無線感測器網路 (Wireless Sensor Networks)是由許多感測器(Sensor node)所組成，而這些感測器一般都以電池當作主要的能量來源。在收集感測器 所感測到的資料過程中，通常是利用無線通訊來進行資料的收集。但是，由於 無線通訊所耗費的能量佔感測器總耗電量很大的部份，若是完全利用 multi-hop routing 的機制將資料傳送到基地台(Base Station)，會造成基地 台附近的感測器因為時常幫忙代傳資料，使得自身能量消耗太快而喪失功能。 因此，利用機器人來收集資料，不旦可以減少整體網路的能量消秏，而且能夠 增加網路的生命期。在這篇論文中，我們提出了兩個利用機器人收集資料的通 訊協定，針對機器人收集資料的路徑做規劃，並且結合k-hop 代傳機制來增加 機器人收集資料的效能，降低感測資料因為代傳的能量耗費。所謂k-hop 代傳 機制，就是每個感測器將資料傳送到機器人最多只能被代傳k-hop，其中k 值 是由使用者自行決定。經由模擬證明，我們提出的資料收集通訊協定，確實可 以減少資料代傳的hop 數，而且所規劃出來的資料收集路徑，確實可以讓機器 人不用經過網路中的每一個感測器，也能夠收集完整個網路的資料。 A wireless sensor network is composed of many small, inexpensive, battery-powered sensor nodes that are capable of sensing, computation, and communication. In data gathering protocols, the communication power is usually a significant component of the total power consumed in a sensor network. Hence, using mobile robot to gather the sensing data from sensor nodes can efficiently reduce the network energy consumption and extend the network lifetime. In this thesis, we propose two data gathering protocols: Infrastructure Data Gathering Protocol (IDGP) and Distributed Data Gathering Protocol (DDGP) to plan the data gathering path of the mobile robot. Our proposed protocols use the k-hop mechanism to increase the efficiency of the mobile robot to collect the sensing data. The k-hop mechanism is that the sensing data of a sensor node are transmitted to the mobile robot only up to k-hops at most, where k is a user-specified parameter. The advantages of our protocols are that we restrict the hop counts of the sensing data transmission by k hops, which reduce energy consumption in multi-hop routing. Besides, in our protocols, sensor nodes’ data transmission can cooperate with mobile robot’s data gathering path, which increases the efficiency of mobile robot to collect the data. Simulation results show our data gathering protocols enables the sensor nodes to transmit the data with less number of hops and simultaneously satisfy a desired value of path length to cover the network by a mobile robot.
