Motion Feasibility Framework for Remotely Operated Vehicles Based on Dynamic Positioning Capability

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Juan A. Ramírez-Macías ◽  
Rafael E. Vásquez ◽  
Asgeir J. Sørensen ◽  
Svein Sævik
Keyword(s):  
Steady State ◽  
Time Domain ◽  
Environmental Data ◽  
Specific Information ◽  
Dynamic Positioning ◽  
Remotely Operated Vehicle ◽  
Site Specific ◽  
Numerical Examples ◽  
Work Training ◽  
System Components

Abstract Knowing whether a remotely operated vehicle (ROV) is able to operate at certain foreknown environmental conditions is a question relevant to different actors during the vehicle’s life cycle: during design stages, buying an ROV, planning operations, and performing an operation. This work addresses a framework to assess motion feasibility in ROVs by using the concept of ROV-dynamic positioning capability (ROV-DPCap). Within the proposed framework, the ROV-DPCap number is defined to measure motion capability, and ROV-DPCap plots are used to illustrate results, for quasi-static standard (L2) and site-specific (L2s) conditions, and dynamic standard (L3) and site-specific (L3s) conditions. Data are computed by steady-state or time-domain simulations from the ROV model, depending on the desired analysis. To illustrate the use of the framework, numerical examples for L2 and L2s motion feasibility analyses for NTNU’s ROV Minerva are provided. Motion feasibility can be used to know whether an ROV is appropriately designed for a specific operation and choose the appropriate one for a certain need, for instance, when designing the DP system components or planning an operation from the environmental data and ROV-specific information. As expected, predictions can be improved when more detailed information about the ROV appears; the same framework can be used to provide more detailed answers to motion feasibility-related questions. The results are likely to be straightforwardly understood by people whose work/training is ROV related and can interpret the graphic results for different operation scenarios.

scholarly journals Malarial parasites as geographical markers in migratory birds?

2006 ◽  
Vol 2 (2) ◽  
pp. 213-216 ◽  
Author(s):  
Sylvia M Fallon ◽  
Robert C Fleischer ◽  
Gary R Graves
Keyword(s):  
North America ◽  
Migratory Birds ◽  
Wide Distribution ◽  
Specific Information ◽  
Population Movements ◽  
Site Specific ◽  
Dendroica Caerulescens ◽  
Bird Populations ◽  
Breeding Populations ◽  
Wintering Range

We tested the hypothesis that malarial parasites ( Plasmodium and Haemoproteus ) of black-throated blue warblers ( Dendroica caerulescens ) provide sufficient geographical signal to track population movements between the warbler's breeding and wintering habitats in North America. Our results from 1083 warblers sampled across the species' breeding range indicate that parasite lineages are geographically widespread and do not provide site-specific information. The wide distribution of malarial parasites probably reflects postnatal dispersal of their hosts as well as mixing of breeding populations on the wintering range. When compared to geographically structured parasites of sedentary Caribbean songbirds, patterns of malarial infections in black-throated blue warblers suggest that host–malaria dynamics of migratory and sedentary bird populations may be subject to contrasting selection pressures.

Value of site-specific information for the design of offshore wind farms

2019 ◽  
Author(s):  
Jorge Mendoza Espinosa ◽  
Jochen Köhler
Keyword(s):  
Safety Margin ◽  
Wind Farms ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Specific Information ◽  
Offshore Wind Farms ◽  
Site Specific ◽  
A Value ◽  
Probabilistic Characterization ◽  
Clear Guideline

<p>Monopiles are the most common offshore wind turbine support structures. They are to be designed so that resonance with the rotor-passing excitation is avoided. However, the estimation of the eigenfrequencies is strongly influenced by the soil-structure interaction, whose characterization with prior information is associated with large uncertainties. No clear guideline is given regarding the safety margin to be left between the structure first natural frequency and the excitation regions. In this paper, the expected consequences of leaving a certain margin are studied and quantified. The decisions regarding the investment in site-specific characterization are coupled into the decision scenario by means of a value of information analysis. The results provide insight on the efficient allocation of resources at the design point in time and the sensitivity of the decisions regarding the probabilistic characterization of the design scenario.</p>

Robust Stabilizing Controller Design for Inverted Pendulum System

2014 ◽  
Vol 71 (1) ◽  
Author(s):  
Hazem I. Ali
Keyword(s):  
Steady State ◽  
Time Domain ◽  
State Feedback ◽  
Inverted Pendulum ◽  
Controller Design ◽  
H Infinity ◽  
Pendulum System ◽  
Stabilizing Controller ◽  
Inverted Pendulum System ◽  
System Uncertainties

In this paper the design of robust stabilizing state feedback controller for inverted pendulum system is presented. The Ant Colony Optimization (ACO) method is used to tune the state feedback gains subject to different proposed cost functions comprise of H-infinity constraints and time domain specifications. The steady state and dynamic characteristics of the proposed controller are investigated by simulations and experiments. The results show the effectiveness of the proposed controller which offers a satisfactory robustness and a desirable time response specifications. Finally, the robustness of the controller is tested in the presence of system uncertainties and disturbance.

scholarly journals On the use of time-domain simulation in the design of Remotely Operated Submergible Vehicles

2017 ◽  
Vol 11 (21) ◽  
pp. 41
Author(s):  
Juan A. Ramírez-Macías ◽  
Persijn Brongers ◽  
Rafael E. Vásquez
Keyword(s):  
Time Domain ◽  
Equations Of Motion ◽  
Simulation Software ◽  
Rigid Body Dynamics ◽  
Time Domain Simulation ◽  
Levels Of Abstraction ◽  
Remotely Operated Vehicle ◽  
Design Concepts ◽  
Use Of Time ◽  
Final Design

Designing a Remotely Operated Vehicle (ROV) is a complicated task in which the design team deals with a considerable amount of uncertainty before the device is able to be tested at full scale. A way to cope with such uncertainty is to use simulation software to evaluate design concepts along the different levels of abstraction of the process. In this work, the use of aNySIM, the Maritime Research Institute Netherlands (MARIN) multibody time-domain simulation tool, as a part of the design process of an ROV is addressed. The simulation software is able to solve the equations of motion of the vehicle based on rigid body dynamics, including features such as hydrodynamics, hydrostatics, thrusters, thrust allocation, and PID control. Different simulation scenarios are proposed to evaluate different concept solutions to the design, including thruster parameters and distribution. The results are further used to select the concept solutions to be implemented in the final design.

scholarly journals A M/M/1 Queueing Network with Classical Retrial Policy

2021 ◽  
Vol 12 (1S) ◽  
pp. 329-337
Author(s):  
S. Shanmugasundaram, Et. al.
Keyword(s):  
Steady State ◽  
Queue Length ◽  
Queueing Network ◽  
State Probability ◽  
Queueing Model ◽  
Steady State Probability ◽  
Numerical Examples ◽  
System Length ◽  
Number Of Customers ◽  
Little's Formula

In this paper we study the M/M/1 queueing model with retrial on network. We derive the steady state probability of customers in the network, the average number of customers in the all the three nodes in the system, the queue length, system length using little’s formula. The particular case is derived (no retrial). The numerical examples are given to test the correctness of the model.

scholarly journals THE URBIS PROJECT: IDENTIFICATION AND CHARACTERIZATION OF POTENTIAL URBAN DEVELOPMENT AREAS AS A WEB-BASED SERVICE

2016 ◽  
Vol XLI-B4 ◽  
pp. 227-233
Author(s):  
Nina Manzke ◽  
Martin Kada ◽  
Thomas Kastler ◽  
Shaojuan Xu ◽  
Norbert de Lange ◽  
...  
Keyword(s):  
Urban Areas ◽  
Landscape Fragmentation ◽  
Urban Land ◽  
End Users ◽  
Information Services ◽  
Urban Land Use ◽  
Specific Information ◽  
Remotely Sensed Data ◽  
Web Based ◽  
Site Specific

Urban sprawl and the related landscape fragmentation is a Europe-wide challenge in the context of sustainable urban planning. The URBan land recycling Information services for Sustainable cities (URBIS) project aims for the development, implementation, and validation of web-based information services for urban vacant land in European functional urban areas in order to provide end-users with site specific characteristics and to facilitate the identification and evaluation of potential development areas. The URBIS services are developed based on open geospatial data. In particular, the Copernicus Urban Atlas thematic layers serve as the main data source for an initial inventory of sites. In combination with remotely sensed data like SPOT5 images and ancillary datasets like OpenStreetMap, detailed site specific information is extracted. Services are defined for three main categories: i) baseline services, which comprise an initial inventory and typology of urban land, ii) update services, which provide a regular inventory update as well as an analysis of urban land use dynamics and changes, and iii) thematic services, which deliver specific information tailored to end-users' needs.

Quantitative risk assessment in the Water Safety Plan: case studies from drinking water practice

2009 ◽  
Vol 9 (2) ◽  
pp. 127-132 ◽  
Author(s):  
Gertjan Medema ◽  
Patrick Smeets
Keyword(s):  
Drinking Water ◽  
Case Studies ◽  
Level Of Detail ◽  
Specific Information ◽  
Water Safety ◽  
Site Specific ◽  
Safety Plan ◽  
Water Safety Plan ◽  
System Assessment

System assessment is the part of the Water Safety Plan that evaluates whether a water supply system is capable of producing drinking water that meets the health-based targets. System assessment can be done at increasing level of detail, requiring more site specific information as the level of detail increases. Four case studies are presented with increasing level of detail, showing the type of information that is required for each of these levels and how each level informs risk management. The first case study shows how a system assessment can be performed without other site specific information than the type of source water and the type of treatment processes. The required data for the system assessment are collected from the large body of literature available. The second case study uses site specific microbial indicator data. The third study uses pathogen data and the fourth case study combines data on pathogens, microbial indicators and process parameters. The case studies show that the level of detail required largely depends on the risk management question.

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