Automated vehicles introduce the potential for non-traditional seating postures, including various degrees of recline. To date, there have been no human surrogate studies in the literature describing reclined occupant response in frontal or other crashes, which suggests that new biofidelity reference targets are needed to evaluate anthropomorphic test device (ATD) and human body model (HBM) predictions. The goal of this study was to develop and demonstrate a methodology for performing biofidelity reference tests for reclined occupants that incorporate methods for capturing these complex kinematics and kinetics. The test methodology developed here is demonstrated with a frontal impact sled test performed with one post mortem human surrogate (PMHS). A simplified, generic, semi-rigid seat pan and minimal back support (at 50 degrees reclined with the vertical) was used to support the occupants as they underwent a 50 km/h crash pulse while restrained with a three pretensioner force- limited seat-integrated belt restraint. Occupant kinematics, seat deflections, belt spool-in and spool-out, and buck motion were collected with an optoelectronic motion tracking system and lumbar spine and pelvic load timing were collected with additional instrumentation. Boundary conditions are critical for finite element (FE) model validation. The forces beneath the seat pan, toe pan and buckle were measured in 6 degrees of freedom (DOF). Additionally, the forces at the lap belt and shoulder belt were measured.

This is the first effort in the field to develop and evaluate a methodology for reclined occupant biofidelity reference testing, which can (and will) be used for:​ i) additional PMHS testing to generate biofidelity reference targets for assessing the performance of occupant models in reclined postures;​ and can also be extended to:​ ii) generate reference data for other reclined configurations and iii) to assess the performance of new and novel restraint system designs.