The novelty of the current work is precisely to propose a statistical procedure to combine estimates of the modal parameters provided by any set of Operational Modal Analysis (OMA) algorithms so as to avoid preference for a particular one and also to derive an approximate joint probability distribution of the modal parameters, from which engineering statistics of interest such as mean value and variance are readily provided. The effectiveness of the proposed strategy is assessed considering measured data from an actual centrifugal compressor. The statistics obtained for both forward and backward modal parameters are finally compared against modal parameters identified during standard stability verification testing (SVT) of centrifugal compressors prior to shipment, using classical Experimental Modal Analysis (EMA) algorithms. The current work demonstrates that combination of OMA algorithms can provide quite accurate estimates for both the modal parameters and the associated uncertainties with low computational costs.

翻译：本研究的创新之处在于提出了一种统计方法，用于融合任意一组运行模态分析算法提供的模态参数估计值，从而避免对特定算法的偏好，并推导出模态参数的近似联合概率分布。基于该分布可便捷地获取工程统计量（如均值与方差）。通过实际离心压缩机的实测数据对所提策略的有效性进行了验证。最终将正反双向模态参数的统计结果，与出厂前采用经典实验模态分析算法进行标准稳定性验证测试所识别的模态参数进行了对比。研究表明，通过融合运行模态分析算法，能够以较低计算成本获得高精度的模态参数估计及其相关不确定性度量。