VWGoA - Ex. 1002
`Volkswagen Group of America, Inc., Petitioner
`Case No. IPR2015-00276
`1
`
`

`
`
`
`AUTOMOTIVE
`ELECTRONICS
`HANDBOOK
`
`
`
`Ronald K. Jurgen Editor in Chief
`
`WAHEHAM.’ FnEE;o,LtaRA7:¥i“' »
`59 MARION new ’
`WAREHAM, MA! 0252.1
`
`V
`
`McGraw—HilI, Inc.
`NewYork San Francisco Washington, DC. Auckland Bogota
`Caracas Lisbon London Madrid Mexico City Milan
`Montreal New Delhi San Juan Singapore
`Sydney Tokyo Toronto
`
`2
`
`

`
`
`
`Related McGraw-Hill Books of Interest
`
`
`Handbooks
`
`Avallone and Baumeister - MARK’S STANDARD HANDBOOK FOR MECHANICAL ENGINEERS
`Benson - AUDIO ENGINEERING HANDBOOK
`
`Brady - MATERIALS HANDBOOK
`Chen - COMPUTER ENGINEERING HANDBOOK
`Considine - PROCESS/INDUSTRIAL INSTRUMENTS AND CONTROL HANDBOOK
`Coombs - PRINTED CIRCUITS HANDBOOK
`Coombs - ELECTRONIC INSTRUMENT HANDBOOK
`Di Giacomo - DIGITAL BUS HANDBOOK
`
`Fink and Beaty - STANDARD HANDBOOK FOR ELECTRICAL ENGINEERS
`Fink and Christiansen - ELECTRONICS ENGINEERS’ HANDBOOK
`Ganic - McGRAw-HILL HANDBOOK OF ESSENTIAL ENGINEERING INFORMATION
`
`Harper - ELECTRONIC PACKAGING AND INTERCONNECTION HANDBOOK
`Harper and Sampson - ELECTRONIC MATERIALS AND PROCESSES HANDBOOK
`Hicks - STANDARD HANDBOOK OF ENGINEERING CALCULATIONS
`Hodson - MAYNARD’S INDUSTRIAL ENGINEERING HANDBOOK
`Johnson - ANTENNA ENGINEERING HANDBOOK
`
`Juran and Gryna - JURAN’S QUALITY CONTROL HANDBOOK
`Kaufman and Seidman - HANDBOOK OF ELECTRONICS CALCULATIONS
`Lenk - McGRAw-HILL ELECTRONIC TESTING HANDBOOK
`Lenk - LENK’S DIGITAL HANDBOOK
`Mason - SWITCH ENGINEERING HANDBOOK
`Schwartz - COMPOSITE MATERIALS HANDBOOK
`Townsend - DUDLEY’S GEAR HANDBOOK
`Tuma - ENGINEERING MATHEMATICS HANDBOOK
`
`Waynant - ELECTRO-OPTICS HANDBOOK
`Woodson - HUMAN FACTORS DESIGN HANDBOOK
`
`Other
`
`
`
`Boswell - SUBCONTI{Ie§£§$INd2:_
`Gieck - ENGINEERING'FO'1%
`Ginsberg - PRINTED CIR ‘
`Johnson - ISO 9000
`Lenk ' MCGRAW-HILL CIRCUIT ENCYCLOPEDIA AND TROUBLESHOOTING GUIDE,
`VOLS. 1 AND 2
`
`Lubben - JUST—IN-TIME MANUFACTURING
`Markus and Sclater - McGRAw—HILL ELECTRONICS DICTIONARY
`
`Saylor - TQM FIELD MANUAL
`Soin - TOTAL QUALITY CONTROL ESSENTIALS
`Whitaker - ELECTRONIC DISPLAYS
`
`Young - ROARK’S FORMULAS FOR STRESS AND STRAIN
`
`To order or to receive additional information on these or any other
`McGraw—Hill titles, please call 1-800-822-8158 in the United States.
`In other countries, please Contact your local McGraw—Hill office.
`
`BC14BCZ
`
`3
`
`

`
`Library of Congress Cataloging-in-Publication Data
`
`
`
`Automotive electronics handbook / Ronald Jurgen, editor in chief.
`p.
`cm.
`Includes index.
`ISBN 0-07-033189—8
`1. Automobiles»-Electronic equipment.
`TL272.5.A982
`1994
`629.25 '49—dc
`
`I. Jurgen, Ronald K.
`
`94-39724
`CIP
`
`Copyright © 1995 by McGraw—Hill, Inc. All rights reserved. Printed in the
`United States of America. Except as permitted under the United States
`Copyright Act of 1976, no part of this publication may be reproduced or dis-
`tributed in any form or by any means, or stored in a data base or retrieval
`system, without the prior written permission of the publisher.
`
`234567890 AGM/AGM 9098765
`
`ISBN 0-07-033189-8
`
`The sponsoring editor for this book was Stephen S. Chapman, the editing
`supervisor was Virginia Carroll, and the production supervisor was
`Suzanne W B. Rapcavage. It was set in Times Roman by North Market
`Street Graphics.
`
`Printed and bound by Arcata Graphics/Martinsburg.
`
`McGraw—Hill books are available at special quantity discounts to use as pre-
`miums and sales promotions, or for use in corporate training programs. For
`more information, please write to the Director of Special Sales, McGraw-
`Hill, Inc., 11 West 19th Street, New York, NY 10011. Or contact your local
`bookstore.
`
`Information contained in this work has been obtained by McGraw-
`Hill, Inc. from sources believed to be reliable. However, neither
`McGraw—Hill nor its authors guarantee the accuracy or complete-
`ness of any information published herein, and neither McGraw—
`Hill nor its authors shall be responsible for any errors, omissions,
`or damages arising out of use of this information. This work is
`published with the understanding that McGraw-Hill and its authors
`are supplying information, but are not attempting to render engi-
`neering or other professional services.
`If such services are
`required, the assistance of an appropriate professional should be
`
`sought.
`
`This book is printed on acid-free paper.
`
`4
`
`

`
`-This book is dedicated to Robert H. Lewis and to
`the memories of Douglas R. Jurgen and Marion
`Schappel.
`
`5
`
`

`
`
`
`
`
`TENTS
`
`Contributors
`Preface
`xvii
`
`xv
`
`Part 1
`
`Introduction
`
`Chapter 1. Introduction RonaIdK.Jurgen
`
`1.1 The Dawn of a New Era / 1.3
`1.2 The Microcomputer Takes Center Stage / 1.4
`1.3 Looking to the Future / 1.5
`References / 1.6
`
`Part 2 Sensors and Actuators
`
`Chapter 2. Pressure Sensors Randy Frank
`
`2.1 Automotive Pressure Measurements / 2.3
`2.2 Automotive Applications for Pressure Sensors / 2.5
`2.3 Technologies for Sensing Pressure / 2.15
`2.4 Future Pressure-Sensing Developments / 2.23
`Glossary / 2.24
`Bibliography / 2.24
`
`1.3
`
`2.3
`
`Chapter 3. Linear and Angie Position Sensors Paul Niclrson
`
`3.1
`
`3.1 Introduction / 3.1
`3.2 Classification of Sensors / 3.1
`3.3 Position SensorTechnologies / 3.2
`3.4 Interfacing Sensors to Control Systems
`Glossary / 3.17
`References / 3.17
`
`/ 3.16
`
`Chapter 4. Flow Sensors Robert E. Bicking
`
`4.1
`
`4.1 Introduction / 4.1
`4.2 Automotive Applications of Flow Sensors
`4.3 Basic Classification of Flow Sensors / 4.3
`4.4 Applicable Flow MeasurementTechno1ogies / 4.4
`Glossary / 4.8
`Bibliography / 4.9
`
`/ 4.1
`
`6
`
`

`
`viii
`
`CONTENTS
`
`Chapter 5. Temperature, Heat, and Humidity Sensors Randy Frank
`
`5.1 Temperature, Heat, and Humidity / 5.1
`5.2 AutomotiveTemperature Measurements / 5.5
`5.3 Humidity Sensing and Vehicle Performance / 5.12
`5.4 Sensors forTemperature / 5.14
`5.5 Humidity Sensors / 5.21
`5.6 Conclusions / 5.22
`Glossary / 5.23
`Bibliography / 5.23
`
`Chapter 6. Exhaust Gas Sensors Hans-Martin Wiedenmann,
`Gerhard Hétzel, Harald Neumann, Johann Riegel, and Helmut Weyl
`
`6.1 Basic Concepts / 6.1
`6.2 Principles of Exhaust Gas Sensors for Lambda Control
`6.3 Technology of Ceramic Exhaust Gas Sensors / 6.11
`6.4 Factors Affecting the Control Characteristics of Lambda = 1 Sensors / 6.14
`6.5 Applications / 6.18
`6.6 Sensor Principles for Other Exhaust Gas Components / 6.20
`Bibliography / 622
`
`/ 6.5
`
`Chapter 7. Speed and Acceleration Sensors William C. Dunn
`
`7.1 Introduction / 7.1
`7.2 Speed-Sensing Devices / 7.2
`7.3 Automotive Applications for Speed Sensing / 7.6
`7.4 Acceleration Sensing Devices / 7.8
`7.5 Automotive Applications for Accelerometers / 7.18
`7.6 New Sensing Devices / 7.22
`7.7 Future Applications I 7.24
`7.8 Summary / 7.26
`Glossary / 7.27
`References / 7.28
`
`Chapter 8. Engine Knock Sensors William G. Wolber
`
`8.1 Introduction / 8.1
`8.2 The Knock Phenomenon / 8.2
`8.3 Technologies for Sensing Knock / 8.4
`8.4 Summary / 8.9
`Glossary / 8.9
`References / 8.9
`
`Chapter 9. Engine Torque Sensors William G. Wolber
`
`9.1 Introduction / 9.1
`9.2 Automotive Applications ofTorque Measurement
`9.3 DirectTorque Sensors / 9.6
`9.4 Inferred Torque Measurement
`9.5 Summary / 9.13
`Glossary / 9.13
`References / 9.14
`
`/ 9.8
`
`/ 9.3
`
`5.1
`
`6.1
`
`7.1
`
`8.1
`
`9.1
`
`7
`
`

`
`CONTENTS
`
`ix
`
`10.1
`
`Chapter 10. Actuators Klaus ML'iIIer
`
`10.1 Preface / 10.1
`10.2 Types of ElectromechanicalActuators / 10.2
`10.3 AutomotiveActuators / 10.19
`10.4 Technology for Future Application / 10.27
`Acknowledgments / 10.30
`Glossary / 10.30
`Bibliography / 10.31
`
`Pa rt 3 Control Systems
`
`Chapter 11. Automotive Microcontrollers Davids. Boehmer
`
`11.3
`
`11.1 Microcontroller Architecture and Performance Characteristics / 11.3 «
`11.2 Memory / 11.24
`11.3 Low-Speed Input/Output Ports / 11.31
`11.4 High-Speed I/O Ports / 11.36
`11.5 Serial Communications / 11.41
`11.6 Anal0g—t0-Digital Converter
`/ 11.45
`11.7 Failsafe Methodologies / 11.49
`11.8 FutureTrends / 11.51
`Glossary / 11.54
`Bibliography / 11.55
`
`Chapter 12. Engine Control Gary C. Hirschlieb, Gottfried Schiller,
`and Shari Stottler
`
`12.1 Objectives of Electronic Engine Control Systems / 12.1
`12.2 Spark Ignition Engines / 12.5
`12.3 Compression Ignition Engines / 12.32
`
`Chapter 13. Transmission Control Kurt Neuffer, Wolfgang Bullmer,
`and Werner Brehm
`
`13.1 Introduction / 13.1
`13.2 System Components / 13.2
`13.3 System Functions / 13.7
`13.4 Communications with Other Electronic Control Units / 13.17
`13.5 Optimization of the Drivetrain / 13.18
`13.6 Future Developments / 13.19
`Glossary / 13.20
`References / 13.20
`
`Chapter 14. Cruise Control Richard Valentine
`
`14.1 Cruise Control System / 14.1
`14.2 Microcontroller Requirements for Cruise Control
`14.3 Cruise Control Software / 14.4
`14.4 Cruise ControlDesign / 14.6
`14.5 Future Cruise Concepts / 14.7
`Glossary / 14.8
`Bibliography / 14.8
`
`/ 14.3
`
`12.1
`
`13.1
`
`14.1
`
`8
`
`

`
`CONTENTS
`
`Chapter 15. Braking Control
`
`Jerry L. Cage
`
`15.1 Introduction / 15.1
`15.2 Vehicle Braking Fundamentals / 15.1
`15.3 Antilock Systems
`/ 15.8
`15.4 Future Vehicle Braking Systems
`Glossary / 15.15
`References / 15.16
`
`/ 15.14
`
`Chapter 16. Traction Control Armin czinczel
`
`16.1 Introduction / 16.1
`16.2 Forces Affecting Wheel Traction: Fundamental Concepts / 16.3
`16.3 Controlled Variables / 16.5
`16.4 Control Modes / 16.6
`16.5 Traction Control Components / 16.11
`16.6 Applications on Heavy Commercial Vehicles / 16.13
`16.7 Future Trends / 16.14
`Glossary / 16.14
`Bibliography / 16.15
`
`15.1
`
`16.1
`
`Chapter 17. Suspension Control Akatsu Yohsuke
`
`17.1
`
`17.1 Shock Absorber Control System / 17.1
`17.2 Hydropneumatic Suspension Control System / 17.4
`17.3 Electronic Leveling Control System / 17.5
`17.4 Active Suspension / 17.8
`17.5 Conclusion / 17.17
`Glossary / 17.18
`Nomenclature / 17.18
`Bibliography / 17.18
`
`Chapter 18. Steering Control Makoto sato
`
`18.1 Variable-Assist Steering / 18.1
`18.2 Four—Wheel Steering Systems (4WS)
`Glossary / 18.33
`References / 18.33
`
`/ 18.15
`
`Chapter 19. Lighting, Wipers, Air Conditioning/Heating
`Richard Valentine
`
`19.1 Lighting Controls / 19.1
`/ 19.9
`19.2 Windshieldwiper Control
`19.3 Air Conditioner/Heater Control
`/ 19.15
`19.4 Miscellaneous Load Control Reference / 19.20
`19.5 Future Load Control Concepts / 19.25
`Glossary / 19.26
`Bibliography / 19.27
`
`18.1
`
`19.1
`
`9
`
`

`
`Part 4 Displays and Information Systems
`
`Chapter 20. Instrument Panel Displays Ronald K. Jurgen
`
`20.1 The Evolution to Electronic Displays / 20.3
`20.2 Vacuum Fluorescent Displays / 20.3
`20.3 Liquid Crystal Displays / 20.4
`20.4 Cathode—Ray Tube Displays / 20.6
`20.5 Head-up Displays / 20.6
`20.6 Electronic Analog Displays / 20.8
`20.7 Reconfigurable Displays / 20.9
`References / 20.9
`
`Chapter 21. Trip Computers Ronald K. Jurgen
`
`21.1 Trip Computer Basics / 21.1
`21.2 SpecificTrip Computer Designs / 21.2
`21.3 Conclusion / 21.4 ~
`References / 21.6 »
`
`Chapter 22. On- and Off-Board Diagnostics Wolfgang Bremer,
`Frieder Heintz, and Robert Hugel
`
`22.1 Why Diagnostics? / 22.1
`22.2 On-Board Diagnostics / 22.6
`22.3 Off-Board Diagnostics / 22.7
`22.4 Legislation and Standardization / 22.8
`22.5 Future Diagnostic Concepts / 22.15
`Glossary / 22.18
`References / 22.19
`
`Part 5 Safety, Convenience, Entertainment,
`and Other Systems
`
`Chapter 23. Passenger Safety and Convenience Bernhard K. Mattes
`
`/ 23.3
`23.1 Passenger Safety Systems
`23.2 Passenger Convenience Systems
`Glossary / 23.13
`Bibliography / 23.13
`
`/ 23.11
`
`Chapter 24. Antitheft Systems ShinichiKato
`
`24.1 Vehicle Theft Circumstances / 24.1
`24.2 Overview of Antitheft Regulations / 24.2
`24.3 ABasic Antitheft System / 24.3
`
`CONTENTS
`
`.xi
`
`20.3
`
`21.1
`
`22.1
`
`23.3
`
`24.1
`
`10
`
`10
`
`

`
`xii
`
`CONTENTS
`
`Chapter 25. Entertainment Products
`
`Tom Chrapkiewicz
`
`25.1
`
`25.1 Fundamentals of Audio Systems / 25.1
`25.2 ABrief History of Automotive Entertainment
`25.3 Contemporary Audio Systems
`/ 25.5
`-
`25.4 FutureTrends / 25.12
`Glossary I 25.17
`References / 25.18
`
`/ 25.4
`
`Chapter 26. Multiplex Wiring Systems Fred Miesterfeld
`
`26.1
`
`26.1 Vehicle Multiplexing / 26.1
`26.2 EncodingTechniques / 26.9
`26.3 Protocols / 26.23
`26.4 Summary and Conclusions / 26.53
`Glossary / 26.56
`References / 26.64
`
`Part 6 Electromagnetic Interference and Compatibility
`
`Chapter 27. Electromagnetic Standards and Interference
`James P. Muccioli
`
`27.3
`
`27.1 SAE Automotive EMC Standards / 27.3
`27.2 IEEE Standards Related to EMC / 27.11
`27.3 The Electromagnetic Environment of an Automobile Electronic System / 27.13
`Bibliography / 27.18
`'
`
`Chapter 28. Electromagnetic Compatibility James R Muccioli
`
`28.1
`
`28.1 Noise Propagation Modes / 28.1
`28.2 Cabling / 28.2
`28.3 Components / 28.4
`/ 28.9
`28.4 Printed Circuit Board EMC Checklist
`28.5 Integrated Circuit Dec0upling—A Key Automotive EMI Concern / 28.10
`28.6 IC Process Size Affects EMC / 28.14
`Bibliography / 28.19
`
`Part 7 Emerging Technologies
`
`Chapter 29. Navigation Aids and intelligent Vehicle-Highway Systems Robert L.
`French
`
`29.3
`
`29.1 Background / 29.3
`29.2 Automobile Navigation Technologies / 29.4
`29.3 Examples of Navigation Systems / 29.10
`29.4 Other IVHS Systems and Services
`/ 29.15
`References / 29.18
`
`11
`
`11
`
`

`
`Chapter 30. Electric and Hybrid Vehicles George G. Karady, Tracy Blake,
`Raymond S. Hobbs, and Donald B. Karner
`
`30.1
`
`CONTENTS
`
`xiii
`
`30.1 Introduction / 30.1
`30.2 System Description / 30.5
`30.3 Charger and Protection System / 30.6
`30.4 Motor Drive System / 30.8
`30.5 Battery / 30.17
`30.6 Vehicle Control and Auxiliary Systems / 30.19
`30.7 Infrastructure / 30.21
`30.8 Hybrid Vehicles / 30.23
`Glossary / 30.24
`References / 30.25
`
`Chapter 31. Noise Cancellation Systems
`
`Jeffrey N. Denenberg
`
`A 31.1
`
`31.1 Noise Sources / 31.1
`31.2 Applications / 31.5
`Glossary / 31.10
`Bibliography / 31.10
`
`Chapter 32. Future Vehicle Electronics Randy Frank and Salim Momin
`
`32.1
`
`32.1 Retrospective / 32.1
`32.2 IC Technology / 32.1
`32.3 Other SemiconductorTechnologies / 32.5
`32.4 Enabling the Future / . 32.11
`32.5 Impact on Future Automotive Electronics / 32.15
`32.6 Conclusions / 32.20
`Glossary / 32.21
`Bibliography / 32.23
`
`lndex /
`
`1.1
`
`12
`
`12
`
`

`
`13
`
`13
`
`

`
`
`
`CONTRIBUTORS
`
`Robert E. Bicking Honeywell, Micro Switch Division (CHAR. 4)
`
`Tracy Blake Arizona State University (CHAR 30)
`David S. Boehmer
`Intel Corporation (CHAP. 11)
`
`Werner Brehm Robert Bosch GmbH (CHAP. 13)
`
`Wolfgang Bremer Robert Bosch GmbH (CHAR 22)
`
`Wolfgang Bullmer Robert Bosch GmbH (CHAR13)
`
`Jerry L. Cage Allied Signal, Inc. (CHAR 15)
`Tom Chrapkiewicz Philips Semiconductor (CHAR 25)
`
`Armin Czinczel Robert Bosch GmbH (CHAR 16)
`
`Jeffrey N. Denenberg Noise Cancellation Technologies, Inc. (CHAR 31)
`
`William C. Dunn Motorola Semiconductor Products (CHAR 7)
`
`Randy Frank Motorola Semiconductor Products (CHAPS. 2, 5, 32)
`
`Robert L. French R. L. French &Ass0ciates (CHAR 29)
`
`Frieder Heintz Robert Bosch GmbH (CHAP. 22)
`
`Gary C. Hirschlieb Robert Bosch GmbH (CHAR 12)
`
`Raymond S. Hobbs Arizona Public Service Company (CHAP. 30)
`
`Gerhard Hiitzel Robert Bosch GmbH (CHAR 6)
`
`Robert Hugel Robert Bosch GmbH (CHAR. 22)
`
`Ronald K. Jurgen Editor (CHAPS. 1, 20,21)
`
`George G. Karady Arizona State Univeristy (CHAR 30)
`
`Donald B. Karner Electric Transportation Application (CHAR 30)
`
`Shinichi Kato Nissan Motor Co., Ltd. (CHAR 24)
`
`Bernhard K. Mattes Robert Bosch GmbH (CHAR23)
`
`Fred Miesterfeld Chrysler Corporation (CHAR. 26)
`
`Salim Momin Motorola Semiconductor Products (CHAR 32)
`
`James P. Muccioli
`
`JASTECH (CHAPS. 27,28)
`
`Klaus Miiller Robert Bosch GmbH (CHAR 10)
`
`Kurt Neuffer Robert Bosch GmbH (cHAR13)
`
`Harald Neumann Robert Bosch GmbH (CHAR 6)
`
`Paul Nickson Analog Devices, Inc. (CHAR 3)
`
`Johann Riegel Robert Bosch GmbH (CHAR 6)
`
`14
`
`14
`
`

`
`xvi
`
`CONTRIBUTORS
`
`Makoto Sato Honda R&D Co., Ltd. (CHAP. 18)
`
`Gottfried Schiller Robert Bosch GmbH (CHAP. 12)
`
`Shari Stottler Robert Bosch GmbH (CHAP. 12)
`
`Richard Valentine Motorola Inc. (CHAPS. 14,19)
`
`Helmut Weyl Robert Bosch GmbH (CHAP. 6)
`
`Hans-Martin Wiedenmann Robert Bosch GmbH (CHAP. 6)
`
`William G. Wolber Cummins Electronics Co., Inc. (CHAPS. 8, 9)
`
`Akatsu Yohsuke Nissan Motor Co., Ltd. (CHAP. 17)
`
`15
`
`15
`
`

`
`
`
`PREFACE
`
`Automotive electronics as we know it today encompasses a wide variety of devices and sys-
`tems. Key to them all, and those yet to come, is the ability to sense and measure accurately
`automotive parameters. Equally important at the output is the ability to initiate control
`actions accurately in response to commands. In other words, sensors and actuators are the
`heart of any automotive electronics application. That is why they have been placed first in this
`handbook where they are described in technical depth. In other chapters, application-specific
`discussions of sensors and actuators can be found.
`
`The importance of sensors and actuators cannot be overemphasized.'Ihe future growth of
`automotive electronics is arguably more dependent on sufficiently accurate and low-cost sen-
`sors and actuators than on computers, controls, displays, and other technologies. Yet it is those
`nonsensor, nonactuator technologies that are to many engineers the more “glamorous” and
`exciting areas of automotive electronics.
`In the section on control systems, a key in—depth chapter deals with automotive microcom-
`trollers. Without them, all of the controls described in the chapters that follow in that sec-
`tion——engine, transmission, cruise, braking, traction, suspension, steering, lighting, windshield
`wipers, air conditioner/heater—would not be possible. Those controls, of course, are key to car
`operation and they have made cars over the years more drivable, safe, and reliable.
`Displays, trip computers, and on— and off—board diagnostics are described in another sec-
`tion, as are systems for passenger safety and convenience, antitheft, entertainment, and multi-
`plex wiring. Displays and trip computers enable the driver to readily obtain valuable
`information about the car’s operation and anticipated trip time. On- and off-board diagnostics
`have of necessity become highly sophisticated to keep up with highly sophisticated electronic
`controls. Passenger safety and convenience items and antitheft devices add much to the feel-
`ing of security and pleasure in owning an automobile. Entertainment products are what got
`automotive electronics started and they continue to be in high demand by car buyers. And
`multiplex wiring, off to a modest start in production cars, holds great promise for the future in
`reducing the cumbersome wiring harnesses presently used.
`The section on electromagnetic interference and compatibility emphasizes that interfer-
`ence from a variety of sources, if not carefully taken into account early on, can raise havoc
`with what otherwise would be elegant automotive electronic designs. And automotive systems
`themselves, if not properly designed, can cause interference both inside and outside the auto-
`mobile.
`
`In the final section on emerging technologies, some key newer areas are presented:
`
`I Navigation aids and intelligent vehicle-highway systems are of high interest worldwide
`since they hold promise to alleviate many of vehicle—caused problems and frustrations in
`our society.
`
`I While it may be argued that electric vehicles are not an emerging technology, since they
`have been around for many years, it certainly is true that they have yet to come into their
`own in any really meaningful way.
`
`I Electronic noise cancellation is getting increasing attention from automobile designers
`seeking an edge over their competitors.
`
`16
`
`16
`
`

`
`xviii
`
`PREFACE
`
`The final chapter on future vehicle electronics is an umbrella discussion that runs the
`gamut of trends in future automotive electronics hardware and software. It identifies poten-
`tial technology developments and trends for future systems.
`Nearly every chapter contains its own glossary of terms. This approach, rather than one
`overall unified glossary, has the advantage of allowing terms to be defined in a more applica-
`tion-specific manner———in the context of the subject of each chapter. It should also be noted
`that there has been no attempt in this handbook to cover, except peripherally, purely mechan-
`ical and electrical devices and systems. To do so would have restricted the number of pages
`available for automotive electronics discussions.
`
`Finally, the editor would like to thank all contributors to the handbook and particularly
`two individuals: Otto Holzinger of Robert Bosch GmbH in Stuttgart, Germany and Randy
`Frank of Motorola Semiconductor Products in Phoenix, Arizona. Holzinger organized the
`many contributions to this handbook from his company. Frank, in addition to contributing
`two chapters himself and cocontributing a third, organized the other contributions from
`Motorola.Without their help, this handbook would not have been possible.
`
`Ronald K. Jurgen
`
`17
`
`17
`
`

`
`CHAPTER 2
`
`
`PRESSURE SENSORS “
`
`Randy Frank
`Technical Marketing Manager
`Motorola Semiconductor Products
`
`2.1 AUTOMOTIVE PRESSURE MEASUREMENTS
`
`Various pressure measurements are required in both the development and usage of vehicles
`to optimize performance, determine safe operation, assure conformance to government regu-
`lations, and advise the driver. These sensors monitor vehicle functions, provide information to
`control systems, and measure parameters for indication to the driver. The sensors can also
`provide data log information for diagnostic purposes.
`Depending on the parameter being measured, different units for indicating pressure will
`be used. Since pressure is force per unit area, basic units are pounds per square inch (psi) or
`kilograms per square centimeter. For example, tire pressure is usually indicated in psi. Mani-
`fold pressure is typically specified in kiloPascals (kPa). A Pascal, which is the international
`unit (SI or Systems Internationale) for pressure, is equal to 1 Newton per meter2 or 1 kg - in"
`- s”2. Other common units of pressure measurement include: inches, feet, or centimeters of
`water; millibars or bars, inches, or millimeters of mercury (Hg), and torr. The conversion con-
`stants as defined per international convention are indicated inTable 2.1.
`Pressure can be measured by a number of devices that provide a predictable variation when
`pressure is applied. Sensors used on vehicles range from mechanical devicesmwith position
`movement when pressure is applied—to a rubber or elastomer diaphragm, to semiconductor-
`based silicon pressure sensors. Various pressure—sensing techniques are explained in Sec. 2.3.
`The type of pressure measurement that is made can be divided into five basic areas which
`are independent of the technology used for the measurement: gage, absolute, differential, liq-
`uid level, and pressure switch.
`
`2.1.1 Gage Pressure Measurements
`
`The silicon pressure sensor technology explained in Sec. 2.3.5 is used to visualize the differ-
`ence between gage, absolute, and differential pressure (refer to Fig. 2.1). For gage pressure
`measurements, the pressure is applied to the top of a (silicon) diaphragm (Fig. 2.1), creating a
`positive output. The opposite (back) side of the diaphragm is exposed to atmospheric pres-
`sure. Gage vacuum is a special case of gage pressure. For gage vacuum measurements, vacuum
`is applied to the back side of the diaphragm resulting in a positive output signal. Gage and
`gage vacuum are single—sided pressure measurements. Gage pressure is frequently indicated
`by psig.
`
`18
`
`18
`
`

`
`2.4
`
`‘sfifxfsfiizs AND ACTUATORS
`
`TABLE 2.1 Pressure Unit Conversion Constants
`
`(Most commonly used per international conventions)
`psi*
`In H2Ol
`In Hg*
`K Pascal Millibar
`cm H205
`mm Hg‘
`1.000
`27.680
`2.036
`6.8947
`68.947
`70.308
`51.715
`3.6127 x 10”
`1.000
`7.3554 x 10‘2
`0.2491
`2.491
`2.5400
`1.8683
`0.4912
`13.596
`1.000
`3.3864
`33.864
`34.532
`25.400
`0.14504
`4.0147
`0.2953
`1.000
`10.000
`10.1973
`7.5006
`0/01450
`0.40147
`0.02953
`0.100
`1.000
`1.01973
`0.75006
`1.4223 x 10”
`0.3937
`2.8958 x 10'”
`0.09806
`0.9806
`1.000
`0.7355
`1.9337 x 10'2
`0.53525
`3.9370 x 104
`0.13332
`1.3332
`1.3595
`1.000
`
`psi*
`In H2Ol
`In Hg*
`K Pascal
`Millibar
`cm H2O§
`mm Hg‘
`
`
`
`
`
`p
`
`* PSI = pounds per square inch
`" At 39 °F
`* At 32 °F
`9 At 4 °C
`1 At 0 °C
`
`2.1.2 Absolute Pressure Measurements
`
`An absolute pressure measurement is made with respect to a fixed (usually a vacuum) refer~
`ence sealed within the sensor (Fig. 2.1). For a 100—kPa—rated absolute unit, the diaphragm is
`fully deflected with standard atmospheric pressure. Application of a Vacuum restores the
`diaphragm to its undeflected (flat) position.The result is a high-level output with no vacuum
`applied and a low—level signal at full vacuum unless the zero is established at the full-scale
`deflection of the diaphragm. Pressure can also be applied to absolute units with appropriately
`designed diaphragms to withstand the additional applied stress. Absolute pressure is fre-
`quently indicated by psia.
`-
`
`2.1.3 Differential Pressure Measurements
`
`Differential or Delta-P measurements are also shown in Fig. 2.1. The higher pressure is
`applied to the top of the diaphragm and the lower pressure, possibly a reference pressure, is
`applied to the opposite side. The diaphragm’s deflection is a result of the pressure difference.
`
`Gage ]
`
`Absolute
`
`
`
`Differential l
`
`FIGURE 2.1 Types of pressure measurements: (a) gage,
`(b) absolute, and (C) differential.
`
`19
`
`19
`
`

`
`Typically, the pressure differential is only a small percentage of the total line pressure and a
`system fault can expose one side of the sensor to the full line pressure. This must be taken into
`account when choosing the sensor and determining the rated pressure range" that will be
`required. Differential pressure is frequently indicated by psid.
`
`PRESSURE SENSORS
`
`2.5
`
`2.1.4 Liquid Level Measurements
`
`The height of a column of liquid can be measured by a pressure sensor. The term head is fre-
`quently used in hydraulics to denote pressure. Measurements of inches or feet of water and
`centimeters of mercury are direct indications of the effect of pressure on liquid level. Other
`liquid levels are dependent on their specific weight and can be calculated by h = (PL — PH)/w,
`where (PL — PL) is the pressure differential caused by the height of the fluid column and w is
`the specific weight of the liquid. The vapor pressure in a sealed enclosure will have an effect
`on the measurement of liquid height. Returning the reference side of a differential pressure
`sensor to the top of the enclosure will compensate for vapor pressure.
`
`2.1.5 Pressure Switch
`
`A pressure switch is typically achieved by mounting an electric contact on a diaphragm (rub-
`ber or any elastic material).The application of sufficient pressure (or vacuum) on one side of
`the diaphragm causes the movable contact to meet a stationary contact and close the circuit.
`A pressure switch can also be achieved by any of the previously described techniques
`merely by establishing a reference threshold voltage that is calibrated to indicate the point
`that the pressure changes from an acceptable to unacceptable (or low to high) level. Once the
`threshold voltage is achieved, additional electronic circuits can be used to produce an elec-
`tronic switch that can control loads such as an indicator lamp.
`
`2.2 AUTOMOTIVE APPLICATIONS FOR PRESSURE SENSORS
`
`Automotive requirements for pressure measurements range from the basic——oil pressure—to
`the sophisticated—air pressure differential from one side of the vehicle to the other. This sec-
`tion elaborates on the various possibilities for pressure measurements that exist either in the
`‘* development, laboratory, or pilot phases of the vehicle, to actual volume production. Table 2.2
`lists a number of potential pressure measurements versus vehicle systems and provides an
`indication of the pressure range and type of measurement.
`'
`Automotive specification and testing guidelines have been developed and published by the
`Society of Automotive Engineers (SAE) specifically for manifold absolute pressure (MAP)
`sensors. These documents are intended to assist in establishing test methods and specifications
`for other sensors. Other SAE documents that may apply to sensors are summarized in Table 2.3.
`The packaging and testing requirements for automotive sensors can represent 50 to 80 per-
`cent of the sensor cost and over 90 percent of the warranty and in-service problems. The pres-
`sure-sensing applications that are presented in the following sections will include packaging
`requirements that are of particular concern.
`
`2.2.1
`
`Existing Applications for Pressure Sensors
`
`A late twentieth century production vehicle is likely to have a number of pressure sensors for
`measurements such as manifold pressure and engine oil pressure, and has the potential for
`
`20
`
`20
`
`

`
`2.6
`
`SENSORS AND ACTUATORS
`
`TABLE 2.2 Pressure Sensing Requirements for Various Vehicle Systems
`
`
`System
`Engine control
`
`Elect transmission
`(continuously variable
`transmission)
`Idle speed control
`
`Elect power steering
`(also elect assisted)
`Antiskid brakesl
`traction control
`Air bags
`Suspension
`Security/keyless entry
`HVAC (climate control)
`Driver information
`
`Memory seat
`Multiplex/diagnostics
`
`Parameter
`Manifold absolute pressure
`Turbo boost pressure
`Barometric pressure (altitude)
`EGR pressure
`Fuel pressure
`Fuel vapor pressure
`Mass air flow
`Combustion pressure
`Exhaust gas pressure
`Secondary air pressure
`Transmission oil pressure
`Vacuum modulation
`
`AC clutch sensor/switch
`Power steering pressure
`Hydraulic pressure
`
`Brake pressure
`Fluid level
`Bag pressure
`' Pneumatic spring pressure
`Passenger compartment pressure
`Air flow (PC) Compressor pressure
`Oil pressure
`Fuel level
`Oil level
`Coolant pressure
`Coolant level
`Windshield washer level
`Transmission oil level
`Tire pressure
`Battery fluid level
`Lumbar pressure
`Multiple usage of sensors
`
`* Gage measurement but absolute sensors used for failsafe
`
`Pressure range
`100 kPa
`200 kPa
`100 kPa
`7.5 psi
`15 pSl———450 kPa
`15 in H20
`
`100 Bar, 16.7 Mpa
`100 kPa
`100 kPa
`80 psi
`100 kPa
`
`300-500 psi
`500 psi
`500 psi
`
`500 psi
`12 in H20
`7.5 psi
`1 MPa
`100 kPa
`300—500 psi
`80 psi
`15 in H20
`15 in H20
`200 kPa
`24 in H20
`12 in H20
`12 in H20
`50 psi
`1-2 in below
`7.5 psi
`
`Type
`Absolute
`Absolute
`Absolute
`Gage
`Gage
`Gage
`Differential
`Differential
`Gage
`Gage
`Gage
`Absolute
`
`Absolute*
`Absolute*
`Absolute*
`
`Absolute*
`Gage
`Gage
`Absolute*
`Absolute
`Absolute*
`Gage
`Gage
`Gage
`Gage
`Gage
`Gage
`Gage
`Gage/absolute
`Optical
`Gage
`
`TABLE 2.3 SAE Specifications That Effect Pressure Sensors
`
`
`SAE J1211
`
`Recommended environmental practices for electronic equipment design
`Performance levels and methods of measurement of electromagnetic radiation from
`vehicles and devices
`Performance levels and methods of measurement of EMR from vehicles and devices
`SAEJ1816
`(narrowband RF)
`SAE J1113
`Electromagnetic susceptibility procedures for vehicle components (except aircraft)
`SAE J1407
`Vehicle electromagnetic radiated susceptibility testing using a large TEM cell
`SAE J1338
`Open-field whole—vehicle radiated susceptibility 10 kHz—~18 GHZ, electric field
`SAE J1850
`Class B data communication network interface
`SAE J1930
`Diagnostic acronyms, terms, and definitions for electrical/electronic components
`SAE J1812
`Failure mode severity classification
`SAE J1346
`Guide to manifold absolute pressure transducer representative test method
`
`Guide to manifold absolute pressure transducer representative specification SAE J1347
`
`SAEJ551
`
`
`
`21
`
`21
`
`

`
`PRESSURE SENSORS
`
`2.7
`
`several other pressure measurements. Tighter emissions control and improved efficiency may
`necessitate further sensor use in future systems.
`
`Manifold, Barometric and Turbo Boost Pressure. Manifold absolute pressure (MAP) is
`used as an input to fuel and ignition control in internal combustion engine control systems.
`The speed-density system that uses the MAP sensor has been preferred over mass air flow
`(MAF) control because it’s less expensive, but stricter emission standards are causing more
`manufacturers to use mass air flow for future models.
`
`Higher resolution from 32-bit engine controllers, with greater analog-to-digital (A/D) con-
`version capability and higher operating frequencies, will provide greater accuracy for a given
`MAP sensor during the critical transitions of the engine cycle. As shown in Fig. 2.2, previous
`changes from 8-bit to 16-bit controllers have resulted in a two-time improvement in resolu-
`tion in the digital conversion for the intake manifold pressure. The 8-bit control unit per-
`formed the A/D conversion on a 4-ms timer interrupt in order to maintain a balance with
`other controls, with the resulting 1.1-ms lag time (worst case) during periods of overlapping
`interrupts. The 16-bit microcontroller performs the A/D conversion every 2 ms, which reduces
`the lag time to 0.3 ms. The actual system improvements that can result from using the higher
`performing microcontrol units is a result of other factors such as more precise and faster con-
`trol of fuel injectors and sparkplugs, and additional and/or more accurate sensors and control
`algorithms.
`
`Analog Signal
`
`Analog Signal
`
`
`
`Using Sbit CPU
`
`Using New 16bit CPU
`
`FIGURE 2.2 Effect of