Research On Welding Information Detection Technology Based On Line Laser Vision

The welding technology is also moving towards the direction of intelligence and automation.Welding automatic tracking system is just to meet this practical need.The accuracy of welding information directly determines the accuracy of welding seam.This article designed a line-based laser vision online measurement system,focusing on the measurement system accuracy and real-time.The main content of this paper can be divided into:(1)The principle of laser triangulation is analyzed in detail.The optical path diagram of the measurement system is designed,and hardware equipment is selected to complete the construction of the hardware system.(2)The paper studys imaging model of the camera and the measurement model of the line structured light.The calibration principle and calibration method of the laser plane of the camera and line were elaborated,and the final calibration method was determined.We can acquire the internal and external parameters of the camera and the positional parameters of the plane of the line laser through calibration experiments.They lay the foundation for the next three dimensional calculation of welding information.(3)A series of image processing and feature recognition steps are performed on the acquired laser stripe image.The image processing part mainly includes window processing,image preprocessing,threshold segmentation,morphology processing and image refinement.According to the particularity of the line laser,we improve the iterative method for acquiring the threshold.The feature recognition part includes straight line detection,pre-weld feature recognition,post-weld feature recognition and wire fill calculation,and the traditional algorithm of the line detection is improved.(4)We design the software of the measurement system,and measure the groove and weld seam by using the system.After 10 repeated measurement experiments,the execution time of the system was within 750 ms.The maximum pre-weld error was 0.269 mm.The maximum post-weld error was 0.201 mm.The maximum error of the groove area is 0.329 mm.The maximum error of the excess height of the area is 0.516 mm,in line with the real-time and accuracy requirements of industrial production.