Proposal for Supplement 6 to the 02 series of amendments to UN Regulation No. 117
Document GRRF-76-26
12 February 2014

Proposal to elaborate on the concept of tyre deceleration (dω/dt) in the test procedures. 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.

Submitted by Russia, UTAC, ETRTO, and NAMI
Status: Superseded
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Previous Documents, Discussions, and Outcomes
4.10.2. | Proposal for Corrigendum 4 to the 02 series of amendments to Regulation No. 117
4.10.3. | Proposal for Corrigendum 5 (Russian only) to the 02 series of amendments to Regulation No. 117
4.12.3. | Proposal for Supplement 5 to the 02 series of amendments to Regulation No. 117

55. The World Forum considered the pending proposal for amendments to Regulation No. 117 listed under agenda item 4.12.3 (document ECE/TRANS/WP.29/2013/66) and recommended its submission to AC.1 for voting, subject to the correction of para. 47 below (see WP.29-162-05).

56. Page 1, the title, replace “Supplement 5” by “Supplement 6”. Page 2, paragraph 6.2.3, correct the wet grip index G for normal tyres other than traction tyres to read 0.80.

[The proposal was adopted as amended as “Supplement 6 to the 02 series of amendments to UN Regulation No. 117” by a vote of 36 in favor and none either opposed or abstaining.]

7. (b) | Regulation No. 117

24. Recalling the purpose of ECE/TRANS/WP.29/2013/66, the Chair of GRRF stressed that WP.29 was expecting GRRF to conclude its deliberation about the wet grip limit values. The GRRF experts introduced their positions (GRRF-76-05, GRRF-76-07, GRRF-76-08, GRRF-76-11, GRRF-76-12, GRRF-76-26, GRRF-76-27, GRRF-76-28). The expert from the EC reported on the concerns expressed by the Directorate-General for Mobility and Transport of the European Commission (DG Move). GRRF confirmed the limit values proposed in para. 6.2.2. for Tyres of C2 category and agreed to amend the proposed limit values in para. 6.2.3. for Tyres of C3 category in ECE/TRANS/WP.29/2013/66. GRRF requested the secretariat to submit this amendment as reproduced in WP.29-162-05 to WP.29 and AC.1 for consideration at their March 2014 session.

24bis. The expert from the Russian Federation presented GRB-59-02 proposing a tyre rolling resistance test results evaluation using a mathematical algorithm, to be added as an alternative to the existing one in the text of the Regulation. He also presented the results of a validation study of the proposed algorithm for tyres of the C1 category performed in France, in cooperation with the Russian Federation (GRB-59-07 and GRB-59-08). GRRF noted that this proposal may be submitted by GRB to WP.29 as a supplement to UN Regulation No. 117. GRRF recommended further steps for a better understanding of the proposed method’s sensitivity, suggesting: (i) extending the validation study for tyres of categories C2 and C3 and (ii) verifying the application of the proposed alternative in the conditions of the conformity of production. The GRRF Chair invited the experts to provide their comments on the proposal to the GRB secretariat with a copy to the expert from the Russian Federation.

6. | Regulation No. 117 (Tyre rolling noise and wet grip adhesion)

15. The expert from the Russian Federation made a presentation (GRB-58-12) to introduce a revised proposal (ECE/TRANS/WP.29/GRB/2013/10) that would introduce a “Deceleration Calculator” software for the deceleration test method in the test procedure for measuring rolling resistance. The expert from France informed GRB that the proposed calculator had been verified for a first cycle of tests by the Technical Union for the Automobile, Motorcycle and Cycle Industries (UTAC). However, he added that the method should be still thoroughly analysed. The expert from ETRTO expressed some doubts on the variability of the method by temperature change and stated that further work was needed to demonstrate equivalence. The expert from the Russian Federation recalled that full cooperation was offered by the Russian experts as well as data sharing and asked GRB to take into consideration the positive experience developed by the industrial sector of his country in this field. The expert from France proposed to host a meeting of experts (date to be defined) in UTAC to further the exchange of views and finalize the proposal. The Chair of GRB suggested that other laboratories would start similar activities to evaluate the proposed method and devise possible alternative calculators to provide wider choice to future users. Finally, GRB endorsed the ad hoc meeting with the experts of ETRTO and the Russian Federation which was proposed by the expert from France to test the proposed “Deceleration Calculator”. It was also noted that once that the calculator was accepted by GRB as a valid alternative to the current one, it could be hosted on the WP.29 website, as an example, with an anonymous reference.

Related and Previous Documents
GRB/2013/10
GRRF-76-27
GRRF-76-28
WP.29-162-05
Relates to UN R117 |