Design and sled testing of a high back booster seat prototype offering improved side impact protection

Current booster seats do not offer effective protection in side impact. Previous studies have suggested that the level of protection provided by boosters in side impact can be substantially improved through relatively minor design changes to booster seat geometry. Previous studies have also shown that booster seat performance can be significantly enhanced by rigidly anchoring booster seats to the vehicle structure. The aim of this study is to demonstrate how the level of side impact protection in booster seats can be increased through attention to booster seat geometry and booster seat anchorage. A high back booster seat prototype was designed and manufactured. It incorporates a rigid attachment, deep side wings, and a height adjustment system. It was then tested in side impact using a Hybrid III 6 year old dummy on a sled with a non-intruding side door structure. The improved design features of the prototype were then compared, in terms of the level of protection provided to the dummy, to the performance of two current booster seats available on the Australian market. Different upper side wings configurations were also tested. The prototype was also tested in frontal impact to verify that the level of protection had been maintained in that impact direction. Unlike current booster seat designs, the prototype succeeded in fully containing the dummy in all tests, therefore preventing contact with the side door structure. In 90 degree impacts, the prototype was found to reduce the HIC36 results by up two thirds when compared to the two current booster seats. The upper neck loads were also considerably reduced. While side wing height and depth was found to be an important feature in achieving these reductions in injury risk, side wing angle was found to have less of an effect. This study confirms that it is possible to offer significantly improved side impact protection in booster seats by using a rigid anchorage system, deep side wings and a height adjustment system.