18. The representative of ITU informed the World Forum about the possible collaboration between the secretariat of its organization and the WP.29 secretariat on Intelligent Transport Systems (ITS). Accordingly, he announced that a draft memorandum of understanding on this collaboration would be finalized in short time.
19. WP.29 was informed about the latest developments of UNECE activities on ITS. The secretariat reported that the public consultation on the strategic package on ITS deployment received several comments from a broad range of stakeholders. WP.29 noted that upon consolidation of all the comments, the strategic package would be complemented by a road map to be presented and endorsed at the February 2012 session of the Inland Transport Committee (ITC). WP.29 requested the secretariat to make publicly available on the UNECE ITS website the comments received.
20. The World Forum adopted the guidelines on establishing requirements for highpriority warning signals (ECE/TRANS/WP.29/2011/90) concerning ITS and requested the secretariat to distribute it as an annex to the report of the current session (as ECE/TRANS/WP.29/1091/Add.1).
42. GRE noted that WP.29 had adopted, at its June 2011 session, the guidelines on establishing requirements for high-priority warning signals (ECE/TRANS/WP.29/2011/90) as an annex to the report (ECE/TRANS/WP.29/1091/Add.1). The secretariat reported that the public consultation on the strategic package on ITS deployment had been completed and that upon consolidation of all the comments, the strategic package would be complemented by a road map (ECE/TRANS/WP.29/2011/114) to be considered by WP.29 at its November 2011 session and by the Inland Transport Committee (ITC) at its February 2012 session.
J and NL presented their respective documents (AEBS/LDWS-19-03 and AEBS/LDWS-19-04).
OICA questioned the value of 45km/h mentioned in the second bullet of the NL document justifications. NL clarified that the value of 1,2 seconds referred to in the document addresses the TTC, which varies as long as the vehicle decelerates.
F was of the opinion that the warning time exists to permit the driver to react, hence must be adapted to the driver’s reaction time. In addition, the expert from F wondered why the reaction time is different for the light and the heavy vehicles, while the drivers are all human.
OICA pointed the equal importance of nuisance of too early warnings and the driver’s reaction. The system would become counterproductive should early warnings be too frequent. A too early warning in addition would be design restrictive.
Mr. Clasen referred to the document WP29/1091/Add.1, paragraphs 64-66, which urges the designers to avoid too early warnings.
J acknowledged this document and recalled the row 1 performance requirement (warning time). The delegate from J stressed that the current discussion addresses Row 2 vehicles, and J believed that the J proposal for 0.8s is acceptable in terms of nuisance.
Mr. Clasen recalled that the light vehicles are more agile, hence the driver’s reaction by avoidance via steering can occure later, and recalled the existence of the build-up time on hydraulic braking vehicles.
The Chair recalled that NL requested at the previous meeting some figures about the pressure build-up time for hydraulic braking systems.
CLEPA answered that the Industry experience of build-up time for these vehicles and systems is rather inexistent, the reference value would address ESP, and this would apply to 2 wheels only. The expert from CLEPA informed that a value between 0.8 and 1.5 seconds can be reasonable.
The Chair pointed out that the consequence of such pressure build up time would be that there would be not a full braking during the emergency braking phase.
Mr. Clasen informed that the temperature influences the pressure build-up time due to the transmission oil viscosity and the brake disks friction coefficient.
As a summary, the Chair pointed out that 3 Contracting Parties (J, NL and F) are asking to specify a value for the advanced warning timing, and that D had already indicated their support for the joint OICA/CLEPA proposal at the previous meeting. ROK took no position on this issue.
The Chair suggested, in an attempt to make progress, to separate in the discussions for the stationary target the cells B2 (early warning) and C2 (late warning)) and to do the same afterwards for the moving target.
In response, industry presented their proposal for flexibility for the moving target scenario (document AEBS/LDWS-19-05), indicating that they could accept a 0.8 sec value for the 1st warning provided this could done by optical means.
Moving target scenario
The Chair then suggested to discuss first the moving target scenario.
J could not accept the Industry proposal because they considered braking more important than the warning annoyance. J confirmed their support of the NL proposal.
For the moving target scenario in the Industry position, J could not accept “Optical only”.
NL could not accept optical only for the 1st warning. In the case of the moving target scenario the expert was of the opinion that the nuisance is not that critical.
F pointed out that the distance between the target and the subject vehicle with 1s TTC in the moving target scenario is 4m and proposed the 1st warning at 1.4 s and asked Industry about the driver’s acceptance with that limit (same as in Row 1).
D could support the Industry proposal.
ROK had no opinion but welcomed the flexibility of Industry.
The Chair considered that the discussions indicated some possibility of compromise about the warning timing for the moving target scenario (except from France)
F repeated their support for “optical only” but wanted 1.4 s warning time delay, with 0.8 s for the 2nd warning signal.
Mr. Clasen pointed out that long warning time would jeopardise the manufacturer’s wish to increase the speed reduction because the total time would then not be acceptable. OICA added that such warning time would question the speed reduction, in addition to the security margin and the vehicle dynamics. Also, Industry pointed out the fact that the regulation provides only the minimum values and provides freedom to the manufacturer to do better. One manufacturer gave the example of one of his production line, where 10% of the production are N2, the others are N1. The warning time at 0.8s would permit to use the N1 category AEBS system on the N2 vehicles, while forbidding this would make the AEBS too expensive.
F pointed out the EuroNCAP draft protocol of 1.2 s for driver’s reaction and could agree with this value of 1.2s.
It was stressed that EuroNCAP only addresses the M1 vehicles and that the protocol is still under discussion.
The Chair cautioned that the lack of flexibility by one Contracting Party would entail the risk that the informal group has to turn to its parent body, i.e. GRRF, for seeking guidance or even resolution on this technical matter.
F confirmed its position, and repeated to agree with 1.2 s for the 1st warning.
The Chair concluded by regretting that the informal group could not find a compromise for the warning time for the moving target scenario and announced his intention to request guidance from GRRF.
The Chair suggested to discuss the “optical only” 1st warning based on the assumption that a compromise could be later found for the value of warning time.
F confirmed the willing of 1.2s for the 1st signal.
OICA stressed that there is currently no experience of the system on these vehicles, and the need to get millions of kms with different drivers before making a decision on a possible compromise, in view of the risk to completely jeopardise the market confidence in this system.
The Chair therefore suggested asking guidance to GRRF on this issue as well.
Stationary target scenario
The group then started discussions on the stationary target scenario. The Chair recalled his proposal for a compromise for B2 and C2 cells, i.e. separating the values for the 1st warning from those for the 2nd warning.
OICA recalled their offer for flexibility for moving target scenario, and could not be more flexible for the stationary target scenario. The expert recalled the distance of 40 m in front of the target in case of a 0.8s warning time, in particular in view that the system is currently purely theoretical. The proposal is to amend the text such that the warning time is given BEFORE the start of the emergency braking phase. OICA was cautious in accepting an “optical only” warning in this case in view of the fact that the Contracting Parties did not accept the “optical only” for the moving target scenario.
NL found that the parameter for the stationary target scenario is the sensor recognition of a stationary target. NL recalled that a TTC of 1.8 sec provides at least 30m between the subject vehicle and the target. NL could accept optical only.
D supported the Chair’s proposal.
J could support 0.8s for the timing, and could not accept “optical only”.
F could accept the Chair’s proposal.
ROK could also support the Chair’s proposal.
OICA could not accept the J position, and was willing to have a further Industry internal consultation about the Chair’s proposal.
Temporary conclusion: no conclusive decision on warning times. See also item 5.2. below.