An Improved Optimal Sensor Placement Method Based On The Representative Least Square

The selection of sensor measurement points is the primary problem to be solved in structural health monitoring.Large-scale structural nodes have many nodes and complex dynamic characteristics.It is impractical to install sensors at each node.In order to enable the information measured by the monitoring system to truly reflect the dynamic characteristics of the structure and extract more comprehensive response information,a good arrangement of measuring points is needed.Different sensor optimization methods have different application backgrounds.Representative least square method is based on the inherent characteristics of the structure and load conditions to select the sensor location.In this paper,in-depth exploration and research of this method,an improved sensor based on representative least square is proposed optimize the layout method.The main contents of this article are as follows:(1)It summarizes the commonly used sensor optimization methods and evaluation criteria,and briefly introduces the theoretical basis and physical significance of the least squares method.The algorithm is based on the mathematical background and implicit assumptions of the effective independent method.It is an approximate unbiased estimation of load-dependent sensor placement method.The sensor placement is achieved by achieving the best subspace approximation of structural response(2)For the problem of representative least squares method,it introduces the commonly used iterative calculation methods of linear equations,and comparatively analyzes the iterative calculation process and calculation efficiency of Jacobi,Gauss-seidel,Sor,Krylov subspace iterative methods.After a comparative analysis of the number of iterations,CPU time and calculation of residuals,the BICGSTAB method was introduced to solve the representative least square arrangement method.(3)Aiming at the problem that the traditional representative least squares method does not consider the angle between modals in the iterative calculation,this paper proposes an improved representative least squares method in which the largest off-diagonal element of the modal guarantee matrix is the weighting coefficient.This method fully considers the orthogonality of the modal vectors when selecting the measuring points,and ensures the integrity of the modals under the premise that the angle between the modal vectors is large.The method is verified by numerical simulation examples,and the layout scheme is evaluated using various evaluationcriteria.The results show that the improved algorithm is superior to the original representative least squares algorithm.(4)The NREL5 MW wind turbine blade structure was established and its actual working conditions were considered.The improved representative least square method,the original representation least square method,and the effective independent method were used to arrange the sensor of the wind turbine blade,and the layout schemes were compared using different evaluation criteria.The analysis shows that the improved characterization least square method can obtain a better sensor placement scheme,which further verifies the practicability of the algorithm.