Researchand Application Of Arc Welding Robot Adaptive Control Technology

Considering the actual situation and requirement of MIG welding of automobile parts,this paper proposes a real-time method to acquire the feature information of the work piece to be welded in the welding process.Based on the geometric area of the groove and the consistency of the predicted metal filling quantity,online adjustment and optimization of welding process parameters.This paper mainly completed the following aspects:To solve the influence by all kinds of interference factors and the size of vison sensor issues,a structure light sensor is developed.The main hardwares of vision sensor are selected,and thelight path and structure is designed.As a result,the size of sensor is decreased,and theanti-interference performance is enhanced.According to the actual requirements of the production and the coordinates of ABB robot TCP and Z-axis calibration tools,a simple hand-eye calibration method using bevel feature points is proposed,and a calibration method is established for the visual inspection system from two Dimensional images in the three-dimensional coordinates of the actual relationship;Considering the laser stripe image with strong interference,the Gaussian filter,the bilateral filter and the median filtering method are studied,and the median filtering method is optimized.Then,the method is combined with sharpening filter and adaptive thresholding to deal with the laser image pre-Edge detection method has been improved and Canny edge detection algorithm has been optimized to improve the edge extraction of different welding images and improve the accuracy and adaptability of edge detection.Based on the analysis of the characteristics of welding images,a complete set of image processing algorithms is developed.Image processing method to deal with the ROI region of the image time is not more than 56 ms,fully able to meet the follow-up laser stripe image feature point extraction;The traditional method of slope and Hough transform are used to extract the pixel coordinates of the weld feature points,and the performance of the method of extracting the pixel coordinates of the feature points of the weld is compared.Finally,use the Hough transform method to extracting weld characteristic points;Considering the problem of welding quality deterioration caused by the change of the cross-sectional area of workpiece joint,welding seam automatic tracking and self-adaptive filling are used to control the metal filling quantity to ensure the quality of weld formation.The adaptive filling control strategy is designed and the relationship between the weld cross section and the welding parameters is fitted by the large step calibration of welding parameters and Newton difference method.At last,the adaptive control software of arc welding robot is designed by adopting the modular programming idea.Taking the welding of frame girder as an example,the experimental results using the hardware and software platform in this paper show that the adaptive control system of arc welding robot designed in this paper can be applied to the automatic welding of automobile frame,It can solve the filling problem of groove change in the welding process of automobile frame,and meet the quality requirements of weld forming...