摘要
微震信号动态范围大、无法预知信号幅度,直接采样接收信号会造成较大信号失真,针对该问题设计了一种自动调节增益的微震信号采集系统。该系统实时快速地根据微震信号幅度变化自动调节放大器增益,将信号调节到A/D输入范围。滤波器设计采用抽取滤波的方法,先对信号过采样,然后使用抽取滤波器对信号进行滤波和抽取,将信号数据率降低到奈奎斯特采样率,这种方法降低了对抗混叠滤波器性能的要求。通过实验验证分析,该设计能采集动态范围可达136 dB,所采集到的信号信噪比高、失真度小。
Microseismic signals have a large dynamic range and unpredicted signal amplitude,if the signal is directly sampled,it will cause great loss. To solve this problem,a microseismic signal acquisition system which can automatically adjust the gain was designed. According to the magnitude change of microseismic signal,it can quickly and automatically adjust the gain of the amplifier in real time,so that it can adjust the signal to fit the A / D conversion range. Filter use decimation filtering method. Firstly,the signal was oversampled. And then using the decimation filter for signal filtering and decimation,which will reduce the signal data rate to the Nyquist sampling rate and reduce the anti-aliasing filter performance requirements. Through experimental verification of analysis,the design can capture a dynamic range up to 136 d B. The collected signal has high SNR and small distortion.
出处
《仪表技术与传感器》
CSCD
北大核心
2016年第4期108-110,共3页
Instrument Technique and Sensor
基金
国家自然科学基金项目(61362020)
广西自然科学基金项目(2013GXNSFAAA019327
2013GXNSFFA019004)
广西研究生教育创新计划资助项目(YCSZ2013067)
关键词
微震
信号采集
抽取滤波
过采样
microseismic
signal acquisition
decimation filter
oversampling
