scholarly journals Modern Walking Robots: A Brief Overview

2021 ◽  
Vol 3 (2) ◽  
pp. 32-39
Author(s):  
Vyacheslav Lyashenko ◽  
M. Ayaz Ahmad ◽  
Nataliya Belova ◽  
Svitlana Sotnik
Keyword(s):  
Electricity Consumption ◽  
Swing Phase ◽  
Walking Robots ◽  
Moments Of Inertia ◽  
Advantages And Disadvantages ◽  
Cross Country ◽  
High Level ◽  
Inertia Forces ◽  
Leg Movements ◽  
Mode Coefficient

In this review, we would like to present some of the most interesting modern designs of walking robots: bipedal, quadropedal, hexopedal, and octopods. Their advantages and disadvantages are highlighted. It has been determined that structures with eight or more limbs are ineffective due to high level of electricity consumption. The use of more than six number of legs does not give noticeable advantages in profile cross-country ability or maneuverability, however, it allows to reduce the forces and moments of inertia forces due to decrease in mode coefficient (ratio of time spent by propulsor in support to time of entire step), and, consequently, smoother leg movements in swing phase.

Improving the Energy Efficiency of Movement and Cross-Country Capacity of an Articulated Mobile Wheeled Robot by Controlling an Individual Electric Traction Drive

2021 ◽  
pp. 17-23
Author(s):  
M.M. Zhileykin
Keyword(s):  
Energy Efficiency ◽  
Load Capacity ◽  
Walking Robots ◽  
Wheeled Robot ◽  
Operation Algorithm ◽  
Driving Wheel ◽  
Cross Country ◽  
Electric Traction ◽  
High Level

Articulated wheel-walking robots having a good combination of weight and load capacity, as well as high cross-country capacity and maneuverability are among the promising schemes of mobile robotic systems. One of the main requirements for such complexes is a high level of autonomy. In this regard, the task of improving the energy efficiency of the articulated mobile wheeled robot movement (especially in long-term transport mode) by reducing the driving wheel skid becomes urgent. An algorithm for the operation of the antiskid system of such a robot with an individual traction electric drive has been developed. It provides an increase in the energy efficiency of robot movement and cross-country capacity by reducing the skid of the driving wheels. The efficiency of the antiskid system operation algorithm has been proved by the simulation methods.

scholarly journals A survey: which features are required for dynamic visual simultaneous localization and mapping?

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Zewen Xu ◽  
Zheng Rong ◽  
Yihong Wu
Keyword(s):  
Simultaneous Localization And Mapping ◽  
Dynamic Environments ◽  
Visual Features ◽  
Advantages And Disadvantages ◽  
Intelligent Robots ◽  
Localization And Mapping ◽  
High Level ◽  
Static World ◽  
Robotic Applications ◽  
Significant Attention

AbstractIn recent years, simultaneous localization and mapping in dynamic environments (dynamic SLAM) has attracted significant attention from both academia and industry. Some pioneering work on this technique has expanded the potential of robotic applications. Compared to standard SLAM under the static world assumption, dynamic SLAM divides features into static and dynamic categories and leverages each type of feature properly. Therefore, dynamic SLAM can provide more robust localization for intelligent robots that operate in complex dynamic environments. Additionally, to meet the demands of some high-level tasks, dynamic SLAM can be integrated with multiple object tracking. This article presents a survey on dynamic SLAM from the perspective of feature choices. A discussion of the advantages and disadvantages of different visual features is provided in this article.

scholarly journals Distributed Simulation Platforms and Data Passing Tools for Natural Hazards Engineering: Reviews, Limitations, and Recommendations

2021 ◽  
Author(s):  
Lichao Xu ◽  
Szu-Yun Lin ◽  
Andrew W. Hlynka ◽  
Hao Lu ◽  
Vineet R. Kamat ◽  
...  
Keyword(s):  
Natural Hazards ◽  
Data Exchange ◽  
Distributed Simulation ◽  
Distributed Data ◽  
Interactive Simulation ◽  
Integrated Simulation ◽  
Domain Specific ◽  
Advantages And Disadvantages ◽  
High Level ◽  
Data Passing

AbstractThere has been a strong need for simulation environments that are capable of modeling deep interdependencies between complex systems encountered during natural hazards, such as the interactions and coupled effects between civil infrastructure systems response, human behavior, and social policies, for improved community resilience. Coupling such complex components with an integrated simulation requires continuous data exchange between different simulators simulating separate models during the entire simulation process. This can be implemented by means of distributed simulation platforms or data passing tools. In order to provide a systematic reference for simulation tool choice and facilitating the development of compatible distributed simulators for deep interdependent study in the context of natural hazards, this article focuses on generic tools suitable for integration of simulators from different fields but not the platforms that are mainly used in some specific fields. With this aim, the article provides a comprehensive review of the most commonly used generic distributed simulation platforms (Distributed Interactive Simulation (DIS), High Level Architecture (HLA), Test and Training Enabling Architecture (TENA), and Distributed Data Services (DDS)) and data passing tools (Robot Operation System (ROS) and Lightweight Communication and Marshalling (LCM)) and compares their advantages and disadvantages. Three specific limitations in existing platforms are identified from the perspective of natural hazard simulation. For mitigating the identified limitations, two platform design recommendations are provided, namely message exchange wrappers and hybrid communication, to help improve data passing capabilities in existing solutions and provide some guidance for the design of a new domain-specific distributed simulation framework.

GLOBAL ECONOMIC SANCTIONS, GLOBAL BANK LINKAGES AND INFORMATION ASYMMETRY: AN EVIDENCE FROM CROSS-COUNTRY DATA

2021 ◽  
Author(s):  
LE THANH HA ◽  
HOANG PHUONG DUNG ◽  
PHAM HONG CHUONG ◽  
TO TRUNG THANH
Keyword(s):  
Data Base ◽  
Economic Sanctions ◽  
Negative Association ◽  
Alternative Measure ◽  
Model Combining ◽  
Institutional System ◽  
Cross Country ◽  
The Rich ◽  
High Level ◽  
European Economic Review

This paper investigates the effects of global economic sanctions (GESs) on global bank linkages (GBLs) by using 4,032 pairs of 66 countries during the 2001–2013 period. We use the structural gravity model combining with the rich database of the Global Sanction Data Base introduced by Felbermayr et al. [(2020). The global sanctions data base. European Economic Review, 129, 1–23]. Our empirical results show a negative association between the GESs and GBLs. The differential effects of GESs on the GBLs are conditional on the sanction types. Furthermore, the consequences of global sanctions become more severe for countries featuring higher information asymmetries, captured either by a high level of world uncertainty, an occurrence of crisis and shocks or by a weak institutional system. Our results are robust and reliable when we use an alternative measure of bank connections, and in the context of controlling the potential endogeneity of global sanction.

Numerical Simulations of Ocean Drilling System Behavior With a Surface or a Subsea BOP in Waves and Current

2008 ◽  
Author(s):  
Celso K. Morooka ◽  
Raphael I. Tsukada ◽  
Dustin M. Brandt
Keyword(s):  
System Behavior ◽  
Traditional System ◽  
Drilling Rig ◽  
Advantages And Disadvantages ◽  
Ocean Drilling ◽  
Sea Bottom ◽  
Drilling System ◽  
Drilling Rigs ◽  
High Level ◽  
Drilling Bit

Subsea equipment such as the drilling riser and the subsea Blow-Out Preventer (BOP) are mandatory in traditional systems used in deep sea drilling for ocean floor research and petroleum wellbore construction. The drilling riser is the vertical steel pipe that transfers and guides the drill column and attached drilling bit into a wellbore at the sea bottom. The BOP is used to protect the wellbore against uncontrolled well pressures during the offshore drilling operation. Presently, there is a high level of drilling activity worldwide and in particular in deeper and ultra-deeper waters. This shift in depth necessitates not only faster drilling systems but drilling rigs upgraded with a capacity to drill in the deep water. In this scenario, two general drilling systems are today considered as alternatives: the traditional system with the subsea BOP and the alternate system with the surface BOP. In the present paper, the two systems are initially described in detail, and a numerical simulation in time domain to estimate the system behavior is presented. Simulations of a floating drilling rig coupled with the subsea and surface BOP in waves and current are carried out for a comparison between the two methods. Results are shown for riser and BOP displacements. Critical riser issues for the systems are discussed, comparing results from both drilling system calculations. Conclusions are addressed showing advantages and disadvantages of each drilling system, and indicating how to correct the problems detected on each system.

scholarly journals EXPLORING ALS AND DIM DATA FOR SEMANTIC SEGMENTATION USING CNNS

2018 ◽  
Vol XLII-1 ◽  
pp. 347-354 ◽  
Author(s):  
F. Politz ◽  
M. Sester
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Semantic Segmentation ◽  
Point Clouds ◽  
Good Alternative ◽  
Aerial Images ◽  
Learning Approaches ◽  
Advantages And Disadvantages ◽  
Sensing Applications ◽  
High Level

<p><strong>Abstract.</strong> Over the past years, the algorithms for dense image matching (DIM) to obtain point clouds from aerial images improved significantly. Consequently, DIM point clouds are now a good alternative to the established Airborne Laser Scanning (ALS) point clouds for remote sensing applications. In order to derive high-level applications such as digital terrain models or city models, each point within a point cloud must be assigned a class label. Usually, ALS and DIM are labelled with different classifiers due to their varying characteristics. In this work, we explore both point cloud types in a fully convolutional encoder-decoder network, which learns to classify ALS as well as DIM point clouds. As input, we project the point clouds onto a 2D image raster plane and calculate the minimal, average and maximal height values for each raster cell. The network then differentiates between the classes ground, non-ground, building and no data. We test our network in six training setups using only one point cloud type, both point clouds as well as several transfer-learning approaches. We quantitatively and qualitatively compare all results and discuss the advantages and disadvantages of all setups. The best network achieves an overall accuracy of 96<span class="thinspace"></span>% in an ALS and 83<span class="thinspace"></span>% in a DIM test set.</p>

scholarly journals The History of Science and the History of Knowledge

2020 ◽  
Vol 30 (1) ◽  
pp. 63-90
Keyword(s):  
History Of Science ◽  
Subject Matter ◽  
Modern Science ◽  
Manhattan Project ◽  
Necessary Condition ◽  
Contemporary History ◽  
History Of Knowledge ◽  
Advantages And Disadvantages ◽  
History Of ◽  
High Level

The article examines the state of the history of science as a discipline and its objectives in the context of its origins and current transformations. The establishment of this discipline and its assumptions about the nature of science together with its goals and structure are briefly discussed. The history of science became a discipline only at the beginning of the second half of the 20th century, and its start is associated with the work of chemist James Conant, a high-level administrator in Manhattan project who was also president of Harvard University and a high-ranking bureaucrat. It was based also on the narrative developed by Alfred North Whitehead, Edwin Burtt, Alexandre Koyré and other historians of science, which claimed modern science was the creator of modernity and a necessary condition for the geopolitical domination of the West. In that understanding, modern science meant science since the time of Galileo and Newton. The author provides a critical analysis of this foundation narrative for the discipline and of its consequences while showing how contemporary history of science has overcome it. The contradiction between modernism and historicism has been resolved in favor of the latter. A key role in this was played by the book The Structure of Scientific Revolutions by Thomas Kuhn, which held the potential to undo the presumed monolithic unity of science by rejecting teleology and introducing incommensurability and discontinuities into the historical process. By rejecting explanation of the knowledge of other times and places in terms of modern science, the discipline faced a radical multiplication of independent types of knowledge. This was facilitated by the reorientation to the study of knowledge practices that took place in the 1980s. As a result, the subject matter of the history of science began to erode, and this launched discussion of the prospects for a transition to a history of knowledge based on the study of practices. The sweep of this change of vision is illustrated by the example of classifying sciences according to both their subject matter and the similarities in their research practices. Finally, the advantages and disadvantages of the new discipline along with its prospects and the challenges it faces are discussed.

Study on Open CNC Control System Based on GUC Motion Controller

2012 ◽  
Vol 241-244 ◽  
pp. 1482-1486
Author(s):  
Jian Wen Zhao ◽  
Wei Xie
Keyword(s):  
Control System ◽  
Numerical Control ◽  
System Model ◽  
Numerical Control System ◽  
Motion Controller ◽  
Motion Platform ◽  
Open Cnc ◽  
Advantages And Disadvantages ◽  
Open Numerical Control System ◽  
High Level

This paper mainly focuses on designing an open CNC system. At first, the advantages and disadvantages of the three popular open numerical control technologies were discussed, and on the basis of demands analysis, this paper chose motion controller plus PC as the whole system model. Then, according to the system model, this article designed the hardware system for the control system, including choosing multi-axis motion control card, servo motors and their drivers. Thirdly, based on the features of this open numerical control system, the paper designed and put the software into three levels, namely low level of control software, mid-level of communication software, and high-level of management software respectively. Finally, in order to test the control performance of this open numerical control system, some experiments were carried out on a two-dimension motion platform, the results are satisfactory and error analysis on these experiments is also given out.

scholarly journals Biofuels as an instrument of Russia hydrocarbons and agrarian exports competitiveness

2020 ◽  
Vol 175 ◽  
pp. 13029
Author(s):  
Denis Ushakov ◽  
Oleg Patlasov
Keyword(s):  
Oil And Gas ◽  
Raw Materials ◽  
Oil And Gas Industry ◽  
Business Value ◽  
Creative Economy ◽  
Gas Industry ◽  
Hydrocarbon Production ◽  
Advantages And Disadvantages ◽  
High Level ◽  
Science Intensity

Paper analyzes the prospects of biofuels second and third generation in the structure of the global energy balance, demonstrates a sharp decline in oil and gas revenues in the Russian budget, describes advantages and disadvantages of biodiesel and bioethanol production. The connection between the growth of Russia’s export potential in terms of hydrocarbon products processing with EU standards implementation has been proved. The problems of the realization of programs on the oxygenate technologies development in the Union State of Russia-Belarus were revealed. The capacity of the market of 3-4 generations fuel with using non-food raw materials and various types of biomass was estimated. Was proved that at a high level of growth in business value and profitability of production there are incentives to organize deep processing in Russia’s hydrocarbon production. It is proved that the oil and gas industry in a creative economy should increase its science intensity and depth of raw materials processing, including ones in related industries.

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