1、Analysis Techniques for Racecar Data Acquisition Second Edition Jorge Segers About the Author Jorge Segers has been involved with racing disciplines such as GT and sportscar racing, single seaters, and tour ing cars since 1998. He apprenticed at GLPK Carsport and became team manager three years late
2、r. R-408 After finishing studies in automotive engineering, he worked at BPR Competition Engineering as track engineer and later as development manager at Eurotech Racing. He has worked for other teams such as Henrik Roos Motorsports (FIA GT ), Racing for Holland ( Le Mans 24 Hours), DKR Engineering
3、 , Carsport Modena, and W-Racing Team. In 2010 he founded JS Engineering BVBA, which provides engineering services to the motor racing industry and supplies data acquisition hardware to a multitude of organizations. In 2013 he began working for the German team Phoenix Racing where he is an engineer
4、in the DTM championship with Audi. Jorge Segers Whether measuring the performance of a Formula One racecar or that of a road-legal street car on the local drag strip, the dynamics of vehicles and thei r drivers remain the same. Identical analysis techniques apply. This book contains a collection of
5、techniques for analyzing data recorded by any vehicles data acquisition system. It deta ils how to measure the performance of the vehicle and driver, what can be learned from it, and how this information can be used to advantage the next time the vehicle hits the track. In addition to updates throug
6、hout, this new edition contains three new chapters. Chapter eight covers the techniques that are available to analyze tire performance. Chapter 17 gives an introduction to metric-driven analysis, a technique that is used throughout the book . Chapter 18 was added to explain what kind of information
7、the data contains about the track being driven on. Since the best-selling first edition was published in 2008, data recording technology has developed making it possible to obta in more advanced and accurate data regarding the performance of race cars at less cost. Analysis Techniques for Racecar Da
8、ta Acquisition Second Edition INTERNATIONAL.Analysis Techniques for Racecar Data Acquisition R-408_book.indb 1 12/30/13 7:53 AMOther SAE books of interest: Hands-On Race Car Engineer By John H. Glimmerveen (Product Code: R-323) Kinetic Energy Recovery Systems for Racing Cars Edited by Alberto Borett
9、i (Product Code: PT-159) Engine Failure AnalysisInternal Combustion Engine Failures and Their Causes By Stefan Zima and Ernst Greuter (Product Code: R-320) For more information or to order a book, contact SAE International at 400 Commonwealth Drive, Warrendale, PA 15096-0001, USA; phone 877-606-7323
10、 (U.S. and Canada only) or 724-776-4970 (outside U.S. and Canada); fax 724-776-0790; email CustomerServicesae.org; website http:/ /books.sae.org. R-408_book.indb 2 12/30/13 7:53 AMAnalysis Techniques for Racecar Data Acquisition, Second Edition By Jrge Segers Warrendale, Pennsylvania, USA R-408_book
11、.indb 3 12/30/13 7:53 AM Copyright 2014 SAE International eISBN: 978-0-7680-8081-0400 Commonwealth Drive Warrendale, PA 15096-0001 USA E-mail: CustomerServicesae.org Phone: 877-606-7323 (inside USA and Canada) 724-776-4970 (outside USA) Fax: 724-776-0790 Copyright 2014 SAE International. All rights
12、reserved. No part of this publication may be reproduced, stored in a retrieval system, distributed, or transmitted, in any form or by any means without the prior written permission of SAE International. For permission and licensing requests, contact SAE Permissions, 400 Commonwealth Drive, Warrendal
13、e, PA 15096-0001 USA; email: copyrightsae.org; phone: 724-772-4028; fax: 724-772-9765. ISBN 978-0-7680-6459-9 SAE Order Number R-408 DOI 10.4271/R-408 Segers, Jrge. Analysis techniques for racecar data acquisition / by Jrge Segers. Second Edition. pages cm Includes bibliographical references and ind
14、ex. ISBN 978-0-7680-6459-9 1. Automobiles, RacingDynamicsData processing. 2. Automobiles, RacingPerformanceMeasurement. 3. Automobiles, Racing Testing. I. Title. TL243.S43 2014 629.282dc23 2013037907 Information contained in this work has been obtained by SAE International from sources believed to b
15、e reliable. However, neither SAE International nor its authors guarantee the accuracy or completeness of any information published herein and neither SAE International nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is publ
16、ished with the understanding that SAE International and its authors are supplying information, but are not attempting to render engineering or other professional services. If such services are required, the assistance of an appropriate professional should be sought. To purchase bulk quantities, plea
17、se contact: SAE Customer Service E-mail: CustomerServicesae.org Phone: 877-606-7323 (inside USA and Canada) 724-776-4970 (outside USA) Fax: 724-776-0790 Visit the SAE International Bookstore at books.sae.org R-408_book.indb 4 12/30/13 7:53 AMDedicated to Daan and Savitri R-408_book.indb 5 12/30/13 7
18、:53 AMR-408_book.indb 6 12/30/13 7:53 AMvii Contents Preface to the Second Edition xiii Preface to the First Edition. xv Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii Chapter 1 Introduction . 1 1.1 What Is This Book All About? .1 1.2 What Is Data
19、Acquisition? 5 1.3 Hardware .11 1.4 Recent Hardware Trends 12 Chapter 2 Data Analysis Software Requirements.17 2.1 General Requirements for Data Acquisition Software 17 2.2 Different Ways of Displaying Data 18 2.3 Keeping Notes with Data Files .26 2.4 Mathematical Channels .28 2.5 Data Overlays .29
20、2.6 Filtering .30 2.7 Exporting Data to Other Software Packages 31 2.8 Getting Organized 32 Chapter 3 The Basics .39 3.1 Check the Cars Vital Signs 39 3.2 Lap Markers and Segment Times .45 3.3 Comparing Laps .48 3.4 Track Mapping .58 3.5 The Beginners Data Logging Kit .62 3.6 A Possible Approach to
21、the Testing of Sensor Readings 72 Chapter 4 Straight-Line Acceleration .77 4.1 Torque and Horsepower .77 4.2 Traction and Longitudinal Slip .83 4.3 TCS and Slip Ratios .88 4.4 Time versus Distance .92 4.5 The Importance of Corner Exiting Speed 93 4.6 Drag Racing Specifics .95 R-408_book.indb 7 12/30
22、/13 7:53 AMviii Contents Chapter 5 Braking .101 5.1 Braking Quickness .101 5.2 Braking Effort .102 5.3 Braking Points 104 5.4 Lock-up 106 5.5 Brake Balance .107 5.6 Pedal Travel 114 5.7 ABS .114 5.8 Brake Temperature Measurement 116 Chapter 6 Gearing.123 6.1 Up-shifting .123 6.2 Down-shifting 131 6.
23、3 The Gear Chart 133 6.4 Total Gear Ratio Channel .134 6.5 Determining Correct Gear Ratios 136 6.6 Determining in Which Gear to Take a Corner 136 Chapter 7 Cornering .139 7.1 The Cornering Sequence .139 7.2 The Traction Circle 142 7.3 Effects of Speed .148 7.4 Driver Activities That Indicate Vehicle
24、 Balance 152 7.5 The Understeer Angle 156 7.6 Vehicle Balance with a Yaw Rate Sensor 163 7.7 Front and Rear Lateral Acceleration 166 Chapter 8 Understanding Tire Performance 169 8.1 Estimating Grip Levels .169 8.2 Working with Tire Pressure Monitoring Systems .175 8.3 Working with Infrared Tire Temp
25、erature Sensors 180 8.4 Where Does Tire Temperature Come From? .182 8.5 Working Temperature Range of the Tires .184 8.6 Lateral Load Transfer and Tire Temperature .188 8.7 Tire Workload Distribution .193 8.8 Camber Evaluation with Tire Temperature Sensors. . . . . . . . . . . . . . . . . . . . . . .
26、 . . 194 8.9 Tire Pressure Evaluation with Tire Temperature Sensors 196 Chapter 9 Quantifying Roll Stiffness Distribution199 9.1 Measuring Suspension Roll Angle .199 9.2 The Roll Gradient .201 R-408_book.indb 8 12/30/13 7:53 AMix Contents 9.3 Using Roll Gradients as a Setup Tool .208 9.4 Front to Re
27、ar Roll Angle Ratio .212 9.5 Using the Roll Ratio as a Setup Tool 215 9.6 Suspension Troubleshooting 218 9.7 Pitch Gradient 219 Chapter 10 Wheel Loads and Weight Transfer 221 10.1 Lateral Weight Transfer 221 10.2 Longitudinal Weight Transfer .230 10.3 Banking and Grade Effects 231 10.4 Total Wheel L
28、oads .234 10.5 Determining Wheel Loads with Modal Analysis .240 10.6 Measuring Wheel Loads with Suspension Load Cells 250 10.7 Tire Spring Rates 253 10.8 Chassis Torsion .255 Chapter 11 Shock Absorbers .257 11.1 Shock Absorber V elocity Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . .
29、 . . . . . . . . . . . . 257 11.2 Determining in Which Range to Tune the Shock Absorbers 260 11.3 Shock Speed Ranges .265 11.4 The Shock Speed Histogram 266 11.5 The Shock Speed Box Plot 279 11.6 Shock Speed Run Charts .282 Chapter 12 Suspension Analysis in the Frequency Domain .287 12.1 Introducing
30、 Frequency Analysis .287 12.2 Frequency Analysis versus Time-Space Analysis .292 12.3 Theoretical Analysis .295 12.4 Suspension Optimization Using Frequency Analysis .303 12.5 Modal Analysis .304 12.6 Modal Frequency Issues 309 12.7 Nonlinear Considerations 315 12.8 Frequency Analysis from Sensor Da
31、ta 316 Chapter 13 Aerodynamics 321 13.1 Aerodynamic Measurements 321 13.2 Air Density .323 13.3 Dynamic Pressure .326 13.4 Ride Height Measurement 328 13.5 Estimating Drag and Downforce from Logged Data 331 13.6 The Coast-down Test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32、 . . . . . . . . . . . . . . . . 334 R-408_book.indb 9 12/30/13 7:53 AMx Contents 13.7 The Constant Velocity Test 339 13.8 A Worked out Example of a Straight-Line Test .343 13.9 Airbox Efficiency 350 Chapter 14 Analyzing the Driver 353 14.1 Improving Driver Performance 353 14.2 Driving Style Evaluat
33、ion .356 14.3 Throttle Application .357 14.4 Braking 368 14.5 Shifting Gears .380 14.6 Steering 380 14.7 The Driving Line 383 14.8 Driver Consistency over Multiple Laps .394 Chapter 15 Simulation Tools 395 15.1 Introduction 395 15.2 Suspension Kinematics Simulation. . . . . . . . . . . . . . . . . .
34、 . . . . . . . . . . . . . . . . . . . . . 397 15.3 Lap Time Simulation .400 15.4 A Worked out Example .418 15.5 How to Integrate Lap Time Simulation in Daily Data Acquisition Tasks 421 15.6 Putting the Driver in the Simulation .423 Chapter 16 Using the Data Acquisition System for Race Strategy .431
35、 16.1 Fuel Consumption .431 16.2 Lap Time Variation During a Race .437 Chapter 17 Data Analysis Using Metrics 443 17.1 What Are Metrics? .443 17.2 Why Use Metrics? .444 17.3 How to Create Metrics .446 Chapter 18 Track Data .453 18.1 What Can Be Learned from the Data about the Racetrack? 453 18.2 Rac
36、etrack Metrics .455 18.3 Speed and Gear Histograms 456 18.4 The Friction Circle .457 18.5 How Bumpy Is the Track Surface? .459 R-408_book.indb 10 12/30/13 7:53 AMxi Contents Chapter 19 Introduction to Measurement 461 19.1 Introduction 461 19.2 Analog-Digital Conversion: Accuracy Implications 462 19.
37、3 Sensor Selection and Application 464 19.4 Measurement Uncertainty 467 19.5 Temperature Sensors .472 19.6 Pressure Sensors 478 19.7 Displacement Sensors 481 19.8 Acceleration Sensors .482 19.9 Speed Sensors .484 19.10 Strain Gages 485 19.11 Torque Sensors 487 19.12 The Pitot Tube 488 19.13 Oxygen S
38、ensors .489 19.14 GPS .490 19.15 Laser Distance Sensors .492 19.16 Surface Acoustic Wave Technology 494 List of Symbols 495 English Letters .495 Greek Symbols .501 References 503 Bibliography 505 Index .507 About the Author 515 R-408_book.indb 11 12/30/13 7:53 AMR-408_book.indb 12 12/30/13 7:53 AMxi
39、ii Preface to the Second Edition When the first edition of this book was first published in 2008, my goal was to create a book presenting up-to-date techniques to analyze data collected from onboard data logging systems in race cars. Since the first edition, I have received a great deal of feedback
40、from people all over the world indicating that I was successful in obtaining this goal. I am extremely happy that this book has been able to fill a void in this ever- developing area. However, since 2008 my personal understanding of this subject has evolved. First of all, the technology has develope
41、d, making it possible to obtain more advanced and accurate data regarding the performance of race cars at less cost. There are a number of observa- tions that have led me to write this second edition. Some race series have actively restricted data logging to decrease the teams running budgets. In th
42、ese cases, it is extremely important that a maximum of information be extracted and interpreted from the hardware that is at hand. Although I do not agree with the philosophy of limiting data acquisition by sporting regulations, it does level the field, as everybody will have access to the same info
43、rmation. This means that a team that uses the data more efficiently will have an edge over the competition. The opposite is also true. The ever-decreasing cost of electronics makes advanced sensors and logging capabilities more accessible for everybody. With this comes the risk of infor- mation over
44、load. There will be a point where a team will no longer be able to process all the available data. Therefore, techniques need to be provided that will help in drawing the right conclusions quickly from very large data sets. I wanted to include newly gained knowledge since the first publication. Expe
45、rience is a continuous process, and I felt that the time had come to upgrade the book. There were some items in the first edition that needed to be addressed, explained better, or with more examples. The book contains three new chapters. The first (chapter 8) covers the techniques that are available
46、 to analyze tire performance. The second (chapter 17) gives an introduction to metric-driven analysis, a technique that is used throughout the book. Finally, a chapter was added to explain what kind of information the data contains about the track being driven on (chapter 18). R-408_book.indb 13 12/
47、30/13 7:53 AMR-408_book.indb 14 12/30/13 7:53 AMxv Preface to the First Edition A proven way for athletes to be successful in any sporting discipline is for them to record their performance, analyze what has happened, and draw conclusions from the factors that influence that performance. Marathon ru
48、nners log their running speed and distance along with their heart rate to optimize their training schedules. Football players record their games on video to evaluate techniques, performance, and tactics. Chess players write down every move in a game to replay and analyze it afterward. They measure s
49、omething, learn from it, and try to use it to their advantage the next time. In motor racing, sophisticated recording devices are used in conjunction with numerous sensors to record what the car and its driver are doing. Engineers often are employed full-time to maintain the system, analyze the recorded data, and draw the correct conclu- sions from it. Motor racing is known for high-end technology, and this technology changes every day. Ten years ago, race car data acquisition was somewhat limited to well-funded teams in high-profile championships. Nowadays, the cost o
