In recent years, products that make use of integrated safety that use the environmental data to optimize occupant restraints have been on the market. Pre-safe system in the integrated safety category is an adaptive and smart protection system that utilizes the occupant information and the monitoring information on the accident prediction. These pre-safe systems need the proper algorithm corresponding to the crash scenario for the crash unavoidable state. Due to the crash scenario categories for the real world accidents is quite various, the development of the algorithm and the occupant protection system to reduce the injury is quite complex and costly. For this reason, a development process for pre-safe related integrated safety systems demands new tools based on the biomechanics to help design and assessment.

The virtual development and assessment process with a viewpoint on the efficiency of the restraint development has been developed. The real time controlled restraint system is adapted for support this process. The virtual development process with real time controlled restraint system offers an optimized guide line in terms of injury reduction over various crash scenarios. With this virtual development process, definition of the proper restraint characteristics and the algorithm for the various crash scenarios can be achieved more easily and fast. Based on the accident data analysis, there are a large number of crashes where the drivers did not put the brake. For this reason, the active safety technologies like brake assist system are being developed. Brake assist system also can make difference in occupant kinematics and injuries. The frontal impact occupant analysis model with pre-crash brake system was developed. Developed model had the braking stage that produces deceleration of 0.8g for 0.9 seconds. The significant change in the dummy posture was observed during pre-crash braking and this change led the increase of occupant injuries. In order to enhance occupant protection during pre-crash braking, pre-crash seat belt system was applied. The pre-crash seat belt system was modeled with MADYMO-SIMULINK Coupling model in order to control the webbing tension force of the pre-crash seat belt. Numerical simulations were performed with pre-crash seat belt of various tension force limits in the driver side NCAP model.

The increase of seat belt webbing tension force indicates that the occupant injury risk could be reduced due to the initial restraint effect. The chest acceleration, chest deflection and neck injury in the event of crash are basically functions of seat belt webbing tension prior to crash. The results showed the tendency of lower injury level with more retraction in certain dynamic conditions. But excessive retraction of seat belt may cause the upward trend in the chest deflection due to the initial deflection of chest generated by retraction. Conclusion and Relevance to session submitted The effectiveness of this process is evaluated and the obtained restraint characteristics will be used as a basis to define the appropriate integrated safety features and the performance criteria.