四轮随机路面激励下的七自由度车辆响应特性

为了研究不同等级道路下车辆动态响应以及轮胎动载荷的变化情况,根据国家路面不平度分级标准,采用滤波白噪声法建立了随机路面时域模型并与标准路面的功率谱密度对比验证模型的准确性。通过四个车轮之间的传递函数建立了四轮随机路面时域激励模型;并以该模型作为不平路面激励,考虑悬架拉伸和压缩状态时的不同阻尼,建立七自由度整车行驶动力学模型。研究了车辆质心垂向加速度、俯仰角、侧倾角以及轮胎动载荷随路面等级的变化情况。结果表明:车辆和轮胎的动态响应随着路面不平度的增加而增加。可见,搭建的整车模型能够很好地反映不同路面下车辆的动态响应,为车路耦合的深入研究奠定基础。

Seven Degrees of Freedom Vehicle Response Characteristic Under Four Wheel Random Pavement Excitation

In order to investigate vehicle dynamic response and the changes of tire dynamic load under the different grade roads. According to the national road roughness grading standards, filtered white noise method was used to build the time domain model under the random road and compared with power spectral density of standard pavement to verify the accuracy of the model. The four-wheeled time domain excitation model was established according to the transfer function between four wheels, and as an uneven pavement excitation. Considered the different damping of the suspension when it is in tension and compression, a seven degrees of freedom vehicle dynamics model was established to investigate the changes of vehicle vertical acceleration, pitch angle, roll angle and tire dynamic load under the different grade roads. The results show that: with the increase in road roughness, the vehicle and tire dynamic response also increase. It is concluded that the vehicle model can well reflect the vehicle dynamic response under different road conditions, it lays the foundation for in-depth research on vehicle-road coupling.