft Prof.dr.ir. F.C.A. Groen Vrije Universiteit Amsterdam Prof.dr.ir. A. Vlaicu Technical University Cluj-Napoca, Romania The work presented in this thesis was supported by Ubiquitous Communications (UBICOM) pro- gramme, funded by Delft University of Technology DIOC research programme. ISBN-10: 90-9020777-5 ISBN-13: 978-90-9020777-3 Copyright ©2006 by Stelian-Florin Persa Printed by Wöhrmann Print Service Devoted to my wife Monica, my daughter Irina and to my parents Table of Contents Chapter 1 Introduction . 1 1.1 Previous Work . 2 1.2 Problem Formulation and Requirements Outline. 4 1.3 System Concept . 5 1.4 Objectives . 6 1.5 Contributions . 7 1.6 Thesis Outline. 8 Chapter 2 Survey of Positioning Technologies . 9 2.1 Introduction . 9 2.2 Types of AR Systems . 9 2.2.1 Monitor-based Display . 9 2.2.2 Video See-through Display . 10 2.2.3 Optical See-through Display . 11 2.3 Relative Position Measurements . 11 2.3.1 Odometry . 11 2.3.2 Inertial Navigation . 12 2.3.2.1 Accelerometers . 13 2.3.2.2 Gyroscopes . 14 2.4 Absolute Position Measurements . 16 2.4.1 Active Landmarks. 16 2.4.1.1 Wireless Location Systems. .16 2.4.1.2 Ground-Based RF Systems. 17 2.4.1.3 Loran. 17 2.4.1.4 Cell-based tracking . 18 2.4.1.5 The GUIDE system. 18 2.4.1.6 Ultrasonic Tracking . 19 2.4.1.7 Global Positioning Systems (Space-based Radio System). 20 2.4.2 Passive Landmarks . 21 2.4.2.1 Geomagnetic Sensing . 21 2.4.2.2 Inclinometers . 22 2.4.2.3 Vision-Based Positioning . 23 2.4.2.4 Camera Model and Localization. 24 2.4.3 Model-Based Approaches. 25 2.5 Multi-Sensor Fusion and Inertial Navigation . 26 2.6 Summary of Sensing Technologies . 28 2.7 Conclusions . 30 Chapter 3 Sensor Selection, Errors and Calibration . 31 3.1 Introduction . 31 3.2 Building an Inertia Measurement Unit . 32 i 3.2.1 Position and Orientation Sensing Hardware. 33 3.2.2 Gyroscopes . 34 3.2.3 Accelerometers . 35 3.2.4 Magnetometers . 36 3.2.5 Global Positioning . 37 3.2.5.1 GPS positioning . 38 3.2.5.2 The Garmin GPS25 GPS receiver . 39 3.2.5.3 GPS protocols . 40 3.2.5.4 Spatial reference systems . 41 3.2.6 Differential GPS . 42 3.3 Sensor Errors . 43 3.3.1 Accelerometer calibration procedure . .44 3.3.2 Gyroscope calibration procedure . 46 3.3.3 Overall Sensor Alignment . 50 3.4 Results and Conclusions. 51 Chapter 4 Inertial Navigation and Sensor Data Fusion . 53 4.1 Introduction . 53 4.2 Coordinate Frames . 54 4.2.1 Strapdown Attitude Representations . 54 4.2.1.1 The Euler angle representation . ..