1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2016 SAE InternationalAll rights reserved. No part of this publi
3、cation 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 SAE.TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada)Tel: +1 724-776-4970 (out
4、side USA)Fax: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/J2517_201608SURFACE VEHICLERECOMMENDED PRACTICEJ2517 AUG2016Issued 2000-06Revised 2010-09Reaf
5、firmed 2016-08Superseding J2517 SEP2010Hybrid III Family Chest Potentiometer Calibration ProcedureRATIONALEJ2517 has been reaffirmed to comply with the SAE five-year review policy.TABLE OF CONTENTS1. SCOPE AND PURPOSE 22. REFERENCES 22.1 Applicable Documents 22.1.1 SAE Publications. 22.2 Related Pub
6、lication . 32.2.1 Federal Publication . 33. CALIBRATION PROCEDURE 33.1 Chest Potentiometer Assembly. 33.2 Calibration Fixture . 33.3 Calibration Procedure . 53.4 Use of the Calibration Coefficients 64. NOTES 64.1 Marginal Indicia . 6APPENDIX A SAMPLE HIII-5F CHEST POTENTIOMETER CALIBRATION VALUES 7F
7、IGURE 1 CALIBRATION FIXTURE SIDE VIEW 4FIGURE 2 CALIBRATION FIXTURE FRONT VIEW 4TABLE 1 CALIBRATION SETUP DIMENSIONS . 5TABLE 2 CALIBRATION POINTS 5SAE INTERNATIONAL J2517 AUG2016 Page 2 of 71. SCOPE AND PURPOSEThis procedure establishes a recommended practice for establishing the sensitivity of the
8、 chest displacement potentiometer assembly used in the Hybrid III family of Anthropomorphic Test Devices (ATDs, or crash dummies). This potentiometer assembly is used in the Hybrid III family to measure the linear displacement of the sternum relative to the spine (referred toas chest compression). A
9、n inherent nonlinearity exists in this measurement because a rotary potentiometer is being used to measure a generally linear displacement. As the chest cavity is compressed the potentiometer rotates, however the relationship between the compression and the potentiometer rotation (and voltage output
10、) is nonlinear.Crash testing facilities have in the past used a variety of techniques to calibrate the chest potentiometer, that is to establish a sensitivity value (mm/ (volt/volt) or mm/ (mvolt/volt). These sensitivity values are used to convert recorded voltage measurements to engineering units,
11、in this case chest compression in mm. Some of these techniques intended to correct for the nonlinearity and others did not. Of those that did correct for the nonlinearity, there was a variation in techniques used. This variation in calibration procedures was in part identified by the SAE Dummy Testi
12、ng Equipment Committee (DTEC), and led to overall variability in chest compression measurements between laboratories. The intent of this recommended practice is to minimize the variations in chest deflection measurements between crash testing laboratories. Before this procedure was written, a round
13、robin showed variations for the Small Female of 10% among 8 labs for the chest pot sensitivity value. A follow-up round robin of this procedure showed a worst case variation of 2.7% among 10 labs, with a standard deviation of 0.9%. The initial version of SAE J2517 released in May 2000 attempted to f
14、ix this problem by recommending a two-point calibration which was not intended to correct for the nonlinearity (which, for example, is as large as 3% for the Small Female but is small near the peak). It also did not require the measurement of a starting position of the potentiometer before each cras
15、h test, thus it did not correct for the difference in starting chest geometry between a subject dummy and its design intent. It was intended to be a simple and reproducible calibration procedure which crash test facilities could easily adopt with little or no modifications to their facilities. In pr
16、actice, most laboratories did not adopt the procedure since it did not correct for the nonlinearities.Recent attempts to reduce dummy-to-dummy and lab-to-lab variations at lower deflection levels (around 25 mm) have renewed interest in adopting a calibration procedure to correct for the nonlinearity
17、 of the measurement system. This current revision of this procedure uses a multipoint calibration with a third order regression to correct for the nonlinearities of the system with a standardized method. It requires changes in the calibration method of the transducer, the data collection procedures
18、when used in a dummy, and the processing procedures after test data is collected. Following this standardized methodology will minimize linearity errors as well as lab-to-lab variations.2. REFERENCES2.1 Applicable Documents2.1.1 SAE PublicationsAvailable from SAE, 400 Commonwealth Drive, Warrendale,
19、 PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.SAE J211-1 Instrumentation for Impact TestPart 1Electronic InstrumentationSAE J2570 Performance Specifications for Anthropomorphic Test Device TransducersSAE J2706 Hybrid III Six-Year-Old Child Dummy
20、 Users ManualSAE J2856 Users Manual for the 50th Percentile Male Hybrid III Test DummySAE J2857 Hybrid III 3-Year-Old Child Dummy Users ManualSAE Engineering Aid 25 Users Manual for the Small Adult Female Hybrid III Test DummySAE Engineering Aid 26 Users Manual for the Large Male Hybrid III Test Dum
21、mySAE INTERNATIONAL J2517 AUG2016 Page 3 of 72.2 Related Publication2.2.1 Federal PublicationAvailable from the Superintendent of Documents, U.S. Government Printing Office, Mail Stop: SSOP, Washington, DC 20402-9320.Federal Safety Standards, Motor Vehicle Regulation No. 572, Test Dummies Specificat
22、ionsAnthropomorphic Test Dummy for Applicable Test Procedures.3. CALIBRATION PROCEDURE3.1 Chest Potentiometer AssemblyThe chest potentiometer assembly consists of the potentiometer, potentiometer bracket, arm connector and arm. These components will be treated as an assembly during the calibration p
23、rocess. The assembly should be removed from the dummy as described in SAE Documents J2856, J2706, J2857 and Engineering Aids 25 and 26. Next it should be placed in a fixture as described in 3.2, calibrated as described in 3.3, and replaced in the dummy. There should be no mechanical adjustments or d
24、isassembly of the potentiometer assembly once the calibration is completed. Any adjustments to the assembly would require re-calibration.3.2 Calibration FixtureThe potentiometer assembly is placed in a calibration fixture that duplicates the nominal design position of arm, which is referenced as Xo
25、in Figure 1. (This starting position represents the design position of the uncompressed chest.) The fixture should also be capable of stroking the arm relative to the potentiometer a distance of Xc as listed in Table 2. (This represents a position of the sternum when the chest is compressed.) The fi
26、xture does not need to be of a specific design, it simply needs to duplicate the position of the potentiometer at the points referenced in Table 2. As shown in Figure 2, the rotational position of the arm assembly about the longitudinal (foreaft in dummy) axis is not critical. The potentiometer can
27、either be installed in the fixture with the arm parallel to the slider track, or at a slight angle as installed in the dummy. (This angle between the slider track and arm should be less than 10 degrees, however.) SAE INTERNATIONAL J2517 AUG2016 Page 4 of 7FIGURE 1 - CALIBRATION FIXTURE FIGURE 2 - CA
28、LIBRATION FIXTURESIDE VIEW FRONT VIEWNOTE: The dimensions given are to the center of the ball. If a fixture is used that goes to the edge of the ball, the ball radius Rb must be added to Xa to get the starting position.RbXbXANote: Anglebetween armand slider trackless than 10degrees.XcXoXr Note: Draw
29、ing not to scale.Arm shape shownrepresents adult dummyarm.SAE INTERNATIONAL J2517 AUG2016 Page 5 of 7TABLE 1 - CALIBRATION SETUP DIMENSIONSDummy TypeInitial Position, Xo, (mm)Reference Dimension, Xa (mm)Reference Dimension, Xb (mm)Reference Dimension, Xr, (mm)Ball Radius,Rb, (mm)3 year old Hybrid II
30、I 40 50 15 10 3.26 year old Hybrid III 44 54 12 10 3.210 year old Hybrid III 62 72 26 10 3.2Small female Hybrid III 67 81 27 14 4.850th percentile male Hybrid III 70 84 16 14 4.8Large adult male Hybrid III 94 108 37 14 4.8TABLE 2 - CALIBRATION POINTSDummy Type Calibration Points, Xc, (mm)3 year old
31、Hybrid III -6, -3, 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 396 year old Hybrid III -8, -4, 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 4810 year old Hybrid III -8, -4, 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 42, 46, 50Small Female Hybrid III -10, -5, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 5
32、0, 55,6050th percentile male Hybrid III -10, -5, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75Large adult male Hybrid III -10, -5, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 803.3 Calibration ProcedureAt the initial position, Xo, loosen the set screw locking the pot
33、 shaft to the arm coupling and adjust the pot so that the output reading is 0.0 V (2.5 mV/V). Tighten the set screw to lock the pot shaft to the coupling, and recheck the Vo output level.Set the fixture to each of the calibration points, Xc, shown in Table 2 within 0.25 mm. Take a sensor output read
34、ing (S) at each of the Displacements (D) for the Xc calibration points listed in Table 2. Record the actual displacement values (D) in mm and the sensor output readings (S) in mV/V. Complete a third order regression through the calibration data to relate the sensor output readings S (mV/V) to the di
35、splacement values D (mm) according to the following equation:D = A*S3 + B*S2 + C*S + M (Eq. 1)where:D is the actual displacement in mm,S is the sensor output reading in mV/VA, B, C, and M are the calibration coefficientsFrom the regression analyses determine values for A, B, C, and M. These are the
36、calibration coefficients that will be storedfor the sensor and used to convert test data to engineering units. A sample of a calibration dataset is located in Appendix A of this procedure.SAE INTERNATIONAL J2517 AUG2016 Page 6 of 73.4 Use of the Calibration CoefficientsThe potentiometer assembly sho
37、uld be re-installed in the dummy without any mechanical adjustment of the potentiometer. Prior to a crash test, the original zero offset level must be preserved by either not zeroing the potentiometer (by signal conditioning or post-processing) or the amount that was zeroed must be added during post
38、-processing. During the test the absolute voltage output time history should be recorded. This voltage signal is then converted to engineering units by:1. Convert voltage signal to mV/V at the sensor. This is the sensor reading S.2. Convert the sensor reading S to displacement D by using the equatio
39、n:D = A*S3 + B*S2 + C*S + M (Eq. 2)where:D is the displacement relative to the thorax design position in mmS is the sensor output reading in mV/VA, B, C, and M are the calibration coefficientsNOTE: Make sure to use sufficient significant digits on all coefficients to assure accuracy of the conversio
40、n to engineering units. It is recommended to use 5 significant digits (example 0.000012345).3. Subtract the offset in the displacement D at time zero (To) from the displacement time history to get a zeroed deflection Dz. Dz is the deflection of the sternum relative to the spine box during the crash
41、test.4. NOTES4.1 Marginal IndiciaA change bar (l) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a compl
42、ete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only.PREPARED BY THE SAE CHEST POT CALIBRATION TASK GROUPOF THE SAE DUMMY TESTING EQUIPMENT COMMITTEEOF THE SAE HUMAN BIOMECHANICS A
43、ND SIMULATIONS STANDARDS STEERING COMMITTEESAE INTERNATIONAL J2517 AUG2016 Page 7 of 7APPENDIX A - SAMPLE HIII-5F CHEST POTENTIOMETER CALIBRATION VALUESFIGURE A1 - CALIBRATION CURVECalibration Points (Xc)Measured Displacement D (mm)Sensor Ouput Readings S (mV/V)Actual Displacement (mm)Error (mm)Line
44、arity (% F.S.)-10 9.99 -21.594 10.02 -0.032 0.046-5 4.99 -10.787 4.97 0.016 0.0220 -0.01 -0.711 0.10 -0.111 0.1585 -5.00 9.893 -5.20 0.197 0.28110 -10.00 19.450 -10.11 0.113 0.16215 -15.00 28.845 -15.07 0.074 0.10620 -20.00 37.564 -19.79 -0.214 0.30625 -25.02 46.616 -24.78 -0.236 0.33730 -30.04 56.1
45、23 -30.15 0.107 0.15235 -35.01 64.427 -34.92 -0.089 0.12740 -40.00 73.342 -40.14 0.137 0.19645 -45.00 81.599 -45.05 0.049 0.07050 -50.01 89.887 -50.05 0.044 0.06255 -55.03 98.088 -55.08 0.046 0.06660 -60.02 105.896 -59.92 -0.100 0.143Max Non-Linearity 0.34Calibration Curve y = 9.0712E-07x3 - 7.6531E-04x2 - 4.9261E-01x - 2.4934E-01R2 = 0.99997-70-60-50-40-30-20-1001020-40 -20 0 20 40 60 80 100 120Sensor Output Readings S (mV/V)MeasuredDisplacement D(mm)
