Sensitivity of different methods for simultaneous evaluation of emissivity and temperature through multispectral infrared thermography simulation

International audienc

Etude de sensibilité de différentes méthodes de séparation pour l’évaluation simultanée de l’émissivité et de la température par thermographie infrarouge multispectrale

International audienceCette étude porte sur l'´evaluation simultanée de l'émissivité et de la température de surface d'objets observés par thermographie infrarouge in-situ. La mesure de la température par thermographie infrarouge se heurte au manque de connaissances des propriétés radiatives de la scène réelle. Une cible virtuelle composée de quatre matériaux différents est définie. L'éclairement reçu depuis cette cible par une caméra infrarouge est estimé par la méthode des radiosités progressives mise en oeuvre sur carte graphique. Ces simulations nous permettent d'évaluer la sensibilité de quatre méthodes de séparation de l'émissivité et de la température

Study and development of an image synthesis software for the simulation of in-situ 3D scenes monitored by infrared cameras

International audienceThis study addresses the development of a software for the simulation of radiative exchanges in in-situ 3D scenes. By using the progressive radiosity method, implemented on a graphic card to improve the computation speed, a direct solution to the radiative transfer equation is proposed. The software integrates the SMARTS2 atmospheric model to take into account the solar irradiance. Moreover, a camera model has been implemented to simulate the acquisition chain from the camera's irradiance to the digital signal. To validate the software, a comparison between simulated data and actual measurements is proposed. Finally, prospects for extending the software are presented

Étude comparative de deux approches, thermocouples intégrés et thermographie infrarouge, pour la surveillance thermique d'une infrastructure de transport

National audienceCette étude s’intéresse à l’évaluation et à l’amélioration de solutions d’instrumentationthermique pour la surveillance long terme d’infrastructures de transport de nouvelle génération. Unsite d’essais a été équipé de thermocouples et d’un système de thermographie infrarouge couplé ausuivi de paramètres environnementaux. Une méthode de reconstruction spatiale des images infrarougesest présentée. Les donnéee de mesure acquises sur site, puis post-traitées, sont analysées sur le plantemporel. Une conclusion sur les résultats obtenus et des perspectives sont proposées

Étude et développement d'un simulateur d'échanges radiatifs dans des scènes 3D statiques et dynamiques surveillées par thermographie infrarouge

International audienc

A Kriging-based Interacting Particle Kalman Filter for the simultaneous estimation of temperature and emissivity in Infra-Red imaging

International audienceTemperature estimation through infrared thermography is facing the lack of knowledge of the observed material's emissivity. The derivation of the physical equations lead to an ill-posed problem. A new Kriged Interacting Particle Kalman Filter is proposed. A state space model relates the measurements to the temperature and the Kalman filter equations yield a filter tracking the temperature over time. Moreover, a particle filter associated to Kriging prediction is interacting with a bank of Kalman filters to estimate the time-varying parameters of the system. The efficiency of the algorithm is tested on a simulated sequence of infrared thermal images

Étude et développement d'un simulateur d'échanges radiatifs dans des scènes 3D statiques et dynamiques surveillées par thermographie infrarouge

International audienc

Study of adapted instrumentation architectures and measurements post-processing approaches for Infrared thermography applied to thermal monitoring in outdoor conditions

International audienceTechnological progress in uncooled infrared focal plane array sensors has contributed significantly to enlarge the scope of applications of such sensing technique in many domains: Leisure, Manufacturing, Process Survey, Building insulation diagnostic, Civil Engineering, Road works, etc.. . Different outdoor situations and objects of interest monitored by an in-house designed measurement architecture are presented. Designed instrumentation architectures and measurements correction from varying environmental conditions and geometrical considerations are discussed. A first step toward joint estimation of emissivity and temperature is introduced for outdoor applications. Then moving object detection by an AI approach applied on thermal image sequences is also presented and discussed. Finally conclusion and perspectives are proposed

Study of complementary multi-sensors data influence on infrared thermography measurements for in-situ long-term monitoring

International audienc

Study of measurements bias due to environmental and spatial discretization in long term thermal monitoring of structures by infrared thermography

International audienceThe purpose of this study is to characterize the influence of environmental parameters for long-term in-situ structure monitoring as well as projections errors due to camera view and digitization. Measurements made on an instrumented test site have been made during the last 3 years, bringing an interesting dataset to exploit. The model used to convert the gathered data to temperature is firstly presented and discussed. Then, the effect of camera resectioning on infrared measurements is commented. Finally, the effect of the environmental parameters is studied and perspectives are proposed