Determination of Instability Critical Speed of Articulated Vehicle on Ramp Section Based on Response Surface Method

Abstract

In order to improve the driving safety of vehicles on the ramp section, aiming at the lateral instability problems such as sideslip and rollover in the corner driving of semi-trailer trains, the six-axis articulated vehicle, which is the representative model of current highway freight transportation in China, is selected as the research object. The TruckSim simulation software is used to establish the vehicle dynamic model of nonlinear articulated vehicle, and the orthogonal simulation test of different loading quality and different road adhesion coefficient is designed. The vertical reaction force and lateral displacement of the wheel are taken as the evaluation indexes of vehicle sideslip and rollover, and the critical speed of instability under various road conditions is obtained. On the basis of surface function fitting, combined with the simulation experimental data, the response surface mathematical model of instability critical speed, road adhesion coefficient and loading quality is established. The comparison calculation shows that only 2.23% of the calculation error of the mathematical model reduces the error of the traditional model and improves the calculation accuracy of the model. The results show that the critical speed threshold of instability decreases with the increase of loading mass. With the increase of road adhesion coefficient, the threshold of instability critical speed increases. When the road adhesion coefficient reaches 0.6, the change of instability critical speed threshold tends to be steady. The research results can provide a reference for the evaluation of rollover and sideslip during the turning of articulated vehicle and the determination of anti-instability warning speed of articulated vehicle crossing the ramp section safely.