Integrated optimal placement of displacement transducers and strain gauges for better estimation of structural response

Although a variety of sensors provide more comprehensive information and advanced features of structures, their distinct properties and limitations considerably complicate the design procedure of multi type sensor systems. This paper is focused on the optimal design of integrated sensor systems with both strain gauges and displacement transducers. Unlike traditional sensor placement approaches, in which these two types of sensors are often designed separately to monitor structural deformations and displacements respectively, the integrated design procedure presented in this study treats the sensor system as a whole. The number and locations of strain gauges and displacement transducers are optimized simultaneously, and their measurement data are fused together to better predict the unobserved structural response. The theoretical criterion for the optimization procedure is first formulated based on the strain and displacement mode shapes extracted from finite element models. Then, the initial candidate sensor locations are reduced to a smaller optimal set with minimized prediction error of structural response. A two-dimensional cantilever beam is then analyzed as a numerical example to investigate the effectiveness and accuracy of the presented optimal sensor placement approach. The results indicate that the integrated sensor system provides better estimation of structural response than single-type sensor system.