Mrs Meyerson presented an updated analysis of injuries in US pole side impact crashes (PSI-02-11). Mrs Meyerson advised that the FMVSS 214 pole test benefits analysis presented at the Bonn meeting (PSI-01-16) had conservatively not included any benefits for the abdomen and pelvis in vehicle to pole/tree side impact crashes as the MAIS had always occurred at the head or thorax.
There were serious abdomen and pelvis injuries in the US pole/tree side impact statistics, but the abdomen and pelvis had not been recorded as the location of the Maximum AIS (MAIS) injury in these crashes. The US should therefore be seeing some benefits by way of reduced abdomen and pelvis injuries in pole/tree side impact crashes, although no benefits had been claimed in the FMVSS 214 pole test benefits analysis.
Mr Langner presented an update of GIDAS and CCIS in-depth pole side impact data, by angle of impact, injured body region and casualty age (PSI-02-12). Mr Langner undertook to provide further analysis based on vehicles manufactured in the last 5 years only and including serious injuries.
Mr Belcher presented an analysis of vehicle structural deformation in oblique, perpendicular and offset perpendicular pole side impact crash tests conducted by Australia (PSI-02-13). All tests had been conducted at 32 km/h. Mr Belcher noted that the perpendicular and offset perpendicular tests produced marginally more structural deformation than the oblique test at 32 km/h, but the 32 km/h oblique test was theoretically predicted to produce more structural deformation than a perpendicular or offset perpendicular test conducted at 29 km/h.
Mr Belcher also noted that the oblique impact looked very much like a perpendicular impact and, in that respect, it would be easy for an oblique impact to be mistaken for a perpendicular impact in the statistical coding of field crashes.
Mrs Meyerson presented a summary of NHTSA’s motivations for including an oblique pole test in FMVSS 214 (PSI-02-14). Mrs Meyerson advised that NHTSA had analysed NASS/CDS field crash cases where the side airbags should have deployed, but did not. NHTSA had decided on the oblique impact angle as a result of side airbag system failures / limitations observed in lab tests and from analysis of field crash data.
Mr Terrell asked if NHTSA knew what sensors were being used in the case study vehicles and commented that he did not notice pressure sensors in the vehicles on display at the EuroNCAP exhibition in Brussels he had attended the day before.
Mr Wiacek advised that he had noticed that many manufacturers of US market vehicles were now moving towards multiple pressure sensors instead of single b-pillar acceleration type sensors.
Mr Limmer advised that two sensors are generally required to fire a side airbag, including one at the airbag control module near the vehicle centre of gravity. In an oblique impact the signal at the airbag control module can sometimes be a bit noisier than in a perpendicular impact. Mr Limmer stated that some cars give really good b-pillar acceleration signals while other cars do not and noted that impacts that occur at the end of the door can be difficult to detect with pressure sensors. It is therefore a matter of designing the most appropriate sensing system for each vehicle model.