强磁场下微弱信号检测系统设计

The Design of Weak Signal Detection System in Strong Magnetic Field

为获知母线电流的分布情况,给母线配置提供参考,设计了一个以高精度运放INA114和RAM处理器S3C2440为基础的检测装置,使其在强磁场环境下能完成微小电压和温度信号的测量。阐述了强磁场环境的特点和影响,重点分析了系统的硬件构成,软件设计和系统所采取的抗干扰措施。其中,硬件设计采用了功率谱估计的方法确定信号频段,通过Labview的仿真实验验证了该方法的可行性,并以该频段信息为参考依据设计了低通滤波器。最后,通过试验数据证明了该系统的可靠性,其测量误差小于5%,且在强磁场环境下能实现每秒采集一次数据,实时跟踪电流变化的功能。

In order to measure the electric current of busbar, a measuring device is designed to provide a reference for busbar configuration. This device is based on INAll4 which is an operational amplifier circuit with high precision and processor $3C2440 of ARM. Weak voltage signal and temperature signal can be detected under the strong magnetic field by the detecting system. The characteristic feature and the adverse effects of the strong magnetic field are introduced, and the characteristics of hardware, software, Anti-interference measures are also analyzed. We use the way of power spectral estimation to confirm the signal information of the frequency, which is proved validity by LabVIEW simulation result. According to the signal frequency, a low pass filter is designed in the hardware. Finally, the test data proves that the accuracy of the system can be within 5 %. In strong magnetic field the device can collect data once per second and track the change of the current in time.