Sitting posture influence in autonomous vehicles for the evaluation of occupant safety in side impact

Autonomous vehicles will give vehicle drivers greater freedom to engage in other activities while the vehicle is in operation that will lead to changes in the seating configurations as well as driver posture. Although it is expected that these vehicles will prevent crashes, collisions will still happen. Ensuring the adequate protection of occupants in these new unconventional positions is the main challenge. The objective of this study was to evaluate and analyse occupant responses in non-standard seating positions that may be expected to occur in automated vehicles occupants under side impact conditions. Finite Elements Method simulations were performed using the WorldSID 50th male dummy positioned in the driver position. A validated simplified vehicle model with fully deformable driver-side components was used. To explore the sensitivity to side impact across various occupant activities, five scenarios were defined: normal driving (S0), fall-back ready (S1), work (S2), leisure (S3) and relax/sleep (S4). All scenarios were subjected to the Euro NCAP Side Tests Protocols (deformable barrier and oblique pole impact). As the distance from the pole impact point to the B-pillar decreased, the structure deformation increased due to the B-Pillar deformation. In cases S2 and S3 predicted thorax injury values were the highest, whereas scenarios S3 and S4 were the worst situation in deformable barrier impact test. Good pelvis protection was provided in all pole impact scenarios, but pelvis injury values were the highest in all scenarios in deformable barrier impact test. Attending to the new scenarios due to the new available driver activities, current safety standards are not enough to guarantee the highest level of protection. Reclined seating scenarios required a wide range of impact positions to be covered since injury responses were influenced by the initial impact alignment of the dummy relative to the vehicle and the pole. Large rotations of the seatback lead to high chest compressions.