A system to detect deformations in state of the art materials
FGUSAL/DICYT Researchers at the Polytechnic School of Ávila from the University of Salamanca have developed a new system able to detect deformations in estate of the art materials. By using photogrammetry algorithms and computational vision scientist can identify relevant modifications for objects stability. To test their new methodology they have applied to a Proof of Concept project that focuses on fire extinguishers deformations.
Diego González Aguilera, leader of the research group of Information Technologies for 3D Digitalization of Complex Objects (TIDOP), explains to DiCYT "our aim is to be able to determine in a non-destructive way the deformations suffered by some materials". In this case, the analysis we are performing will allow the substitution current fire extinguisher manufacture materials by new materials such as kevlar or polyparaphenylene terephthalamide.
Given certain digital images, researchers analyze objects in all kinds of situations. "For some time we have been applying algorithms of photogrammetry and computational vision to the forensic field, the analysis of traffic accidents, architecture and engineering," he explains, "but companies in this sector demand a low-cost technology to diagnose deformations of materials". For this reason, TIDOP group has adapted its previous work to this new project, called SICMES, which offers a degree of precision unthinkable until very recently.
Besides being expensive, "traditional methods employ sensors attached to the material itself that measure deformations according to the different refills applied to the extinguisher," says Luis Javier Sánchez Aparicio. The problem is that with the alteration of the materials may also affect the sensors providing unreliable measurements.
A non-invasive method
By contrast, researchers propose a non-invasive system as it does not require physical contact with the object to be controlled. The developed prototype consists of two low cost SLR cameras with macro lenses that are synchronized through a small switchboard, as well as a lighting device and a support for the whole structure to maintain the device while taking images .
Tests materials , extinguishers in this case, are subjected to different processes as refill processes in our example. Meanwhile the system is taking images according to prefixed time intervals. In this way, scientists monitor when deformations occur. The comparison between initial images and those that have been taken later reveals the changes and allow "to better know the mechanical characteristics of the material with greater precision".
The images allow us to obtain a 3D model in which a series of deformations are calculated," says Álvaro Bautista de Castro, another researchers working on the project. "Within these deformations we specify a certain area and generate a coloured map that shows those areas with major and minor deformations".
Thus, SICMES project "tries to introduce a breakthrough concept in materials analysis with the aim of replacing traditional sensors with a more flexible and lower cost system" that could be also apply to other fields such as architecture or engineering.
The tests with fire extinguishers have been made thanks to the Proof of Concept call from the General Foundation of the University of Salamanca, within the TCUE program of the Regional Government of Castilla y León, co-financed with FEDER funds.