一种新型涡流传感器激励信号源的设计

Design of a new excitation signal source for eddy current sensor

在涡流检测系统中,涡流传感器需采用正弦或脉冲等信号加以激励,激励信号源是影响系统性能的关键部件之一.在介绍了直接数字合成(Direct Digital Synthesis,DDS)基本原理的基础上,设计了一种基于DDS技术的新型涡流激励信号源,它以高速单片机和复杂可编程逻辑器件为核心控制器,在波形存储器、D/A转换器、低通滤波器、触摸屏等外围模块的配合下,可产生频率、相位等参数可控的激励信号.实验表明,该信号源可产生任意波形激励信号,工作性能稳定,参数调节方便,能较好地满足涡流检测对激励源提出的要求.

In the eddy current testing system,the sensor probe needs to be driven by some excitation signal,and the excitation signal source is one of the most important components that influence the system performance.By introducing the principle of direct digital synthesis（DDS）,a new type of signal source based on DDS was proposed.The high speed microcontroller and the complex programmable logic device（CPLD） were served as the core control units,and other modules,such as waveform memory,D/A converter,low-pass filter and touch screen,were used as peripheral circuits.It could generate excitation signal with adjustable frequency and phase parameters.Experiment results show that the excitation signal source can generate arbitrary waveform and satisfy the requirement of the eddy current testing with the merits of outstanding stability and flexible parameter adjustment.