一种无线传感器网络中汇聚节点的本地时钟和传感器节点的RTC时钟同步校准的方法

摘要

为了降低传感器节点的功耗,应尽可能地让传感器节点在没有业务需求时进入休眠状态.由于传感器节点进入休眠状态后只有RTC时钟模块在运行,且RTC模块内部晶体振荡器受温度等因素的影响较大,造成RTC时钟精度不高进而可能会导致传感器节点不能准确地在预设的时间被自动唤醒,无法完成与汇聚节点的通信业务.为此,提出一种新的无线传感器网络中汇聚节点的本地时钟和传感器节点的RTC时钟同步校准方法,该方法摒弃了以往直接对传感器节点内部RTC模块的晶体振荡器进行温度参数补偿的做法,并由传感器节点根据汇聚节点的本地时钟来调整自己的RTC时钟,以便传感器节点和汇聚节点的时钟动态地保持一致.%In order to reduce the power consumption of the sensor nodes as far as possible,the sensor nodes in the absence of business need to turn into the dormant state.However,while the sensor nodes are in the dormant state,only the internal RTC clock module is working.As the crystal oscillator of RTC module is greatly affected by temperature and other factors,it will result in low precision of RTC clock.The sensor node will miss the preset time and fail to communicate with the sink node when it is automatically awakened.Such a new synchronization calibration method about local clock of sink node and RTC clock of sensor nodes in wireless sensor networks was proposed.The method abandons the previous practice that directly making temperature parameters compensation on internal crystal oscillator of the RTC module in sensor nodes.In the method,the sensor nodes adjust their own RTC clock dynamically to make the clock time of sensor nodes and sink node keep consistent according to the local clock of sink node.