scholarly journals ALGORITHMS OF SEAFLOOR INDUSTRIAL MACHINERY INSPECTION USING AUV

2020 ◽  
Author(s):  
А.В. Инзарцев ◽  
М.А. Панин ◽  
В.А. Бобков
Keyword(s):  
Autonomous Underwater Vehicles ◽  
A Priori ◽  
Laser Scanner ◽  
Final Model ◽  
New Information ◽  
Object Based ◽  
Object Inspection ◽  
Priori Information ◽  
Available Information ◽  
The Given

АНПА могут быть применены для автоматизированной инспекции объектов подводных добычных комплексов. При наличии априорной информации об объекте (его модели) целью обследования может быть детальная фотосъемка заданных фрагментов объекта. Для выхода АНПА к этим фрагментам используются алгоритмы точной навигационной привязки к объекту на базе анализа последовательности стереоизображений и имеющейся информации о расположении характерных точек объекта. В случае отсутствия априорной информации целью обследования может быть построение детальной 3D модели объекта (с помощью лазерного сканера или многолучевого эхолокатора). Для этого АНПА производит первоначальное обнаружение (локализацию) объекта. Далее его траектория формируется динамически от одной видовой позиции к другой по мере поступления новой информации об объекте. В качестве критерия при выборе очередной видовой позиции используется оценка ее информативности (т.е. объем получаемой новой информации об объекте). Итоговая модель объекта формируется по собранной информации с использованием методов фотограмметрии. В работе рассматриваются подходы и алгоритмы, которые могут быть использованы при обследовании объектов для этих двух случаев. Autonomous underwater vehicles (AUV) can be used for automatized inspection of the objects of marine mining complexes. If a priori information about the object (or its model) is available, the examination can be aimed at detailed photographing the given fragments of the object. Routing AUV to these fragments relies on algorithms of precise navigation referencing to the object based on analysis of the sequence of stereo images and available information about specific points of the object. In case of the necessary information absence, the inspection may target the goal of building the detailed 3D model of the object (using a laser scanner or multibeam echosounder). In that case, AUV performs the initial detection (localization) of the object at first. Then its motion trajectory is generated dynamically from one view position to another as new information about the object becomes available. A criterion of the viewing position selection used is its informational value (i.e., the amount of further information received about the object). The final model is built using gathered information processed with methods of photogrammetry. The paper considers approaches and algorithms applicable for object inspection in two above described cases.

scholarly journals Finding the next-best scanner position for as-built modeling of piping systems

2014 ◽  
Vol XL-5 ◽  
pp. 313-320 ◽  
Author(s):  
K. Kawashima ◽  
S. Yamanishi ◽  
S. Kanai ◽  
H. Date
Keyword(s):  
A Priori ◽  
Laser Scanner ◽  
Point Clouds ◽  
Computational Time ◽  
Piping System ◽  
Terrestrial Laser Scanner ◽  
View Planning ◽  
Piping Systems ◽  
Petroleum Refineries ◽  
Priori Information

Renovation of plant equipment of petroleum refineries or chemical factories have recently been frequent, and the demand for 3D asbuilt modelling of piping systems is increasing rapidly. Terrestrial laser scanners are used very often in the measurement for as-built modelling. However, the tangled structures of the piping systems results in complex occluded areas, and these areas must be captured from different scanner positions. For efficient and exhaustive measurement of the piping system, the scanner should be placed at optimum positions where the occluded parts of the piping system are captured as much as possible in less scans. However, this "nextbest" scanner positions are usually determined by experienced operators, and there is no guarantee that these positions fulfil the optimum condition. Therefore, this paper proposes a computer-aided method of the optimal sequential view planning for object recognition in plant piping systems using a terrestrial laser scanner. In the method, a sequence of next-best positions of a terrestrial laser scanner specialized for as-built modelling of piping systems can be found without any a priori information of piping objects. Different from the conventional approaches for the next-best-view (NBV) problem, in the proposed method, piping objects in the measured point clouds are recognized right after an every scan, local occluded spaces occupied by the unseen piping systems are then estimated, and the best scanner position can be found so as to minimize these local occluded spaces. The simulation results show that our proposed method outperforms a conventional approach in recognition accuracy, efficiency and computational time.

scholarly journals Model and method development for determining the completeness of information for remote detection of landmarks for autonomous mobile robots

2021 ◽  
Vol 6 (2(62)) ◽  
pp. 37-41
Author(s):  
Oleksandr Poliarus ◽  
Andrii Lebedynskyi ◽  
Yevhenii Chepusenko ◽  
Nina Lyubymova
Keyword(s):  
Method Development ◽  
A Priori ◽  
Weather Conditions ◽  
Threshold Level ◽  
Remote Detection ◽  
Measurement Information ◽  
Priori Information ◽  
The Given ◽  
Physical Principles ◽  
Approach Unity

The object of research is the completeness of information for making a navigation decision by an autonomous mobile robot when it performs a task in an unfamiliar area without GPS. It is difficult to identify a landmark in the absence and abundance of information. One of the most problematic places is the mathematical description of the criterion according to which an autonomous robot makes a decision about the completeness of information. The paper substantiates a model and method for determining the completeness of information by a robot equipped with several landmarks detection tools operating on different physical principles. It is shown that the implementation of the method requires a priori information on the probability of detecting various landmarks by passive and active means against a continuous and discontinuous background at different illumination of objects, in day and night conditions under different weather conditions. The values of the probability of detecting a specific type of landmark obtained in such studies serve as the basis for constructing an information cadastre for a job performing tasks on the ground. Three formulas are proposed for determining the coefficient of completeness of information, taking into account a priori and a posteriori inventories, and recommended areas of application. The value of this coefficient depends on the threshold level of the probability of detecting a landmark. The reliability of a decision made by a robot is greatest when it is made under conditions of a certain level of completeness of information. The proposed method can be used for other technical objects from which the measurement information is received. Compared with the known methods, it expands the boundaries of application and reveals the possibility of assessing the completeness of information in constantly changing conditions. Along with a change in these conditions, the characteristics of the completeness of information also change. The coefficient of completeness of information can approach unity even in the absence of separate means of detecting landmarks, and then the method makes it possible to assess the need for their use in the given conditions.

BUDGET ESTIMATION AND CONTROL FOR BAG-OF-TASKS SCHEDULING IN CLOUDS

2011 ◽  
Vol 21 (02) ◽  
pp. 219-243 ◽  
Author(s):  
ANA-MARIA OPRESCU ◽  
THILO KIELMANN ◽  
HARALAMBIE LEAHU
Keyword(s):  
A Priori ◽  
Task Completion ◽  
Time Intervals ◽  
Tasks Scheduling ◽  
Cloud Environments ◽  
Elastic Applications ◽  
Estimation And Control ◽  
Priori Information ◽  
And Control ◽  
The Given

Commercial cloud offerings, such as Amazon's EC2, let users allocate compute resources on demand, charging based on reserved time intervals. While this gives great flexibility to elastic applications, users lack guidance for choosing between multiple offerings, in order to complete their computations within given budget constraints. In this work, we present BaTS, our budget-constrained scheduler. Using a small task sample, BaTS can estimate costs and makespan for a given bag on different cloud offerings. It provides the user with a choice of options before execution and then schedules the bag according to the user's preferences. BaTS requires no a-priori information about task completion times. We evaluate BaTS by emulating different cloud environments on the DAS-3 multi-cluster system. Our results show that BaTS correctly estimates budget and makespan for the scenarios investigated; the user-selected schedule is then executed within the given budget limitations.

scholarly journals Strategies for generating panoramic video images without information about scene correspondences for multispectral distributed aperture systems

2021 ◽  
Vol 45 (4) ◽  
pp. 589-599
Author(s):  
I.A. Kudinov ◽  
M.B. Nikiforov ◽  
I.S. Kholopov
Keyword(s):  
A Priori ◽  
Region Of Interest ◽  
Regions Of Interest ◽  
Video Images ◽  
Panoramic Video ◽  
Minimum Number ◽  
Priori Information ◽  
The Given ◽  
Analytical Expressions ◽  
Selection Of

We derive analytical expressions for calculating the number of elementary computational operations required to generate several personal regions of interest in a panoramic computer-vision distributed-aperture system using two alternative strategies: strategy 1 involves acquisition of a complete panoramic frame, followed by the selection of personal regions of interest, while with strategy 2 the region of interest is directly formed for each user. The parameters of analytical expressions include the number of cameras in the distributed system, the number of users, and the resolution of panorama and user frames. The formulas obtained for the given parameters make it possible to determine a strategy that would be optimal in terms of a criterion of the minimum number of elementary computational operations for generating multiple personal regions of interest. The region of interest is generated using only a priori information about the internal and external camera parameters, obtained as a result of their photogrammetric calibration with a universal test object, and does not take into account information about scene correspondences at the boundaries of intersecting fields of view.

Method for measuring distortions of a speech signal during its transmission over a communication channel to a biometric identification system

2020 ◽  
pp. 65-72
Author(s):  
V. V. Savchenko ◽  
A. V. Savchenko
Keyword(s):  
Speech Signal ◽  
Communication Channel ◽  
Speaker Identification ◽  
A Priori ◽  
Small Samples ◽  
Practical Implementation ◽  
Identification System ◽  
New Information ◽  
Discrimination Criterion ◽  
A Priori Uncertainty

This paper is devoted to the presence of distortions in a speech signal transmitted over a communication channel to a biometric system during voice-based remote identification. We propose to preliminary correct the frequency spectrum of the received signal based on the pre-distortion principle. Taking into account a priori uncertainty, a new information indicator of speech signal distortions and a method for measuring it in conditions of small samples of observations are proposed. An example of fast practical implementation of the method based on a parametric spectral analysis algorithm is considered. Experimental results of our approach are provided for three different versions of communication channel. It is shown that the usage of the proposed method makes it possible to transform the initially distorted speech signal into compliance on the registered voice template by using acceptable information discrimination criterion. It is demonstrated that our approach may be used in existing biometric systems and technologies of speaker identification.

Innovative Approach to Information Search by Example of a Patent Analysis of an Important Substitution Plan

2020 ◽  
pp. 143-157
Author(s):  
Maria A. Milkova
Keyword(s):  
Information Search ◽  
Topic Modeling ◽  
Cognitive Biases ◽  
A Priori ◽  
Import Substitution ◽  
Innovative Approach ◽  
Iterative Search ◽  
Comprehensive Picture ◽  
Priori Information ◽  
Selection Of

Nowadays the process of information accumulation is so rapid that the concept of the usual iterative search requires revision. Being in the world of oversaturated information in order to comprehensively cover and analyze the problem under study, it is necessary to make high demands on the search methods. An innovative approach to search should flexibly take into account the large amount of already accumulated knowledge and a priori requirements for results. The results, in turn, should immediately provide a roadmap of the direction being studied with the possibility of as much detail as possible. The approach to search based on topic modeling, the so-called topic search, allows you to take into account all these requirements and thereby streamline the nature of working with information, increase the efficiency of knowledge production, avoid cognitive biases in the perception of information, which is important both on micro and macro level. In order to demonstrate an example of applying topic search, the article considers the task of analyzing an import substitution program based on patent data. The program includes plans for 22 industries and contains more than 1,500 products and technologies for the proposed import substitution. The use of patent search based on topic modeling allows to search immediately by the blocks of a priori information – terms of industrial plans for import substitution and at the output get a selection of relevant documents for each of the industries. This approach allows not only to provide a comprehensive picture of the effectiveness of the program as a whole, but also to visually obtain more detailed information about which groups of products and technologies have been patented.

Approach to spatial modeling of networks and groups of objects on the basis of the weighted graph construction procedure

2020 ◽  
Vol 964 (10) ◽  
pp. 49-58
Author(s):  
V.I. Bilan ◽  
A.N. Grigor’ev ◽  
G.G. Dmitrikov ◽  
E.A. Dudin
Keyword(s):  
Spatial Configuration ◽  
Weighted Graph ◽  
Edge Length ◽  
Buffer Zones ◽  
Typical Structure ◽  
Spatial Graph ◽  
Object Based ◽  
Complementary Graph ◽  
Spatial Parameters ◽  
The Given

The direction of research on the development of a scientific and methodological tool for the analysis of spatial objects in order to determine their generalized spatial parameters was selected. An approach to the problem of modeling networks and groups of objects based on the synthesis of a weighted graph is proposed. The spatial configuration of objects based on the given conditions is described by a weighted graph, the edge length of which is considered as the weight of the edges. A generalization to the typical structure of a spatial graph is formulated; its essence is representation of nodal elements as two-dimensional (polygonal) objects. To take into account the restrictions on the convergence of the vertices described by the buffer zones, a complementary graph is formed. An algorithm for constructing the implementation of a spatial object based on the sequential determination of vertices that comply with the given conditions is proposed. Using the software implementation of the developed algorithm, an experiment was performed to evaluate the spatial parameters of the simulated objects described by typical graph structures. The following parameters were investigated as spatial ones

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