Improved optimal sensor placement methods based on effective independence

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 (EI). The obtained optimal sensor locations using the two improved methods (EI-AAA and EI-MKE) were compared with those gained by EI 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.