The agenda includes a review of the schedule with next meetings on 7th July and 24th August, continuation of database analysis presentation from RDW, review of decisions and work for the next meeting, report to IWG RD-ASEP.

Task Force Data Analysis (Sub Group to IWG RD-ASEP) held its 13th meeting on Wednesday, 3rd June 2026. The group reviewed database analysis including statistical analysis of differences between expected and measured sound levels, sub-model construction, and optimization calculations for parameter tables. Discussion addressed model construction concerns, vehicle failure differentiation, and data collection requirements including approval values according to UN R117. Next meetings are scheduled for Tuesday, 7th July and Monday, 24th August 2026.

This presentation analyzes RD-ASEP model performance using test run data from Annex_9_test_runs where both left and right sound were measured. Current model shows 1.3% of measurements above L_exp; without the 2 dB margin this increases to 8.4%. Model overestimates at low speeds and underestimates at higher accelerations. Tyre rolling sound parameters have most influence on results and dominate most of the data set. Optimizing all 13 parameters reduces mean absolute error from 2.1 to 1.1 dB. More high acceleration measurements are needed to reliably calibrate the dynamic component.

The session will cover database analysis including review of documents and discussion points from pilots view, AVAS term dL Dynamic factor x, review of decisions and work for the next meeting.

The Task Force Data Analysis held its 12th session on 28 April 2026. Database version 3 requires further corrections to reflect IWG decisions on v_test, parallel and serial hybrids, and German input; version 4 will be delivered. The group reviewed German input on database issues and decided to establish an Excel list documenting observations, background information, and proposed solutions. Additional data are needed on gear shifting during pass-by measurement, ICE ON/OFF shifting, low speed measurements below 30 km/h, high performance vehicles with acceleration greater than 5 m/s² at high speeds, and EV data.

The Task Force Data Analysis (Sub Group to IWG RD-ASEP) will hold its 12th meeting on Tuesday, 28th April 2026. The agenda includes a review of the meeting schedule with targeted meetings on 19th May, 3rd June, and 9th June, review of database version 3 status and input from Germany on database issues, review of analysis performed, and review of decisions and work for the next meeting.

The Data Analysis task force met with limited participation from Japan, Netherlands, and the pilot. The group reviewed corrections made to vehicle load issues and reference speeds. They determined that corrections to PMR and L_urban calculations would be too time-consuming without adding substantial benefit and are not currently used by the model. A proposal for generic reference acceleration determination requires further assessment, as initial analysis indicates the formula overestimates acceleration potential. The data review process should be closed, so the official work with the database can start.

The Task Force Data Analysis has almost completed data revision for RD-ASEP specifications, identifying inconsistencies and proposing corrections. Key considerations include: updating database limits to UN R51.03 phase 3, clarifying vehicle reference speed interpretation, correcting reported loads exceeding 100%, selecting correct parameter tables, defining run interdependency, strengthening tyre rolling sound specifications, resolving minimum dynamic calculation inconsistencies, improving gear shifting detection, reconsidering sound level maximum basis, increasing performance validity threshold, accepting runs outside control range with manufacturer agreement, and reviewing AVAS term application for hybrid vehicles.

The Task Force Data Analysis agenda covers welcome and agenda adoption; review of meeting schedule with sessions scheduled through June 2026; discussion of actions and considerations for the IWG and Editing group; review of vehicle review list Version 19; database status and release timing; decisions and work for subsequent meetings; and closing remarks.