2735 | FM Page i Tuesday, March 10, 1998 10:49 AM Understanding Automotive Electronics 2735 | FM Page ii Tuesday, March 10, 1998 10:49 AM 2735 | FM Page iii Tuesday, March 10, 1998 10:49 AM Understanding Automotive Electronics Fifth Edition By: William B. With Contributions to Previous Editions by: Norman P. Mansour Gerald Luecke Charles W. Mansir Newnes Boston, Oxford, Johannesburg, Melbourne, New Delhi, Singapore 2735 | FM Page iv Tuesday, March 10, 1998 10:49 AM Newnes is an imprint of Butterworth–Heinemann.
Copyright © 1998 by Butterworth–Heinemann A member of the Reed Elsevier group All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Recognizing the importance of preserving what has been written, Butterworth– Heinemann prints its books on acid-free paper whenever possible. Butterworth–Heinemann supports the efforts of American Forests and the Global ReLeaf program in its campaign for the betterment of trees, forests, and our environment.
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69 Chapter 3 Electronics Fundamentals. 96 Chapter 4 Microcomputer Instrumentation and Control. 144 Chapter 5 The Basics of Electronic Engine Control. 183 Chapter 6 Sensors and Actuators.
221 Chapter 7 Digital Engine Control System. 258 Chapter 8 Vehicle Motion Control. 294 Chapter 9 Automotive Instrumentation. 365 Chapter 11 Future Automotive Electronic Systems.
415 Answers to Quizzes. 433 UNDERSTANDING AUTOMOTIVE ELECTRONICS vii 2735 | FM Page viii Tuesday, March 10, 1998 10:49 AM 2735 | FM Page ix Tuesday, March 10, 1998 10:49 AM Preface Since the introduction of electronics for emission control on engines, the evolution of electronics in automobiles has advanced rapidly. The pace of development has inspired four revisions of this book in roughly ten years to avoid obsolescence. Rarely in history have technical developments moved at such a pace.
Electronics have recently been incorporated on new automotive subsystems and have become standard implementation on many others. Such features as antilock braking systems and airbags could only be achieved practically through the use of electronics. These features are rapidly becoming standard features owing to strong pressures in the highly competitive North American automotive market. The first edition of this book was devoted primarily to electronic engine control because this was the chief application at that time.
A number of automotive systems which were discussed in the chapter on the future of automotive electronics in the second, third, and fourth editions are now in production. These systems are presented in the appropriate chapters of this fifth edition. This latest edition covers most of the automotive subsystems incorporating electronics except for entertainment systems. These systems have been omitted partly due to space limitations and because automotive entertainment systems are closely related to home entertainment systems, which are discussed in many excellent publications.
In its revised form, this book explains automotive electronics as of the late 1990s. It should prepare the reader for an understanding of present as well as future developments in this field into at least the early part of the next century. Ribbens November 1997 UNDERSTANDING AUTOMOTIVE ELECTRONICS ix 2735 | FM Page x Tuesday, March 10, 1998 10:49 AM 2735 | FM Page xi Tuesday, March 10, 1998 10:49 AM Understanding Automotive Electronics 2735 | FM Page xii Tuesday, March 10, 1998 10:49 AM 2735 | CH 1 Page 1 Tuesday, March 10, 1998 10:52 AM AUTOMOTIVE FUNDAMENTALS 1 Automotive Fundamentals Picture yourself in the not-too-distant future driving your new car along a rural interstate highway on a business trip. The cruise control is maintaining the speed at a steady 100 km/hr (62 mph) and there is relatively little traffic.
As you approach a slower car, the speed-control system slows your car to match the speed of the slower car and maintain a safe distance of about 53 m (165 ft) behind the slowe/r car. When oncoming traffic clears, you enter the passing lane and your car automatically increases speed as you pass the slower car. You press a button on the steering column and an image of a road map appears faintly visible (so as not to obscure the road ahead) on the windshield in front of you. This map shows your present position and the position of the destination city.
The distance to your destination and the approximate arrival time are displayed on the digital instrument cluster. You are talking on your cellular phone to your office about some changes in a contract that you hope to negotiate. After the instructions for the contract changes are completed, a printer in your car generates a copy of the latest contract version. The onboard entertainment system is playing music for you at a comfortable level relative to the low-level wind and road noise in the car.
After completing your phone conversation, you press another button on the steering wheel and the music is replaced by a recorded lesson in French verb conjugation, which you have been studying. Suddenly, the French lesson is interrupted by a message delivered in natural-sounding synthesized speech. “You have fuel remaining for another 50 miles at the present speed. Your destination is 23 miles away.
Recommend refueling after exiting the highway. There is a station that accepts your electronic credit near the exit (you know, of course, that the electronic credit is activated by inserting the fuel nozzle into the car). Also, the left rear tire pressure is low and the engine control system reports that the mass air flow sensor is intermittently malfunctioning and should be serviced soon.’’ After this message has been delivered, the French lesson returns. A short time later, the French lesson is again interrupted by the electronic voice message system: “Replace the disk in the Navigation CD player with disk number 37 for detailed map and instructions to your destination, please.’’ Then the French lesson returns.
You insert the correct disk in the Navigation CD player as requested and the map display on the windshield changes. The new display shows a detailed map of your present position and the route to your destination. As UNDERSTANDING AUTOMOTIVE ELECTRONICS 1 2735 | CH 1 Page 2 Tuesday, March 10, 1998 10:52 AM 1 AUTOMOTIVE FUNDAMENTALS you approach the city limits, the car speed is automatically reduced to the legal limit of 55 mph. The voice message system speaks again: “Leave the highway at exit 203, which is one-half mile away.
Proceed along Austin Road to the second intersection, which is Meyer Road. Turn right and proceed 0. Your destination is on the right-hand side of the road. Don’t forget to refuel.’’ This scenario is not as farfetched as it sounds.
All of the events described are technically possible. Some have even been tested experimentally. The electronic technology required to develop a car with the features described exists today. The actual implementation of such electronic features will depend on the cost of the equipment and the market acceptance of the features.
USE OF ELECTRONICS IN THE AUTOMOBILE Microelectronics will Electronics have been relatively slow in coming to the automobile provide many exciting primarily because of the relationship between the added cost and the benefits. new features for auto- Historically, the first electronics (other than radio) were introduced into the mobiles. commercial automobile during the late 1950s and early 1960s. However, these features were not well received by customers, so they were discontinued from production automobiles.
Environmental regula- Two major events occurred during the 1970s that started the trend tions and an increased toward the use of modern electronics in the automobile: (1) the introduction of need for economy have government regulations for exhaust emissions and fuel economy, which resulted in electronics required better control of the engine than was possible with the methods being being used within a used; and (2) the development of relatively low cost per function solid-state number of automotive digital electronics that could be used for engine control. Electronics are being used now in the automobile and probably will be used even more in the future. Some of the present and potential applications for electronics are 1. Electronic engine control for minimizing exhaust emissions and maximiz- ing fuel economy 2.
Instrumentation for measuring vehicle performance parameters and for diagnosis of on-board system malfunctions 3. Vehicle motion control 5. Safety and convenience 6. Entertainment/communication/navigation Many of these applications of electronics will be discussed in this book.
CHAPTER OVERVIEW This chapter will give the reader a general overview of the automobile with emphasis on the basic operation of the engine, thus providing the reader with the background to see how electronic controls have been and will be 2 UNDERSTANDING AUTOMOTIVE ELECTRONICS 2735 | CH 1 Page 3 Tuesday, March 10, 1998 10:52 AM AUTOMOTIVE FUNDAMENTALS 1 applied. The discussion is simplified to provide the reader with just enough information to understand automotive mechanics. Readers who want to know the mechanics of an automobile in more detail are referred to the many books written for that purpose. THE AUTOMOBILE PHYSICAL CONFIGURATION The earliest automobiles consisted of carriages (similar to those drawn by horses) to which a primitive engine and drivetrain and steering controls were added.
Typically, such cars had a strong steel frame that supported the body of the car. The wheels were attached to this frame by a set of springs and shock absorbers that permitted the car to travel over the uneven road surfaces of the day while isolating the car body from much of the road irregularities. This same general configuration persisted in most passenger cars until some time after World War II, although there was an evolution in car size, shape, and features as technology permitted. This early configuration is depicted in Figure 1.1, in which many of the important automotive systems are illustrated.
These systems include the following: 1. Entertainment/communication/navigation In Figure 1.1 the frame or chassis on which the body is mounted is supported by the suspension system. The wheels’ brakes are connected to the opposite end of the suspension components. The steering and other major mechanical systems are mounted on one of these components and attached as necessary through mechanical components to other subsystems.
This basic vehicle configuration was used from the earliest cars through the late 1960s or 1970s, with some notable exceptions. The increasing importance of fuel efficiency and government-mandated safety regulations led to major changes in vehicle design. The body and frame evolved into an integrated structure to which the power train, suspension, wheels, etc. Once again with a few notable exceptions, most cars had an engine in front configuration with the drive axle at the rear.
While it is an advantage for several reasons (e., crash protection, efficient engine cooling) to have the engine in front, this location has a disadvantage from a traction standpoint. Because the engine is a UNDERSTANDING AUTOMOTIVE ELECTRONICS 3 2735 | CH 1 Page 4 Tuesday, March 10, 1998 10:52 AM 1 AUTOMOTIVE FUNDAMENTALS Figure 1. Systems of the Automobile FPO relatively heavy component, its location influences weight distribution (fore and aft). Ideally, the engine should be located near the drive wheels for optimal drive traction.
It is this fact that has led car makers to configure the front wheels as drive wheels. This change has led to the engine being mounted transversely (i.