افزايش طول عمر شبكه حسگر دوربين با پوشش كامل به منظور پايش و تشخيص ارتفاع هدف

چكيده انگليسي :

104 Maximization of Lifetime of Camera Sensor Network with Full Coverage for Surveillance and Height Estimation Fahimeh Fooladgar f fooladgar@ec iut ac ir Date of Submission 2012 02 28 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Shadrokh Samavi samavi96@cc iut ac irAbstract Research activities in wireless sensor networks have been growing in recent years In such a network sensor nodes collect scalar data such as temperature pressure humidity and etc Scalar data are not sufficientfor some applications like automatic surveillance and environmental monitoring With recent advances in thetechnology of image sensors and embedded processors most of attentions have been concentrated on camerasensor networks These networks consist of camera nodes such that each camera node integrates imagesensor embedded processor and wireless transceiver Each camera node has the ability to locally processimage data extract suitable data and collaborate with other nodes based on the network application Therefore these networks are being utilized in many applications such as environmental monitoring andtarget tracking Target detection localization and tracking in a specific region are the most important issuesin these applications Due to quantization in CCD cameras the obtained information from these nodes is notvery accurate In this thesis we propose a geometrical model for target localization error In this model theconical intersection region formed by corresponding pixels of two cameras is investigated Thus todetermine the amount of error in the target localization via two cameras the intersection of the correspondingcones of each camera is utilized For specifying the points of intersection we propose three approaches Since the field of view of each pixel is considered as a cone the proposed approaches can easily be applied toany configuration of cameras Another advantage of the proposed approach is that it can be generalized to amulti camera system where more than two cameras are used to have more accurate estimation of the targetlocation In such a system each added camera leads to cone intersection formations and the results of theseintersections determine the amount of target localization error This error can be decreased by selectingcameras in the network with appropriate positions Camera selection problem in camera sensor networks isessential not only to improve the accuracy of the network but also to compensate for the processing energyand bandwidth limitation of each sensor node Hence for more accurate estimation of the target height and toprolong the lifetime of the network we propose the priority as well as a genetic search algorithm In thesealgorithms the precision of height estimation and also the resource constraint of the network are considered Therefore the accuracy of the measurements and also the lifetime of the network are increased We proposethree selection metrics cost distance between the nodes and the overlapped region between camera nodes The cost metric consist of remaining battery of each node routing cost and essentiality of each node in thenetwork The proposed selection metrics are utilized such that the computational overhead is decreased andthe lifetime of the network is increased Simulation results show that the distance and overlap metricsdecrease the computational overhead while the network lifetime is also decreased This is because thesemetrics are not considered the energy consumption of each node On the other hand by considering the costmetric the lifetime of networks is increased Consequantly to balance the tradeoff between these metrics andalso to improve the accuracy of the measurment the combination of these metrics must be used Keywords Camera sensor network height estimation camera selection network lifetime

فولادگر، فهيمه

افزايش طول عمر شبكه حسگر دوربين با پوشش كامل به منظور پايش و تشخيص ارتفاع هدف

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