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Validation of utilizing a self-propelled crash sled to simulate occupant accelerations in minor rear-end impacts

A novel, electrically self-propelled, mobile, free-standing crash sled was constructed with a relatively minimal budget (i.e., ≤ $10,000). The crash sled was designed to simulate occupant driver or passenger seat movement in minor impacts at varying angles with minimal, if any, component replacement necessary between tests. Validation of the crash sled in a rear-end only configuration for determination of occupant accelerations was performed. Minor rear-end crash tests involving human occupants were conducted utilizing a 2007 Toyota Camry target vehicle and a 2005 Toyota Camry bullet vehicle with changes in velocity for the target vehicle ranging between 2.8 km/h and 7.7 km/h. Vehicle instrumentation consisted of tri-axial accelerometers affixed to the center tunnels near their respective center of gravities. Human occupant instrumentation occurred only in the target vehicle and involved tri-axial accelerometers at the head, thorax, and lumbar spine. Peak longitudinal head and lumbar occupant accelerations were recorded at 2.6 to 11.2 g and 1.5 to 4.8 g, respectively. Following the vehicle crash tests, the target vehicle seat was removed and attached to the crash sled in the same orientation. Rear impact crash sled testing was then conducted with changes in velocity ranging between 2.1 km/h and 9.0 km/h utilizing the same human occupant involved in the Toyota target vehicle testing. Crash sled instrumentation consisted of a tri-axial accelerometer affixed near the center of gravity. Human occupant instrumentation for the crash sled tests was identical to the vehicle impacts. Peak longitudinal head and lumbar occupant accelerations were recorded at 1.6 to 12.1 g and 1.0 to 5.2 g, respectively for the crash sled tests. Analysis of all test results, in addition to direct comparisons for similar vehicle and sled impact magnitudes, indicated the crash sled tests accurately predicted occupant head and lumbar accelerations in vehicle-to-vehicle minor rear-end impacts of similar severity.