DYNAMIC BEHAVIOR OF A VEHICLE ON A RUTTED ROAD

铺砌道路上的车轮车辙会影响车辆的机动性，有时还会引发致命事故。然而，目前对这种在车辙路面上不稳定的机动性能的原因所知还不够。本研究的目的是提供车辆在车辙路面上运行的动力学行为的一些信息。为了评估车辆在车辙路面上的稳定性和可控性，我们在车辙路面和平坦路面上进行了各种运行测试。基于RMS（均方根）值、显影谱和计算机模拟模型的分析，得到以下结论：车辙路面转向变量的均方根值是平坦路面的数倍。簧载侧位移是由刚体运动引起的，其频率含量在1Hz以下，在车辙路面的不稳定转向中起着重要作用。随着车速的增加，车轮辙面对横向运动的影响更为显著。越困难的变道条件下，簧载运动对横向非簧载运动的影响越大。在有车辙的道路上驾驶困难的另一个可能的原因可能是车辆运动对转向的反应的不稳定延迟。本文所建立的计算机仿真模型虽然需要进行一些修改，但在分析车辙路面上的车辆运动方面似乎是有效的。

Wheel ruts on paved roads affect the maneuverability of a vehicle and sometimes trigger fatal accidents. At present, however, not enough is known about the cause of this unstable maneuverability on a rutted road.It is the purpose of this research to provide some information on the dynamic behavior of a vehicle running on a rutted road. In order to evaluate the stability and controllability of a vehicle on a rutted road, we performed various running tests both on a rutted road and on a flat road. Based on analyses using RMS (Root Mean Squared) values, the Developing Spectrum, and a computer simulation model, the following conclusions were obtained.1. The RMS values of steering variables for a rutted road are several times as large as those for a flat road.2. The lateral displacement at sprung, which results from the rigid body motion and has a frequency content below 1Hz, plays an important role in unstable steering on a rutted road.3. The effects of wheel ruts on lateral motion become more significant with running speed increased.4. The harder the lane-changing conditions, the larger the effects of sprung motion on lateral unsprung motion.5. Another likely cause of difficulty in steering on a rutted road may be the unstable delay of response of the vehicle motion to steering.6. The computer simulation model developed here, though some modifications are required, seems to be effective in analyzing vehicle motion on a rutted road.