关键词:行驶平顺性;振动模型;MATLAB;频域模拟;功率谱
Abstract
The riding comfort is one of the most important performances of vehicle. It can influence only the feeling of passengers, but also the prevention of crash by avoiding making the driver tired. With the development of society and improvement of living standards, the ride comfort of a bus is required more and more strictly. It has become an important index for the bus performance evaluations in the competition of the vehicle market. So it is paid more and more emphasis gradually.
This dissertation introduces the concept, evaluating indicator, evaluation method and the present status of vehicle riding comfort, summarized the research history, introduced many kinds of appraisal methods of the vehicle ride comfort, and analyzed the influence factors, such as the vertical, rolling and pitching motions, as well as the loading distribution, considering vibration characteristics of the vehicles. Based on the Huanghai DD6119 bus, a 3-D 8 degrees of freedom (DOFs) vehicle vibration model is established. The dynamical equations of the vehicle are established by using the Lagrange method, and their matrix forms have been derived. Under the random road excitation with the correlation of four wheels, the linear time-domain simulation is performed by MATLAB software. Furthermore, the analysis of the vehicle body, suspension, and seat vertical vibrations and calculation of weighted acceleration RMS (aw) and Weighted-level (Law) are conducted. Using the international standard ISO2631, we evaluated the ride comfort of the DD6119 bus.