摘要
针对目前无线传感器网络性能偏低不能满足机械振动信号高精度同步采集需求的问题,提出了一种基于跨层设计的同步采集方法(SACD)。研究基于双核心设计的采集节点,提高任务调度实时性,降低采样间隔的抖动;实现帧起始定界符(SFD)的硬件跨层通信,避免命令传输过程中协议栈层与层、节点模块与模块之间的随机延时误差,提高时钟同步和同步触发精度;研究晶振频率偏移动态补偿方法,降低因采样间隔不相同导致的同步采集累积误差。实验结果表明,节点间最大同步触发误差的均值为1.107 2μs,最大值为1.28μs,连续采集10 s时的最大同步累积误差为7.54μs,能有效地提高机械振动无线传感网络同步采集精度。
Aiming at the problem that the low performance of current wireless sensor networks can not meet the requirement of high accuracy machine vibration signal synchronous acquisition,a synchronous acquisition method based on cross-layer design （SACD） is proposed.The acquisition node based on dual core design is researched to improve the real-time performance of task scheduling and reduce the sampling interval jitter.The cross-layer communication of start of frame dehmiter （SFD） is achieved,which avoids the random delay errors among the layers in protocol stack as well as the node modules during the command transmission process,and improves the accuracies of clock synchronization and synchronous triggering.The crystal oscillator frequency offset dynamic compensation method is studied,which reduces the accumulated synchronous acquisition errors due to different sampling intervals.Experimental results show that the mean of the maximum synchronous triggering errors among the nodes is 1.107 2 μs and the maximum value is 1.28 μs; the maximum accumulated synchronous acquisition error is 7.54 ps in 10 s continuous acquisition.The proposed method can effectively improve the accuracy of synchronous acquisition in machine vibration wireless sensor networks.
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2014年第5期1143-1148,共6页
Chinese Journal of Scientific Instrument
基金
国家自然科学基金(51375514
5125546)
高等学校博士学科点专项科研基金(2013019113001)资助项目
关键词
机械振动监测
无线传感器网络
同步采集
跨层设计
machine vibration monitoring
wireless sensor networks（WSNs）
synchronous acquisition
cross-layer design
