拾取回波信号时脉冲声控制方案的设计

Design of Impulsive Sound Control Schedule with Picking up the Echo-Signal

在空气声中采用脉冲声进行吸声与隔声测量时,由于声源与传声器是分置工作的,脉冲声生成过程中,传声器与声源是同步工作方式。但在水声管中测量时,换能器往往采用"收发合置"的工作方式,脉冲声生成的方式是不同的。因此,提出了在拾取回波信号时脉冲声的时序控制方案。以MSP430F149单片机为硬件核心,设计了满足其时序要求的控制电路,利用MSP430F149单片机串行口通信,开发了基于LabWindows/CVI虚拟仪器技术的上位机测试平台,辅以信号发生器、数字示波器、功率放大器、信号调理器等测试仪器,通过对响应及驱动信号进行截短处理,在消声室中成功产生了可控脉冲声信号,为"收发合置"方式在水下环境中产生可控脉冲声奠定了基础。

Impulsive sound signal is usually generated by the synchronous work of sensor and transducer in air acoustic measurement, while this procedure can not be executed for monostatie transducer because of its time- sharing work. A time sequence control schedule is suggestted for the monostatic transducer generating the im- pulse sound in order to simulate the case that the transducer can only pick up the echo-signal. The time se- quence control circuit is designed based on MSP430F149. A host PC measurement platform is developed with LabWindows/CVI. Otherwise, a digital signal generator, a digital oscilloscope, a power amplifier and a signal conditioning equipment are employed to construct the whole measurement system. By truncating the response and driver signal, a controllable impulsive sound signal is successfully generated in the anechoic chamber, which lays the foundation of impulsive sound generation for the monostatic transducer in the underwater meas- urement.