Search results for "scanner Laser"
showing 6 items of 6 documents
Measure of a limestone weathering degree using Laser Scanner.
2013
The weathering degree of the building materials and natural stones is generally quantified as the decrement of some mechanical features that can be measured experimentally by means of compressive tests or point load tests in the laboratory or Schmidt hammer tests carried out in situ. Such destructive or damaging tests are unacceptable in case of cultural heritage since even small amounts of damage must be avoided. This work shows a correlation between Schmidt hammer rebound values and the reflectivity that is detected by means of terrestrial scanner laser; therefore it allows assessing the weathering degree of buildings or stones in situ. The results demonstrate that such an investigation c…
Valutazione dell’alterazione con laser scanner negli ammassi a struttura orientata e nella diagnostica dei beni monumentali
2011
The applications of laser technology in the field of Rock Mechanics are at a stage of development that allow a reliable use for the reliefs of the mesostructure and for the morphological reconstruction of monuments in place of traditional techniques such as, for example, photogrammetry. The most recent research suggests that the laser may also allow assessment of characteristics such as roughness, which is known to affect the shear strength of discontinuities. Assessing the ratio between the energy of the reflected ray and the one emitted by the instrument, called "reflectivity (I)", it seems possible, also get information on the status of surface discontinuities or areas of historic monume…
Sviluppo e rappresentazione digitale di superfici architettoniche complesse per la documentazione e il restauro
2015
Questa ricerca presenta la metodologia che è stata utilizzata nella rappresentazione delle colonne del Tempio C nel parco archeologico di Selinunte (TP). Tale metodologia – basata sull'impiego di superfici matematiche ausiliarie e tools di modellazione NURBS – ha permesso di sviluppare sul piano le superfici mesh di modelli 3D texturizzati realizzati da dati acquisiti con tecniche di rilevamento laser scanning e fotogrammetriche.
The 3D modelling of musive surfaces for a monitoring protocol
2022
In questo lavoro l'utilizzo della metodologia digitale tridimensionale per la scansione di superfici musive è stato indagato nell'ambito dell'intervento di restauro di un mosaico pavimentale all'interno della Cappella Palatina di Palermo. Grazie alla possibilità di sezionare il modello di maglia con un software di rappresentazione digitale, è stato possibile confrontare la superficie della maglia con una superficie piana di riferimento allo scopo di valutare uno dei declini della posta dei pavimenti musivi, ovvero l'abrasione delle superfici In this paper the use of three-dimensional digital methodology for scanning musive surfaces was investigated within the restoration intervention on a f…
Strain fields measurement of non-rigid solid by scanning laser coupled with camera
2013
International audience; Abstract. Today, the techniques of measurement without contact by scanning laser are increasingly used. These techniques allow to measure 3D objects without contact and the measurement rates can reach few thousand points by second that is very adapted to complex shapes. To measure displacements and deformations, it is necessary to follow a solid particle in its motion between two configurations of the body before and after displacement. The method of stereovision based on grayscale patterns, obtained by applying a spray, is generally used. The results are obtained by two correlations: spatial and temporal correlations. An alternative method consists to use a scanner …
ESTIMATION ET CORRECTION DES ERREURS SYSTEMATIQUES D'UN SYSTEME DE MESURE 3D ASSOCIANT SCANNER NAPPE LASER ET MMT
2012
Les techniques de mesure sans contact par scanning laser permettent d'acquérir un grand nombre de points, à une cadence très rapide. Elles sont de plus en plus utilisées pour des applications industrielles telles que la rétro-conception, le contrôle de forme,... Toutefois, les incertitudes de mesures sont plus importantes que celles obtenues par les techniques classiques de mesure par contact. Nous proposons une procédure de correction des erreurs systématiques basée sur démarche expérimentale et qui concerne la mesure de pièces présentant une surface mate (peu de présence de bruit spéculaire). Les paramètres retenus dans la procédure sont les paramètres de positionnement du capteur par rap…