PSI - Issue 64

Francesco Calabrò et al. / Procedia Structural Integrity 64 (2024) 1759–1766 1763 Francesco Calabrò, Giovanna E. Minniti, Antonino Fotia, Raffaele Pucinotti / Structural Integrity Procedia 00 (2019) 000 – 000 5

Once the frames and the information related to them have been acquired, we move on to the data processing phase. Then, through the proposed model, the individual frames are processed which involves: (i) the image acquisition; (ii) the pretreatment; (iii) the processing; (iv) the degradation identification (Davis and Goldberg; Fotia and Pucinotti). In fact, it is highlighted that, if the proposed system (under definition and development and already applied to the case of a steel bridge) recognizes the degradation only in some of the processed frames, it is however able to correlate the results of the different processing through the homologous points, thus returning the complete and appropriately correct (Fotia and Pucinotti; Fotia et al.).

Fig. 1. Workflow of proposed methodology

The comparison of individual frames, acquired with subsequent flights (after processing with an edge detection algorithm) allows the identification of changes that occurred in the time between subsequent measurements. The proposed methodology also consists of a results visualization system that allows comparing the evolution of the recorded variations over time. The repeatability of the flight plan, and therefore of the acquisition of images always from the same positions, allows us to obtain easily comparable frames, creating a database containing the temporal evolution. This information, made available on a specially created platform, allows the operator to verify, through "visual processing", the real changes undergone by the analyzed details. In particular, a filter of the 0-1 type therefore determines the possible addition of the image itself in the database every time a variation is identified compared to the previous temporal acquisition. Furthermore, the acquisition data and analysis results can then be made available within a user-interrogatable platform, making the results accessible to end users to establish priorities for intervention. 4. Case Study 4.1. General Frame The selected case study involves a conventional masonry structure located in Calabria, Italy, showcasing a significant structural lesion on its primary facade. This building, emblematic of the prevalent masonry construction in the region, serves as a compelling subject for a detailed investigation, particularly in the context of the proposed monitoring system.