In a series of HyGe sled tests on the Hybrid III dummy, the effects of seat belt and seat geometry on dummy trajectory were examined. A three dimensional spatial measurement system was used to evaluate the dummy behaviour alongside the standard instrumentation results.

The first part of the test series compared dummy size and then went on to examine the effect of the influence of belt parameters. These included belt length, stiffness and effects of weblocks and pre-tensioners. An understanding was gained of the effects of these parameter changes and the degree to which a car with poor occupant protection performance in a crash may be improved without re-developing the vehicle structure. The second part assessedd ummy behaviour when the seat was out of the standard position. These tests involved changing seat back angle, cushion angle and cushion friction. The results show the effect on injury levels of changes from the settings used in compliance testing. The results in this paper provide guidance to improved occupant protection through changes in restraint system design.