A Global View on Interior fittings - ECER21 vs MVSS201

400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 Web: SAE TECHNICAL PAPER SERIES2003-01-1175Interior Fittings – A Global ViewMichael Keranen and James HanfordVisteon CorporationReprinted From: Advances in Interiors & Instrument Panels(SP-1753)2003 SAE World CongressDetroit, Michigan March 3-6, 2003All 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.For permission and licensing requests contact:SAE Permissions400 Commonwealth DriveWarrendale, PA 15096-0001-USAEmail: permissions@Fax: 724-772-4028Tel: 724-772-4891For multiple print copies contact:SAE Customer ServiceTel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (outside USA)Fax: 724-776-1615Email: CustomerService@ISSN 0148-7191Copyright © 2003 SAE InternationalPositions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. A process is available by which discussions will be printed with the paper if it is published in SAE Transactions.Persons wishing to submit papers to be considered for presentation or publication by SAE should send the manuscript or a 300 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USA2003-01-1175Interior Fittings – A Global ViewMichael Keranen and James HanfordVisteon Corporation Copyright © 2003 SAE InternationalABSTRACTIn today's global economy, the automotive design engineer's responsibilities are made more complex by the differences between regulatory requirements of the various global markets. This paper compares instrument panel head impact requirements of FMVSS 201 with its European counterparts, ECE 21, and EEC/74/60, Interior Fittings. It describes the similarities and differences between these regulations and explains the unique requirements for each market. It then compares processes for development and validation testing in both markets. It also covers related topics like self-certification, witness testing, radii, projections, and interior compartment doors. The cockpit design engineer will gain an understanding of the factors involved in ensuring that their design fully meets the requirements of the subject regulations.INTRODUCTIONInterior Fittings is a broad description that covers regulations from several countries. This paper will discuss the similarities and differences between FMVSS 201, EEC 74/60, and ECE 21. The latter two regulations are almost identical so effectively we will be comparing the Interior Fittings requirements of the US and Europe. One of the first and major differences between meeting the requirements of the two different markets is the necessity of obtaining a Whole-Vehicle-Type-Approval (WVTA) certificate when selling to the countries of the European Union. This certificate is obtained by undergoing "witness testing" by a third party authorized by the European governments to oversee testing required by the European regulations. Designing a vehicle to meet the requirements of a foreign market is often referred to as homologating a vehicle. Homologation is a generic term that means validating a product to the requirements of the market in which you intend to sell. So, a vehicle is homologated to the requirements of Japan, or Australia, or in this case the European Union. While witness testing and a WVTA certificate are required for Europe, verification for the US market is all self-certification, where the government relies on the automakers to take appropriate action to ensure that their products meet all the requirements of the applicable regulations. This paper will concentrate on the details of the European Interior Fittings regulations and the differences from the US regulation with an emphasis on their application to instrument panels and floor consoles. This paper will not cover other parts of the vehicle with the same thoroughness as instrument panels and consoles.INTERIOR FITTINGS COMPARISON – U.S. TO EUROPEFMVSS 201 – Occupant Protection in Interior Impact - includes pendulum head impact testing at 12 mph (if the vehicle has dual airbags) and interior compartment door requirements (See figure 1 in the appendix, for a picture of the impact testing device). European Interior Fittings is head impact testing at 15 mph as well as radii, projections, and surface area requirements on knobs, switches, levers and surfaces. First, the requirements and processes used to comply with FMVSS 201 will be described, and then the requirements and processes used to comply with European Interior Fittings will be described, and compared to the requirements of FMVSS 201.GENERATING IMPACT ZONES FOR FMVSSBefore conducting impact on physical parts the instrument panel head impact zones must be developed and the impact points selected. There are an infinite number of points one could choose to hit in the impact zone, so only the worst case points are chosen and evaluated.The zones are set up using an apparatus that could be described as a ball on a string (see Figures 2, 3, and 4). The string is anchored first at the Design Seating Reference Points (generally referred to as the SgRP) of all front seating positions with the length to the outside edge of the 165mm diameter sphere infinitely adjustable from 736 mm to 840 mm. It is sufficient to hold it at the shorter of the two lengths and swing the ball down until ittouches the instrument panel. Then the ball is swung from side to side keeping the string to the SgRP tight. The line scrubbed on the instrument panel is the lower boundary of the head impact zone. Line P L in figure 5 is the lower boundary of the passenger side head impact zone. Line D L in figure 5 is the lower boundary of the driver side head impact zone. The same is done from a point forward and up from the SgRP, called the adjusted SgRP, if the vehicle has adjustable seats. If the vehicle does not have adjustable seats, then the 736 mm and 840 mm arcs are only struck from the SgRP. The adjusted SgRP is 125 mm forward in vehicle and 19 mm up from the SgRP. It can also be the amount of actual rise resulting from the slope of the seat track over a 125 mm horizontal movement. From the adjusted SgRP the 840 mm length is used to get the top arcs of the head impact zones for all possible front seating positions. There is one possible exception that can occur. If the headform contacts the windshield when the ball-on-string is swung down from the adjusted SgRP, the string is shortened from its maximum length of 840 mm until the headform clears the windshield on its downswing. If this occurs, then this shorter length is used for the top edge of the head impact zone. Line P U and Line D U are the tops of the passenger and driver head impact zones as shown in figure 5. In the case of the vehicle shown in figure 5, there are only two designated front seating positions so there are only two sets of arcs comprising the driver and passenger head impact zones. In vehicles with a third designated seating position for the center seat occupant, there would be three sets of head impact zone arcs.Once the arcs described above have been constructed, several exemption zones bound them on their ends and below. These are the steering wheel exemption zone, the right hand exemption zone and the reference line, which defines the bottom of the zone. The steering wheel exemption zone is simply a vertical plane parallel to the longitudinal axis of the vehicle, positioned half the headform diameter (82.5 mm, since the headform is 165 mm in diameter) inboard of the edge of the steering wheel (see vertical Line E L in Figure 5). This bounds the left edge of the impact zones. The right hand exemption zone is a plane parallel to the longitudinal axis of the vehicle 125 mm inboard of the right hand instrument panel to a-pillar attachment (see vertical Line E R in Figure 5). The reference line bounds the lower edge of the impact zone (see Line R in Figure 5). The reference line is a line between the steering wheel and right hand exemption zones, defined by the points of contact of vertical tangents to the rearmost surface of the panel. Any point below the reference line is exempt from impact.For the US zones we typically do the impact zone setup on CAD using proprietary software developed in-houseand called GENPAD ®(SAE Paper # 2002-01-1241). If it is desired to lay the zones out on physical hardware anh-point fixture is required. This necessitates the build of a fixture to locate the SgRP and adjusted SgRP, and enable adjustable attachment of the apparatus to the vehicle, so that the zones can be constructed on the actual parts (see the horizontal bars, and eyebolts of the h-point fixture in the lower area of figure 5). The locations of the SgRP and Adjusted SgRP are verified by measurement. Once it is proven that the fixture is accurate the zones are constructed on the instrument panel.GENERATING IMPACT ZONES FOR EUROPEFor Europe an initial zone can be done on CAD but the witnessing agency will require that the zones be laid out on actual hardware, when parts become available. The arcs are exactly the same as for FMVSS as described above, but the exemption zones are different. EXEMPTION ZONES FOR EUROPEThe steering wheel exemption zone is not a vertical plane as for FMVSS, but is defined with the steering wheel in all possible positions of use. The steering wheel is increased in the plane of the wheel by a band 127 mm inboard from the wheel. The smallest common area bounded by bands generated with the steering wheel in all positions of use is the steering wheel exempt area. This area extends outboard to the pillar at the top and bottom. A horizontal plane tangent to the bottom of the steering wheel with the wheel in its up-most position is the lower boundary of the steering wheel exempt zone, unless this plane is below the reference line, in which case the reference line becomes the lower boundary. At the top, when the 127 mm arc about the wheel hits the twelve o'clock position the line is continued horizontally outboard to the pillar (see Line E around the steering wheel in figure 6).The right hand exempt zone in the case of a left hand drive vehicle is a vertical line 100 mm inboard from the side glazing, but is not shown in the figure. Normally this line doesn't provide much relief because it barely reaches the instrument panel so in practice it is ignored. The reference line is the line made up of points constructed from vertical tangents to the rearmost surface of the instrument panel, across the entire width of the instrument panel. All areas below the reference line are exempt from the impact requirements, although these areas are not exempt from the radii, projection and surface area requirements of Europe, which will be described later in this paper. PICKING THE IMPACT POINTSOnce the impact and exempt zones have been determined, the impact points can be selected. Since there are an infinite number of points that could be selected, it is necessary to narrow it down to the worst-case points to make the task manageable. This isaccomplished by a cross functional team consisting of a design and release engineer, the head impact test engineer and a knowledgeable head impact engineer. Together they decide, knowing the structure and historical hard points from other programs, what the worst case points will be and select them accordingly. See figure 7 for a typical layout of head impact points. For Europe, the witness authority picks the points.GENERATING IMPACT ANGLESOnce the points are selected an angle of impact needs to be generated for each impact point. Again, there are differences between the US and European methods. The US method is based off of SAE J921, and establishes a trajectory at the point of impact. The test lab adjusts the angle of the fixture, which holds the instrument panel during impact, or the angle of the test device to ensure that the head impact test device's trajectory at the point of impact matches the trajectory described in SAEJ921. In a cross-car section of the instrument panel containing the impact point, a vertical line whose origin and pivot is the adjusted seating reference point is rocked down until it is tangent to the instrument panel. The angle of impact is perpendicular to this line for any impact point in that section.The European method differs in that the first point of contact with the ball is the impact point. For Europe, two angles from vertical, and the length of the string from the adjusted seating reference point to the center of the ball, serve to locate the ball, and define the impact angle. One angle is from vertical back to the string, and the other is from vertical down to the point of contact with the panel, and they are both read from the protractor of the device shown in figure 8. From the two angles, the angle of the trajectory of the headform can be determined, and again the trajectory of the test device is matched to that of the ball and protractor. The witness, after selecting the impact points on actual hardware, uses the device in figure 8 to determine the impact angles.IMPACT TESTINGOnce the impact zones and angles are determined and parts have been procured, impact testing can commence. In the US, as mentioned previously, all certification is self-certification. The government expects automakers to meet the regulations without a representative present, and without documentation being sent to the government. Occasionally, the government will buy a vehicle or part and conduct a test according to its established and published procedures as an audit. If there is an issue with the test, the government will check the process that the automaker followed to ensure that the automaker exercised due-diligence in their efforts to meet the requirement. If it is determined that there is a non-compliance with a regulation, the government can order a recall. Meeting the European regulations is different. To get a WVTA certificate for a vehicle line requires witness testing and completion and submission of documentation by the authorized third party.The desired result of impact testing for both the US and Europe is decelerations that do not exceed 80 g's continuously for more than 3 m-sec (See figure 9 for a picture of a typical deceleration with a 3 m-sec length of time depicted on it). There are two accelerometers in the headform of the test device. Common practice has been to average the result of the two for Europe, at the request of the witness, and to use the highest result of the two accelerometers for US testing. The European witness looks carefully at the parts after impact, having painted the headform before impact, for signs of paint transfer on contacted edges. More details will be provided below about the radii required by the European regulations. A unique US requirement is that of interior compartment doors. During instrument panel head impact testing, interior compartment doors are required to stay closed, where the European regulation has no such requirement.INTERIOR COMPARTMENT DOORSFMVSS 201 includes interior compartment door requirements. Interior compartment doors have been defined as doors over compartments designed for the storage of personal effects. Interior compartment doors must stay closed during the impact sequence described above, and during inertial loading. The inertial loads are described as 10g vertical, 10g transverse and 30g longitudinal inertial loads, and SAE procedure J839b, section 5, is referenced in this section of the regulation. Section 5 of the procedure states: "Due to the complexity of physical testing it is judged to be more practical and more accurate to base evaluations on mathematical analysis." (SAE J839b, May 1965) Therefore the analysis of interior compartment doors is done by calculation, with the goal of ensuring that the doors stay closed during the described inertial events. As for Europe, interior compartment doors are not required to stay closed during instrument panel head impact testing, nor is there an inertial analysis required. RADII, PROJECTIONS, AND SURFACE AREASThe European Interior Fittings regulations are more extensive in that they have radii, projection, and surface area requirements, which apply to the whole interior of the vehicle and that are not found in FMVSS. Refer to figures 10 and 11 throughout this discussion. There are three main zones specified by the regulation. Section 5.1 defines the area of the vehicle above the reference line of the instrument panel, and in front of the front seat h-point. Section 5.2 defines the area of the vehicle below the reference line of the instrument panel, and in front of the front seat h-point. Section 5.3 includes all those objects that have not been covered by Sections 5.1 and5.2, and the area in front of the transverse plane passing through the torso reference line of the rear-most seat occupants, up to the instrument panel. In general, contactable edges on the instrument panel above the reference line (the white line extending across the instrument panel in figure 10) must have radii > 2.5 mm, and contactable edges below the reference line must have radii > 3.2 mm. In general, all knobs, switches and levers on the instrument panel regardless of whether they are above or below the reference line must meet the following radii, surface area, and projection requirements (See figure 12 for a picture of the projection measuring device. This device is a 165 mm diameter hemisphere with a 50 mm flat-ended movable ram. When the ram moves, the amount of its movement, i.e. the projection of the object, is recorded on the dial indicator):• For projections < 3.2 mm, the object must have radii > 0.5 mm and the height/width ratio of theobject must be < 0.5 (i.e. the width of theprojection must be at least twice the heightwhere the height is the amount of projection).• For projections > 3.2 mm but < 9.5 mm, radii must be at least 2.5 mm and the surface areamust be > 200 mm2. The surface area ismeasured at a section cut 2.5 mm from the pointprojecting furthest.• For projections > 9.5 mm, the object must either retract or break away to a projection < 9.5 mmwhen acted on by a longitudinal horizontal forceof 37.8 daN (approximately 85 lbs). If the objectretracts to less than 9.5 mm the standardrequirements for knobs apply, as describedabove. If the object breaks away, the remainingprojection must be < 9.5 mm and the crosssectional area of the original part must be 6.5cm2. The cross sectional area of the original partis measured at a cross section into the part 6.5mm from the point of maximum projection.The requirements described above only apply to surfaces, edges, knobs, switches and levers that are contactable. This is a key point and applies throughout the entire interior fittings regulation. Contact with surfaces and edges, on any part of the interior, is checked with the 165 mm diameter spherical headform. Contact above the reference line with knobs, switches and levers, is also checked with the headform. Contact below the reference line of the instrument panel with knobs, switches and levers, is checked using the kneeform, as shown in figure 13. The kneeform is used below the reference line and during its use no part of the kneeform should extend above the reference line. It is held parallel to the vehicle's longitudinal axis and can be rotated about a cross car axis up to 30 degrees up or down, so that either the top surface or bottom surface of the device is parallel to ground.It is important to note that the required radii are all minimum radii. It is good practice to design with larger radii to ensure that tolerances do not yield a lower bound than the minimum requirement.The requirements above only apply to "hard" parts. This is the case for the entire regulation. A hard part is described as consisting of materials that are harder than 50 Shore A. The hardness is measured with a hardness tester as shown in figure 14. Materials having a hardness less than 50 Shore A are removed before evaluation, and only the remaining object is evaluated.REQUIREMENTS FOR FLOOR CONSOLESThe requirements for floor consoles are simpler to understand, even though coverage of the floor console could extend across three sections of the regulation. Some parts of the console could be covered in Section 5.1 if they are above the reference line of the instrument panel. Other parts forward of the h-point and below the reference line are covered in Section 5.2. And, other parts not mentioned in 5.1, and 5.2, and rearward of the front seat h-point in Section 5.3. Contactable knobs, switches and levers forward of the front seat h-point must meet the same requirements for knobs, switches and levers as described above, and assuming the floor console is below the reference line of the instrument panel, edges and surfaces below the reference line of the instrument panel must have radii > 3.2 mm. Objects mounted rearward of the front seat h-point, but in front of the transverse plane of the torso reference line of the rear-most seat occupants, are required to project less than 25 mm and have radii > 3.2 mm. Hand-brake controls and shifters are not covered in this paper. Objects below the h-points of the front seats are exempt, but it should be noted, that unless these objects are at least blunted (radii > 0.5 mm), they could cause concern to the witness.REQUIREMENTS FOR STORAGE COMPARTMENTSStorage compartments that have lids aren't described neatly in the regulation. The criteria the witness will apply depend on the design of the lid and features inside the storage compartment. If a lid is so designed that it has a feature that will hold the lid in an open position, such as a floor console lid with a stop that holds it open in the ninety-degree position, the witness will require that all contactable edges and projections inside the storage compartment and on the underside of the lid, including the latch, meet the requirements described above. Also, if there are features inside a storage compartment, such as coin holders, cup holders, tissue holders, cell phone holders, or power points etc. that would encourage the use of the storage compartment while operating the vehicle, the witness will require that all contactableedges and projections in the storage compartment comply with the requirements above. The normal "position-of-use" of the door/lid is what determines whether the requirements apply to the interior of the storage compartment. If there is no reason a driver would use the storage compartment while driving, and there are no positive stops that keep the door open on its own, the witness may determine that the door's position-of-use is closed and the requirements would not apply.INTERIOR FITTINGS EVALUATION BY WITNESSWhile FMVSS 201 only requires impact testing and an inertial analysis, the European Interior Fittings regulation requires much more, as described, and all in the presence, and under the direction of an authorized witness authority. Typically, the static evaluation of the entire interior of the vehicle is done first, and the physical instrument panel impact testing is done last. There are other areas of the vehicle that may require impact, such as the sun visors, but this paper only focuses on the instrument panel and floor console. The static evaluation for radii, projections and surface areas, on surfaces, edges, knobs, switches, and levers is done on the entire interior of the vehicle. This evaluation can take the witness a whole day as they examine each detail of every object in the vehicle, assessing its compliance. The dynamic physical instrument panel head impact testing is done last, and has been described above. The witness will paint the headform before the impact test, and examine the parts closely after the test. They are looking for evidence of paint transfer on a contacted edge that might have occurred during the dynamic event. Contacted edges can result from fracture of a part or crush of one part in relation to another part. For instance, if impacting on a finish panel next to a radio (which is typically more solidly mounted) the finish panel can be pushed in during the test and remain so after the test. If there is paint on the edge of the radio, the witness will check this edge to ensure that it has the proper radii > 2.5 mm, assuming it is above the reference line of the instrument panel.Once the arduous witness evaluation is complete and the requested documentation supplied to the witness authority, assuming there have been no issues, the witness authority compiles their documentation and generates a report to the European governing body, recommending approval of the vehicle for a WVTA certificate. If there are no issues with the supplied data and documentation, they will grant a WVTA certificate thus allowing the automaker to start selling vehicles in that market. CONCLUSIONThere are major differences between the requirements of FMVSS 201 and the European Interior Fittings requirements; ECE 21, and 74/60 EEC (later revised by 78/632 EEC, and 2000/4/EC). The same machine can carry out the actual impact on the instrument panel, albeit at different speeds: 12 mph for US, and 15 mph for Europe. The impact zones are very similar aside from the left and right hand exempt areas. But, the European requirement has many important differences that make it a larger task to meet. There is witnessed testing required for the instrument panel impact, and there are radii, surface area and projection requirements that do not appear in the US law. The details of the radii, surface area and projection requirements apply to the entire occupant compartment of a vehicle, and the complexity of the regulation requires an intimate knowledge of all the details of the law, in order to mitigate the risk of non-compliance. ACKNOWLEDGMENTSThe authors would like to thank Mark Turner, and Ravi Thyagarajan for their encouragement in publishing this paper.REFERENCES1. NHTSA Website – 2. FMVSS 201 regulation last updated June 20023. ECE 21 regulation dated Dec 20004. 74/60 EEC, 78/632 EEC, and 2000/4/EC regulationsdated August 2002.5. SAE J839b, May 1965 – Passenger Car Side DoorLatch Systems6. SAE J921, June 1965, Instrument Panel LaboratoryImpact Test Procedure7. SAE Paper # 2002-01-1241 – GENPAD® -Ergonomic PackagingDEFINITIONS, ACRONYMS, ABBREVIATIONSH-point: Hip point of the occupantFMVSS: Federal Motor Vehicle Safety Standards NHTSA: National Highway Traffic Safety Administration RCE: Regulatory Compliance EngineerSAE: Society of Automotive EngineersSgRP: Seating Reference Point, with respect to ground (also known as the design seating reference point) WVTA: Whole Vehicle Type ApprovalAPPENDIXFigure 1 – Head Impact Test DeviceFigure 2 – Establishing the Head Impact ZoneFigure 3 - Establishing the Head Impact ZoneFigure 4 - Establishing the Head Impact ZoneFigure 5 – US Head Impact ZonesFigure 6 – European Head Impact ZonesFigure 7 – Example of a Typical Head Impact Point LayoutFigure 8 – European Impact AnglesFigure 9 – Example Deceleration CurveFigure 10 – European Radii and Projection Details。