双波长滤光片式红外测量焊接温度场系统

A Real-time Infrared Measurement System of Welding Temperature Field with the Dual-wavelength Type Optical Filter

研制了一种新颖的单镜头双波长红外图像比色测温系统来实时检测焊接温度场。此系统的主要特点是采用一种双波长的红外滤光片从焊缝正面摄取双波长红外图像。双波长滤光片的具体结构形式是用两个不同波长的半圆滤光片拼接成一个整圆滤光片 ,其两个半圆的波长值根据比色测温的要求而设计 ,本文研制的双波长滤光片的波长分别为 0 .80 5 0 μm与 0 .895 0 μm。此测温系统的CCD摄像机从焊缝正面摄取焊接热图像时 ,将双波长滤光片的接缝对准焊接熔池中心 ,就可以在一幅图像的两半边同时取得两种波长的焊接温度场红外图像。由于双波长滤光片的中间接缝很窄 ,可以将接缝两边对称点上的两个波长的信息视作同一温度下的双波长信息来进行比色测温计算 ,从而求出近熔化区的焊接温度场 ,并可推算出含熔化区的焊接温度场。此系统的优点是结构简单 ,实用性好 ,适用于焊接现场。

A new infrared temperature measure system based on the calorimetric method has been developed to survey the welding temperature field in real time.There is a special dual wave length optical filter set in the system,which makes it possible that infrared images with two different wavelengths can be synchronously sampled through one camera lens.The filter was built by joining of two half round filters,which are designed to have different wavlengths.The values of the dual wavelength are designed according to the requirement of the calorimetric method and are 0.8050μm and 0.8950μm in this paper.By animing the joint line of the filter at the center of the welding pool,the dual wavelength infrared images of the welding temperature field can be caught with a single lens CCD camera,i.e.the two half rounds of the image are different on the wave length.Since the joint line of the filter is very narrow,the bilateral symmetrical points' gray scales of the images can be treated as dual wavelength data of the same point.In this way,the each pint's temperature of the welding field near the pool can be calculated with the calorimetric method.Based on it,the welding temperature including the fusion region can be further derived.The advantage of the system is that the infrared temperature measurement device has been simplified for practical application of measuring the welding temperature field.