Text prepared by the European Tyre and Rim Technical Organisation (ETRTO) in order to correct inconsistencies in time measurement accuracy in annex 6.

The Russian Federation has developed a “Deceleration Calculator” for use in the UN R117 procedures. Following work by an ad hoc group (including NAMI, UTAC, and ETRTO) formed to review and validate this tool, Russia has prepared this new proposal, modifying the version (document GRB/2013/10) submitted at the last GRB session. The changes primarily concern the explanation of the tool rather than the basic mathematical equations.

Regulation 117, Annex 6 specifies several time duration values while Annex 6, Appendix 1 gives only one control accuracy value for time in its paragraph 4 (d): plus or minus 0.02 second. This means that this accuracy value applies to all the time durations specified in Regulation 117, Annex 6 and quoted above. This is not realistic for durations of more than one minute and not well fitted to the need of data acquisition for deceleration method. Therefore, Russia and ETRTO propose to introduce two accuracy sets of values in paragraphs 4 and 5 of Regulation 117, Annex 6, Appendix 1:

1. a control accuracy of +/- 0.2 % s and a corresponding instrumentation accuracy of +/- 0.1 % s for the time increments specified in Annex 6 paragraph 3.5.a for the data acquisition in the deceleration method, both in ∆ω/∆t or dω/dt form, and
2. a control accuracy of +/- 5% and an instrumentation accuracy of maximum +/-10 sec for the other time durations specified in Annex 6.

Testing and Evaluation of the variant method using the dω/dt form.

Report of the ad‐hoc working group organized in accordance with the recommendation of the 58th GRB session to consider testing and evaluation of the variant method using the dω/dt form proposed by Russia.

Text prepared by the Russian Federation to elaborate on the concept of tyre deceleration (dω/dt) in the test technology.