New crack measurement methodology. Tag recognition

In this paper, a new methodology for measuring the cracking for the Structural Health Monitoring (SHM) of cultural heritage, is presented. This methodology is characterized by being minimally invasive on the artifact to preserve, which is one of the main qualities required in this field. The approach used is to determine the relative distance between two optical tags, using advanced fitting algorithms for the objective function. In this work, we have taken into account different objective-function kinds, in order to find the best configuration to determine the fitting parameters, useful to the SHM. In order to validate the fitting algorithms, some measurements evaluated on simulated tags are presented. Moreover, to validate the methodology, some real measurements are shown.