An Examination of the Factors that Affect Testing Variation in Pedestrian Head Impact Equipment

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 will present a study of the various factors in the test setup and method that can introduce variation to the head form speed and impact point accuracy. Furthermore, the authors will present a novel design for the impactor arm that dampens the recoil that occurs during the launching of the pedestrian head form to improve the test accuracy and long term durability of the equipment.