Multi-objective Optimization Design of Occupant Restraint System Based on Dynamic Weighted Injury Criteria

In order to increase the C-NCAP rating score of a certain developing vehicle under 50FFB and 64OBD crash conditions, the weights of Injury Criteria are calculated, and a DWIC (Dynamic Weighted Injury Criteria) optimization objective is proposed under these two impact conditions. The sensitivity analysis method is used to determine the main factors of occupant injury, then the optimal Latin superelevation method is utilized to design the test matrix, acquiring 64 groups of calculation results. Based on this, the surrogate model of restraint system with DWIC formula is established. Finally, multi-objective optimization is achieved with NSGA-II algorithm to obtain the optimal parameters of the constrained system. The results show that the head and neck injury criteria of driver are reduced by 19.2% and 25.9% respectively, improving 50FFB score by 1.31 points. Rating score under 64OBD condition is improved by 0.94 points. Compared with the original weight, the score improvement is increased by more than 30%. Thus, optimization process based on DWIC is proven to be effective in achieving better rating score for specified vehicle model and evaluation procedures, which would be further used in MPDB tests.