Maximilian J.Stanglmeierab , Florian K. Paternosterb , Susanne Paternostera , Raphael J.Bichlera , Peer-OliverWagnera , Ansgar Schwirtzb
aBMW Group, Knorrstraße 147, 80788, München, Germany
bDepartment of Biomechanics in Sports, Technical University of Munich, Uptown München-Campus D, Georg-Brauchle-Ring 60/62, 80992, München, Germany
Highlights
- Seating angels affect the biomechanical quality of in-vehicle sleeping position.
- Combination of 40° seat pan and 155° backrest is suggested for in-vehicle sleeping.
- Eight of nine combinations can be considered as suitable for sleeping.
- People prefer a flat-as-possible position for sleeping.
Occupants of autonomous vehicle have frequently indicated the desire to sleep or rest while driving, yet little has been known regarding the suitable design criteria for a biomechanically reasoned in-vehicle sleeping position. This study was aimed at evaluating the biomechanical quality of different backrest and seat pan angle combinations, and at predicting the most favourable sleeping positions based on vehicle restriction. More specifically, the interface pressure distribution and subjective suitability rating of 23 subjects was assessed in a total of nine (3 × 3) combinations of seat pan (20°, 30°, 40°) and backrest (145°, 155°, 165°) angles. Biomechanical quality was evaluated with an interface pressure score (IPS) based on sensitivity weighted pressures and the total contact area. Two-way repeated measures ANOVA revealed that IPS significantly improves with increasing seat pan angle whereas backrest angles of 155° or 165° lead to significant better IPS compared to flatter ones (145°). The overall highest IPS was observed for a 40°-seat pan angle in combination with a 155°-backrest angle. Subjective suitability rating revealed that people prefer a combination of 165° backrest angle with a seat pan of 20°; however, eight of nine combinations can be considered as suitable for sleeping. Therefore, the combination of a 40°-seat pan angle and 155° backrest is recommended by the present study for an in-vehicle sleeping position due to the increased biomechanical quality.