基于DDS技术的模块化多频涡流检测系统设计

摘要

Multi-frequency eddy current test technology can eliminate the noise in the NDT process effectively, and improve the resolution and reliability of NDT. DDS was a new technology of frequency synthesizer,so when the multi-frequency eddy current test system was parted modularly, this paper designed the signal source based on DDS technology, the power band pass filter based VCVS and the analogue orthogonal lock-in amplifer. The system was easy to integrate and reconfigurate. The experiments show that this system works well in 100 Hz ～ 1 MHz range.%多频涡流检测技术能有效地抑制无损检测过程中的干扰因素,提高检测的分辨率和可靠性.DDS技术是频率合成的新技术,因此,在对多频涡流检测系统进行模块化划分的基础上,设计了基于DDS技术设计信号发生模块,基于VCVS的有源带通滤波模块和模拟正交锁定放大模块等,系统整体具有易于集成和重构的特点.实验结果证明:该系统工作稳定,可用于100 Hz～1 MHz范围内的多频涡流无损检测.