面向高密度地震动观测的ARM信号采集系统

The ARM Signal Collection System for High Density Ground Motion Observation

地震动观测是地震烈度速报与地震预警的前提和基础。而高密度台站是地震动观测的重要发展方向之一。高密度地震动观测背景下,如何在不影响其计量性能的前提下,降低硬件成本是亟待解决的问题。针对此问题,以ARM处理器为核心设计了一种高精度、多通道、低成本的信号采集系统,它以CPLD作为协处理器,控制24 bit AD进行8通道同步信号采集,并对信号进行必要的预处理,之后CPLD将AD采集的信号存储在FIFO中,由ARM控制FIFO,读出FIFO中存储数据传输给ARM。通过实验数据的分析,信号采集系统的电压噪声均方根小于25μV,其动态范围大于107 d B。

The observation of ground motion is the precondition and basis for seismic intensity quick-report and earthquake warning.The high density station is one of the important development direction for ground motion observation.Under the background of high density ground motion observation,it is an urgent problem how to reduce the hardware cost and have no effect on its measurement performance.For this problem,a high-precision and low-cost signal sampling system is designed with ARM processor.As the coprocessor,CPLD controls the 24-bit AD for 8-channel synchronous signal data acquisition,and processes the signals data in the same time.The signal data are stored in FIFO.ARM controls FIFO to deliver the signals to ARM.Through the analysis of experimental data,the voltage noise of the signal data acquisition system is less than 25μV,and its dynamic range is more than 107 dB.