1、 SURFACE VEHICLE INFORMATION REPORT J2949 MAR2015 Issued 2015-03 H-III50M Ankle Update to Eliminate Signal Noise RATIONALE This Information Report is intended to provide a comprehensive background and validation document of a recommended solution for an electrical signal noise issue that was created
2、 by the 1996 NHTSA regulated version of the 45 degree foot ankle bumper design. FOREWORD In 1986, the Hybrid III 50thPercentile Male Test Dummy was specified in the NHTSA final rule (Federal Register Vol. 51, No. 143, page 26688-26710) to replace the Hybrid II Test Dummy. The ankle joint of the feet
3、 in the regulation had approximately 30 degrees dorsiflexion. In 1991, Ford petitioned NHTSA to increase the ankle dorsiflexion. In 1996, NHTSA updated the final rule to incorporate an improved ankle dorsiflexion design, which allows 45 degree dorsiflexion. The design also introduced an ankle bumper
4、 to prevent potential metal-to-metal contact. The modified NHTSA drawings in 1996 are 78051-600, -601, and -611, and 730-1 and -2. In 2007, IIHS identified signal noise from the foot accelerometer signals in high-speed frontal crashes. An investigation concluded the noise was generated by two possib
5、le areas of the current ankle design. The first location is the possible metal-to-metal contact between the ankle joint ball shaft and the bumper retainer. The second location is between the ankle ball shaft and its mounting hole in the welded foot assembly. In 2008, SAE Hybrid III Task Force initia
6、ted a task to redesign the ankle joint, seeking solutions to eliminate the potential metal-to-metal contact while maintaining the ankle range of motion as specified in the 1996 NHTSA final rule. This information report summarizes the final design and the validation test results from the SAE Hybrid I
7、II Task Force. This design concept could also be applied to the Hybrid III Small Female and Large Male ankle joint designs. TABLE OF CONTENTS 1. SCOPE AND PURPOSE 2 2. REFERENCES 2 2.1 Applicable Documents 2 2.2 Related Publication . 2 3. ABREVIATIONS 3 4. TECHNICAL REQUIREMENTS 3 4.1 1996 Regulatio
8、n Limbs . 3 4.2 Recommended Ankle Joint Update 4 5. NOTES 7 5.1 Marginal Indicia . 7 _ 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 an
9、d suitability for any particular use, including any patent infringement arising therefrom, 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
10、 suggestions. Copyright 2015 SAE International 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 SAE. TO
11、PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standa
12、rds/J2949_201503 SAE INTERNATIONAL J2949 Issued MAR2015 Page 2 of 17 APPENDIX A Drawings for Design in this Standard 8 FIGURE 1 Foot Accelerations with the Ankle Design in 1996 NHTSA Regulation (Test CEF 0508) 4 FIGURE 2 Design of Upgraded Ankle Joint . 4 FIGURE 3 Design of the Upgraded Interfaces a
13、bove and below the Ankle Joint 5 FIGURE 4 Alignment marks for the clamping nuts . 5 FIGURE 4 Foot Accelerations with the New Design (Test CF09007) 6 FIGURE 5 Examples of Ball of Foot Pendulum Impacts 7 FIGURE 6 Examples of Ball of Foot Pendulum Impacts 7 TABLE 1 Test Matrix 6 1. SCOPE AND PURPOSE Th
14、is Information Report documents the signal noise discovered with the 1996 NHTSA regulated version of the 45 degree foot, and defines a recommended solution to resolve the problem. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this specification to the extent specif
15、ied herein. Unless otherwise indicated, the latest issue of SAE publications shall apply. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J2856 Users
16、Manual for the 50thPercentile Male Hybrid III Dummy, September 2009. 2.2 Related Publication The following publications are provided for information purposes only and are not a required part of this SAE Technical Report. 2.2.1 Federal Publication Available from the Superintendent of Documents, U.S.
17、Government Printing Office, Mail Stop: SSOP, Washington, DC 20402-9320. Motor Vehicle Regulation No. 572 Test Dummies Specifications - Anthropomorphic Test Dummy for Applicable Test Procedures 2.2.2 Reprographic Technologies Available from Reprographic Technologies, 9107 Gaither Road, Gaithersburg,
18、MD 20877, (301) 4195070 as well as from the Department of Transportation Docket Management System Parts Lists and Drawings Part 572 Subpart E - Hybrid III Test Dummy - December 1998 SAE INTERNATIONAL J2949 Issued MAR2015 Page 3 of 17 3. ABREVIATIONS IIHS Insurance Institute for Highway Safety H-III5
19、0M Hybrid III 50th Percentile Male Crash Test Dummy H-III TF Hybrid III Task Force SHCS Socket Head Cap Screw FHCS Flat Head Cap Screw NHTSA National Highway Traffic Safety Administration - of the United States Department of Transportation 4. TECHNICAL REQUIREMENTS 4.1 1996 Regulation Limbs The H-II
20、I50M dummy was first adopted in Part 572 in July 1986, Federal Register Vol. 51, N0. 143, and amended in December 26, 1996, Federal Register Vol 61, No. 249. The NHTSA amendment in 1996 introduced a new design to increase ankle dorsiflexion and femur flexion ranges. These regulations define drawings
21、 for the construction of the dummy as well as performance criteria through certification tests in Part 572 Subpart E. The 1996 version of the drawing package defines the 1996 NHTSA regulation of the dummy. Drawings 78051-600, -601, and -611, and 7310-1, and -2 from this drawing package are most rele
22、vant and are included in Appendix A. 4.1.1 Description of Problem High-speed frontal crash tests conducted by IIHS with HIII50M dummy (with the 1996 version of the ankle design) have shown signal noise in the foot accelerometer signals. Post crash investigation of the dummy revealed the noise was ge
23、nerated by two possible areas of the current ankle design. One is the possible metal-to-metal contact between the ankle joint ball shaft and the bumper retainer. The second location is between the ankle ball shaft and its mounting hole in the welded foot assembly. The signal noise can propagate thro
24、ugh the dummys lower leg, which has been shown to produce signal noise in the tibia and femur load cell signals. The signal noise can artificially increase peak injury measures, even after appropriate filtering is applied. In some cases peak injury measure timing from the lower extremity channels oc
25、cur during a period of ringing in the foot accelerometer channels. In those cases, IIHS had used exclusion zones to limit the reporting of peak lower extremity injury measures to time periods occurring before or after the known time period with signal noise. Despite the addition of the rubber ankle
26、joint bumpers that were introduced in the 1996 revision, the IIHS test data has shown metal-to-metal contact can still occur. In order to address this problem, the SAE Hybrid III Task Force members agreed to redesign the ankle joint. As part of this revision, the Task Force also decided to improve t
27、he mechanical interface at the foot and lower tibia load cell attachment points, which could be another source of mechanical noise. 4.1.2 Tests Demonstrating Problem IIHS identified the signal noise from foot accelerometer channels in high-speed frontal crash tests. Typical accelerations from the fe
28、et are shown in Figure 1. SAE INTERNATIONAL J2949 Issued MAR2015 Page 4 of 17 Right Foot Z Acceleration (g) Right Foot X acceleration (g) FIGURE 1 - FOOT ACCELERATIONS WITH THE ANKLE DESIGN IN 1996 NHTSA REGULATION (TEST CEF 0508) 4.2 Recommended Ankle Joint Update 4.2.1 Description of Solution In o
29、rder to prevent the metal-to-metal contact between the ball shaft and the ankle shell in the Hybrid III ankle joint, the ankle bumper metal insert and the ball retainer have been merged to allow some metal material space to be taken by rubber without changing the overall dimension of the assembly. T
30、his change eliminates metal-to-metal contact. A dowel pin/hole feature has been added to prevent the ankle bumper from being installed in the wrong orientation. Figure 2 shows the new design. FIGURE 2 - DESIGN OF UPGRADED ANKLE JOINT In addition to the modifications mentioned above, the ankle joint
31、interface locations were improved to eliminate joint looseness, due to the machining tolerances specified for each part. The new design employs clamping nuts to reduce the slop, which eliminates any play at the two connection interfaces. Figure 3 shows the new ankle design with the clamping nut. -14
32、0-120-100-80-60-40-200200 0.05 0.1 0.15 0.2Time (sec)-150-100-500501000 0.05 0.1 0.15 0.2Time (sec)Orientation dowel pin Rubber wrap all around the ball retainer SAE INTERNATIONAL J2949 Issued MAR2015 Page 5 of 17 FIGURE 3 - DESIGN OF THE UPGRADED INTERFACES ABOVE AND BELOW THE ANKLE JOINT Alignment
33、 marks were designed for the ankle shell and the shell of the foot bone to assist the alignment of the clamping nut to the shaft of the tibia bone or the ball shaft, see Figure 4. These alignment marks help to prevent potential damage to the half moon feature of the clamping nut due to the misalignm
34、ent. FIGURE 4 - ALIGNMENT MARKS FOR THE CLAMPING NUTS 4.2.2 Drawings Drawings are provided to construct the upgraded ankle joint design. 4.2.2.1 To Make a New Ankle Bumper To make a new ankle joint, the following updated drawings are required: 78051-640, -641, -642, -643, -644, -645, -646, -648, -64
35、9, -650, -651, -652, and -653. 4.2.2.2 To Upgrade a 1996 Regulation Ankle Joint The whole ankle joint and foot requires replacement. The foot bone can be modified by adding the counter bore to allow the implementation of the clamping nut between the ankle ball shaft and the foot. Clamping Nuts Screw
36、 driver slot Alignment marks SAE INTERNATIONAL J2949 Issued MAR2015 Page 6 of 17 4.2.3 Tests Demonstrating Acceptability 4.2.3.1 Vehicle Testing Vehicle crash tests were conducted by IIHS to verify if the new design is able to reduce or eliminate the signal noise issue as described in section 4.1.2.
37、 In each IIHS test an instrumented HIII 50M dummy was placed in the driver seating position. Figure 4 contains examples of the foot acceleration results using the new design in vehicle testing. TABLE 1 - TEST MATRIX Test ID Ankle/Foot Design Test Configuration Vehicle Information Accelerometer Signa
38、l Noise on Foot CEF0508 Old 40 MPH, 40% frontal offset 2005 Chevy Uplander Yes CEF0507 Old 40 MPH, 40% frontal offset 2005 Ford Ranger Minor noise CF09004 New 30 MPH into 10 inch pole, 25% offset 2004 Chrysler Concorde No CF09005 New 35 MPH into 10 inch pole, 22% offset the pole 2005 Kia Rio No CF09
39、006 New 40 MPH into 10 inch pole, 23% offset 2005 Kia Rio No CF09007 New 40 MPH into 10 inch pole, 24% offset 2004 Chrysler Concord No Right Foot Z Acceleration (g) Right Foot X acceleration (g) FIGURE 4 - FOOT ACCELERATIONS WITH THE NEW DESIGN (TEST CF09007) 4.2.3.2 Mass and Center of Gravity Verif
40、ication The center of gravity of the parts was measured and it meets the H-III50M specifications. 4.2.3.3 Pendulum Testing Comparing Original and Update Ankle Designs Pendulum testing was also performed comparing the original and updated HIII50M ankles. An updated European Foot Impact was used to pe
41、rform the tests. It was proven difficult to achieve a similar type of signal noise found in the IIHS vehicle testing. The conclusion of this study was that the ankles appeared to be similar in impacts to the ball of the foot in a component, pendulum type of testing. Figure 5 and 6 shows an example o
42、f the results. -500501001500 0.05 0.1 0.15 0.2Time (sec)-40-200204060800 0.05 0.1 0.15 0.2Time (sec)SAE INTERNATIONAL J2949 Issued MAR2015 Page 7 of 17 FIGURE 5 - EXAMPLES OF BALL OF FOOT PENDULUM IMPACTS FIGURE 6 - EXAMPLES OF BALL OF FOOT PENDULUM IMPACTS 5. NOTES 5.1 Marginal Indicia A change bar
43、 (I) 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 complete revision of the document, including techn
44、ical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. PREPARED BY THE DUMMY TESTING AND EQUIPMENT COMMITTEE -200-1000100200300-100 0 100 200Toe Z accel (New Ankle) gToe Z accel(NewAnkle) g-1000100200300-100 0 100 200Toe Z acc
45、el (original ankle) gToe Z accel(originalankle) g(New Ankle) SAE INTERNATIONAL J2949 Issued MAR2015 Page 8 of 17 APPENDIX A DRAWINGS FOR DESIGN IN THIS STANDARD SAE INTERNATIONAL J2949 Issued MAR2015 Page 9 of 17 SAE INTERNATIONAL J2949 Issued MAR2015 Page 10 of 17 SAE INTERNATIONAL J2949 Issued MAR
46、2015 Page 11 of 17 SAE INTERNATIONAL J2949 Issued MAR2015 Page 12 of 17 SAE INTERNATIONAL J2949 Issued MAR2015 Page 13 of 17 SAE INTERNATIONAL J2949 Issued MAR2015 Page 14 of 17 SAE INTERNATIONAL J2949 Issued MAR2015 Page 15 of 17 SAE INTERNATIONAL J2949 Issued MAR2015 Page 16 of 17 SAE INTERNATIONAL J2949 Issued MAR2015 Page 17 of 17
