在高精度传感器网络定位系统中,基于到达时间差(TDOA)的定位系统得到了越来越普遍的研究.首先设计了一套基于ZigBee技术的无线通信节点,通过扩展超声波测距装置构建了TDOA定位系统所需的硬件平台.在分析定位节点和信标节点的工作特性的基础上提出了基于事件驱动的定位机制,既保证系统响应速度高效又能有效降低系统功耗,改善了空间中能量碰撞和信号串扰问题.另外还针对TDOA测距过程中存在的误差进行实验分析与修正,最终有效地减小了测距误差的影响,从而提高了系统定位精度.%The method based on time difference of arrival( TDOA) in the high-precision wireless sensor network positioning system has received more and more research attention. A set of wireless communication nodes based on ZigBee protocol is designed to form a hardware platform by adding ultrasonic ranging devices. The character istics of beacon and common nodes are analyzed, then a positioning mechanism based on event-driven is pro posed which can not only ensure the system a high response speed but also a considerable reduction in the power consumption of the system. It can solve the problems of energy collisions and signal crosstalk in the air as well. Finally, corrections to the ranging errors are made based on large amounts of experimental analysis. As a result, the influence of ranging errors is largely reduced and the positioning precision is improved.
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