Testing of car speed approximation equation from yaw mark using radio control car simulator

Abstract

© Published under licence by IOP Publishing Ltd. In forensic science, yaw mark is one of the interesting evidences from the traffic accident. It caused by a vehicle wheel slides on the surface of the road when the speed before braking of the vehicle is high enough. Therefore, prediction of the vehicle speed is important to compare with the legal maximum speed. This research focused on the simulation of a car's braking on a curve using the radio control car. High-speed video and Tracker Video Analysis (Tracker) software were used to investigate the positions and speeds of the radio control car. The braking path from Tracker software was assumed as the yaw mark in the real accident scene. The equation of the braking path was investigated using the total least-squares spiral curve fitting. The speeds of the car for each position of the braking path were calculated by the method from Daily's research and the new method modified from Daily's research. The predicted speed was compared with the one measured from Tracker. The results were similar at the beginning of the braking path, but increasingly different when the speed of the radio control car decreased. Moreover, the modified Daily's method can investigate the speed better than the Daily's method for the speed based on a clothoid spiral fitting and Archimedean spiral fitt ing. Findings from this study can be used to develop instructional materials for intermediate mechanics to demonstrate a real application.