Semi-automatic calibration procedure for the vision-robot interface applied to scale model decoration

Robotica ◽  
1992 ◽  
Vol 10 (4) ◽  
pp. 303-308
Author(s):  
Luis Gonzaga Trabasso ◽  
Cezary Zielinski
Keyword(s):  
Three Dimensional ◽  
Robot Vision ◽  
Work Load ◽  
Calibration Procedure ◽  
Scale Model ◽  
Three Dimensional Objects ◽  
University Of Technology ◽  
Scale Models ◽  
Set Up ◽  
Small Work

SUMMARYA semi-automatic method for calibrating a robot-vision interface is presented. It puts a small work-load on the operator, requires a simple calibration jig and a solution of a very simple system of equations. It has been extensively used in an experimental robotic cell set up at Loughborough University of Technology, where various aspects of the manufacturing and the decoration of scale models are being investigated. As an extension of the calibration procedure, the paper also shows practical solutions for the problem of dealing with three dimensional objects using a single camera.

Small-Scale Models for Testing Masonry Structures

2010 ◽  
Vol 133-134 ◽  
pp. 497-502 ◽  
Author(s):  
Alvaro Quinonez ◽  
Jennifer Zessin ◽  
Aissata Nutzel ◽  
John Ochsendorf
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Three Dimensional ◽  
Model Testing ◽  
Scale Model ◽  
Small Scale ◽  
Material Strength ◽  
Masonry Structures ◽  
Scale Models ◽  
Set Up

Experiments may be used to verify numerical and analytical results, but large-scale model testing is associated with high costs and lengthy set-up times. In contrast, small-scale model testing is inexpensive, non-invasive, and easy to replicate over several trials. This paper proposes a new method of masonry model generation using three-dimensional printing technology. Small-scale models are created as an assemblage of individual blocks representing the original structure’s geometry and stereotomy. Two model domes are tested to collapse due to outward support displacements, and experimental data from these tests is compared with analytical predictions. Results of these experiments provide a strong understanding of the mechanics of actual masonry structures and can be used to demonstrate the structural capacity of masonry structures with extensive cracking. Challenges for this work, such as imperfections in the model geometry and construction problems, are also addressed. This experimental method can provide a low-cost alternative for the collapse analysis of complex masonry structures, the safety of which depends primarily on stability rather than material strength.

3-D Object Projection Method of Multi-Camera Revolve Batch Rendering

2012 ◽  
Vol 256-259 ◽  
pp. 2894-2897
Author(s):  
Xiao Ming Bai ◽  
Xiao Fang Xie ◽  
Ji Hong Yu
Keyword(s):  
Projection Method ◽  
Recognition Rate ◽  
Three Dimensional ◽  
Random Projection ◽  
Three Dimensional Objects ◽  
Space Projection ◽  
Projection Images ◽  
Three Dimensional Models ◽  
Set Up ◽  
Moving Path

3-D object recognition was different from 2-D one. In order to improve recognition rate, it was necessary to establish a full features base. With object as center, the paper offered a view space projection method of Multi-Camera Revolve Batch Rendering. Firstly, constructed three dimensional models for object, set positions for model and camera of top view. Then by the max panel stick to one of axis angle, copied camera with equal interval. Set up the moving path for hemisphere, and constraint to corresponding camera. In the last, established batch script with output parameters, automatic preservation random projection images for three dimensional objects.

How much is there really? Why stereology is essential in lung morphometry

2007 ◽  
Vol 102 (1) ◽  
pp. 459-467 ◽  
Author(s):  
Ewald R. Weibel ◽  
Connie C. W. Hsia ◽  
Matthias Ochs
Keyword(s):  
Quantitative Data ◽  
Functional Performance ◽  
Three Dimensional ◽  
Specimen Preparation ◽  
Three Dimensional Objects ◽  
Lung Structure ◽  
Lung Morphometry ◽  
Set Up ◽  
Function Models ◽  
Free Set

Quantitative data on lung structure are essential to set up structure-function models for assessing the functional performance of the lung or to make statistically valid comparisons in experimental morphology, physiology, or pathology. The methods of choice for microscopy-based lung morphometry are those of stereology, the science of quantitative characterization of irregular three-dimensional objects on the basis of measurements made on two-dimensional sections. From a practical perspective, stereology is an assumption-free set of methods of unbiased sampling with geometric probes, based on a solid mathematical foundation. Here, we discuss the pitfalls of lung morphometry and present solutions, from specimen preparation to the sampling scheme in multiple stages, for obtaining unbiased estimates of morphometric parameters such as volumes, surfaces, lengths, and numbers. This is demonstrated on various examples. Stereological methods are accurate, efficient, simple, and transparent; the precision of the estimates depends on the size and distribution of the sample. For obtaining quantitative data on lung structure at all microscopic levels, state-of-the-art stereology is the gold standard.

scholarly journals Curvature Adaptive 3D Scanning Transformation Calculation

2018 ◽  
Vol 62 (4) ◽  
pp. 107-116
Author(s):  
Adrián Mezei ◽  
Tibor Kovács
Keyword(s):  
Real Time ◽  
Point Cloud ◽  
Three Dimensional ◽  
Point Clouds ◽  
3D Scanning ◽  
Laser Line ◽  
3D Scanner ◽  
Three Dimensional Objects ◽  
Laser Scanners ◽  
Set Up

Three-dimensional objects can be scanned by 3D laser scanners that use active triangulation. These scanners create three-dimensional point clouds from the scanned objects. The laser line is identified in the images, which are captured at given transformations by the camera, and the point cloud can be calculated from these. The hardest challenge is to construct these transformations so that most of the surface can be captured. The result of a scanning may have missing parts because either not the best transformations were used or because some parts of the object cannot be scanned. Based on the results of the previous scans, a better transformation plan can be created, with which the next scan can be performed. In this paper, a method is proposed for transforming a special 3D scanner into a position from where the scanned point can be seen from an ideal angle. A method is described for estimating this transformation in real-time, so these can be calculated for every point of a previous scan to set up a next improved scan.

scholarly journals Spatially Resolved Spectral Imaging by A THz-FEL

2020 ◽  
Vol 5 (2) ◽  
pp. 38
Author(s):  
Akinori Irizawa ◽  
Masaki Fujimoto ◽  
Keigo Kawase ◽  
Ryukou Kato ◽  
Hidenori Fujiwara ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Spectral Imaging ◽  
High Sensitivity ◽  
Far Infrared ◽  
Inorganic Materials ◽  
Large Intensity ◽  
Three Dimensional Objects ◽  
Spatially Resolved ◽  
Transmission Imaging ◽  
Set Up

Using the unique characteristics of the free-electron-laser (FEL), we successfully performed high-sensitivity spectral imaging of different materials in the terahertz (THz) and far-infrared (FIR) domain. THz imaging at various wavelengths was achieved using in situ spectroscopy by means of this wavelength tunable and monochromatic source. In particular, owing to its large intensity and directionality, we could collect high-sensitivity transmission imaging of extremely low-transparency materials and three-dimensional objects in the 3–6 THz range. By accurately identifying the intrinsic absorption wavelength of organic and inorganic materials, we succeeded in the mapping of spatial distribution of individual components. This simple imaging technique using a focusing optics and a raster scan modality has made it possible to set up and carry out fast spectral imaging experiments on different materials in this radiation facility.

Three-dimensional Reconstruction of Microscopic Image Based on Multi-ST Algorithm

2020 ◽  
Vol 64 (2) ◽  
pp. 20506-1-20506-7
Author(s):  
Min Zhu ◽  
Rongfu Zhang ◽  
Pei Ma ◽  
Xuedian Zhang ◽  
Qi Guo
Keyword(s):  
3D Reconstruction ◽  
Three Dimensional ◽  
Scale Model ◽  
Microscopic Image ◽  
Multi Scale ◽  
Gaussian Pyramid ◽  
Cost Aggregation ◽  
Dimensional Reconstruction ◽  
Image Pairs ◽  
Accurate Matching

Abstract Three-dimensional (3D) reconstruction is extensively used in microscopic applications. Reducing excessive error points and achieving accurate matching of weak texture regions have been the classical challenges for 3D microscopic vision. A Multi-ST algorithm was proposed to improve matching accuracy. The process is performed in two main stages: scaled microscopic images and regularized cost aggregation. First, microscopic image pairs with different scales were extracted according to the Gaussian pyramid criterion. Second, a novel cost aggregation approach based on the regularized multi-scale model was implemented into all scales to obtain the final cost. To evaluate the performances of the proposed Multi-ST algorithm and compare different algorithms, seven groups of images from the Middlebury dataset and four groups of experimental images obtained by a binocular microscopic system were analyzed. Disparity maps and reconstruction maps generated by the proposed approach contained more information and fewer outliers or artifacts. Furthermore, 3D reconstruction of the plug gauges using the Multi-ST algorithm showed that the error was less than 0.025 mm.

Modeling and Assessment of the Produced Water Discharges from Offshore Petroleum Platforms

2007 ◽  
Vol 42 (4) ◽  
pp. 303-310 ◽  
Author(s):  
Zhi Chen ◽  
Lin Zhao ◽  
Kenneth Lee ◽  
Charles Hannath
Keyword(s):  
Random Walk ◽  
Produced Water ◽  
Model Development ◽  
Three Dimensional ◽  
Monitoring Program ◽  
Ecological Monitoring ◽  
Numerical Approach ◽  
Ocean Model ◽  
Scale Model ◽  
Water Stream

Abstract There has been a growing interest in assessing the risks to the marine environment from produced water discharges. This study describes the development of a numerical approach, POM-RW, based on an integration of the Princeton Ocean Model (POM) and a Random Walk (RW) simulation of pollutant transport. Specifically, the POM is employed to simulate local ocean currents. It provides three-dimensional hydrodynamic input to a Random Walk model focused on the dispersion of toxic components within the produced water stream on a regional spatial scale. Model development and field validation of the predicted current field and pollutant concentrations were conducted in conjunction with a water quality and ecological monitoring program for an offshore facility located on the Grand Banks of Canada. Results indicate that the POM-RW approach is useful to address environmental risks associated with the produced water discharges.

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