机械振动系统的频响函数估计方法研究

Study on Frequency Response Function Estimation of Mechanical Vibration System

为提高频率响应函数(FRF)的估计精度,基于主成分和总体最小二乘法的思想,分别提出SISO和MIMO测量条件下的FRF估计模型,模型能考虑输入输出随机噪声影响且理论清晰、简单易行.利用振动传递路径系统模型验证提出方法比传统方法更具有效性.依据不同的测量环境、测量对象、精度和效率等要求,提出FRF测量、估计等环节的有效策略.研究成果为获取精度高、鲁棒性好的FRF提供了有力支撑.

Obtaining the frequency response function of mechanical vibration system is a basic and moreover important work,which involving a number of complex aspects.To improve the estimation accuracy of FRF,the one estimation model of FRF based on principal component analysis is proposed under single input single output（SISO）measurement condition.The other one based on total least squares adapt to multiple input and multiple output（MIMO）,which can overcome the deficiencies of the above method.The both methods can consider not only input random noises but also output random noises,and moreover,are clear theoretical derivation and easy to execute.Then,the two methods are applied to estimate the FRF of the vibration system model,which yield more accurate than traditional methods.Finally,the targeted strategies for acquiring FRF are proposed by considering different measurement environment,measurement structure,calculation accuracy and efficiency.The research results provide a strong support for obtaining higher accuracy,better robustness FRF.