Optimal sensor placement for structural response estimation

A methodology, termed estimation error minimization (EEM) method, was proposed to determine the optimal number and locations of sensors so as to better estimate the vibration response of the entire structure. Utilizing the limited sensor measurements, the entire structure response can be estimated based on the system equivalent reduction-expansion process (SEREP) method. In order to compare the capability of capturing the structural vibration response with other optimal sensor placement (OSP) methods, the effective independence (EI) method, modal kinetic energy (MKE) method and modal assurance criterion (MAC) method, were also investigated. A statistical criterion, root mean square error (RMSE), was employed to assess the magnitude of the estimation error between the real response and the estimated response. For investigating the effectiveness and accuracy of the above OSP methods, a 31-bar truss structure is introduced as a simulation example. The analysis results show that both the maximum and mean of the RMSE value obtained from the EEM method are smaller than those from other OSP methods, which indicates that the optimal sensor configuration obtained from the EEM method can provide a more accurate estimation of the entire structure response compared with the EI, MKE and MAC methods.