前轮主销间隙对汽车蛇行工况下稳定性的影响

The Effects of Kingpin Clearance of Front Wheels upon Vehicle Stability Under Slalom Maneuver

主销间隙是影响汽车蛇行工况下稳定性的重要参数。将转向机构简化为平面连杆机构,并就机构中转向节主销与衬套间隙对蛇形工况下汽车稳定性的影响进行分析。考虑以上间隙建立了四自由度车辆操纵运动系统数学模型,基于该模型,应用数值分析方法对间隙参数变化时样车质心侧偏角的稳定性进行仿真分析。结果表明,间隙参数变化时车辆蛇行动力学行为表现为由倍周期进入单周期、混沌,然后从倍周期回到单周期。随着间隙的增大,汽车蛇行失稳的上临界频率几乎无变化,但下临界频率逐渐加大,失稳频率带宽也相应加大,且混沌区域的窗口动力学特性有明显差异。

Kingpin clearance is an important parameter influencing automobile stability under slalom maneuver. In this paper the steering mechanism was simplified into a plane linkage mechanism and the effects of the clearance between the knuckle kingpin and bushing on vehicle stability under slalom maneuver was also analyzed. A 4-DOF mathematical model of vehicle maneuvering system was thus proposed. On the basis of this inodeI, a numerical method was developed for simulating the stability of prototype vehicle＇s side slip angle as the clearance changes. According to the results, the vehicle slalom dynamical bebavior manifests itself as a transition from the period-tripling to single cycle and chaos, and finally back to single cycle from the period-tripling. With the increase in clearance, nearly no change is displayed in the upper critical frequency of vehicle slalom instability. Howeveh an increase is shown in the lower critical frequency. The instability frequency bandwidth, accordingly, bears an increase as well and a marked difference manifests itself in the characteristics of window dynamics in chaotic areas.