周期时变转子系统参数识别技术研究

Parametric identification technique for a periodic time-varying rotor system

针对周期时变转子振动系统,提出了基于方波脉冲函数展开的参数识别方法。将振动系统状态空间方程用方波脉冲级数展开,利用方波脉冲函数具有脱关性及正交性等性质,并根据矩阵分块与谱分解理论,推导出周期时变系统参数识别递推公式。通过对二自由度刚度周期时变系统仿真模型和实际非对称转子系统进行结构参数识别,结果表明,在合适计算步长下刚度值识别准确,平均绝对百分误差分别小于0.5%与1%,验证了该方法的正确性和有效性,有较大的工程应用价值。

For a periodic time-varying rotor system,parametric identification method based on the square wave pulse function was proposed.Firstly,the state-space matrix equation of the system was expanded with the square wave pulse function.Then recursion formulas for parametric identification of the system were derived adopting decorrelation and orthogonality of the square wave pulse function according to the matrix partition and spectral decomposition theory.Structural parametric identifications for a 2-DOF stiffness periodic time-varying system simulation model and an actual asymmetric rotor system were conducted with the proposed method.The results showed that their stiffness values are recognized correctly under appropriate calculation steps with the mean absolute percentage error of less than 0.5% and 1%,respectively;the correctness and effectiveness of the proposed method are verified,so it is valuable for engineering application.