铰接式车辆行驶稳定性的理论分析与数值计算

Theoretical analysis and numerical calculation for driving stability of articulated-frame vehicles

为了获得车辆稳定行驶的临界车速,对铰接式车辆沿直线或大曲率半径曲线行驶时的稳定性进行了研究。将铰接式车辆简化为前、后两车节组成的系统,考虑了轮胎侧偏特性和液压转向机构的弹性,建立了铰接式车辆行驶稳定性线性动力学方程。给出了铰接式车辆行驶稳定性的两种判别方法:特征值方法和时不变输入下稳态响应方法。给出了稳定性因数表达式和临界车速计算方法和公式。指出了铰接式车辆的两种失稳形式:由于轮胎侧偏导致的失稳和由于转向机构缺陷导致的失稳。初步讨论了铰接式车辆侧向运动的频率响应特性。给出了两种铰接式车辆的临界车速动力修改灵敏度分析方法:基于时不变输入下稳态响应方法的直接求导法和基于复特征值分析的特征值法。以ZL10装载机为例进行了实例数值计算,得到了该车的临界车速。

In order to obtain critical speed when articutaled-frame vehicles(AFV) drive stability, the driving stability of AFV with hydraulic steering system moving along a straight or a small curvature road was studied.Idealized into a model composed of a front and rear body,taking both the elastic characteristics of hydraulic steering system and tire ride slip behavior into account, a linear dynamic equation system for the driving stability of AFV was established.Two methods of judging the driving stability of AFV were presented:the eigenvalue method and the method of steady response under constant input,and the expressions of stability factor and critical vehicle speed were derived.Two forms of instability of AFV were shown.The frequency response characteristics were discussed preliminarily.Two methods on sensitivity analysis for dynamic correction of AFV critical speed were suggested,i.e. direct derivation method based on the steady response and eigenvalue method based on complex eigenvalue analysis.Finally,the critical speed of the ZL10 loader was calculated as an example.