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Evaluation of ergodic capacity taking into account of area coverage in a multilink MIMO cellular network for supporting guaranteed QoS

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IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 2007年第7期E90A卷 1292-1299页

作者： Yoshimoto, Akiyo Hattori, Takeshi Sophia Univ Fac Sci & Technol Tokyo 1028554 Japan

Multilink MIMO technique is a promising technology for cellular networks with a guaranteed quality-of-service. It will provide high capacity and wide coverage. We evaluated the downlink performance of the multilink MIMO system from the perspective of quality-of-service. The presence of Rayleigh fading, shadowing, and path loss was assumed. To evaluate the proposed system, we developed a performance measure for MIMO cellular system. The measure is ergodic capacity taking into account area coverage. Our numerical results show that the area coverage of proposed multilink MIMO system is greatly improved compared with that of the conventional singlelink MIMO system. Using the proposed measure, we also found that the multilink MIMO system could achieve high capacity with guaranteed QoS for a wide coverage.

关键词： distributed antenna system (DAS) multiple-input multiple-output (MIMO) area coverage channel capacity quality-of-service

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Extensions of Receding Horizon Task Assignment for area coverage in Dynamic Environments

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IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 2023年第3期59卷 3114-3128页

作者： Hong, Youkyung Jung, Sunggoo Kim, Suseong Cha, Jihun Elect & Telecommun Res Inst Daejeon 34129 South Korea NASA Jet Prop Lab Pasadena CA 91109 USA

This article presents a task reassignment strategy that can flexibly handle changes in dynamic environments. Most existing studies have only considered static environments where the mission is predetermined and unexpected events do not occur. However, in practice, the environment in which unmanned aerial vehicles perform their mission is complex and includes various pop-up events. Therefore, task reassignment is essential through reoptimization to adjust the previous plan, which is no longer optimal whenever dynamic events occur. The importance of this article is that the modified receding horizon task assignment algorithm is applied for accurate and efficient task reassignment. In addition, this article aims to provide a complete system architecture from operator input to motor commands for autonomous area coverage missions. Reliable performance validation is also performed through various simulations and a challenging outdoor flight experiment with real hardware implementation.

关键词： Task analysis Batteries Vehicle dynamics Optimization Autonomous aerial vehicles Uncertainty Aerodynamics area coverage mission planning optimization task assignment unmanned aerial vehicle

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A texture-polarization method for estimating convective-stratiform precipitation area coverage from passive microwave radiometer data

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JOURNAL OF APPLIED METEOROLOGY 2001年第9期40卷 1577-1591页

作者： Olson, WS Hong, Y Kummerow, CD Turk, J Univ Maryland Baltimore Cty Joint Ctr Earth Syst Technol Greenbelt MD 20771 USA NASA Goddard Space Flight Ctr Greenbelt MD 20771 USA Aerosp Corp Los Angeles CA 90009 USA Colorado State Univ Dept Atmospher Sci Ft Collins CO 80523 USA Naval Res Lab Monterey CA USA

Observational and modeling studies have revealed the relationships between convective-stratiform rain proportion and the vertical distributions of vertical motion, latent heating, and moistening in mesoscale convective systems. Therefore, remote sensing techniques that can be used to quantify the area coverage of convective or stratiform rainfall could provide useful information regarding the dynamic and thermodynamic processes in these systems. In the current study, two methods for deducing the area coverage of convective precipitation from satellite passive microwave radiometer measurements are combined to yield an improved method. If sufficient microwave scattering by ice-phase precipitation is detected, the method relies mainly on the degree of polarization in oblique-view, 85.5-GHz radiances to estimate the fraction of the radiometer footprint covered by convection. In situations where ice scattering is minimal, the method draws mostly on texture information in radiometer imagery at lower microwave frequencies to estimate the convective area fraction. Based upon observations of 10 organized convective systems over ocean and nine systems over land, instantaneous, 0.5 degrees -resolution estimates of convective area fraction from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) are compared with nearly coincident estimates from the TRMM precipitation radar (PR). TMI convective area fraction estimates are low-biased relative to PR estimates, with TMI-PR correlation coefficients of 0.78 and 0.84 over ocean and land surfaces, respectively. TMI monthly average convective area percentages in the Tropics and subtropics from February 1998 are greatest along the intertropical convergence zone and in the continental regions of the Southern (summer) Hemisphere. Although convective area percentages from the TMI are systematically lower than those derived from the PR, the monthly patterns of convective coverage are similar. Systematic differences in TMI

关键词： .relationships Rainfall heating fraction footprint polarization Radiometer radiances latent Passive Microwave area coverage Convective–Stratiform mesoscale convective convective area

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Ergodicity-Based Cooperative Multiagent area coverage via a Potential Field

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IEEE TRANSACTIONS ON CYBERNETICS 2017年第8期47卷 1983-1993页

作者： Ivic, Stefan Crnkovic, Bojan Mezic, Igor Univ Rijeka Fac Engn Rijeka 51000 Croatia Univ Rijeka Dept Math Rijeka 51000 Croatia Univ Calif Santa Barbara Dept Mech Engn Santa Barbara CA 93106 USA

This paper considers a problem of area coverage where the objective is to achieve given coverage density by use of multiple mobile agents. We present an ergodicity-based coverage algorithm which enables a centralized feedback control for multiagent system based on radial basis function (RBF) representation of the ergodicity problem and a solution of an appropriately designed stationary heat equation for the potential field. The heat equation uses a source term that depends on the difference between the given goal density distribution and the current coverage density (time average of RBFs along trajectories). The agent movement is directed using the gradient of that potential field. The heat equation driven area coverage has a built-in cooperative behavior of agents which includes collision avoidance and coverage coordination. The algorithm is robust, scalable, and computationally inexpensive.

关键词： area coverage cooperation ergodicity feedback control heat equation multiagent system

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A novel energy-efficient clustering protocol with area coverage awareness for wireless sensor networks

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PEER-TO-PEER NETWORKING AND APPLICATIONS 2017年第3期10卷 519-536页

作者： Tri Gia Nguyen So-In, Chakchai Nhu Gia Nguyen Phoemphon, Songyut Khon Kaen Univ Dept Comp Sci Appl Network Technol ANT Lab Fac Sci Khon Kaen Thailand Duy Tan Univ Fac Informat Technol Da Nang Vietnam Duy Tan Univ Grad Sch Da Nang Vietnam

coverage is a key metric in evaluating the monitoring capacity and quality of services in wireless sensor networks. The energy consumption of self-contained sensors is also a challenging problem for energy-efficient use while still achieving better coverage performance. Although techniques have been developed to mitigate the problem of area coverage, particularly together with efficient clustering methods, none focuses intensively on the sensor activation stage, which is used to maintain coverage while optimizing energy usage. In this research, we thus propose a cover set to find the minimum set of sensors that completely cover the sensing ranges within an interest area as a criterion for sensor activation. Our main goal is to select an optimal number of active sensors considering residual energy and the cover set and to keep alive the important sensors for the sensing coverage task as long as possible. Additionally, this research proposes an area coverage-aware clustering protocol (ACACP) with energy consumption optimization with respect to the activation sensor, network clustering, and multi-hop communication to improve overall network lifetime while preserving coverage. Throughout the intensive simulation, given a diversity of deployments with scalability concern, the results demonstrate the effectiveness of ACACP when compared with other competitive approaches such as ECDC and DECAR, including state-of-the-art clustering protocols such as LEACH, in terms of coverage ratio and overall network lifetime.

关键词： area coverage Clustering coverage-awareness Multi-hop communication Sensor activation Wireless sensor networks

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Probabilistic cooperative mobile robot area coverage and its application to autonomous seabed mapping

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INTERNATIONAL JOURNAL OF ROBOTICS RESEARCH 2018年第1期37卷 21-45页

作者： Paull, Liam Seto, Mae Leonard, John J. Li, Howard MIT CSAIL 77 Massachusetts Ave Cambridge MA 02139 USA Univ Montreal DIRO 2920 Chemin Tour Montreal PQ Canada Def R&D Canada Dartmouth NS Canada Univ New Brunswick Dept Elect Engn Fredericton NB Canada

There are many applications that require mobile robots to autonomously cover an entire area with a sensor or end effector. The vast majority of the literature on this subject is focused on addressing path planning for area coverage under the assumption that the robot's pose is known or that error is bounded. In this work, we remove this assumption and develop a completely probabilistic representation of coverage. We show that coverage is guaranteed as long as the robot pose estimates are consistent, a much milder assumption than zero or bounded error. After formally connecting robot sensor uncertainty with area coverage, we propose an adaptive sliding window filter pose estimator that provides a close approximation to the full maximum a posteriori estimate with a computation cost that is bounded over time. Subsequently, an adaptive planning strategy is presented that automatically exploits conditions of low vehicle uncertainty to more efficiently cover an area. We further extend this approach to the multi-robot case where robots can communicate through a (possibly faulty and low-bandwidth) channel and make relative measurements of one another. In this case, area coverage is achieved more quickly since the uncertainty over the robots' trajectories is reduced. We apply the framework to the scenario of mapping an area of seabed with an autonomous underwater vehicle. Experimental results support the claim that our method achieves guaranteed complete coverage notwithstanding poor navigational sensors and that resulting path lengths required to cover the entire area are shortest using the proposed cooperative and adaptive approach.

关键词： area coverage cooperative localization marine robotics

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A Multirobot System for Distributed area coverage and Signal Searching in Large Outdoor Scenarios

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JOURNAL OF FIELD ROBOTICS 2016年第8期33卷 1087-1106页

作者： Garzon, Mario Valente, Joao Jesus Roldan, Juan Cancar, Leandro Barrientos, Antonio Del Cerro, Jaime UPM CSIC Ctr Automat & Robot Calle Jose Gutierrez Abascal 2 Madrid 228006 Spain Univ Carlos III Madrid Dept Ingn Sistemas & Automat Ave Univ 30 Madrid 28911 Spain SENER Ingn & Sistemas SA Calle Severo Ochoa 4 Parque Tecnol Madrid Madrid Spain

This work presents a complete multirobot solution for signal searching tasks in large outdoor scenarios. An evaluation of two different coverage path-planning strategies according to field size and shape is presented. A signal location system developed to simulate mines or chemical source detections is also described. The solution presented is a pioneer in evaluating multimaster robotics operative system architectures with a fleet of robots in real scenarios. This solution minimizes the use of communications bandwidth required for full operation. Finally, field results are provided, and the advantages of the implemented solution are analyzed.

关键词： coverage area coverage Positioning systems Outdoors Building systems field size signals Robot bandwidth requirement multi-robot systems

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Graph-based path planning for intelligent UAVs in area coverage applications

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JOURNAL OF INTELLIGENT & FUZZY SYSTEMS 2020年第6期39卷 8191-8203页

作者： Akshya, J. Priyadarsini, P. L. K. SASTRA Deemed Univ Sch Comp Thanjavur India

In recent times, Unmanned Air Vehicles (UAVs) are being deployed for several tasks of terrain coverage such as surveillance, photogrammetry, smart irrigation, civil security, and disaster management. In these applications, one of the most vital issues to be addressed is, covering the area under observation with minimum traversal for the UAV. So, the problem addressed in this paper is as follows: For a given geographic area and the given parameters describing the UAV's coverage capacity, the problem is to find an optimal route that covers the given geographic area. In this paper, an optimal path planning algorithm for the area under observation, given as a closed curve, is proposed. The algorithm partitions the given area of interest into multiple non-uniform rectangles while considering other parameters such as the flying altitude of the UAV and obstacles that could be encountered during its flight. The problem is transformed into Traveling Salesman Problem by constructing a graph from the rectangular partitioning. Effective approximate solutions are provided to this problem, using the Minimum Spanning Tree (MST) approximation algorithm and Ant Colony Optimization (ACO). The experimental results show that ACO outperforms the MST based algorithm as it does not get stuck in local minima.

关键词： Travelling salesman problem minimum spanning tree area coverage path planning ant colony optimization UAV

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Tradeoff Between area coverage and Energy Usage of a Self-Reconfigurable Floor Cleaning Robot Based on User Preference

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IEEE ACCESS 2020年 8卷 76267-76275页

作者： Muthugala, M. A. Viraj J. Samarakoon, S. M. Bhagya P. Elara, Mohan Rajesh Singapore Univ Technol & Design Engn Prod Dev Pillar Singapore 487372 Singapore

Floor cleaning robots have been developed to cope with the issues arisen with conventional cleaning methods that involve extensive human labor. hTetro is a self-reconfigurable floor cleaning robot that has been introduced to improve area coverage. Polyomino tiling theory is utilized by hTetro to plan area coverage. Energy usage and area coverage are distinct for different tiling arrangements, and they are often conflicting entities. Therefore, hTetro needs to maintain the tradeoff between area coverage and energy usage to improve its performance. This paper proposes a novel method to determine the tradeoff between area coverage and energy usage of a tiling theory-based self-reconfigurable floor cleaning robot per user preference. A linguistic option such as "High coverage" that represents user preference has uncertainty since fuzzy linguistic terms do not possess definitive meaning. Moreover, the meaning of such user preference depends on the present status of the robot. Thereby, a novel fuzzy inference system is proposed to determine the tradeoff between area coverage and energy usage by interpreting the meaning of user preference while accounting for the present status of the robot. A Weighted Sum Model (WSM) based Multiple-criteria decision-making (MCDM) method is adapted per user preference interpreted by the fuzzy inference system. The behavior of the proposed system has been evaluated considering heterogeneous test cases. The behavior of the test cases confirms the applicability of the proposed concept for adapting the tradeoff between area coverage and energy usage of a self-reconfigurable floor cleaning robot based on user preference.

关键词： Cleaning Robot kinematics Morphology Shape Linguistics Navigation Self-reconfigurable robot cleaning robot energy usage area coverage fuzzy linguistic information user preference human-friendly robotics

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FoV-Based Quality Assessment and Optimization for area coverage in Wireless Visual Sensor Networks

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IEEE ACCESS 2020年 8卷 109568-109580页

作者： Jesus, Thiago C. Costa, Daniel G. Portugal, Paulo Vasques, Francisco State Univ Feira de Santana Dept Technol BR-44036900 Feira De Santana BA Brazil Univ Porto INTEGI INESC TEC Fac Engn P-4200465 Porto Portugal

Wireless visual sensor networks are commonly employed on several applications contexts such as smart cities, intelligent transportation systems and industrial management, aiming at the use of visual data from cameras to provide enhanced information and to expand the networks utilities. In these scenarios, some applications may require high-definition images when performing more specialized tasks, for example in face and text recognition, adding an important monitoring requirement when using camera-based sensors. In fact, it is important to ensure that the network is able to gather visual data with the associated required quality to each task, and such perceived quality may be processed as a function of the Field of View (FoV) of the visual sensors. In order to address this issue, new quality metrics are proposed for wireless visual sensor networks that are deployed to perform area coverage, exploiting for that different perceptions of the FoV. Those metrics are proposed along with redeployment optimization methods for visual sensor nodes aiming at the improvement of the perceived monitoring quality, which are based on greedy and evolutionary-based approaches. The proposed metrics and algorithms are expected to be more realistic than previous solutions, allowing flexible processing of variables as cameras & x2019;positions, orientations and viewing angles, providing then high flexibility on the definition of parameters and significantly contributing to the development of sensor networks based on visual sensors.

关键词： Visualization Monitoring Measurement Cameras Wireless sensor networks Optimization Task analysis Wireless sensor networks area coverage optimization visual quality quality of monitoring quality metric visual sensing field of view mathematical modelling

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