133 research outputs found

    A new software application for footwear industry

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    Today, the footwear industry is facing many challenges. First, consumers demand for new products with better comfort and design; second, competition is becoming stronger in current global market. Due to these factors, flexibility and rapidity in developing new products are key factors for the medium and long-term survival and success of the footwear industry. This paper proposes a new software application based in simple image processing techniques for optimization of two important steps of the processes involved in footwear manufacturing: the shoe sole halogenation and lead roughing process. The application presented in this paper has a friendly interface where the sole contour points for shoe sole halogenation and lead roughing are automatically determined. The operator can easily change and set new points to improve details within the interest region where tools will be applied, when the halogenation or the roughing process is executed. Another feature of this application is the automatic transformation of the 2D coordinates of the dominant points to 3D real world coordinates. This feature simplifies further ongoing work ā€“ automatic code generation for different industrial robots to execute the halogenation and roughing processes

    Automatic pre-bended customized prosthesis for pectus excavatum minimal invasive surgery correction

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    Pectus excavatum is the most common deformity of the thorax. A minimally invasive surgical correction is commonly carried out to remodel the anterior chest wall, by employing an intrathoracic convex prosthesis in substernal position. The process of prosthesis modeling and bending still remains an area of improvement. The authors developed a new system, i3DExcavatum, which can automatically model and bend the bar preoperatively based on a thoracic CT-scan. This paper presents a comparison between automatic and manual bending. The i3DExcavatum was used to personalize prosthesis for 41 patients who underwent pectus excavatum surgical correction between 2007 and 2012. Regarding the anatomic variations, the soft tissue thicknesses external to the ribs show that symmetric or asymmetric patients have always asymmetric variations by comparing both patientsā€™ sides. It highlighted that the prosthesis bar should be modeled according to each patient ribs position and dimension. The average differences between the skin and costal line curvature lengths were 84Ā±4 mm and 96Ā±11mm, for male and female patients, respectively. On the other hand, the i3DExcavatum ensured a smooth curvature of the surgical prosthesis and was capable to predict and simulate a virtual shape and size of the bar for asymmetric or symmetric patients. In conclusion, the i3DExcavatum allows preoperative personalization according to the thoracic morphology of each patient. It reduces surgery time and minimizes the margin error induced by the manual bended bar shape that only uses a template that copies the chest wall curvature

    IntegraĆ§Ć£o de um servidor web num sistema de pesagem

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    O presente artigo, descreve a integraĆ§Ć£o das novas tecnologias de informaĆ§Ć£o (TIs) via Web nos sistemas tradicionais de pesagem, dotando estes de grandes facilidades de interligaĆ§Ć£o com outros sistemas ou equipamentos. Destas facilidades podem ser distinguidas as seguintes: leitura dos valores do peso local e remotamente; facilidades de ligaĆ§Ć£o com sistemas de informaĆ§Ć£o, bases de dados e outras formas de gestĆ£o e controlo centralizados; fĆ”cil ligaĆ§Ć£o dos equipamentos em rede, possibilitando o controlo centralizado dos equipamentos e de todo o material por eles pesado; facilidades de teleassistĆŖncia e telemanutenĆ§Ć£o

    Stereo vision calibration procedure for 3D surface measurements

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    In reverse engineering, rapid prototyping or quality control with complex 3D object surfaces, there is often the need to scan a complete 3D model using laser digitizers. Those systems usually use one camera and one laser,- using triangulation techniques; complex 3D objects can cause information gaps in the model obtained. To overcome this problem, another camera can be used. Traditional calibration procedures for those systems normally result in a full 3D camera calibration, involving individual implicit camera parameters, a rigid motion equation relating the explicit cameras parameters of each camera and the intersection with the laser line. This paper presents a new stereo vision laser strip calibration procedure for 3D surface measurements. In this calibration procedure the laser plane is the one that matters, only one set of laser-coplanar calibration points for camera calibration is needed, and a dead zone scan area is considered, since the digitalization arm is mounted in a 3 degree freedom machine PC-based Motion Control with multiple scan paths.FundaĆ§Ć£o para a CiĆŖncia e a Tecnologia (FCT

    Calibration procedure for 3D surface measurements using stereo vision and laser stripe

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    This paper proposes a new stereo vision calibration procedure and laser strip detection for 3D surface measurements. In this calibration procedure the laser plane is the one that matters, only one set of laser-coplanar calibration points is needed for image cameras calibration; and a dead- zone scan area is considered, since the igitalization arm is assembled in a 3 degree-freedom machine PC-based Motion Control with multiple scan paths. It is also presented some algorithms for 3D surface treatment.FundaĆ§Ć£o para a CiĆŖncia e a Tecnologia (FCT

    Automatic trajectory generation for the milling of sculpted surfaces acquired from laser scanning systems

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    The present work describes a set of algorithms for the milling of sculpted surfaces acquired from laser scanning systems. The milling operations cover three operations: roughing, semi-finishing and finishing. The developed algorithms use techniques ranging from computer vision to computer graphics following a different approach when compared with the usual milling techniques, usually feature based. The implementation of 3D path simulator was also described and testing of the different milling trajectories presented.FundaĆ§Ć£o para a CiĆŖncia e a Tecnologia (FCT

    Calibration procedure for 3D measurement systems using two cameras and a laser line

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    Prova tipogrĆ”ficaIn order to ensure the precision of the measurement of complex 3D object surfaces using non-contact laser scanning systems, a novel stereo vision calibration procedure based on a laser line projection plane is presented. This calibration procedure can also be used in measurement systems based on a single camera and a laser line projection. This procedure, while using only laser-coplanar points, is oriented towards laser line detection and allows the matching of two images on the laser projection plane without the use of a rigid motion equation. These features make this procedure very precise, simple and, consequently, easier to implement.FundaĆ§Ć£o para a CiĆŖncia e a Tecnologia (FCT) - SFRH/BD/18155/200

    Automatic Denavit-Hartenberg parameter identification for serial manipulators

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    An automatic algorithm to identify Standard Denavit-Hartenberg parameters of serial manipulators is proposed. The method is based on geometric operations and dual vector algebra to process and determine the relative transformation matrices, from which it is computed the Standard Denavit-Hartenberg (DH) parameters (ai, ai, di, Īøi). The algorithm was tested in several serial robotic manipulators with varying kinematic structures and joint types: the KUKA LBR iiwa R800, the Rethink Robotics Sawyer, the ABB IRB 140, the Universal Robots UR3, the KINOVA MICO, and the Omron Cobra 650. For all these robotic manipulators, the proposed algorithm was capable of correctly identifying a set of DH parameters. The algorithm source code as well as the test scenarios are publicly available.FCT - FundaĆ§Ć£o para a CiĆŖncia e a Tecnologia(SFRH/BD/86499/2012

    Validation of percutaneous puncture trajectory during renal access using 4D ultrasound reconstruction

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    "Progress in Biomedical Optics and Imaging, vol. 16, nr. 43"Background: An accurate percutaneous puncture is essential for disintegration and removal of renal stones. Although this procedure has proven to be safe, some organs surrounding the renal target might be accidentally perforated. This work describes a new intraoperative framework where tracked surgical tools are superimposed within 4D ultrasound imaging for security assessment of the percutaneous puncture trajectory (PPT). Methods: A PPT is first generated from the skin puncture site towards an anatomical target, using the information retrieved by electromagnetic motion tracking sensors coupled to surgical tools. Then, 2D ultrasound images acquired with a tracked probe are used to reconstruct a 4D ultrasound around the PPT under GPU processing. Volume hole-filling was performed in different processing time intervals by a tri-linear interpolation method. At spaced time intervals, the volume of the anatomical structures was segmented to ascertain if any vital structure is in between PPT and might compromise the surgical success. To enhance the volume visualization of the reconstructed structures, different render transfer functions were used. Results: Real-time US volume reconstruction and rendering with more than 25 frames/s was only possible when rendering only three orthogonal slice views. When using the whole reconstructed volume one achieved 8-15 frames/s. 3 frames/s were reached when one introduce the segmentation and detection if some structure intersected the PPT. Conclusions: The proposed framework creates a virtual and intuitive platform that can be used to identify and validate a PPT to safely and accurately perform the puncture in percutaneous nephrolithotomy.The authors acknowledge to Foundation for Science and Technology (FCT) - Portugal for the fellowships with references: SFRH/BD/74276/2010.info:eu-repo/semantics/publishedVersio
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