基于ZigBee的地磁车辆检测系统设计

Design of geomagnetic vehicles detecting system based on ZigBee wireless sensor network

为改善现有车位检测系统无法在露天场合工作、及在恶劣天气环境下不稳定等缺陷,设计了一种基于ZigBee无线传感网络和高灵敏度各向异性磁阻(AMR)传感器的无线车辆检测系统。车位检测节点采用TI公司的CC2530和Honeywell公司的HMC5883L,通过检测车辆对地磁场的扰动来判断车位上是否有车辆存在;车位检测节点采集的数据通过网状拓扑结构的ZigBee网络向上传递至协调器节点;上位机与协调器进行通信并采用阈值比较算法判断车辆的存在。在各种环境条件下的测试结果表明该系统在100m的距离范围内拥有较高的信号强度(RSSI)和数据链路质量(LQI),能实时检测并判断车位上有无车辆。系统整体体积较小、功耗低且电池寿命长,拥有着潜在的应用前景。

To modify the incapability in outdoor scenario and instability under bad weather conditions of existing vehicle detecting systems , a wireless vehicle detecting system was designed based on high sensitive anisotropic magneto resistive （AMR） sensor and ZigBee wireless sensor networks （WSN） .The vehicle detecting nodes ,which measured the disturbance of geomagnetic field so as to determine the existence of vehicles was composed of TI’s CC2530 chip and HMC5883L chip of Honeywell;statistics detected by the vehicle detecting nodes were congregated by the coordinator node through mesh topology WSN .The upper computer monitor communicated with coordinator node and determined the existence of vehicles using threshold comparison algorithm .Results of tests under diverse real‐world application settings indicated that the detecting system maintained relatively high RSSI and LQI in the distance of 100 m and was capable to determine existence of cars on parking sites .The entire system was confined in a small dimension with low power consumption and long battery life .Therefore it possessed potential practical prospect .