基于虚拟样机的汽车稳态转向特性改进研究

Improvement of Stable Steering Characteristic of Vehicle Based on Virtual Prototype

利用ADAMS建立了满足操纵稳定性分析和行驶平顺性分析的某汽车虚拟样机。基于该样机,研究了螺旋弹簧刚度和横向稳定杆直径对汽车稳态转向特性的影响规律,即适当增加该车前悬架螺旋弹簧刚度和横向稳定杆直径能显著提高其稳态转向特性,但随着刚度的增加,中性转向点侧向加速度的增长率却显著下降。进一步的研究表明:当前螺旋弹簧刚度和横向稳定杆直径分别从30N/mm和20mm时增加至32.5N/mm和21mm时,中性转向点的侧向加速度也由5.32m/s2增加至6.18m/s2,稳态转向特性得到明显提高,驾驶员座椅总加权加速度均方根值由0.6027m/s2增加至0.6268m/s2,行驶平顺性略有下降。

Utilizing Adams, the dynamics virtual prototype of a whole vehicle was established, which was satisfied with the steering stability and ride quality analysis. Based on the model, the law of the stable steering characteristic of vehicle, influenced by changing the stiffness of the front screw spring and the diameter of the lateral stable pole, was discussed. By properly increasing the stiffness of the front screw spring and the diameter of the lateral stable pole, the stable steering characteristic of the vehicle was improved greatly; but with the increasing of the stiffness, the increase rate of the lateral acceleration at neutral steering point decreased rapidly. Further research presented： when the stiffness of the front screw spring increased from 30N/mm to 32.5N/mm and the diameter of the lateral stable pole increased from 20mm to 21mm, the lateral acceleration at neutral steering point also increased from 5.32 m/s^2 to 6.18 m/s^2, the root mean square value of total weighted acceleration of driver＇s seats increased from 0.6027 m/s^2 to 0.6268 m/s^2; The result shows that the stable steering characteristic of vehicle improves greatly, but the effect on the riding quality is not evident.