Structured light camera calibration

2013 ◽  
Vol 21 (1) ◽  
Author(s):  
P. Garbat ◽  
W. Skarbek ◽  
M. Tomaszewski
Keyword(s):  
Information Technology ◽  
Camera Calibration ◽  
High Speed ◽  
Moving Objects ◽  
Structured Light ◽  
Video Camera ◽  
High Definition ◽  
University Of Technology ◽  
Is Integration ◽  
Calibration Techniques

AbstractStructured light camera which is being designed with the joined effort of Institute of Radioelectronics and Institute of Optoelectronics (both being large units of the Warsaw University of Technology within the Faculty of Electronics and Information Technology) combines various hardware and software contemporary technologies. In hardware it is integration of a high speed stripe projector and a stripe camera together with a standard high definition video camera. In software it is supported by sophisticated calibration techniques which enable development of advanced application such as real time 3D viewer of moving objects with the free viewpoint or 3D modeller for still objects.

Real-time cooperative interaction between structured-light and reflectance ranging for robot guidance

Robotica ◽  
1985 ◽  
Vol 3 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Ernest W. Kent ◽  
Thomas Wheatley ◽  
Marilyn Nashman
Keyword(s):  
Real Time ◽  
Moving Objects ◽  
Structured Light ◽  
Video Camera ◽  
The Other ◽  
Cooperative Interaction ◽  
Complex Objects ◽  
Improved Performance ◽  
Log Linear

SUMMARYWhen applied to rapidly moving objects with complex trajectories, the information-rate limitation imposed by video-camera frame rates impairs the effectiveness of structured-light techniques in real-time robot servoing. To improve the performance of such systems, the use of fast infra-red proximity detectors to augment visual guidance in the final phase of target acquisition was explored. It was found that this approach was limited by the necessity of employing a different range/intensity calibration curve for the proximity detectors for every object and for every angle of approach to complex objects. Consideration of the physics of the detector process suggested that a single log-linear parametric family could describe all such calibration curves, and this was confirmed by experiment. From this result, a technique was devised for cooperative interaction between modalities, in which the vision sense provided on-the-fly determination of calibration parameters for the proximity detectors, for every approach to a target, before passing control of the system to the other modality. This technique provided a three hundred percent increase in useful manipulator velocity, and improved performance during the transition of control from one modality to the other.

A High Speed Boat for the Hydrodynamic Testing of Fouling Control Coatings

2017 ◽  
Author(s):  
J. Travis Hunsucker ◽  
Harrison Gardner ◽  
Geoffrey Swain
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Load Cell ◽  
Structure Characterization ◽  
Hydrodynamic Drag ◽  
Experimental Uncertainty ◽  
High Definition ◽  
Fouling Control ◽  
Drag Forces ◽  
Fouling Control Coatings

An 8.2 m high speed boat was modified to measure the drag and to provide real time video of ship hull fouling control coatings under boundary layer conditions that developed at speeds up to 15 m/s. It consists of a through hull Hydrodynamic Drag Meter (HDM) placed in a wet-well built into the aft section of the boat. The HDM consists of a load cell attached to a floating element balance and a high definition video camera to observe fouling. Test panels are attached to the load cell such that they remain flush with the hull. Fouled test panels are placed in the facility to observe the velocities required for fouling removal and changes in drag forces associated with different fouling community structure. Characterization studies of the HDM were undertaken to understand the overall accuracy of the novel testing system. These experiments included 1) Smooth acrylic drag measurement with the HDM and a Preston tube and 2) Drag measurements with the HDM on panels with 60- grit and 220-grit sandpaper. Smooth panel wall shear stress values obtained using the HDM were within experimental uncertainties of results from Preston tube. Roughness function values for 60-grit and 220-grit sandpaper agree within the experimental uncertainty of the Nikuradse-type roughness function for uniform roughness. Skin friction coefficients of a smooth panel determined on the HDM had an experimental uncertainty of around 5% for Froude numbers greater than 1. Roughness function values for a 220-grit and 60-grit sandpaper surface had maximum uncertainties of 11% and 13% respectively.

scholarly journals 3D Reconstruction with Single-Shot Structured Light RGB Line Pattern

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4819
Author(s):  
Yikang Li ◽  
Zhenzhou Wang
Keyword(s):  
3D Reconstruction ◽  
Moving Objects ◽  
Structured Light ◽  
Color Space ◽  
Reconstruction Technique ◽  
Single Shot ◽  
Line Pattern ◽  
Hsv Color Space ◽  
Phase Map ◽  
Line Segmentation

Single-shot 3D reconstruction technique is very important for measuring moving and deforming objects. After many decades of study, a great number of interesting single-shot techniques have been proposed, yet the problem remains open. In this paper, a new approach is proposed to reconstruct deforming and moving objects with the structured light RGB line pattern. The structured light RGB line pattern is coded using parallel red, green, and blue lines with equal intervals to facilitate line segmentation and line indexing. A slope difference distribution (SDD)-based image segmentation method is proposed to segment the lines robustly in the HSV color space. A method of exclusion is proposed to index the red lines, the green lines, and the blue lines respectively and robustly. The indexed lines in different colors are fused to obtain a phase map for 3D depth calculation. The quantitative accuracies of measuring a calibration grid and a ball achieved by the proposed approach are 0.46 and 0.24 mm, respectively, which are significantly lower than those achieved by the compared state-of-the-art single-shot techniques.

scholarly journals Hybrid Mamdani Fuzzy Rules and Convolutional Neural Networks for Analysis and Identification of Animal Images

Computation ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 35
Author(s):  
Hind R. Mohammed ◽  
Zahir M. Hussain
Keyword(s):  
Neural Networks ◽  
Convolutional Neural Networks ◽  
High Speed ◽  
Moving Objects ◽  
Real Life ◽  
Fuzzy Rules ◽  
High Rate ◽  
Moving Images ◽  
Animal Images

Accurate, fast, and automatic detection and classification of animal images is challenging, but it is much needed for many real-life applications. This paper presents a hybrid model of Mamdani Type-2 fuzzy rules and convolutional neural networks (CNNs) applied to identify and distinguish various animals using different datasets consisting of about 27,307 images. The proposed system utilizes fuzzy rules to detect the image and then apply the CNN model for the object’s predicate category. The CNN model was trained and tested based on more than 21,846 pictures of animals. The experiments’ results of the proposed method offered high speed and efficiency, which could be a prominent aspect in designing image-processing systems based on Type 2 fuzzy rules characterization for identifying fixed and moving images. The proposed fuzzy method obtained an accuracy rate for identifying and recognizing moving objects of 98% and a mean square error of 0.1183464 less than other studies. It also achieved a very high rate of correctly predicting malicious objects equal to recall = 0.98121 and a precision rate of 1. The test’s accuracy was evaluated using the F1 Score, which obtained a high percentage of 0.99052.

scholarly journals Detonation effects of shallow buried explosive in sandy soil on target plate acceleration in a small-scale blast test

2018 ◽  
Vol 192 ◽  
pp. 02028
Author(s):  
Hassan Zulkifli Abu ◽  
Ibrahim Aniza ◽  
Mohamad Nor Norazman
Keyword(s):  
Sandy Soil ◽  
High Speed ◽  
Early Stage ◽  
Time History ◽  
Video Camera ◽  
Small Scale ◽  
Target Plate ◽  
Air Blast ◽  
High Speed Video Camera ◽  
The Impact

Small-scale blast tests were carried out to observe and measure the influence of sandy soil towards explosive blast intensity. The tests were to simulate blast impact imparted by anti-vehicular landmine to a lightweight armoured vehicle (LAV). Time of occurrence of the three phases of detonation phase in soil with respect to upward translation time of the test apparatus were recorded using high-speed video camera. At the same time the target plate acceleration was measured using shock accelerometer. It was observed that target plate deformation took place at early stage of the detonation phase before the apparatus moved vertically upwards. Previous data of acceleration-time history and velocity-time history from air blast detonation were compared. It was observed that effects of soil funnelling on blast wave together with the impact from soil ejecta may have contributed to higher blast intensity that characterized detonation in soil, where detonation in soil demonstrated higher plate velocity compared to what occurred in air blast detonation.

In Situ Observation Method for Quantitative Evaluation of Solidification Phenomena and Solidification Cracks during Welding

2014 ◽  
Vol 782 ◽  
pp. 3-7
Author(s):  
Kenji Shinozaki ◽  
Motomichi Yamamoto ◽  
Kohta Kadoi ◽  
Peng Wen
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Solidification Cracking ◽  
In Situ Observation ◽  
High Speed Video Camera ◽  
Varestraint Test ◽  
Solidification Cracks ◽  
Observation Method ◽  
Solidification Crack

Solidification cracking during welding is very serious problem for practical use. Therefore, there are so many reports concerning solidification cracking. Normally, solidification cracking susceptibility of material is quantitatively evaluated using Trans-Varestraint test. On the other hand, local solidification cracking strain was tried to measure precisely using in-situ observation method, called MISO method about 30 years ago. Recently, digital high-speed video camera develops very fast and its image quality is very high. Therefore, we have started to observe solidification crack using in site observation method. In this paper, the local critical strain of a solidification crack was measured and the high temperature ductility curves of weld metals having different dilution ratios and different grain sizes to evaluate quantitatively the effects of dilution ratio and grain size on solidification cracking susceptibility by using an improved in situ observation method.

Study on Magnetic Barrel Machine Equipped with Three-Dimensional Arrangement of Magnets

2007 ◽  
Vol 329 ◽  
pp. 761-766 ◽  
Author(s):  
Y. Zhang ◽  
Masato Yoshioka ◽  
Shin-Ichiro Hira
Keyword(s):  
High Speed ◽  
Permanent Magnets ◽  
Three Dimensional ◽  
Video Camera ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
The Media ◽  
Set Up

At present, a commercially available magnetic barrel machine equipped with permanent magnets has some faults arising from constructional reason. That is, grinding or finishing ability is different from place to place in the machining region, resulting in the limitation on the region we can use in the container of workpieces. Therefore, in this research, authors made the new magnetic barrel machine equipped with three dimensional (3D) magnet arrangement to overcome these faults. The grinding ability of the new 3D magnetic barrel machine converted was experimentally examined, and compared with that of the traditional magnetic barrel machine. As a result, it was shown that we can use much broader region in the new 3D machine. It was also shown that the grinding ability became higher. The distribution of barrel media in action was recorded by means of a high speed video camera. It was clarified that the media rose up higher and were distributed more uniformly in the container by the effect of the magnet block newly set up. It was supposed that this must be the reason for the above-mentioned improvement of grinding ability.

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