Research On Key Influencing Factors Of Car Roll Crash Based On Equivalent Adhesion Coefficient Model

According to the 2018 Global Status Analysis Report on Road Safety,the annual average number of road traffic deaths is still at a high level.Side impact is the most important type of vehicle crash causing rollover.The vehicle with rollover movement after collision has complex motion form and serious consequences.Once a collision and rollovers accident occurs,its movement process is not repeatable.In the case of video recorder or automobile work information recorder and other data,it is still difficult to recognize the accident circumstances and accurately classify the accident responsibilities.Rollover accident vehicle and the ground are not four wheels indiscriminate contact,aiming at the above problems,this paper carried out the following research:First,on the basis of reviewing literature,domestic and foreign road vehicle adhesion coefficients,vehicle collision analysis and simulation,and statistical analysis methods of variance analysis,multiple linear regression equations and other research status are analyzed,and the recurrence analysis and recurrence of rollover accidents in vehicle accidents are discussed.Simulation needs to be studied in depth.Secondly,after analyzing and studying the characteristics of the road adhesion coefficient and the influence on the braking performance of the vehicle,the calculation model and speed estimation algorithm based on the braking equivalent adhesion coefficient are established.On this basis,the non-synchronous braking equivalent is explained.The definition,function and significance of the adhesion coefficient,introduced the measurement method of the center of mass position of the accident vehicle,and proposed the calculation model of the road equivalent adhesion coefficient when the vehicle rolls over under non-synchronous braking conditions.Then introduced the PC-CRASH software extensive application in the National Vehicle Accident In-depth Investigation System(NAIS).Based on the simulation of a typical collision and rollover accident case,the simulation using general road adhesion coefficient and equivalent adhesion coefficient is analyzed.As a result,combined with EDR technology,the dynamic parameters of the accident vehicle collision process are compared and analyzed,and the advantage of using equivalent adhesion coefficient is proposed.Finally,according to a typical case of a nearly 90-degree side impact rollover accident in the NAIS database,a PC-CRASH simulation analysis was carried out,and the cross ratio method for calculating the initial vehicle speed was proposed,and the error analysis was carried out with the simulation results;based on the dynamic parameters obtained by the simulation,To study the sensitivity and coherence of the parameters that affect the rollover motion of a collision,and at the same time to explore the dynamic parameters of the rollover motion under different conditions(mass,speed,angle).