基于NI CompactRIO的多通道磁场r采集系统的设计与实现

摘要

针对磁法勘探、地磁导航等不同技术领域的地磁测量需求,提出了一种多传感器模块化采集方案,构建了基于NI CompactRIO的多通道磁场采集系统.系统整合了光泵磁力仪,磁通门磁力仪,惯性导航模块以及GPS模块,可满足不同情况下的实验需求.为了解决多传感器组件同时采集时数据无法同步的问题,提出了基于GPS的同步授时技术以保证数据的有效性.利用插值计数器实现了数字倒数插值测频法,在铯光泵磁力仪有效输出范围内,磁测分辨率优于0.006 nT.在吉林大学电磁屏蔽室中,对系统噪声水平进行了评估,评估结果表明采集系统的PSD为7 pT/Hz@1 Hz,符合设计要求.最后在长春南湖和内蒙古桃合木苏木两个实验场地应用采集系统,验证了系统在野外恶劣环境下能够稳定工作,并高效地完成采集任务.%According to the demand of different tech-areas, such as magnetic prospecting, geomagnetic navigation etc. this paper presents a multi sensor module acquisition scheme and builds a multi channel field acquisition system based on NI CompactRIO. The system integrates the optical pump sensor,the magnetic flux gate sensor,the inertial navigation module and the GPS module,which can meet the requirements of different situations. In order to solve the multi sensor data collected at the same time can't be synchronized when the issue is put forward based on GPS time synchronization technology to ensure the validity of data. Using interpolation counters to achieve the Digit-al Interpolation Reciprocal method of frequency measurement and the resolution of magnetic measurement is better than 0.006 nT in the effective output range of the cesium optically pumped magnetometer The system noise level is evaluated in electromagnetic shielding room of Jilin University, the evaluation results show that the acquisition system's PSD is 18.8 pT/ Hz@1 Hz,meeting the design requirements. Finally,the system is applied to the two ex-perimental sites in Changchun Lake NanHu and Taohemusumu area,Inner Mongolia. It is proved that the system can work stably and efficiently in the field.