Vehicle velocity relation to slipping trajectory change: an option for traffic accident reconstruction
Santrauka
In this paper, the relation of the velocity of a vehicle in the slip mode to the parameters of the tire marks on the road surface is examined. During traffic accident reconstructions, the initial velocity of a sideslipping vehicle is established according to the tire mark trajectory radius, and calculations highly depend on the directly measured parameters of the tire marks, in particular cases known as yaw marks. In this work, a developed and experimentally validated 14-degree-of-freedom mathematical model of a vehicle is used for an investigation of the relation between velocity and trajectories. The dependence of initial vehicle velocity on tire yaw mark length and trajectory radius was found as a characteristic relation. Hence, after approximation of the permanent slipping part by a polynomial, the parameters of the latter were related to vehicle velocity. The dependences were established by specific experimental tests and computer-aided simulation of the developed model. Straipsnyje nagrinėjamas posūkio trajektorija slydimo režimu judančio automobilio greičio ryšys su padangų slydimo pėdsakų parametrais. Tiriant eismo įvykius pradinis posūkyje išslydusio automobilio greitis nustatomas pagal padangų pėdsakų trajektorijos spindulį, kurio reikšmė praktikoje labai priklauso nuo tiesiogiai matuojamų pėdsako parametrų. Sudarytas ir eksperimentu validuotas 14 laisvės laipsnių automobilio matematinis modelis šiame darbe naudojamas slydimo trajektorijų tyrimui. Pradinio automobilio greičio priklausomybė nuo slydimo pėdsako ilgio ir trajektorijos spindulio nustatyta kaip charakteringa, o pastovaus slydimo dalį aproksimavus daugianariu, jo parametrais susieti su automobilio greičiu. Priklausomybės nustatytos tikrinant konkrečiais eksperimentiniais bandymais ir sudaryto modelio kompiuterine simuliacija.