Strapdown Inertial Navigation Technology, Second Edition D. H. Titterton J. L. Weston

Transcription

1 Strapdown Inertial Navigation Technology, Second Edition D. H. Titterton J. L. Weston NavtechGPS Part #1147 Progress in Astronautics and Aeronautics Series, 207 Published by AIAA, 2004, Revised, 2nd Edition, 574 pages, Hardback Book ISBN: The book provides an up-to-date guide to the techniques and applications of inertial navigation for use by both practicing engineers and post-graduate students. The book satisfies a need for a book on the subject of inertial navigation that provides both an introduction to the techniques involved as well as information on modern technological developments, combined with a more rigorous mathematical treatment for the reader wishing to explore the subject in greater depth. The text describes the basic concepts of inertial navigation with particular emphasis on modern strapdown system technology, providing detailed information on system mechanizations, instrumentation and computational aspects, design analysis, and applications of such systems. In particular, the text provides up-to-date information on inertial sensor technology and inertial navigation system computational techniques, bringing together the broad experience of the authors within a single volume. The text contains both descriptive passages and also mathematical details where appropriate. MEMS is the focus of much research and development activity at the present time; this technology offers rugged and reliable sensors with a performance capability that lends itself to integration with satellite navigation systems. This second edition has been updated in a number of areas to reflect ongoing developments in the field of inertial navigation technology. In addition to a number of refinements covering sensor technology, geodesy, and error modeling, the major additions to the original text are new chapters on MEMS (micro electro-mechanical systems) technology and system applications. A broad range of applications are addressed in a second new chapter, covering ship s inertial navigation, tactical missiles, well bore surveying systems, automobiles, and sightline stabilization systems, to name but a few. Preface 1 Introduction Navigation Inertial navigation Strapdown technology Layout of the book 4

2 2 Fundamental principles and historical developments of inertial navigation Basic concepts Summary Historical developments The modern-day inertial navigation system Trends in inertial sensor development 15 3 Basic principles of strapdown inertial navigation systems Introduction A simple two-dimensional strapdown navigation system Reference frames Three-dimensional strapdown navigation system - general analysis Navigation with respect to a fixed frame Navigation with respect to a rotating frame The choice of reference frame Resolution of accelerometer measurements System example Strapdown system mechanizations Inertial frame mechanization Earth frame mechanization Local geographic navigation frame mechanization Wander azimuth navigation frame mechanization Summary of strapdown system mechanizations Strapdown attitude representations Introductory remarks Direction cosine matrix Euler angles Quaternions Relationships between direction cosines, Euler angles and quaternions Detailed navigation equations Navigation equations expressed in component form The shape of the Earth Datum reference models Variation of gravitational attraction over the Earth 55

3 4 Gyroscope technology Introduction Conventional sensors Introduction Fundamental principles Components of a mechanical gyroscope Sensor errors Rate-integrating gyroscope Dynamically tuned gyroscope Flex gyroscope Rate sensors Dual-axis rate transducer (DART) Magnetohydrodynamic sensor Vibratory gyroscopes Introduction Vibrating wine glass sensor Hemispherical resonator gyroscope Vibrating disc sensor Tuning fork sensor Quartz rate sensor Silicon sensor Vibrating wire rate sensor General characteristics of vibratory sensors Cryogenic devices Nuclear magnetic resonance gyroscope SARDIN Electrostatically suspended gyroscope Other devices for sensing angular motion Fluidic (flueric) sensors Fluxgate magnetometers The transmission line gyroscope Gyroscope technology Optical sensors Introduction Fundamental principles Ring laser gyroscope Three-axis ring laser gyroscope configuration Fibre optic gyroscope 126

4 5.1.6 Photonic crystal optical fibre gyroscope Fibre optic ring resonator gyroscope Ring resonator gyroscope Integrated optical gyroscope Cold atom sensors Introduction Rotation sensing Measurement of acceleration Gravity gradiometer Summary of gyroscope technology Accelerometer and multi-sensor technology Introduction The measurement of translational motion Mechanical sensors Introduction Principles of operation Sensor errors Force-feedback pendulous accelerometer Pendulous accelerometer hinge elements Two-axes force-feedback accelerometer Open-loop accelerometers Solid-state accelerometers Vibratory devices Surface acoustic wave accelerometer Silicon sensors Fibre optic accelerometer Optical accelerometers Other acceleration sensors Multi-functional sensors Introduction Rotating devices Vibratory multi-sensor Mass unbalanced gyroscope Angular accelerometers Liquid rotor angular accelerometer Gas rotor angular accelerometer Inclinometers Summary of accelerometer and multi-sensor technology 186

5 7 MEMS inertial sensors Introduction Silicon processing MEMS gyroscope technology Introduction Tuning fork MEMS gyroscopes Resonant ring MEMS gyroscopes MEMS accelerometer technology Introduction Pendulous mass MEMS accelerometers Resonant MEMS accelerometers Tunnelling MEMS accelerometers Electrostatically levitated MEMS accelerometers Dithered accelerometers MOEMS Multi-axis/rotating structures MEMS based inertial measurement units Silicon IMU Quartz IMU System integration Summary Testing, calibration and compensation Introduction Testing philosophy Test equipment Data-logging equipment Gyroscope testing Stability tests - multi-position tests Rate transfer tests Thermal tests Oscillating rate table tests Magnetic sensitivity tests Centrifuge tests Shock tests Vibration tests Combination tests Ageing and storage tests 24

6 8.6 Accelerometer testing Multi-position tests Long-term stability Thermal tests Magnetic sensitivity tests Centrifuge tests Shock tests Vibration tests Combination tests Ageing and storage tests Calibration and error compensation Introduction Gyroscope error compensation Accelerometer error compensation Further comments on error compensation Testing of inertial navigation systems Hardware in the loop tests Strapdown system technology Introduction The components of a strapdown navigation system The instrument cluster Orthogonal sensor configurations Skewed sensor configurations A skewed sensor configuration using dual-axis gyroscopes Redundant sensor configurations Instrument electronics The attitude computer The navigation computer Power conditioning Anti-vibration mounts Concluding remarks Inertial navigation system alignment Introduction Basic principles Alignment on a fixed platform Alignment on a moving platform Alignment on the ground 282

7 Introduction Ground alignment methods Northfinding techniques In-flight alignment Introduction Sources of error In-flight alignment methods Alignment at sea Introduction Sources of error Shipboard alignment methods Strapdown navigation system computation Introduction Attitude computation Direction cosine algorithms Rotation angle computation Rotation vector compensation Body and navigation frame rotations Quaternion algorithms Orthogonalisation and normalisation algorithms The choice of attitude representation Acceleration vector transformation algorithm Acceleration vector transformation using direction cosines Rotation correction Dynamic correction Acceleration vector transformation using quaternions Navigation algorithm Summary Generalized system performance analysis Introduction Propagation of errors in a two-dimensional strapdown navigation system Navigation in a non-rotating reference frame Navigation in a rotating reference frame The Schuler pendulum 339

8 Propagation of errors in a Schuler tuned system Discussion of results General error equations Derivation of error equations Discussion Analytical assessment Single channel error model Derivation of single channel error propagation equations Single-channel error propagation examples Assessment by simulation Introductory remarks Error modeling Simulation techniques Motion dependence of strapdown system performance Manoeuvre-dependent error terms Vibration dependent error terms Summary Integrated navigation systems Introduction Basic principles External navigation aids Radio navigation aids Satellite navigation aids Star trackers Surface radar trackers On-board measurements Doppler radar Magnetic measurements Altimeters Terrain referenced navigation Scene matching Continuous visual navigation System integration 401

9 13.6 Application of Kalman filtering to aided inertial navigation systems Introduction Design example of aiding INS-GPS integration Uncoupled systems Loosely coupled integration Tightly coupled integration Deep integration Concluding remarks INS aiding of GPS signal tracking Multi-sensor integrated navigation Summary Design example Introduction Background to the requirement The navigation system requirement Navigation data required Operating and storage environment Performance System reaction time Physical characteristics Why choose strapdown inertial navigation? Navigation system design and analysis process Introduction Choice of system mechanization Error budget calculations System alignment Choice of inertial instruments Computational requirements Electrical and mechanical interfaces Testing, calibration and compensation requirements Performance enhancement by aiding Concluding remarks Alternative applications of IN sensors and systems Introduction 441

10 15.2 Borehole surveying Introduction Historical background Inertial survey system System design requirements System design issues System calibration and test Concluding remarks Ship's inertial navigation systems (SINS) NATO SINS Vehicle stabilization and control Autopilots Passive missile roll control (rollerons) Intelligent transport systems - automotive applications Intelligent transport systems - trains Personal transport Equipment stabilization Aero-flexure compensation Laser beam director Laser radar Seeker-head stabilization Sightline stabilization Relative angular alignment Calibration and measurement Geodetic and geophysical measurements and observation of fundamental physical phenomena Other applications Moving-map displays Safety and arming units Aircraft ejection seats Agricultural survey Artillery pointing Other unusual applications Concluding remarks 508 Appendix A Kalman filtering 511 Appendix B Inertial navigation system error budgets 519

11 Appendix C Inertial system configurations 523 Appendix D Comparison of GPS and GLONASS satellite navigation systems 529 List of symbols 535 Glossary of principal terms 539 Index 549