时变AR模型的一种定阶方法

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振动与冲击 ›› 2012, Vol. 31 ›› Issue (8) : 158-163.

论文

时变AR模型的一种定阶方法

陈宇; 陈怀海; 李赞澄 ;贺旭东

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A New Method for Order Selection of a Time-Varying Autoregressive Model

Chen Yu; Chen Huai-hai; Li Zan-cheng ; He Xu-dong

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文章历史 +

摘要

自回归（AR）模型的定阶对其分析结果的准确性、效率和可靠性具有重要影响。对时变AR模型的定阶问题进行了深入研究，提出了一种基于采样频率以及分析频率之比的定阶方法。对一质量随时间变化的悬臂梁进行了有限元建模，运用计算所得到的振动响应建立了梁的时变AR模型，利用所提方法进行了该模型的定阶，采用递推最小二乘法对梁的模态频率进行了估计。对一质量时变的悬臂梁进行了试验，对采集的振动响应信号建立了时变AR模型并识别了其振动模态频率。模拟计算和试验结果都表明，提出的时变AR模型定阶方法是有效且可行的,且识别算法具有一定的抗噪性。

Abstract

The order selection of AR model has an important influence on accuracy, efficiency and reliability of the analysis result. This paper gives a deep research on the order selection of time-varying AR model and presents a new method for order selection based on the ratio of the sampling frequency and the analysis frequency. A model of a cantilever beam with time-varying mass is obtained by FEM. The numerical vibration response is used to set up a time-varying AR model and the order is selected by the proposed method. The recursive least squares method is adopted to estimate the beam modal frequencies. An experiment is carried out by a cantilever beam with time-varying mass. With the measured vibration response signal, a time-varying AR model is set up to estimate the modal frequencies. The simulation and the test results indicate that the proposed method of the order selection of time-varying AR model is effective and feasible, and the method is anti-noise to some extent.

导出引用

陈宇;陈怀海;李赞澄;贺旭东. 时变AR模型的一种定阶方法 [J]. 振动与冲击, 2012, 31(8): 158-163

Chen Yu;Chen Huai-hai;Li Zan-cheng;He Xu-dong. A New Method for Order Selection of a Time-Varying Autoregressive Model[J]. Journal of Vibration and Shock, 2012, 31(8): 158-163