scholarly journals LTDA-MAC v2.0: Topology-Aware Unsynchronized Scheduling in Linear Multi-Hop UWA Networks

Network ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 2-10
Author(s):  
Nils Morozs ◽  
Paul D. Mitchell ◽  
Yuriy Zakharov
Keyword(s):  
Real Time ◽  
Oil And Gas ◽  
Packet Scheduling ◽  
Clock Synchronization ◽  
Mac Protocol ◽  
Sensor Nodes ◽  
Computationally Efficient ◽  
Time Optimization ◽  
Asset Monitoring ◽  
Real Time Optimization

This paper investigates the use of underwater acoustic sensor networks (UASNs) for subsea asset monitoring. In particular, we focus on the use cases involving the deployment of networks with line topologies, e.g., for monitoring oil and gas pipelines. The Linear Transmit Delay Allocation MAC (LTDA-MAC) protocol facilitates efficient packet scheduling in linear UASNs without clock synchronization at the sensor nodes. It is based on the real-time optimization of a packet schedule for a given network deployment. In this paper, we present a novel greedy algorithm for real-time optimization of LTDA-MAC schedules. It produces collision-free schedules with significantly shorter frame duration, and is 2–3 orders of magnitude more computationally efficient than our previously proposed solution. Simulations of a subsea pipeline monitoring scenario show that, despite no clock synchronization, LTDA-MAC equipped with the proposed schedule optimization algorithm significantly outperforms Spatial TDMA.

scholarly journals Project Atlantis

2015 ◽  
Vol 137 (03) ◽  
pp. S4-S7
Author(s):  
Matthew A. Franchek
Keyword(s):  
Real Time ◽  
Oil And Gas ◽  
Gas Production ◽  
Bubble Flow ◽  
Oil And Gas Production ◽  
Transient Transport ◽  
University Of Houston ◽  
Time Optimization ◽  
Challenges And Opportunities ◽  
Real Time Optimization

This paper explores the reach and use of subsea engineering. Subsea engineering presents many new challenges and opportunities for engineers from any discipline. The fundamental engineering challenges facing today’s ultra-deepwater oil and gas production reside under a new engineering discipline, the subsea engineer. Designing subsea systems for 30-year-long controllability, safety, maintenance, and real-time optimization are critical issues and present an open-ended problem. Safety is absolutely a primary focus on any subsea production system design. There must be multiple independent safety paths in place to isolate a producing well. The most common subsea safety system is located within the well. Pioneering work performed at the university of Houston provided mathematical relationships to predict the flow regime given gas and liquid velocities, including dispersed bubble flow, elongated bubble flow, slug flow, stratified flow, etc. There is an unexplored coupling between the transient multiphase flow and the heat transfer. The field of modeling multiphase transient transport is important to the subsea architecture design and real-time optimization of subsea production.

scholarly journals Experimental real-time optimization of a solid oxide fuel cell stack via constraint adaptation

Energy ◽  
2012 ◽  
Vol 39 (1) ◽  
pp. 54-62 ◽  
Author(s):  
Gene A. Bunin ◽  
Zacharie Wuillemin ◽  
Grégory François ◽  
Arata Nakajo ◽  
Leonidas Tsikonis ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Real Time ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Fuel Cell Stack ◽  
Time Optimization ◽  
Real Time Optimization

Real-Time Optimization of Wind Farm Energy Capture With Delay Compensated Nested-Loop Extremum Seeking Control

2017 ◽  
Author(s):  
Zhongyou Wu ◽  
Yaoyu Li
Keyword(s):  
Wind Turbine ◽  
Real Time ◽  
Wind Farm ◽  
Optimization Techniques ◽  
Extremum Seeking ◽  
Extremum Seeking Control ◽  
Energy Capture ◽  
Time Optimization ◽  
Real Time Optimization ◽  
Nested Loop

Real-time optimization of wind farm energy capture for below rated wind speed is critical for reducing the levelized cost of energy (LCOE). Performance of model based control and optimization techniques can be significantly limited by the difficulty in obtaining accurate turbine and farm models in field operation, as well as the prohibitive cost for accurate wind measurements. The Nested-Loop Extremum Seeking Control (NLESC), recently proposed as a model free method has demonstrated its great potential in wind farm energy capture optimization. However, a major limitation of previous work is the slow convergence, for which a primary cause is the low dither frequencies used by upwind turbines, primarily due to wake propagation delay through the turbine array. In this study, NLESC is enhanced with the predictor based delay compensation proposed by Oliveira and Krstic [1], which allows the use of higher dither frequencies for upwind turbines. The convergence speed can thus be improved, increasing the energy capture consequently. Simulation study is performed for a cascaded three-turbine array using the SimWindFarm platform. Simulation results show the improved energy capture of the wind turbine array under smooth and turbulent wind conditions, even up to 10% turbulence intensity. The impact of the proposed optimization methods on the fatigue loads of wind turbine structures is also evaluated.

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