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Evaluation of the temperature pattern of a complex body from thermal imaging and 3D information: A method and its MATLAB implementation
摘要： The standard setting of a camera used in Infrared thermography (IRT) is based on the choice of the same values of emissivity and distance for all pixels of a thermal image even if the emissivity depends on the relative position of camera and observed surface. Often this is not a problem. However, the resulting temperature pattern could be inadequate if a body having a complex shape is observed from strongly constrained positions. In order to face this issue, a procedure aimed at providing a correct temperature pattern by using 3D information related to a point cloud is proposed together with its MATLAB implementation (COMAP3 toolbox). For each pixel of a thermal image, the relative position of camera and observed surface is estimated, leading to pixel-specific values of emissivity and distance. The temperature obtained in this way is also mapped onto the point cloud. The effectiveness of the procedure in recognizing areas characterized by peculiar thermal behavior is shown in the case of a historic cylindrical masonry bell tower (Caorle’s bell tower, Venice, Italy).
关键词： Damage recognition,3D thermography,In situ measurements,Thermal imaging,Radiometric JPEG image
更新于2025-09-23 15:23:52
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IRT image segmentation and enhancement using FCM-MALO approach
摘要： Infrared Thermography (IRT) is a method that has modernized the way for monitoring the thermal conditions, finding some potential faults or defects that could be available in electrical systems. In the proposed work, IRT electrical images are taken for diagnosing the faults by the image pre-processing and segmentation process. Initially, the IRT images are changed over into a grayscale image, trailed by image pre-processing is performed where histogram equalization is applied. With the intention of segmenting the faulty portion (high temperature zone) from the electrical equipment, Fuzzy C Means (FCM) strategy is introduced. For optimizing the centroid of FCM algorithm Modified Ant Lion Optimization (MALO) is proposed. From the segmented images, small size portions are removed by using Region Props function. This operation can remove the isolated pixels from the image and extract image components for better representation of images. The optimum results show that the proposed work accomplishes maximum segmentation accuracy compared to existing segmentation algorithms.
关键词： Pre-processing,Infrared thermography images,Fault diagnosis,Segmentation,Region props function,Electrical equipment
更新于2025-09-23 15:23:52
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Enhancing defects characterization in pulsed thermography by noise reduction
摘要： In the field of NDT techniques for aeronautic components of composite materials, the development of automatic and robust approaches for defect detection is largely desirable for both safety and economic reasons. This paper introduces a novel methodology for the automatic analysis of thermal signals resulting from the application of pulsed thermography. Input thermal decays are processed by a proper FIR filter designed to reduce the measurement noise, and then modeled to represent both sound regions and defective ones. Output signals are thus fitted on an exponential model, which approximates thermal contrasts with three robust parameters. These features feed a decision forest, trained to detect discontinuities and characterize their depths. Several experiments on actual sample laminates have proven the increase of the classification performance of the proposed approach with respect to related ones in terms of the reduction of missing predictions of defective classes.
关键词： FIR filter,Decision forest,Pulsed thermography,Model approximation
更新于2025-09-23 15:23:52
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Value of a smartphone-compatible thermal imaging camera in the detection of peroneal artery perforators: Comparative study with computed tomography angiography
摘要： Background: The aim of this study was to investigate the value of a smartphone-compatible thermal imaging camera in the mapping of the peroneal artery perforators. Methods: Twelve consecutive patients scheduled for fibular flap reconstruction were enrolled. The lower limbs were first studied using smartphone-based dynamic infrared thermography (DIRT). During the rewarming, the hotspots were marked, small rubber markers were taped to the registered sites, and then the patients were sent for a CT scan. The diagnostic performance of smartphone-based DIRT was evaluated by comparing the DIRT findings with CT angiography and intraoperative findings. Results: DIRT detected 42 of the 57 dominant perforators in 24 limbs and resulted in a sensitivity of 73.7% and a positive predictive value of 65.6%. Conclusions: The sensitivity and positive predictive value of the smartphone-based DIRT are low. Currently, it should be used as an adjunctive tool together with the established imaging techniques.
关键词： thermography,fibular flap,perforator mapping,peroneal artery perforator flap,computed tomography angiography
更新于2025-09-23 15:23:52
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AR aided Smart Sensing for In-line Condition Monitoring of IGBT Wafer
摘要： This paper describes an augmented reality (AR) aided smart sensing technique, for in-line condition monitoring of IGBT wafers. A series of signal processing algorithms are applied for enabling sensor intelligence. Based on electromagnetic infrared-visible-fusion (IVF), a supplementary palpable 3-D thermography layer is integrated with an IGBT wafer in real world environment. Before the IVF, independent component analysis (ICA) is implemented to identify defects in the wafer. The proposed AR aided smart sensing technique enhances user's perception and interaction between the industrial systems and the surrounding world. In contrast to conventional sensor techniques, it provides a non-destructive testing and evaluation (NDT&E) based high-throughput in-line condition monitoring method. The advantages of non-contact and time efficient of this smart sensing technique potentially bring huge benefit to yield management and production efficiency. AR aided smart sensing can improve the productivity, quality and reliability of power electronic materials and devices, as well as in other industrial applications.
关键词： Wafers,IGBT,Thermography,Non-destructive testing,Pulsed Eddy Current,Augmented Reality,Smart sensing
更新于2025-09-23 15:23:52
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The utility of infrared thermography for evaluating lameness attributable to bacterial chondronecrosis with osteomyelitis
摘要： Bacterial chondronecrosis with osteomyelitis (BCO) is a leading cause of lameness in broilers. Infrared thermography (IRT) is a noninvasive technique for measuring infrared radiation from an object and can be used to evaluate clinical health. Two replicated studies compared the effect of light intensity on broilers grown on a wire flooring model that experimentally increased their susceptibility to and incidence of BCO lameness. Day-of-hatch male broiler chickens were placed into 6 pens on wood shavings litter, and at 1 wk one of 3 light intensity treatments (2, 5, or 10 lux) was allotted. At 4 wk half of the population from each pen was moved to a pen with wire flooring and the same light intensity. At 1, 4, 5, and 8 wk, an IRT image of the legs of 5 clinically healthy broilers from each pen was taken. The right and left proximal femora and tibiae of sound and lame broilers were scored for femoral head necrosis (FHN) and tibial head necrosis (THN) lesion severity. There were minimal effects of light intensity and flooring. In Study 1, but not Study 2, broilers on wire flooring weighed less on day 38 (P = 0.007) and days 57 to 58 (P = 0.003) compared to those on litter. The proportion of broilers that became lame on wire flooring was 52% in Study 1 and 14% in Study 2. The proportion of sound broilers from litter and wire flooring pens with subclinical signs of BCO in their right or left proximal growth plates was over 45% for FHN and 92% for THN, and lame broilers had more severe (P < 0.0001) FHN and THN compared to sound broilers. IRT surface temperatures of the hock joint, shank, and foot were consistently lower (P < 0.0001) in broilers that became lame when compared to sound. Therefore, IRT surface temperatures of broiler leg regions may be useful for detecting lesions attributed to BCO.
关键词： infrared thermography,wire flooring,lameness,bacterial chondronecrosis with osteomyelitis,light intensity
更新于2025-09-23 15:23:52
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Absorption Coefficient Dispersion in Flash Thermography of Semitransparent Solids
摘要： Pulse and flash thermography are experimental techniques which are widely used in the field of non-destructive testing for materials characterization and defect detection. We recently showed that it is possible to determine quantitatively the thickness of semitransparent polymeric solids by fitting of results of an analytical model to experimental flash thermography data, for both transmission and reflection configuration. However, depending on the chosen experimental configuration, different effective optical absorption coefficients had to be used in the model to properly fit the respective experimental data, although the material was always the same. Here, we show that this effect can be explained by the wavelength dependency of the absorption coefficient of the sample material if a polychromatic light source, such as a flash lamp, is used. We present an extension of the analytical model to describe the decay of the heating irradiance by two instead of only one effective absorption coefficient, greatly extending its applicability. We show that using this extended model, the experimental results from both measurement configurations and for different sample thicknesses can be fitted by a single set of parameters. Additionally, the deviations between experimental and modeled surface temperatures are reduced compared to a single optimized effective absorption coefficient.
关键词： Dispersion,Flash thermography,NDT,Absorptance,Infrared thermography,Semitransparency
更新于2025-09-23 15:22:29
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Assessing the Condition of Gas Turbine Rotor Blades with the Optoelectronic and Thermographic Methods
摘要： Gas turbines and their blades in particular might be damaged in the course of the aviation turbojet engine operation process. The degradation process of the blade microstructure is most evident from the change in the colour of its surface. This is assessed using the optoelectronic method. The article presents the concept of non-destructive methods, which are used to assess the degree of degradation of the alloy of a gas turbine blade. The proposed optoelectronic method is the basic method for the preliminary determination of color changes in the surface. Appropriate videoscopes or video-analyzers, capable of recording a test object in various electromagnetic wave ranges (infrared radiation, visible range), are used for this purpose. These preliminary results of the diagnosis make it possible to infer further studies of the blade. For accurate investigation of the state of the alloy microstructure, a non-destructive thermographic method (xenon flash pulsed thermography) was used. The results of studies of the degradation of the microstructure with the use of non-destructive methods were verified through the use of metallographic investigations. Appropriate metallographic specimens were created in order to recognize phase γ' degradation (i.e., the phase strengthening the blade alloy). The results of the presented research allowed for an in-depth assessment of the degree of microstructure degradation of operated blades.
关键词： impulse thermography,Turbine blade,digital image,microstructure degradation
更新于2025-09-23 15:22:29
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Evaluating impact damage to fabric-based personal armor by infrared NDT
摘要： The paper considers the thermo-mechanical mechanism of interaction between the damage agents and armor protection made of polymer fabrics. A simplified mathematical model is proposed to describe the deceleration of a damage agent within an armor fabric due to the dissipation of energy expended on irreversible stretching deformations of fabric fibers, as well as fiber slipping friction and material heating. Woven fabric layers are replaced by solid layers characterized by averaged stiffness and viscosity. A discrete numerical model of a solid material is proposed to reduce a problem with a finite number of degrees of freedom; motion equations are obtained on the basis of the Lagrange equations of the second kind, and for their integration, a stable non-conservative difference scheme is used. The software implementation is based on a functional-object paradigm which allows the modeling of conjugated processes. The parameters of governing equations are identified by using the experimental data. Some illustrative examples of interaction between damage agents and armor barriers with different arrangement of fibers are presented. The proposed model can be used to predict the quality of armor protection with the changing number and location of fibers, as well as to test the armor protection by applying the technique of infrared thermography.
关键词： Armor protection,mathematical model,irreversible deformation,infrared thermography,energy absorption,numerical scheme,composite material,fiber friction
更新于2025-09-23 15:22:29
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Through air drying assisted by infrared radiation: the influence of radiator power on drying rates and temperature
摘要： The use of infrared radiation for heating the web in the through air drying process was investigated in lab scale. The hypothesis was that infrared radiation should be a more efficient method to transfer drying energy to the wet web compared to hot air, but that a certain air flow is still required as a transport medium for the evaporated water. A trial program comprising handsheets made of two types of bleached chemical pulps, five grammages (15, 22, 30 and 60 g/m2), and dried with five radiator power levels was performed on a lab scale through air drying equipment. Drying times of the samples were determined from temperature data recorded with an infrared camera. The use of infrared radiation shortened drying times, especially for low grammage samples. The shortening of the drying time ranged between 10 and 45 %. The most substantial shortenings were obtained for the lowest grammages and the highest radiator power level. However, the increase of power did not linearly shorten drying time. After an initial shortening at the lowest power level, the positive effect of the IR heating decreased as the power was further increased.
关键词： infrared,tissue,TAD,pulp,drying,thermography
更新于2025-09-23 15:22:29