Tobata 1 DEVELOPMENT OF PRE-CRASH ACTIVE SEATBELT SYSTEM FOR REAL WORLD SAFETY

In this paper, potential benefits of a brake operated pre-crash active seatbelt system are analyzed with experimental verifications and numerical simulations. The system is activated at the time of emergency braking operation. The statistical data from real world accidents (Japan) as well as driving simulator analysis show that drivers interact with the brake to avoid crash in about 50% of the total number of accidents. This indicates that an inevitable crash can be detected before the actual time of crash by observing the emergency braking operation activated by the driver. Experimental results show that restriction of occupant's forward movement is achieved by activating the system while braking. Numerical simulation results show that the reduction of chest injury parameters is expected due to restriction of occupant's forward movement. It is also confirmed that higher initial tension of the seat belt reduced both chest deceleration and displacement.