一种通用多通道高频相控发射和采集系统

声呐系统性能检测需要一种多通道可控相位信号和多通道大容量高速数据采集系统。通过多种高速数据采集和信号发射方案的对比,选用基于图形化编程语言LabVIEW和相应的硬件设备,设计、研制了一种32通道发射和128通道高速数据采集系统,用于多数声呐系统的性能检测。发射系统利用直接数字合成技术,生成可以单独调节相位的32通道正弦信号;采集系统采用分块读取减少缓冲区数据占用的方式,实现有限数据采集,并采用减少显示图形更新次数、使用DAQmx配置记录函数等方法,实现连续数据采集。测试结果表明,系统实现在采样率为2 MHz时,128通道中每通道1 300 000点的有限数据采集,以及采样率最高为0.7 MHz的128通道的连续数据采集。利用该系统对高分辨率测深侧扫声呐的发射信号进行检测,发射信号正常,系统工作良好。

A general multi-channel phased transmitting and acquisition system

For sonar performance testing, a general system that can generate multi-channel phased-control transmitting analog signals and can acquire multi-channel receiving arrays'' output signals is needed. Through comparisons with various transmitting and acquisition systems, the visual programming language LabVIEW and corresponding hardware devices are used to develop a general testing system including 32 channels of transmitting and 128 channels of high speed data acquisition, which makes most transmitting and receiving systems coming true. The transmitting system uses direct digital synthesizer to generate 32 channels of transmitting signals with independently adjustable phases. The acquisition system uses the block reading method to implement finite data acquisition at 2 MHz sampling frequency, and uses the methods of lessening refreshing times of display and applying DAQmx configuration and log VI to achieve continuous data acquisition of 128 channels. Testing results show that the system can work at the 2 MHz sampling rate for finite data acquisition of 1 300 000 samples per channel and at the highest 0.7 MHz sampling rate for continuous data acquisition of 128 channels. While using this system to test transmitting signal of High Resolution of Bathymetry Side Scan Sonar, both the transmitting signals and the testing system work well.