双前桥转向的重型汽车多极限环摆振研究

发布时间：2018-02-19 22:16

本文关键词： 双前桥中心流形摆振多极限环自激振动　出处：《合肥工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：双前桥转向系统以其简洁的构造,低廉的造价,使重型卡车实现小半径高效的转向。双前桥系统的在被广泛应用的同时,其双前桥车轮轮胎的磨损也引起人们的重视。摆振是引起轮胎磨损的一个因素,但是摆振不仅会导致轮胎磨损,还会引起操纵系统的自激振动,从而影响汽车的操纵稳定性和乘坐舒适性。因此本文在前人研究的基础上,进一步深入研究双前桥转向系统的摆振现象,分析其摆振机理,并研究其对整车摆振的影响。本文采用具有负斜率特性的干摩擦模型,研究摆振系统发生多极限环自激振动的动力学行为。考虑轮胎和干摩擦的非线性,建立9自由度摆振系统微分方程。首先对该9自由度系统进行定性分析,使用中心流形定理将该系统22维的状态方程进行降维,得到2维的平面系统并对其进行分析。然后使用数值计算的方法对9自由度系统进行数值计算,具体分析其分岔特性及多极限环自激振动特性。接着建立整车动力学模型,用Matlab软件对整车模型进行数值计算,并分析各结构参数对整车摆振的影响。最后总结全文并提出展望。定性分析发现降维后得到的2维系统的Hopf范式的极坐标形式c=0,因此系统在分岔点处发生退化的Hopf分岔。数值计算发现具有负斜率特性的干摩擦模型会诱发摆振系统在一定范围内出现多极限环响应。适当的改变系统结构参数及干摩擦力矩,能够有效抑制系统的自激摆振现象,防止整车在摆振发生时产生蛇形现象。
[Abstract]:With its simple structure and low cost, the double front axle steering system enables heavy trucks to achieve small radius and efficient steering. The double front axle system is widely used at the same time, The wear of the double front axle wheel tire is also paid attention to. The shimmy is a factor that causes the tire wear, but the shimmy not only causes the tire wear, but also causes the self-excited vibration of the control system. Therefore, on the basis of previous studies, this paper further studies the shimmy phenomenon of double front axle steering system, and analyzes the mechanism of shimmy. In this paper, a dry friction model with negative slope characteristics is used to study the dynamic behavior of multi-limit cycle self-excited vibration in a shimmy system. The nonlinearity of tire and dry friction is considered. The differential equation of the nine degree of freedom system is established. Firstly, the nine degree of freedom system is qualitatively analyzed, and the 22 dimensional state equation of the system is reduced by using the center manifold theorem. The 2-D plane system is obtained and analyzed. Then the 9-DOF system is numerically calculated by numerical calculation. The bifurcation characteristics and the self-excited vibration characteristics of multi-limit cycles are analyzed in detail. Then the vehicle dynamics model is established. The whole vehicle model is numerically calculated with Matlab software. Finally, the paper summarizes the full text and puts forward the prospect. Qualitative analysis shows that the polar coordinate form of the Hopf normal form of the reduced dimension system is c0, so the system degenerates at the bifurcation point. Hopf bifurcation. Numerical results show that dry friction model with negative slope characteristics can induce multiple limit cycle responses in a certain range. It can effectively restrain the self-excited oscillation of the system and prevent the snake-like phenomenon when the whole vehicle shimmy occurs.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U463.4

【相似文献】