基于有效独立的改进传感器优化布置方法研究

Improved optimal sensor placement methods based on effective independence

随着结构健康监测技术的发展,传感器优化布置问题日趋突出。综合考虑有效独立法和模态动能法的优缺点,分别以平均加速度幅值和模态动能修正有效独立法的传感器优化布置结果,提出了两种基于有效独立的改进传感器优化布置方法———有效独立-平均加速度幅值法(EI-AAA)和有效独立-模态动能法(EI-MKE)。运用模态动能准则、平均加速度幅值准则、Fisher信息矩阵准则、截断模态矩阵条件数准则、模态置信准则评价并比较上述两种方法及有效独立法、模态动能法、有效独立驱动点留数法和有效独立驱动点残差法。实际钢井字梁采光顶结构算例结果表明,本文提出的有效独立-平均加速度幅值法(EI-AAA)和有效独立-模态动能法(EI-MKE)在考虑截断模态线性独立的同时都能自动选择具有较高平均动态响应和模态动能的测点位置,有较强的抗噪声性能,在六种方法中布置结果最为有效。

Two improved optimal sensor placement methods, namely, the Effective Independence - Average Acceleration Amplitude （EI-AAA） method and the Effective Independence - Modal Kinetic Energy （EI-MKE） method were proposed. The average acceleration amplitude （AAA） and modal kinetic energy （MKE） were used respectively to modify optimal sensor placement results obtained by the effective independence method （El）. The obtained optimal sensor locations using the two improved methods （EI-AAA and EI-MKE） were compared with those gained by El method, MKE method and effective independence driving point residue （EFI-DPR） method. The advantage and disadvantage of these six methods were demonstrated by six evaluation criteria which are modal kinetic energy （MKE）, average acceleration amplitude （AAA）, Fisher information matrix （FIM）, condition number of truncated modal shape matrix and modal assurance criterion （MAC）. A computational simulation on a steel cross beam sunroof structure was carried out to demonstrate the feasibility of the two improved methods and other four methods. The results show that some innovations proposed in the paper are effective and reliable. Among the improved methods, EI-AAA method and EI-MKE method can not only make the truncated mode shapes as linearly independent as possible but also enable the measured modal kinetic energy to maintain the maximum value. They are more feasible in these six optimal sensor placement methods.