| Summary: | 博士 === 國立成功大學 === 資訊工程學系碩博士班 === 101 === In the past few years, there has been much improvement in the technology and the application of WSNs. Researchers have compiled complete sets of standards for real cases (e.g., IEEE 802.15.4[1] and Zigbee) spanning a wide range of applications including home security, private-sector organizations, health care, and the military.
There is more and more applications base on wireless sensor networks. In this thesis, we talk about power consumption issue and methods in wireless sensor network. First, we focus on physical layer and MAC layer. We constructed an
analytical model of the MLPA mechanism with m distinct power levels (m-LPA). For m-LPA, the closed-form expression of the optimal power setting was determined and the mean transmission power was minimized to one third of the original fixed transmission power. Thus, each node can extend the lifetime by 2.5 times. We have shown the relations between m and density in simulation results. Although the mechanism worked smoothly in our study, the sensors don’t need to handle the distance and interference problem.
After first part, we find holes problem in wireless sensor networks often causes traditional routing algorithms to fail. Most of the previous research on the subject addressed the routing-hole problem by using static detour paths to route data packets along the boundaries of holes. In these scenarios, the energy of sensor nodes on static paths depletes quickly, and the hole size enlarges. In this thesis, we propose a scheme for bypassing holes in wireless sensor networks by exploiting energy-aware multiple paths. Our approach not only takes into account shorter paths for bypassing holes, but also eases the loading of the sensor nodes on the boundaries of holes. Simulation results show that the proposed scheme can achieve short detour paths, low energy consumption, and network load balancing.
At last, after we are using m-LPA and multi-path mechanisms to solve power consumption problem in wireless sensor network. We start to focus on energy saving application based on wireless sensor network. In recent years, the public has been paying ever greater attention to problems associated with energy production and consumption. Energy-supply issues rightly constitute one of the most important issues that we face. In the absence of any viable alternative energy supply, a strategy that would result in energy savings is a legitimate goal. In this thesis, we propose a genetic algorithm-based method by which electrical operators in a cyber physical system could be scheduled and controlled. Our method accounts for not only process output
but also environmental variation. We propose that the electrical operators be of the same function but with different capabilities. One set of sensors would be placed
dispersedly around the to-be-affected area for measuring the output of the processes.
Another set of sensors would collect the environmental variation value for prediction purposes. The simulation results show that the application of our proposed GA-based
Actuator Control (GAAC) method to the aforementioned cyber physical system can minimize its power consumption while accomplishing the desired set point.
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