无线传感网络节点隶属度模糊定位算法研究

Research of Fuzzy Localization in Wireless Sensor Networks

摘要:

无线传感网络RSSI算法理论上定位精度很高,但在实际工程应用中易受环境干扰和信号波动影响,无法精确,定位稳定性不好,误差较大,若穷追所有细节将极大增加算法复杂度；针对其中不足,提出基于节点隶属度模糊算法,并应用于RSSI定位模型之中；新算法首先利用岭形分布对RSSI初始信号模糊化取得隶属函数,再根据隶属度近似程度反馈求精,通过隶属程度以逐渐逼近方式定位节点坐标区域；新算法模糊化系数m值越大,抗干扰能力越强,但节点具有更多的相同或相似格贴近度,无法反映节点真实状态,因此m值应根据路径衰减指数和环境干扰物理值共同决定；通过仿真实验结果证明,与RSSI和DV-Hop算法相比,新算法可以减少环境干扰和信号波动带来的影响,具有更高的定位精度和稳定性。

关键词:无线传感器网络;隶属度;模糊算法;RSSI

Abstract:

RSSI algorithm localization accuracy is very high in theory, but it is vulnerable to environmental interference and signal fluctuations, and if pursued all the details will greatly increase the complexity of the algorithm. This paper put forward a fuzzy localization algorithm against the weak points of RSSI algorithm in Wireless Sensor Networks,and applied to the RSSI location model. The new algorithm uses ridge-shaped distribution to fuzzification original RSSI signal. Then feedback and refine results according to the degree of approximation. The bigger value of fuzzy coefficient, the stronger anti disturbance ability, but the nodes have more or more similar lattice close degree, can not reflect the true state of the node, so the coefficient m should be based on attenuation index and environmental interference. Finally, simulation experiment shows that, the new algorithm can reduce the impact of environmental interference and signal fluctuations compared with RSSI and DV-Hop algorithm, which has high localization accuracy and stability.

Key words:wireless sensor networks; membership degree; fuzzy algorithm; RSSI 