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With many vehicles now achieving high marks in NCAP frontal and side impact, many countries around the world are considering or have already implemented pedestrian impact protocols to help address these types of crashes, due to the incidence rate of pedestrian injuries and fatalities. The leading global protocol put forth by the working party No. 29 (WP29) of the United Nations is the Global Technical Regulation (GTR) [1], which includes testing that simulates a pedestrian's head impacting a vehicle's hood through the use of a free flight head form. In conducting this test, it is important to be aware of the sources of variation inherent in the testing equipment and testing methodology so that steps can be taken to mitigate their influence. Testing facilities that can maintain high standards of repeatability can be relied on for producing valid tests that meet the GTR tolerances as well as maintaining reasonable costs and testing throughput.

This paper summarizes a series of matched-pair frontal sled tests using the Test device for Human Occupant Restraint 50th Percentile Male (THOR-50M) anthropomorphic test device (ATD). Testing was conducted to compare the response of an ATD equipped with an on-board data acquisition system (DAS) to that of one equipped with an off-board system. Sled testing was performed using a modified version of NHTSA’s Gold-Standard test method consisting of a generic buck with a ridged seat and a 3-point seatbelt system. Eight tests were conducted, all using a common generic 30 km/h crash pulse with a peak deceleration of 9 G’s, and a 2.5 kN load limiting 3-point seatbelt retractors without pretentioners. Four tests were conducted with each ATD, two tests with a left shoulder belt routing and two with a right shoulder belt routing to allow for evaluation of the ATD repeatability under each belt routing.

Ejection Mitigation testing is now required by the U.S. government through FMVSS 226 [1]. FMVSS 226 contains the requirement of using a linear guided headform in a horizontal impact test into the inflated curtain, or other ejection mitigation countermeasure that deploys in the event of a rollover. The specification provides dimensions for a featureless headform [2] but there are limited specifications for the headform skin surface condition. In the “Response to Petitions” of the 2011 Final Rule for FMVSS 226 [3], the NHTSA declined the option to include a headform cleaning procedure. This research presents a case study to quantify the effect of changes in the friction between the headform and curtain on the measured excursion. The study presented here shows that a change in friction between the headform and curtain can affect excursion values by up to 135 millimeters (mm).

As a part of its ejection mitigation research, the National Highway Traffic Safety Administration (NHTSA) has proposed a linear impact test that uses a featureless head-form to impact a vehicle's side windows' daylight opening at various positions. The test measures the excursion of the head-form beyond the plane of the window glazing. The intention is to evaluate the ability of a vehicle's ejection mitigation countermeasures, such as the curtain airbag or other vehicle features, to manage the impactor energy and limit excursion. However, at this time NHTSA has not yet established the performance criteria for the excursion. Additionally, there is no clear agreement on the energy level to be used for ejection mitigation testing. The agency has considered three energy levels for the head-form impact: 178, 280, and 400 Joules [ 9 ].