open access

https://doi.org/10.14943/doctoral.k11525

https://hdl.handle.net/2115/57288

センサネットワークを用いた森林火災監視システムに関する研究

英語

2014-09-25

Hokkaido University

viii, 77p

Indonesia has been suffered from forest fires. The recent fires in logger-over forest, peatland, andplantation should be classified into one of human-made disasters. In recent years, fires in Indonesia occurred mainly in peatland area and become one of international serious issues due to haze and CO2 emission. One strategy to detection and monitor peat-forest fires in Central Kalimantan, Indonesia is to use a Wireless Sensor Networks (WSNs), which contains miniaturesensor nodes to collect environmental data such as temperature, relative humidity, light and barometric pressure, and to transmit more accurate information to fire-fighter and remote monitor.In this study, in order to get real-time monitoring data of peat-forest fires, we develop the integration system of the WSN data used for the ground sensing with video surveillance data obtained from an unmanned aerial vehicle(UAV), which is used for ground verification of satellite data in large peat forest areas. In data processing of WSN in collaborationwith UAV work, the most important issue is to allow quick responses in order to minimize the scale of thepeat-forest fires.We have an integration of system for the monitor of peat fires using wireless sensor network and the UAV, where a small fire is not detected by the satellite or in the dense smoke conditions.In-network processing data from WSN and UAV is the best strategy for monitoring peat-forest fire disasters. Monitoring wildfire system uses WSN containing the smart sensors to collect environment data such as temperature, humidity, and barometric pressure, and to deliver useful information to fire-fighter or remote monitors. One way to verify the location of wildfire is to use UAV to collect more accurate information. The accuracy and reliability of combination data WSN and UAV are support largely impact to forest fire monitoring.In forest, reliable communication in a dense or sparse environment is very important.Wireless sensor nodes must be able to effectively communicate data back to the base station.While battery power is limited and may not be rechargeable, wireless sensor nodes however can be equipped with a secondary power source such as solar cells. In any case, it is important for sensor nodes to save energy as much as possible.For monitoring and detect using WSN technology, energy can be conserved with multi-hop optimal routing, short transmission range, in-network data aggregation, eliminating data redundancy, minimizing delays, and using low duty-cycle. To maximize the lifetime of the energy-constrained WSNs, communication protocols such as LEACH and HEED have been developed in which the cluster heads are autonomously selected to share the energy loss in the sensor nodes. In this study, we develop optimization where the routers are optimally deployed to maximize the connectivity of the sensor nodes to the routers.The sensors are assumed to be randomly deployed to have wide coverage. We use genetic algorithm and simulated annealing for the optimization. We take the obstacles due to elevation differences into consideration in the optimization. Moreover, we consider the attenuation ofelectromagnetic waves in the forest. To evaluatethe attenuation constant of the forest, we compute homogenized permittivity from the measured complex permittivity of tree trunks and basal area. It is shown that the horizontally polarized electromagnetic waves has smaller attenuation than the vertically polarized waves. We can know the necessary number of routers tohave complete connections of sensors from the optimization results. Moreover, we can make optimal design of WSN topology for any vegetation and topography using the present method.

2014-09-25

甲第11525号

博士(情報科学)

(主査) 教授 五十嵐 一, 教授 小野里 雅彦, 教授 北 裕幸, 准教授 野口 聡

情報科学研究科（システム情報科学専攻）

博士論文

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