CHILD SAFETY IN AUTONOMOUS VEHICLES: "LIVING ROOM" LAYOUT

Autonomous vehicles start to be introduced on our roads and will soon become a reality. Although fatal traffic accidents will be significantly reduced, remaining fatal passenger car crashes should be taken into account to ensure the safety of users. The new highly adaptable interior designs, with totally different layouts from the current ones, may significantly impact occupant safety, especially child passenger safety. Analyzing how these new vehicles affect child safety is a challenge that needs to be addressed. The "living room" layout (face-to-face seating position) is one of the preferences of families traveling with children. Young children need further support and supervision so the possibility of rotating seats to be able to be in front of the small children is a valuable feature for parents. Therefore, new seating orientations away from the forward facing position should be taken into account to ensure children protection. The objective of this study is to evaluate child occupant safety in a "living room" seating position (a possible option in full autonomous vehicles) versus the current forward facing position. Virtual testing methodology was used to perform this study. The virtual PIPER child human body model (HBM) was used. This model is one of the only HBMs developed and validated from child PMHS data (Paediatric Post-Mortem Human Surrogate). The two configurations were defined according with the EuroNCAP child occupant protection test protocol. It was found that the "living room" layout presents worse results according to the child's head injury patterns than in forward facing position. In conclusion, attending to the new seating orientations away from the forward facing position, it is necessary to adapt the restraint systems; otherwise children could suffer potentially dangerous situations.

Numerical Simulation of Airbag and Study on the Effect of Airbag Parameters on Head Injury Criteria

In the case of an accident, inflatable restraints system plays a critical role in ensuring the safety of vehicle occupants. Frontal airbags have saved 44,869 lives, according to research conducted by the National Highway Traffic Safety Administration (NHTSA).Finite element analysis is extremely important in the research and development of airbags in order to ensure optimum protection for occupant. In this work, we simulate a head impact test with a deploying airbag and investigate the airbag's parameters. The airbag's performance is directly influenced by the parameters of the cushion such as vent area and fabric elasticity. The FEM model is analysed to investigate the influence of airbag parameter, and the findings are utilised to determine an optimal value that may be employed in the construction of better occupant safety systems. Keywords: airbag, finite element method, occupant safety, frontal airbag, vent size, fabric elasticity, head injury criteria

Enhancing Occupant Safety by Pre-active Seat Control for Out-of-seat Position before Autonomous Emergency Braking Operation

The pre-active safety seat (PSS) is a recently developed active safety system for securing occupant safety in out-of-seat position (OOSP), which was applied in the Hyundai Genesis G80 in 2020. However, there has not been sufficient quantifiable verification supporting the effectiveness of the PSS. The present study was performed to determine the effectiveness of the PSS for occupant safety in OOSP and to identify areas for additional improvement. Six test conditions were considered to determine the effectiveness of the PSS for augmentation of occupant safety in OOSP. Ten healthy men participated in the tests. Compared with the no PSS condition, maximum head excursion and neck rotation were significantly decreased in the PSS condition by 0.31–0.79-fold and 0.33–0.48-fold, respectively (p < 0.05). The PSS condition in which the seat pan was moved forward to the mid position showed a greater effect in reducing the characteristic motions related to submarining, compared with the condition in which the seat pan was moved rearward to the mid position (p < 0.05). These results suggested that PSS augments occupant safety in OOSP. This study provides valuable insights in ameliorating risks to the occupant in unintended seat positions before braking and/or collision.

Numerical Simulation of Vehicle–Lighting Pole Crash Tests: Parametric Study of Factors Influencing Predicted Occupant Safety Levels

In this paper, numerical simulations of the EN 12767 test procedure for a vehicle–lighting pole crash are presented. A representative soil–vehicle–lighting pole model is first developed. The Geo Metro vehicle model is used, and significant attention is given to representing the soil and its interaction with the traffic pole. Soil is represented using smoothed particle hydrodynamics (SPH) coupled with finite elements (FEs). A parametric study is carried out to investigate the key factors influencing the outcomes and consequently the estimation of the occupant safety levels during crash scenario described in EN 12767. First, a sensitivity study of lighting pole mesh is conducted As a result, the optimal mesh size is used for further studies regarding physical parameters such as soil properties and friction coefficient in vehicle–pole interfaces. Friction and mesh size are found to have a considerable influence on the acceleration severity index (ASI), theoretical head impact velocity (THIV), post-impact velocity and vehicle behavior during the lighting pole crash scenario.

Vehicle occupant safety development with finite element method

Crash tests of vehicles are specified by government programs. This laws are includes only minimum requirements for individual components. Therefore additional consumer protection load cases have been developed by independent private institutes. Finite element method simulations can reduce development periods and the number of cost-intensive real crash tests. The goals of the calculations are that the early detection of component failure, the protection of occupants or pedestrians. The biggest challenge of the future, in the field of vehicle occupant safety is the interaction of the airbags and belt system with dummy by the electric vehicles, which have the concept of autonomous driving function. The aim of the research is to investigate this area using a simulation model.

Life Quality Index–based cost–benefit analysis of equipping life preservers aboard airplanes

The life preservers aboard airplanes play a critical role in ensuring occupant safety in water-related accidents. However, several airlines off-load life preservers to save fuel and costs. In this study, a cost–benefit analysis was performed considering the Life Quality Index to examine the necessity of life preservers aboard aircraft. It was noted that the placement of life preservers aboard airplanes was reasonable and beneficial in the recent 15 years. Although life preservers are primarily required for extended overwater (EOW) operations, the distance from the shoreline for most of the water-related accidents was considerably smaller than that of an EOW operation, and most water-related accidents occurred close to an airport. In other words, air passengers were at risk of water-related accidents, regardless of whether the flight was classified as an EOW flight. Thus, life preservers must be made available for all the occupants on all passenger flights, regardless of the flight path.

Energy Absorption Characteristics of Axially Compressed Double Wall Foam Filled and Empty Square Tubes

Occupant safety has become increasingly important in the recent times. At the instance of an accident or collision, structures with high energy absorption can provide better occupant safety. Thin-walled tubes are widely used as energy absorbers in automobiles and other structures. In the present work, crashworthiness characteristics of double wall empty and double wall foam filled tubes are investigated. Thin wall extruded aluminum square tubes are used in this study. Polymer foam of three different densities, viz., 40 kg/m3, 80 kg/m3, 140 kg/m3 was used as filler material between the two tubes to fabricate a double wall foam filled tube. Both parallel and diamond configurations were considered for double walled empty and foam filled configurations. All the specimens were compressed at a displacement rate of 100 mm/min. Crushing of different configurations was numerically analyzed using nonlinear finite element tool LS-Dyna®. In double wall empty configuration, diamond arrangement absorbed more energy compared to parallel due to the interaction between inner and outer tubes. Results indicate that energy absorption increases with the filling of foam. Compared to double wall tubes, the maximum increase in energy absorption of ∼ 50% is observed in foam filled tubes. Using Computed Tomography (CT) scan of specimens, it is observed that foam filling alters the crushing behavior of the inner and outer tubes.