汽车动力总成刚体惯性参数的辨识

Identification of Vehicle Powertrain Rigid Body Inertia Parameters

本文以某动力总成为研究对象,基于试验模态分析方法进行了动力总成惯性参数辨识。首先给出了动力总成的频响函数及其拟合方法,并推导了动力总成表面响应和激励与坐标原点之间的关系,建立了动力总成运动学方程,进而得到了刚体惯性参数的表达式;然后以矩阵条件数的方法对动力总成模态试验过程中混入的干扰噪声进行了误差分析;基于测试点的矩阵条件数对响应点的位置进行了推导,并将其表达成与动力总成表面物理参数(如长度、面积等)有关的形式,从而得到了响应点的最好和最差布置形式以及最少的测试点数目;采用捶击法进行了动力总成模态试验,并以最小矩阵条件数原则进行了动力总成惯性参数的辨识。最后,本文也给出了关于进一步消除模态试验测量误差的一些措施。

A powertrain is applied as an example in this paper, the powertrain rigid body inertia parameters are identified based on experimental modal analysis. At first, the frequency response function of powertrain and approximate method are presented, and the relation equation between coordinate origin and interface response and excitation on the powertrain is deduced. And then according to the matrix condition number method, the error of powertrain modal test is analyzed which is contaminated by disturbed noise. Based on the matrix condition number of measure points, the positions of response points are deduced, and expressed in the physical parameters, such as length, area, and so on. The best and worst configurations of response points and minimum numbers of measure points are obtained. The modal test of powertrain is performed by using an impulse hammer. And the inertia parameters are estimated and the principle moments of inertia and direction cosines are calculated by taking into account the minimum matrix condition number. Finally, In order to further improve the accurate data, some methods for decreasing test error are suggested.