Papers by Keyword: Image Processing

Abstract: Automatic crack inspection techniques that limit the necessity of human have the potential to lower the cost and time of the process. In this study, a maximum crack width estimation approach is presented. Seventy nine segments of cracks are used for training the neural networks and twenty six segments are used for examination. The maximum width for each segment is measured using laser scanning microscope and segment image is captured and magnified using the microscope camera in order to obtain the extracted crack profile number of pixels. Feed and cascade forward back propagation artificial neural networks are designed and constructed. The input and output for the networks are the crack width in terms of number of pixels and the maximum estimated crack width respectively. It is shown that, the artificial neural networks technique can effectively be used to estimate the crack width. The feedforward back propagation structure which is designed with two layers and training function TRAINLM gives the best results in examination.

Abstract: Friction stir welding (FSW), a new joining process is finding extensive use in the welding of aluminum alloy sheets. The metal transfer modes in the FSW cause the quality of the weld and its properties. The first mode of metal transfer is accomplished by the tool and shoulder, while the second mode occurs around the pin. In the present study, two different welding conditions, which were friction stir welding in the air (CFSW) and underwater friction stir welding (UWFSW) carried out at various welding parameters to weld the AA5052-O aluminum alloy sheets and determine the consequence of the first mode on the tensile strength of welded joints. Considerable grain refinement and enhanced mechanical properties were obtained in UWFSW joints. It Is observed that the first mode affect the tensile strength of the joint, also found that a linear correlation between the first mode and the tensile strength.

Abstract: The void formation in FRP composites is unavoidable and the void content measurement is very important to study its deleterious effects on the mechanical properties of the material. Generally destructive methods are used to calculate the void volume fraction. But the recent advances in X-ray computed tomography can be used to detect and quantify the void content in the composites in a non-destructive manner. In this study average area method is proposed and validated for the void volume measurement from the X-ray CT image slices through digital image processing. The effects of void size, shape and position in the accuracy of the measurement is studied and presented here. The void volume fraction of a CFRP laminate manufactured with compression molding technique is calculated by this method and found to be around 1%.

Abstract: The research presents the atomic structure investigation of amorphous rapidly quenched Co₅₈Ni₁₀Fe₅Si₁₁B₁₆ at.% alloys. The alloys were quenched with linear velocity of cooper wheel surface from 22 to 38 m/s. We found a nonlinear dependence of local atomic ordering from linear velocity of cooling wheel. The average lateral density of ordered atomic clusters of 5 nm size changes from 4% to 8%. The amorphous alloy with metastable disordered structure with lower level of free energy is more stable against the external conditions. This approach can be used to determine the best technological parameters for preparing amorphous metallic alloy with metastable structure.

Abstract: The gloss of a metal surface is an important aspect for product quality evaluation. In general, gloss is influenced by specular reflection of light on a metal surface. Therefore, evaluating the specular reflection is almost the same as evaluating the gloss. We propose a method that uses patterned area illumination to evaluate specular reflection. In specular reflection, the angle of incidence equals the angle of reflection. Consequently, when light (ray) of the area illumination, which has a striped pattern, are projected on a glossy metal surface, a striped pattern forms on the reflected image as a mirror-like reflection, and the sharpness of the striped pattern of the image provides information about the specular reflection on the surface. This characteristic is applied to a metal with a hairline surface finish. A hairline surface presents different glossiness at different viewpoints. When the direction of the striped pattern of illumination is changed, the sharpness of striped pattern on the reflected image varies owing to the surface roughness of the hairline finish. Therefore, we can evaluate the glossiness in various directions by rotating the pattern. The rough relationships between gloss evaluation value and surface roughness were indicated in our study. In order to make the relationship between gloss evaluation and surface roughness for the estimation of surface roughness, we had tried the comparison for the gloss evaluation value and the surface roughness. The more precise relationship for seven directions on hairline-finished metal surface was measured. This report describes the results and considers the possibility of estimation of surface roughness by the gloss evaluation value.

Abstract: In order to obtain a real-time interlaminar crack fracture behavior of the laminate composites, in this paper we propose a method of extracting and measuring of interlaminar crack of laminated composite materials based on 2D image analysis via the Matlab software. Extracting the main crack image were conducted using the Matlab script including four different algorithms: the binarization, region growing, morphological, and skeleton thinning, and then a main interlaminar crack image with 1 pixel width were obtained. The length of the main crack was calculated through the sum of pixels of the skeletonized object. The calculated result was closed to the measured result, and the difference between the calculated value and measured value was 0.2%, which can prove the accuracy of the method in present work. The proposed method is of high precision, with strong anti-inference ability and experimental data is stable and reliable, which is helpful to study the crack propagation behavior of laminated composite materials.

Abstract: IMAQ Vision includes a set of optimized functions for image processing (filtering and geometric transformations) and analysis of different areas of interest (perimeter, area, orientation, height, length and width). Also with this program, it may determine the edges of objects, distances and angles between the edges, an object can be searched based on its shape. Particle analysis provides the ability to count objects within the pharmaceutical or biological applications. Image calibration is done to give the user instead of the unit pixel measurements, in units such as millimeters, inches, microns. This paper aims to examine the pharmaceutical powder containing ketoprofen in order to determine the quality of the particles and if this are optimal for pharmaceutical applications. It aims to detect surface defects in the deposited layer such as cracks or clusters of particles that cause surface irregularity. IMAQ Vision by processing images, increase productivity, versatility and reproducibility also reducing manufacturing costs.

Abstract: Several are the instrumental tests currently available in the diagnosis of retinal diseases. Their outputs are typically images of anatomical portions of the eye. However, these are useful to highlight only few aspects of the characteristic lesions of the occurring pathology. For this reason, the clinician needs to have tools able to perform comparative analysis of the different diagnostic images by using procedures of integration of the different clinical information contained in each of them. In this paper, we will describe a new medical software tool (MicroRetina) tailored for the comparative analysis of images of the fundus oculi, acquired during diagnostic tests that make use of different medical instruments. The developed software is an open system able to manage images acquired by different instruments and it will be able to give a helpful support to one of the existing problem in performing diagnosis by using images of the fundus oculi. In particular, it will allow the clinician to perform in real time the comparative analysis of the different clinical findings allowing him to have further diagnostic information not otherwise available by the analysis of the single images only.

Abstract: Shearing is the cutting of a sheet material with a punch and a die. The cut surface obtained by shearing is composed of rollover, a sheared surface, a fracture surface and burr. It has been reported that rollover is formed by the insufficiency of material and material flow in the lateral direction. However, the rollover in the sheet material on the die and that in the sheet material under the punch have not been evaluated individually in previous studies. In this report, the relationship between the material flow and the formation of rollover in the sheet material on the die is discussed on the basis of experimental results obtained by image processing. The relationship between the material flow and the formation of rollover in the sheet material under the punch also is discussed. Double-sided shearing with a counter punch was carried out. The deformation of the sheet material was observed through reinforced glass using a high-speed CCD camera. The image processing was carried out to investigate the material flow. The results were as follows. When the clearance is small, the material flow in the clearance is toward the sheet material on the die. When the clearance is large, the material flow in the clearance is toward the sheet material under the punch. The area of rollover in the sheet material on the die is equal to the sum of the amount of material flow in the clearance and that in the lateral direction. On the other hand, the area of rollover in the sheet material under the punch is equal to the sum of the amount of material flow in the lateral direction under the punch, that in the clearance and the insufficiency of material. These findings are useful for considering the relationship between the material flow and the formation of rollover in the case that the rollover in the sheet material on the die and that in the sheet material under the punch are evaluated individually.

Abstract: It is very important that a grinding tool surface topography is measured and analyzed. In this paper, a line scan camera is installed in our three dimensional measurement system by shortening a measurement time. In this experiment, a diamond grinding wheel SD140Q100M is employed. As a result, the time can be reduced to about 24[s] from 1380[s]. On the other hand, a voronoi diagram is introduced as an evaluation method of a distribution of cutting edges on the grinding tool. According this method, the dispersion can be visualized. Furthermore, it is found that the voronoi region has a relation to a protrusion height of the cutting edge.