Development of the Pop-Up Engine Hood for Pedestrian Head Protection

The "Pop-up Engine Hood" helps makes it possible for automobile designers to help reduce head injury during pedestrian impact while maintaining streamlined hood design. Some countries have adopted pedestrian protection regulation and there is an on-going discussion in the United Nations WP29 about Global Technical Regulations (GTR) and there is a possibility such regulations may be enhanced in the future. Many car manufacturers have been planning to improve pedestrian safety by various technical applications. In general, pedestrian head protection is achieved by creating space between the hood (which is deformable) and the engine component (which is not). However, this concept is difficult to apply to some vehicles, especially low engine hood vehicles, such as coupes and sport cars. The "Pop-up Engine Hood System" which has recently been used in mass production vehicles in Japan may help with this issue. The system and its key technologies are outlined including: effectiveness of injury reduction mechanism (evaluated using CAE analysis and tests) when a pedestrian contacts directly above or near the actuator, which lifts up the hood; a technique to help reduce the dispersion of head injury due to hood vibration during the hood raising process; and human kinematics during system operation evaluated by using Polar-II dummy (currently available as a pedestrian full scale dummy), and human body FE model. The full text of this paper may be found at: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0067.pdf For the covering abstract see ITRD E145407.