Physics engine application to overturning dynamics analysis on banks and uniform slopes for an agricultural tractor with a rollover protective structure

Abstract

Physics engines have become popular for the realistic animation of video games and movies to model the contact dynamics between two rigid bodies. However, the applicability of a physics engine to collect important physical information such as velocity during contact or impact dynamics of overturning vehicles remains unknown. This study is intended to ascertain whether or not the Bullet physics engine can simulate overturning behaviour of agricultural tractors with a roll over protective structure (ROPS) on a bank slope and on a uniform slope. Visual behaviour data and velocity transition during overturning processes are discussed based on the earlier reported experimental data. The results of vertical and lateral linear velocities, and roll angular velocity were evaluated in terms of Root Mean Square Error (RMSE), and the estimated average error was approximately 0.7. The behaviour time response was short in the simulation results because of the assumption of rigid-body contact. Moreover, the simulation results became smaller, but it is sufficiently accurate to predict the critical ROPS height (CRH) for various agricultural tractors. Therefore, results show that this open source physics engine has sufficient applicability to the overturning dynamics of agricultural tractors with ROPS on banks and uniform slopes.