基于FPGA的红外热成像闪光灯激励电源

红外热成像技术是一种快速有效的无损检测技术,广泛应用于航空航天、轨道交通、核工业等领域。激励电源是红外热成像检测系统中的关键设备,其性能将影响缺陷的检测结果。采用线性放大产生激励的方式存在增益带宽积的限制,较难满足红外热成像技术对激励频率范围和输出功率的要求。本文采用数字的方式将电压进行调制,实现了较大功率的输出,提高了对缺陷的检测效率。为满足红外热成像技术对输出功率、参数调整、以及多种工作模式的要求,本文设计了一款基于FPGA的数字化闪光灯激励电源。该电源主要包括低频正弦产生电路、全桥斩波电路和FPGA控制系统三部分,其中控制系统为核心部分。试验证明,该电源实现脉冲和锁相两种激励模式,参数调整方便,能够满足红外热成像技术对激励电源提出的要求。

The excitation source for the infrared thermography based on FPGA

Infrared thermography is a fast and effective non-destructive testing(NDT) method which has been widely used in the fields of aerospace,rail transit,nuclear and etc.The excitation source is a crucial device for the optical thermography system whose performance has an impact on the test results.There is a limitation of gain bandwidth product by using linear amplification to generate excitation,and it is difficult to meet the requirements of frequency range and high power.In this paper,the voltage is modulated in a digital way to achieve a higher power output and improve the efficiency of defect detection.In order to meet the requirements of power,frequency and multi-mode,an excitation source for the infrared thermography based on FPGA is designed.The excitation source includes the low-frequency sinusoidal generating circuit,full-bridge chopper circuit and FPGA control system,of which the control part is the focus.Experiments′ results show that the excitation source can realize two modes of excitation(pulse mode and lock-in mode),and be easy to adjust,and meet the requirements of infrared thermography on the excitation source.