Documentation: GTR7-13-02 – Dual Pane document (Basis for revision to GTR7-06-10).
Development of the dual pane document continued with the principal discussion revolving around new text in Annex 9.
General points made during this discussion:
Annex 1.
It was agreed to consider that the title of Annex 1 should be changed to read: “Height Measurement Test Procedure” and that similar alterations should be made to the title and wording in Section 5.1.1. with “Minimum height” being changed to “head restraint height”. This will be re-discussed at the next session.
Annex 9.
NHTSA – noted that Annex 9 of the dual pane document was drafted to retain HIII and add in BioRID rather than to immediately delete HIII. They considered this approach may be helpful.
It had been noted that despite their similarities regarding their specification, the mass of the shoes used on HIII is different to that of BioRID. Humanetics explained that they actually market multiple shoes (at least 3 variants) between Hybrid III and BioRID dummies – they will weigh and measure these and report back, to understand if there are significant differences.
Ms Versailles noted that the current GTR7 reflects the detail in FMVSS but didn’t know whether this variance had been identified. She agreed to get NHTSA’s opinion a standard specification.
Para 3.2.1. It was noted that the text provides only for an acceleration sled and it was agreed that the general (but not unanimous) understanding is that this is a sled that is fired from a stationary state rather than being brought to an abrupt stop (deceleration sled).
There was a request to amend the text to allow the use of either type of sled but opinion was split on whether it was acceptable to assume that all of the validation work that had been achieved on acceleration sleds was valid on deceleration devices.
Mr Ammerlaan asked what procedures may have to be defined to ensure that the dummy head did not move before T0 if a deceleration sled were to be used. He felt that this would need some investigation.
Summing up the chair advised that there needed to be a proposal and justification if deceleration sleds were to be adopted by the group. He cautioned that there could be no delay in the programme while deceleration sled validation was undertaken.
Para 3.2.2 It was confirmed that the current drafting provides for BioRID to be used only with sled tests and that this is indicated in section 4.
Para 3.2.2.4 – It was confirmed that this paragraph aims to ensure no movement in dummy head before T0.
Para 3.2.4.3 & 3.2.4.4 – There was discussion and clarification given on “central position of adjustment”. It was noted that for seats where there are shoulder position adjustment separate to backset angle, there should be a definition of the position this should be set to.
This is sometimes integrated with head restraint adjustment (i.e. pivot/articulation in seat just below shoulder height, with the head restraint located on the upper part of the seat) and sometimes separate (similar to lumbar support devices). It was noted that this point is also relevant to static testing, as backset is measured for this test too.
An amendment was made to Annex 9 Para 3.2.4.6, to define the position to which it should be set (i.e. as prescribed by the vehicle manufacturer assuming torso angle is maintained).
In addition, the positional requirements of side bolsters were moved to 3.2.4.6 to allow it to refer to those fitted to seat base and/or backrest.
Concerns were raised about the principle of Annex 9 Para 3.2.4.5 – where the head restraint is positioned fully rearward, what happens when the pivot allows a tilt which would change the effective contact point. The wording was changed to reflect the objective of setting the restraint to its most rearward position.
Annex 9 Figure 9.2. It was suggested that the curves of the “entry gate” could be simplified
by straightening the curve 9the currently reflect the profile of a pulse). It was also considered that the figure may benefit from being redrawn with better quality.
Actions:
Mr Depinet will weigh different types of shoes and report this back to the group.
Chair will prepare an informal document for presentation to the May session of GRSP for information only. This will include elements of the pre-amble and the Chair invited the group to provide contributions.
In keeping with the decision of the informal group that the discussion on the absolute height of head restraints should be had once and at GRSP, NL agreed to prepare a paper on the issue for presentation at the May session of GRSP.
It was agreed that there was a lack of clarity in Annex 9 Para 3.2.8.2 regarding how to measure the “200mm distance and 230-270mm” distances relating to knee and ankle spacing. It was noted that this comes from the Euro NCAP procedure and delegates were asked to consider both the intended meaning and improved text.