The aim of this study is to define the maximum force of seatbelt pretension in the pre-crash-phase tolerable for a car passenger. This is attempted by volunteer tests using a car fitted with a prototype of a reversible system for belt pretension. The volunteers (14 females, 10 males, aged 16 -73 years) represent a broad spectrum of car users. Up to now, 64 tests were conducted in a stationary vehicle to determine the tolerable strain especially under out-of-position (OOP) conditions. The head acceleration measured through accelerometers which were mounted on individually fitted dental adapters, was rather low in all tests with some increase for the OOP experiments. Under the present test set up and conditions, the loadings were assessed by the test persons as tolerable and acceptable. In general, the belt forces measured with shorter and lightweight persons were higher than those measured with tall and heavier persons. This can be improved by a special algorithm, for example, in connection with a weight sensor in the car seat so as to better adapt the system to the anthropometric parameters of the occupant.
Abstract