Study On Automation Of Welding System For Steel Pipe Tower In Transmission Line

With the continuous development of China’s electric power construction,in the power construction field,carrying electricity transmission tower production also got rapid development.But in steel tube transmission tower industry,the longitudinal seam welding efficiency and quality is the bottleneck to the capacity expansion and quality promotion of steel pipe tower production.So developing a real time seam tracking automatic welding control system is very necessary.In this paper,the problems and bottlenecks in the production and processing of steel tubes in transmission lines are taken as the input requirements,the study of automation welding of longitudinal seam welding is carried out.Taken the longitudinal seam welded steel pipe tower as the background,aiming at the shortcoming of existing welding system for the enterprise and the demand to improve efficiency and quality of products,the improvement plan is put forward.The laser vision sensor,data acquisition card is added to the system and the torch motion is controlled by industrial PC.The calibration of the sensor system is the key to the laser vision tracking system.In this paper,the camera and laser plane of the laser vision sensing system are respectively calibrated,and the calibration results are verified.The mean errors in x,y and z directions are 0.0298mm,0.1807mm and 0.1042mm respectively,which can meet the precision requirements of the longitudinal seam welding of steel pipe.Based on the analysis of the laser images captured by the system in the welding situation and no welding situation,an image processing algorithm including filtering,sharpening,Hough linear transformation,linear fitting and chain code boundary search was designed according to the image characteristics.This algorithm can extract the laser line under the interference of arc light and splash.According to the characteristics of v-shaped groove,the algorithm of groove center is designed.This paper,A controller combined a fuzzy controller and P classical control algorithm is developed.When the welding seam tracking deviation is less than or equal to 2mm,in order to improve the steady-state accuracy of the system,the fuzzy controller is acting;when the devation is larger than 2mm,in order to eliminate the deviation as soon as possible,the P controller is working.The welding seam tracking experiments were carried out with simulated welding specimens and actual products.The experimental results show that the detection and control accuracy of the welding seam tracking system is high,and the tracking error is<0.5mm.At the same time,in the case of weld tracking,the work-piece and actual products were used for experimental verification.The experimental results show that the control precision of seam tracking system is high enough to meet the requirement of the production line,and weld forming quality is better.And the improved system makes up for the inadequacy of the original welding systems.It is easier operation,the number of the welder needed reduces from 2 to 3 to 1-2 people,and production efficiency is doubled.At the same time,it reduces the labor intensity of welding workers,saves resources and reduces costs to a large extent.