Study Of Coverage-controlling And Target-tracking Of Wireless Multimedia Sensor Networks

With the development of communication, microelectronics, and MEMS tech-nologies, wireless sensor network was promoted to be given birth. Nowadays, there were two catalogues in wireless sensor networks, i.e., omnidirectional model and wireless multimedia sensor network (WMSNs) model. WMSNs differ from the tra-ditional wireless sensor networks due to their characteristics of directivity and rota-tion capability. At present, many researches are done concentrating on the coverage problem. Besides, the most of the existing studies were focused on coverage using the omnidirectional model. As for the existing research on coverage of wireless mul-timedia sensor networks, characteristics of directivity and rotation capability were taken their into consideration for building sense models, but the Definition and Calculation were given without taking characteristics of directivity and rotation ca-pability into consideration. Therefore, the existing research for practical application has some limitations. Overall, wireless multimedia sensor networks faces many new challenges, and the new solution was urgently needed to guide the effective realiza-tion of wireless multimedia sensor networks.Wireless Multimedia Sensor Network is a kind of directed sense networks. Con-sidering the effect of sensor rotary motion and " delay time" on the definition and cal-culation of "coverage ratio", directional models with or without delay were defined, controlling and increasing in coverage ratio, and target tracking were systematically studied in this dissertation. The resulting achievements can be listed as follows:(1) According to the application features, coverage problem can be divided into two cases with delay and without. Also, sensor nodes can be set inside the target area and above the plane surface of target. Therefore, we built four models by combining the above factors, which were used to lay our research foundations.(2) For the deterministic networks, we studied the coverage effects caused by node number, set distance and node properties. Taking the demand of coverage into consideration, we explored the node number optimization and deployment control-ling too.(3) The perception directivity and position of sensor nodes were stochastic when network initialling. Thus. coverage ratio may be increased by controlling nodes rotating to better direction. In this way, coverage increasing algorithms were developed on the basis of four perception models. Results from simulations showed that those redundancy nodes were closed and that area coverage was increased at the same time.(4) It is very important that only the necessary nodes were awaked to sense completely while target traversing at the cost of less power consuming for WMSNs target trackiing. Then a two-dimensional node scheduling algorithm was presented. Subsequently, a three-dimensional version was proposed by partner extending.(5) The monitor capability based on two kinds of multimedia networks was analyzed. And the relations among sensor intensity, traversing path length, perception radius, perception direction, rotating speed and coverage ratio were obtained. The results can be used to guide node deployment in order to increase path coverage when target traversing.