CONSTRUCTION OF OPTICAL CONTROL ALGORITHMS FOR SMALL-SIZE DISTANT LIGHT OBJECTS

2021 ◽  
pp. 15-27
Author(s):  
V. E. Makhov ◽  
A. I. Potapov ◽  
V. V. Shirobokov ◽  
A. V. Emel'yanov
Keyword(s):  
Light Field ◽  
Digital Camera ◽  
Digital Cameras ◽  
Optoelectronic System ◽  
Advantages And Disadvantages ◽  
Experimental Stand ◽  
Telescopic System ◽  
Characteristic Features ◽  
Principal Possibility ◽  
Distant Light

A mathematical model of the brightness structure of an ensemble of small-sized distant light objects in the plane of a photodetector is presented. The structure and principles of construction of optoelectronic systems for registration of distant and small-sized light objects are considered. A method for constructing of algorithms for determining the parameters of an ensemble of objects of different distances, obtained by an optoelectronic system with a digital camera of the light field, taking into account its characteristic features, is developed. A special experimental stand for the study of objects in distant conditions based on a telescopic system and a digital registrator is presented. The principal possibility of creating a light field correlator is shown. A number of algorithms and functions are described, as well as their capabilities to accurately measure the coordinates and parameters of small-sized light objects. The advantages and disadvantages of algorithms based on the continuous wavelet transform are investigated. A comparative analysis of the accuracy of determining the coordinates, dimensions, and features of small-sized objects by various algorithms is presented. It is shown, that the accuracy of determining the coordinates and parameters of small-sized remote objects by digital cameras of the light field is several times higher than by traditional digital cameras.

scholarly journals RESEARCH OF OPTOELECTRONIC SYSTEMS ON THE BASIS OF A TELESCOPE WITH A LIGHT FIELD DIGITAL CAMERA

2020 ◽  
pp. 4-13
Author(s):  
V. E. Makhov ◽  
V. V. Shirobokov ◽  
A. V. Emelyanov ◽  
A. I. Potapov
Keyword(s):  
High Precision ◽  
Optical System ◽  
Light Field ◽  
Digital Camera ◽  
Scale Model ◽  
Optical Scheme ◽  
Optoelectronic System ◽  
Fundamental Possibility ◽  
Two Component ◽  
Optoelectronic Systems

Within the framework of solving the problems of developing intelligent optoelectronic systems for monitoring remote objects, the possibilities of constructing schemes for registering remote objects with a telescopic system based on a light field digital camera are considered. A technique for calculating a two-component optical scheme for registering distant objects by an optoelectronic system based on a digital camera of a light field is presented, and a layout of an experimental setup for registering a scale model of an object with a two-component optical system consisting of a main mirror of a Newtonian telescope and a digital camera of a light field is presented. The principles of constructing algorithms for determining the main parameters of controlled objects and high-precision calibration of the optical system of the recorder have been developed. The fundamental possibility of constructing a light field correlator on the basis of a telescope is shown. An example of processing a light field file is given. The possibility of high-precision determination of the parameters of remote objects has been investigated.

scholarly journals Optical Inspection Systems for Axisymmetric Parts with Spatial 2D Resolution

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1218
Author(s):  
Aleksandr Kulchitskiy
Keyword(s):  
Control System ◽  
Optical System ◽  
Measurement Accuracy ◽  
Experimental Studies ◽  
Digital Camera ◽  
Digital Cameras ◽  
Bodies Of Revolution ◽  
Optical Inspection ◽  
Inspection Systems ◽  
Projection Error

The article proposes a solution to the problem of increasing the accuracy of determining the main shaping dimensions of axisymmetric parts through a control system that implements the optical method of spatial resolution. The influence of the projection error of a passive optical system for controlling the geometric parameters of bodies of revolution from the image of its sections, obtained by a digital camera with non-telecentric optics, on the measurement accuracy is shown. Analytical dependencies are derived that describe the features of the transmission of measuring information of a system with non-telecentric optics in order to estimate the projection error. On the basis of the obtained dependences, a method for compensating the projection error of the systems for controlling the geometry of the main shaping surfaces of bodies of revolution has been developed, which makes it possible to increase the accuracy of determining dimensions when using digital cameras with a resolution of 5 megapixels or more, equipped with short-focus lenses. The possibility of implementing the proposed technique is confirmed by the results of experimental studies.

scholarly journals Spontaneous Type 2 Diabetic Rodent Models

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yang-wei Wang ◽  
Guang-dong Sun ◽  
Jing Sun ◽  
Shu-jun Liu ◽  
Ji Wang ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Health Care ◽  
Animal Models ◽  
Rodent Models ◽  
Advantages And Disadvantages ◽  
Characteristic Features ◽  
Type 2 Diabetic

Diabetes mellitus, especially type 2 diabetes (T2DM), is one of the most common chronic diseases and continues to increase in numbers with large proportion of health care budget being used. Many animal models have been established in order to investigate the mechanisms and pathophysiologic progress of T2DM and find effective treatments for its complications. On the basis of their strains, features, advantages, and disadvantages, various types of animal models of T2DM can be divided into spontaneously diabetic models, artificially induced diabetic models, and transgenic/knockout diabetic models. Among these models, the spontaneous rodent models are used more frequently because many of them can closely describe the characteristic features of T2DM, especially obesity and insulin resistance. In this paper, we aim to investigate the current available spontaneous rodent models for T2DM with regard to their characteristic features, advantages, and disadvantages, and especially to describe appropriate selection and usefulness of different spontaneous rodent models in testing of various new antidiabetic drugs for the treatment of type 2 diabetes.

scholarly journals Bionic Birdlike Imaging Using a Multi-Hyperuniform LED Array

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4084
Author(s):  
Xin-Yu Zhao ◽  
Li-Jing Li ◽  
Lei Cao ◽  
Ming-Jie Sun
Keyword(s):  
Imaging System ◽  
Color Image ◽  
Digital Camera ◽  
Frame Rate ◽  
Digital Cameras ◽  
Structured Illumination ◽  
Pixel Resolution ◽  
Led Array ◽  
Frequency Aliasing ◽  
Imaging Sensors

Digital cameras obtain color information of the scene using a chromatic filter, usually a Bayer filter, overlaid on a pixelated detector. However, the periodic arrangement of both the filter array and the detector array introduces frequency aliasing in sampling and color misregistration during demosaicking process which causes degradation of image quality. Inspired by the biological structure of the avian retinas, we developed a chromatic LED array which has a geometric arrangement of multi-hyperuniformity, which exhibits an irregularity on small-length scales but a quasi-uniformity on large scales, to suppress frequency aliasing and color misregistration in full color image retrieval. Experiments were performed with a single-pixel imaging system using the multi-hyperuniform chromatic LED array to provide structured illumination, and 208 fps frame rate was achieved at 32 × 32 pixel resolution. By comparing the experimental results with the images captured with a conventional digital camera, it has been demonstrated that the proposed imaging system forms images with less chromatic moiré patterns and color misregistration artifacts. The concept proposed verified here could provide insights for the design and the manufacturing of future bionic imaging sensors.

Designing a Color Filter with High Overall Transmittance for Improving the Color Accuracy of Digital Cameras

2021 ◽  
Vol 2021 (29) ◽  
pp. 1-6
Author(s):  
Yuteng Zhu ◽  
Graham D. Finlayson
Keyword(s):  
White Light ◽  
Digital Camera ◽  
Color Filter ◽  
Digital Cameras ◽  
Spectral Transmittance ◽  
Optimal Filters ◽  
Prior Art ◽  
Average Transmittance ◽  
Tristimulus Values ◽  
Correction Problem

Previously improved color accuracy of a given digital camera was achieved by carefully designing the spectral transmittance of a color filter to be placed in front of the camera. Specifically, the filter is designed in a way that the spectral sensitivities of the camera after filtering are approximately linearly related to the color matching functions (or tristimulus values) of the human visual system. To avoid filters that absorbed too much light, the optimization could incorporate a minimum per wavelength transmittance constraint. In this paper, we change the optimization so that the overall filter transmittance is bounded, i.e. we solve for the filter that (for a uniform white light) transmits (say) 50% of the light. Experiments demonstrate that these filters continue to solve the color correction problem (they make cameras much more colorimetric). Significantly, the optimal filters by restraining the average transmittance can deliver a further 10% improvement in terms of color accuracy compared to the prior art of bounding the low transmittance.

Part Monitoring and Quality Assessment of Conformal Additive Manufacturing Using Image Reconstruction

2018 ◽  
Author(s):  
Michael D. Kutzer ◽  
Levi D. DeVries ◽  
Cooper D. Blas
Keyword(s):  
Additive Manufacturing ◽  
Fused Deposition Modeling ◽  
Digital Camera ◽  
Image Data ◽  
Digital Cameras ◽  
Public And Private ◽  
The Public ◽  
Fused Deposition ◽  
Complex Part ◽  
Deposition Modeling

Additive manufacturing (AM) technologies have become almost universal in concept development, prototyping, and education. Advances in materials and methods continue to extend this technology to small batch and complex part manufacturing for the public and private sectors. Despite the growing popularity of digital cameras in AM systems, use of image data for part monitoring is largely unexplored. This paper presents a new method for estimating the 3D internal structure of fused deposition modeling (FDM) processes using image data from a single digital camera. Relative transformations are established using motion capture, and the 3D model is created using knowledge of the deposition path coupled with assumptions about the deposition cross-section. Results show that part geometry can be estimated and visualized using the methods presented in this work.

scholarly journals MANAGEMENT AND OPERATION MODELS IN ELECTRICAL CHARGING INFRASTRUCTURE (EXAMPLE OF KEY COUNTRIES: USA AND CHINA)

2021 ◽  
pp. 94-108
Author(s):  
Леонид Вячеславович Калимуллин ◽  
Денис Константинович Левченко
Keyword(s):  
Developed Countries ◽  
Practical Experience ◽  
Infrastructure Management ◽  
Electric Transport ◽  
Charging Infrastructure ◽  
Advantages And Disadvantages ◽  
State Initiatives ◽  
The Usa ◽  
Characteristic Features ◽  
Russian Model

Несмотря на существующие государственные инициативы, одним из факторов, сдерживающих развитие электротранспорта в России, является низкий уровень развития электрозарядной инфраструктуры. В данном контексте актуально изучить успешный опыт построения и внедрения моделей функционирования электрозарядной инфраструктуры и управления ею на примере наиболее развитых по данному направлению стран. Целью статьи является исследование моделей функционирования инфраструктуры для электромобилей и управления ею, применяемых в США и Китае, выявление характерных особенностей, преимуществ и недостатков с целью формирования наиболее оптимальных условий для построения российской модели электрозарядной инфраструктуры. Элементы научной новизны заключаются в обобщении и систематизация практического опыта применения моделей функционирования электрозарядной инфраструктуры и управления ею. Despite existing state initiatives, one of the factors limiting the development of electric transport in Russia is the low level of development of electric charging infrastructure. In this context, it is relevant to study the successful experience of building and implementing models for the management and operation of electric charging infrastructure on the example of the most developed countries in this area. The purpose of the article is to study models of infrastructure management and functioning for electric vehicles used in the USA and China, to identify characteristic features, advantages and disadvantages in order to form the most optimal conditions for building a Russian model of electric charging infrastructure. Elements of scientific novelty are the synthesis and systematization of practical experience in the application of models of control and operation of electric charging infrastructure.

Returns to search when consumers use and do not use recommendation agents

2017 ◽  
Vol 29 (4) ◽  
pp. 813-836 ◽  
Author(s):  
Satish Sasalu Maheswarappa ◽  
Bharadhwaj Sivakumaran ◽  
Arun G. Kumar
Keyword(s):  
Digital Camera ◽  
Decision Quality ◽  
Digital Cameras ◽  
Content Type ◽  
Subjective Knowledge ◽  
Decision Confidence ◽  
Optimum Decision ◽  
Decision Satisfaction ◽  
Recommendation Agents ◽  
Quality Decision

Purpose The purpose of this paper is to investigate returns to search (getting a better product and/or a lower price as a result of search) when consumers use/do not use recommendation agents (RAs). Specifically, it studies the effect of RAs/no RAs on decision quality, decision confidence and decision satisfaction taking into account subjective knowledge (SK) and involvement. Design/methodology/approach This paper employed two between-subjects factorial experimental designs with subjects searching for digital cameras in a simulated online digital camera store. The experiment was conducted with graduate students in Chennai, Bengaluru and Mysore in India. Findings Results of two online experiments showed that when consumers used RAs, low search led to better decision quality, whereas when consumers did not use RAs, medium search led to optimum decision quality. When consumers use RAs, SK had a U-shaped influence on the decision quality indicating that decision quality was the lowest for those with medium SK. When consumers did not use RAs, the effect of SK on decision quality was an inverted U-shape, indicating optimum decision quality for medium SK consumers. When consumers did not use RAs, subjects with high involvement made better choices, whereas when consumers used RAs, low involvement subjects made better choices. However, subjects who searched more had higher decision confidence and decision satisfaction even if their choices were not better. Originality/value The effect of RA vs no RA in conjunction with relevant consumer characteristics influencing decision quality of the consumer is demonstrated in this study. The findings have important managerial, consumer and theoretical contributions to make.

scholarly journals INVESTIGATION INTO THE BEHAVIOUR AND MODELLING OF CHROMATIC ABERRATIONS IN NON-METRIC DIGITAL CAMERAS

2019 ◽  
Vol XLII-2/W18 ◽  
pp. 99-106 ◽  
Author(s):  
D. D. Lichti ◽  
D. Jarron ◽  
M. Shahbazi ◽  
P. Helmholz ◽  
R. Radovanovic
Keyword(s):  
Digital Camera ◽  
Chromatic Aberration ◽  
Bundle Adjustment ◽  
Lens Distortion ◽  
Digital Cameras ◽  
Principal Point ◽  
Common Object ◽  
Chromatic Aberrations ◽  
The Impact ◽  
Orientation Parameters

Abstract. Chromatic aberration in colour digital camera imagery can affect the accuracy of photogrammetric reconstruction. Both longitudinal and transverse chromatic aberrations can be effectively modelled by making separate measurements in each of the blue, green and red colour bands and performing a specialized self-calibrating bundle adjustment. This paper presents the results of an investigation with two aims. The first aim is to quantify the presence of chromatic aberration in two sets of cameras: the six individual cameras comprising a Ladybug5 system, calibrated simultaneously in air; and four GoPro Hero 5 cameras calibrated independently under water. The second aim is to investigate the impacts of imposing different constraints in the self-calibration adjustment. To this end, four different adjustment cases were performed for all ten cameras: independent adjustment of the observations from each colour band; combined adjustment of all colour bands’ observations with common object points; combined adjustment of all colour bands with common object points and common exterior orientation parameters for each colour band triplet; and combined adjustment with common object points and certain common interior orientation parameters. The results show that the Ladybug5 cameras exhibit a small (1-2 pixel) amount of transverse chromatic aberration but no longitudinal chromatic aberration. The GoPro Hero 5 cameras exhibit significant (25 pixel) transverse chromatic aberration as well as longitudinal chromatic aberration. The principal distance was essentially independent of the adjustment case for the Ladybug5, but it was not for the GoPro Hero 5. The principal point position and precision were both affected considerably by adjustment case. Radial lens distortion was invariant to the adjustment case. The impact of adjustment case on decentring distortion was minimal in both cases.

scholarly journals Combining multi-spectral proximal sensors and digital cameras for monitoring grazed tropical pastures

2015 ◽  
Vol 12 (21) ◽  
pp. 18007-18051
Author(s):  
R. N. Handcock ◽  
D. L. Gobbett ◽  
L. A. González ◽  
G. J. Bishop-Hurley ◽  
S. L. McGavin
Keyword(s):  
Quality Control ◽  
Near Infrared ◽  
Digital Camera ◽  
Ground Cover ◽  
Sensor Data ◽  
Weather Data ◽  
Research Station ◽  
Digital Cameras ◽  
Tropical Pastures ◽  
Standing Biomass

Abstract. Timely and accurate monitoring of pasture biomass and ground-cover is necessary in livestock production systems to ensure productive and sustainable management of forage for livestock. Interest in the use of proximal sensors for monitoring pasture status in grazing systems has increased, since such sensors can return data in near real-time, and have the potential to be deployed on large properties where remote sensing may not be suitable due to issues such as spatial scale or cloud cover. However, there are unresolved challenges in developing calibrations to convert raw sensor data to quantitative biophysical values, such as pasture biomass or vegetation ground-cover, to allow meaningful interpretation of sensor data by livestock producers. We assessed the use of multiple proximal sensors for monitoring tropical pastures with a pilot deployment of sensors at two sites on Lansdown Research Station near Townsville, Australia. Each site was monitored by a Skye SKR-four-band multi-spectral sensor (every 1 min), a digital camera (every 30 min), and a soil moisture sensor (every 1 min), each operated over 18 months. Raw data from each sensor were processed to calculate a number of multispectral vegetation indices. Visual observations of pasture characteristics, including above-ground standing biomass and ground cover, were made every 2 weeks. A methodology was developed to manage the sensor deployment and the quality control of the data collected. The data capture from the digital cameras was more reliable than the multi-spectral sensors, which had up to 63 % of data discarded after data cleaning and quality control. We found a strong relationship between sensor and pasture measurements during the wet season period of maximum pasture growth (January to April), especially when data from the multi-spectral sensors were combined with weather data. RatioNS34 (a simple band ratio between the near infrared (NIR) and lower shortwave infrared (SWIR) bands) and rainfall since 1 September explained 91 % of the variation in above-ground standing biomass (RSE = 593 kg DM ha−1, p < 0.01). RatioNS34 together with rainfall explained 95 % of the variation in the percentage of green vegetation observed in 2-dimensions (%Green2D) (RSE = 6 %, p < 0.01). The Green Leaf Algorithm index derived from the digital camera images and the rainfall accumulated since the 1 September explained 91 % of the variation in %Green2D (RSE = 9 %, p < 0.01, df = 20), but had a poor relationship with biomass. Although proximal sensors observe only a small area of the pasture, they deliver continual and timely pasture measurements to inform timely decision-making on-farm.

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