Research On Occupant Injury Caused By Automatic Emergency Steering Causing Oblique Impact

Emerging active safety technology and traditional passive safety technology have important significance and value in the two aspects of accident prevention and collision protection.Recent years,the integrated research on the protection of occupant injury combined with the two has attracted the attention of worldwide automobile manufacturers and research scholars,also,has quickly become a research hotspot.Among them,when the automatic emergency steering is used for active collision avoidance,the occupant will have obvious lateral dislocation during the steering process.While the research on the protection of the off-position occupant in the steering phase is still lacking.Therefore,the study of the injury risk of occupants in collision accidents caused by automatic emergency steering have important guiding significance to the occupant injury protection under the active and passive safety integration.Based on the above background,this paper selects the 2010 Toyota Yaris as the target vehicle.takes the car-car oblique impact caused by automatic emergency steering as the research object.Integrates simulation the dynamic response of the occupant in the whole process of steering and collision,and study the risk of injury.According to the occupant's dynamic response and injury risk,the active pre-tensioned seat belt is matched and its pretension parameters are optimized.Firstly,the Toyota Yaris vehicle collision finite element model built by the US National Collision Analysis Center was selected,and the corresponding occupant restraint system model was built.The simulation results were verified by the test results to ensure the model simulation accuracy.Secondly,determine the longitudinal minimum avoidance distance and the optimal lane change trajectory under the premise of ensuring the steering stability,and calculate the dynamic response of the vehicle as well as the occupant in the steering phase.The moment when the probability of collision accident and the risk of potential injury to the occupant are high during the steering process are selected as the initial collision time,and the car-car oblique collision scene with different collision overlap rates caused by automatic emergency steering is constructed.Integrate the vehicle's motion response during the steering phase and the collision phase,and analyze the dynamic response and injury risk of the occupant during the whole process.Finally,according to the results of the integrated simulation analysis,the basic model is equipped with active pre-tension seatbelt,and the collision overlap rate condition with the highest risk of occupant injury is selected as the optimization object,and the multi-objective genetic algorithm is used to optimize the active pre-tension parameters.The results show that the occupant has a very obvious lateral dislocation during the automatic emergency steering phase.This lateral dislocation causes the shoulder belt to fall off prematurely in each collision condition,which makes a very severe hard contact between the occupant's head and steering wheel and causes an excessive risk of head and chest injuries.After matching the active pre-tensioned seat belt,the efficiency of occupant restraint system greatly improved,and avoids the shoulder belt falling off prematurely during the collision process,and the risk of occupant injury is greatly reduced and returns to the desired level.When the collision overlap is 50%,there is still a slight hard contact between the occupant's head and the steering wheel,which causes the greatest injury to the occupant in the three overlapping rate collision conditions.The active pre-tensioned parameters are optimized for the 50% collision overlap rate condition.The optimization results show that the larger active strength and the earlier triggering moment are more conducive to suppressing the degree of dislocation of occupant and reducing the risk of injury.After optimization,there is no hard contact between the head and the steering wheel,and the risk of injury to each part is also significantly reduced.In addition,the optimal active pre-tension parameter group still has good occupant injury protection effect under the collision conditions of 30% and 70% overlap rate.