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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 therefr
2、om, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. TO PLACE A DOCUMENT ORDER; (724) 776-4970 FAX: (724) 776-0790 SAE WEB ADDRESS http:/w
3、ww.sae.org Copyright 2000 Society of Automotive Engineers, Inc. All rights reserved.Printed in U.S.A. SURFACE VEHICLE 400 Commonwealth Drive, Warrendale, PA 15096-0001 STANDARD Submitted for recognition as an American National Standard SAE J2517 ISSUED JUN2000 Issued2000-06 Hybrid III Family Chest P
4、otentiometer Calibration Procedure 1.ScopeThis procedure establishes a recommended practice for establishing the sensitivity of the chest displacement potentiometer assembly used in the Hybrid III family of Anthropomorphic Test Devices (ATDs, or crash dummies). This potentiometer assembly is used in
5、 the Hybrid III family to measure the linear displacement of the sternum relative to the spine (referred to as chest compression). An inherent non- linearity exists in this measurement because a rotary potentiometer is being used to measure a generally linear displacement. As the chest cavity is com
6、pressed the potentiometer rotates, however the relationship between the compression and the potentiometer rotation (and voltage output) is non-linear. Crash testing facilities have in the past used a variety of techniques to calibrate the chest potentiometer, that is to establish a sensitivity value
7、 (mm/(volt/volt) or mm/(mvolt/volt). These sensitivity values are used to convert recorded voltage measurements to engineering units, in this case chest compression in mm. Some of these techniques intended to correct for the non-linearity and others did not. Of those that did correct for the non- li
8、nearity, there was a variation in techniques used. This variation in calibration procedures was in part identified by the SAE Dummy Testing Equipment Subcommittee (DTES), and led to overall variability in chest compression measurements between laboratories. The intent of this SAE Recommended Practic
9、e is to minimize the variations in chest deflection measurements between crash testing laboratories. Before this procedure was written, a round robin showed variations for the Small Female of 10% among 8 labs for the chest pot sensitivity value. A follow-up round robin to test this procedure showed
10、a worst case variation of 2.7% among 10 labs, with a standard deviation of 0.9%. The calibration procedure recommended here uses a two-point calibration and is not intended to correct for the non-linearity (which, for example, is as large as 3% for the Small Female but is small near the peak). It al
11、so does not require the measurement of a starting position of the potentiometer before each crash test, thus it does not correct for the difference in starting chest geometry between a subject dummy and its design intent. It is intended to be a simple and reproducible calibration procedure which cra
12、sh test facilities can easily adopt with little or no modifications to their facilities. More complex procedures could in fact address the non- linearity, but at the likely cost of non-adoption by some facilities. SAE SAE J2517 Issued JUN2000 -2- 2.References 2.1Applicable PublicationsThe following
13、publications form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest version of SAE publications shall apply. 2.1.1SAE PUBLICATIONSAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001 SAE Engineering Aid 23Users Manual for the 50th Pe
14、rcentile Male Hybrid III Test Dummy SAE Engineering Aid 25Users Manual for the Small Adult Female Hybrid III Test Dummy SAE Engineering Aid 26Users Manual for the Large Male Hybrid III Test Dummy SAE Engineering Aid 29Hybrid III Six-Year-Old Child Dummy Users Manual SAE Engineering Aid 31Hybrid III
15、3-Year-Old Child Dummy Users Manual 2.2Related PublicationsThe following publications are for information purposes only and are not a required part of this document. 2.2.1SAE PUBLICATIONAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001 SAE J211-1Instrumentation for Impact TestPar
16、t 1: Electronic Instrumentation 2.2.2FEDERAL PUBLICATIONAvailable from the Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402. FMVSS Part 572Test Dummies SpecificationsAnthropomorphic Test Dummy for Applicable Test Procedures 3.Calibration Procedure 3.1Chest Potentiom
17、eter 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 process. The assembly should be removed from the dummy as described in SAE Engineering Aids 23, 25, 26, 2
18、9, and 31. 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 disassembly of the potentiometer assembly once the calibration is completed. Any adjustments to the assembly would require re-
19、calibration. 3.2Calibration FixtureThe potentiometer assembly is placed in a calibration fixture that duplicates the nominal design position of arm, which is referenced as Xo in Figure 1. (This starting position represents the design position of the uncompressed chest.) The fixture should also be ca
20、pable of stroking the arm relative to the potentiometer a distance of Xc as listed in Table 1. (This represents a position of the sternum when the chest is compressed.) The fixture does not need to be of a specific design, it simply needs to duplicate the position of the potentiometer at the two poi
21、nts referenced in Table 1. 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 either be installed in the fixture with the arm parallel to the slider track, or at a slight angle as installed in the du
22、mmy. (This angle between the slider track and arm should be less than 10 degrees, however.) 3.3Calibration ProcedureA voltage reading, Vo, should be taken at the initial potentiometer position, Xo. Another reading, Vc, should be taken at the calibration point, Xc. The sensitivity (expressed in mm/(m
23、volt/ volt) of the potentiometer should be established as follows in Equation 1: (Eq. 1) Because laboratories may use different excitation values, the sensitivity values should be expressed as a function of the excitation value (thus it should be in the units mm/(mvolt/volt.) SensitivityXcVcVo() Vex
24、citation()= SAE SAE J2517 Issued JUN2000 -3- FIGURE 1CALIBRATION FIXTURESIDE VIEW TABLE 1CALIBRATION DIMENSIONS Dummy Type Initial Position, Xo, (mm) Calibration Point, Xc, (mm) Reference Dimension, Xa (mm) Reference Dimension Xb (mm) Reference Dimension, Xr, (mm) Ball Radius, Rb, (mm) 3 year old Hy
25、brid III40355015103.2 6 year old Hybrid III44425412103.2 Small female Hybrid III67548127144.8 50th percentile male Hybrid III70688416144.8 Large adult male Hybrid III947110837144.8 SAE SAE J2517 Issued JUN2000 -4- FIGURE 2CALIBRATION FIXTUREFRONT VIEW 3.4Use of the Sensitivity ValueThe potentiometer
26、 assembly should be re-installed in the dummy without any mechanical adjustment of the potentiometer. Prior to a crash test, the output from the potentiometer may be zeroed with either signal conditioning or post-processing to eliminate offsets. During the test, the voltage output time history shoul
27、d be recorded. This voltage signal is multiplied by the sensitivity value and then divided by the excitation voltage to calculate a time history of the chest compression. The effects of the non- linearity of the system will not be corrected using the procedure, however the error due to non-linearity
28、 should approach zero as the chest compression approaches the calibration distance, Xc. 4.Notes 4.1Key WordsChest compression, potentiometer, calibration, sensitivity, ATD, crash dummy. PREPARED BY THE SAE DUMMY TEST EQUIPMENT SUBCOMMITTEE OF THE SAE HUMAN BIOMECHANICS AND SIMULATION STANDARDS COMMI
29、TTEE SAE SAE J2517 Issued JUN2000 RationaleNot applicable. Relationship of SAE Standard to ISO StandardNot applicable. ApplicationThis procedure establishes a recommended practice for establishing the sensitivity of the chest displacement potentiometer assembly used in the Hybrid III family of Anthr
30、opomorphic 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 to as chest compression). An inherent non-linearity exists in this measurement because a rotary potentiomet
31、er 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) is non-linear. Crash testing facilities have in the past used a variety of te
32、chniques 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, in this case chest compression in mm. Some of these techniques intended to co
33、rrect for the non-linearity and others did not. Of those that did correct for the non-linearity, there was a variation in techniques used. This variation in calibration procedures was in part identified by the SAE Dummy Testing Equipment Subcommittee (DTES), and led to overall variability in chest c
34、ompression 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 robin showed variations for the Small Female of 10% among 8 labs for the
35、 chest pot sensitivity value. A follow-up round robin to test this procedure showed a worst case variation of 2.7% among 10 labs, with a standard deviation of 0.9%. The calibration procedure recommended here uses a two-point calibration and is not intended to correct for the non-linearity (which, fo
36、r example, is as large as 3% for the Small Female but is small near the peak). It also does not require the measurement of a starting position of the potentiometer before each crash test, thus it does not correct for the difference in starting chest geometry between a subject dummy and its design in
37、tent. It is intended to be a simple and reproducible calibration procedure which crash test facilities can easily adopt with little or no modifications to their facilities. More complex procedures could in fact address the non-linearity, but at the likely cost of non-adoption by some facilities. Ref
38、erence Section SAE Engineering Aid 23Users Manual for the 50th Percentile Male Hybrid III Test Dummy SAE Engineering Aid 25Users Manual for the Small Adult Female Hybrid III Test Dummy SAE Engineering Aid 26Users Manual for the Large Male Hybrid III Test Dummy SAE Engineering Aid 29Hybrid III Six-Ye
39、ar-Old Child Dummy Users Manual SAE Engineering Aid 31Hybrid III 3-Year-Old Child Dummy Users Manual SAE J-211-1Instrumentation for Impact TestPart 1: Electronic Instrumentation Developed by the SAE Dummy Test Equipment Subcommittee Sponsored by the SAE Human Biomechanics and Simulation Standards Committee