EU/TNO WLTP correction algorithms draft study
Download in .doc format

TNO draft report on “Correction algorithms for WLTP chassis dynamometer and coast-down testing”.

Reference Number: WLTP-08-37
Origin: TNO
Date: 17 November 2014
Related Documents:
WLTP-08-38 | EC cover note accompanying the draft TNO WLTP correction algorithms report
Worldwide Harmonized Light Vehicles Emissions Test Procedure | Session 8 | 18-20 Nov 2014

Position paper (WLTP-08-38e) was presented by EU-COM with the aim to decide on a package of procedures for harmonization and a timeframe for inclusion into gtr (priorities A, B, C). The focus lies on issues with priority A (immediate EU implementation & introduction in gtr in phase1B) and B (further investigation and introduction in phase1B). Proposal on item 2.7 (inaccuracy of road load setting on the chassis dyno) was withdrawn during discussions.

A first view was given by ACEA (WLTP-08-46, -08-47 by BMW):
Item 2.2 (drive trace correction) several difficulties are not yet addressed, but most of them could possibly be solved in the timeframe of WLTP phase 1B. The aspects regarding EV vehicles can most likely not be solved in phase 1B. JPN shared the EV concerns. EU COM proposed to exclude EVs in a first step.
Regarding item 4.1 (Veh. conditioning for coast down, tyre pressure monitoring/control) it was suggested to deal with it in TF RLD, because it is no correction. WLTP IWG agreed that TF RLD should prepare a proposal.

Item 6.2 (Rotational inertia mass) needs in view of ACEA further investigation.

JPN will provide its positions in IWG meeting #9, with the focus on items with rank of A or B. (note: inclusion of other items in WLTP phase 2 needs to be discussed separately, see agenda item 11)

India requested information about data basis for indicated possible deviations. EU COM referred to details in the report of TUG / TNO (WLTP-08-37e).

EU will clarify the immediate need for introduction of a cycle correction in European legislation before adoption of WLTP phase 1B.

Chair recommends TF to continue the discussion focusing on the A-Elements and later on the B-Position. All Contracting Parties are strongly requested to give a clear position, if this approach should be handled in general within the scope of WLTP gtr and if yes, which of the proposed items are supported to be harmonized within phase 1B. (Deadline for feedback: 02.01.2015). Additional assessments with a view on technical aspects / possible difficulties and necessary validations are also welcomed.