Real-time seam tracking can improve welding quality and enhance welding efficiency during the welding process in automobile manufacturing.However,the teaching-playing welding process,an off-line seam tracking method,i...Real-time seam tracking can improve welding quality and enhance welding efficiency during the welding process in automobile manufacturing.However,the teaching-playing welding process,an off-line seam tracking method,is still dominant in automobile industry,which is less flexible when welding objects or situation change.A novel real-time algorithm consisting of seam detection and generation is proposed to track seam.Using captured 3D points,space vectors were created between two adjacent points along each laser line and then a vector angle based algorithm was developed to detect target points on the seam.Least square method was used to fit target points to a welding trajectory for seam tracking.Furthermore,the real-time seam tracking process was simulated in MATLAB/Simulink.The trend of joint angles vs.time was logged and a comparison between the off-line and the proposed seam tracking algorithm was conducted.Results show that the proposed real-time seam tracking algorithm can work in a real-time scenario and have high accuracy in welding point positioning.展开更多
The application of deep learning in fabric defect detection has become increasingly widespread.To address false positives and false negatives in fabric roll seam detection,and to improve automation efficiency and prod...The application of deep learning in fabric defect detection has become increasingly widespread.To address false positives and false negatives in fabric roll seam detection,and to improve automation efficiency and product quality,we propose the Multi-scale Context DeepLabV3+(MSC-DeepLabV3+),a semantic segmentation network designed for fabric roll seam detection,based on DeepLabV3+.The model improvements include enhancing the backbone performance through optimization of the UIB-MobileNetV2 network;designing the Dynamic Atrous and Sliding-window Fusion(DASF)module to improve adaptability to multi-scale seam structures with dynamic dilation rates and a sliding-window mechanism;and utilizing the Progressive Low-level Feature Fusion(PLFF)module to progressively restore seam boundary details via shallow feature fusion.Additionally,an enhanced 3-SE attention mechanism is employed,replacing the direct concatenation operation.Experimental results show thatMSCDeepLabV3+outperforms classical and recent segmentation models.Compared to DeepLabV3+with an Xception backbone,MSC-DeepLabV3+achieves a mean intersection over union(mIoU)of 92.30%and the boundary Fscore(BF)of 92.54%,representing improvements of 3.04%and 3.14%,respectively.Moreover,the model complexity is significantly reduced,with the model parameters(params)decreasing to 3.44M and Frames Per Second(FPS)increasing from 101 to 273,demonstrating its potential for deployment in resource-constrained industrial scenarios.展开更多
A vision-based weld seam detector is crucial for intelligent welding in ship stiffened panel as it influences the working efficiency of welding robots.This paper introduces an innovative Run Length Encoding(RLE)based ...A vision-based weld seam detector is crucial for intelligent welding in ship stiffened panel as it influences the working efficiency of welding robots.This paper introduces an innovative Run Length Encoding(RLE)based Line Segment Detector(RSD)that is capable of extracting line segments from point clouds.The RLE is firstly employed to compress point cloud data by encoding them into runs.Then,the directional fea-ture of significant line segments is determined according to the analysis of level line angles,facilitating a global line segment detection mechanism.This enables RSD to capture more complete line segments compared to region-based detection methods.Notably,this method obviates the need for manual param-eter adjustments and does not require any prior information.The effectiveness and superiority of RSD are confirmed by testing various workpieces in a laboratory setting and comparing its performance with other detectors.展开更多
Weld seam detection is an important part of automated welding.At present,few studies have been conducted on annular weld seams,and a lot of defects exist in the point cloud model of the tube sheet obtained by RGB-D ca...Weld seam detection is an important part of automated welding.At present,few studies have been conducted on annular weld seams,and a lot of defects exist in the point cloud model of the tube sheet obtained by RGB-D cameras and photography methods.Aiming at the above problems,this paper proposed an annular weld seam detection network named WeldNet where a voxel feature encoding layer was adaptively improved for annular weld seams,the sparse convolutional network and region proposal network(RPN)were used to detect annular weld seam position,and an annular weld seam detection loss function was designed.Further,an annular weld seam dataset was established to train the network.Compared with the random sampling consistency(RANSAC)method,WeldNet has a higher detection accuracy,as well as a higher detection success rate which has increased by 23%.Compared with U-Net,WeldNet has been proven to achieve a better detection result,and the intersection over the union of the weld seam detection is improved by 17.8%.展开更多
基金Supported by Ministerial Level Advanced Research Foundation(65822576)Beijing Municipal Education Commission(KM201310858004,KM201310858001)
文摘Real-time seam tracking can improve welding quality and enhance welding efficiency during the welding process in automobile manufacturing.However,the teaching-playing welding process,an off-line seam tracking method,is still dominant in automobile industry,which is less flexible when welding objects or situation change.A novel real-time algorithm consisting of seam detection and generation is proposed to track seam.Using captured 3D points,space vectors were created between two adjacent points along each laser line and then a vector angle based algorithm was developed to detect target points on the seam.Least square method was used to fit target points to a welding trajectory for seam tracking.Furthermore,the real-time seam tracking process was simulated in MATLAB/Simulink.The trend of joint angles vs.time was logged and a comparison between the off-line and the proposed seam tracking algorithm was conducted.Results show that the proposed real-time seam tracking algorithm can work in a real-time scenario and have high accuracy in welding point positioning.
文摘The application of deep learning in fabric defect detection has become increasingly widespread.To address false positives and false negatives in fabric roll seam detection,and to improve automation efficiency and product quality,we propose the Multi-scale Context DeepLabV3+(MSC-DeepLabV3+),a semantic segmentation network designed for fabric roll seam detection,based on DeepLabV3+.The model improvements include enhancing the backbone performance through optimization of the UIB-MobileNetV2 network;designing the Dynamic Atrous and Sliding-window Fusion(DASF)module to improve adaptability to multi-scale seam structures with dynamic dilation rates and a sliding-window mechanism;and utilizing the Progressive Low-level Feature Fusion(PLFF)module to progressively restore seam boundary details via shallow feature fusion.Additionally,an enhanced 3-SE attention mechanism is employed,replacing the direct concatenation operation.Experimental results show thatMSCDeepLabV3+outperforms classical and recent segmentation models.Compared to DeepLabV3+with an Xception backbone,MSC-DeepLabV3+achieves a mean intersection over union(mIoU)of 92.30%and the boundary Fscore(BF)of 92.54%,representing improvements of 3.04%and 3.14%,respectively.Moreover,the model complexity is significantly reduced,with the model parameters(params)decreasing to 3.44M and Frames Per Second(FPS)increasing from 101 to 273,demonstrating its potential for deployment in resource-constrained industrial scenarios.
基金the Oceanic Interdisciplinary Pro-gram of Shanghai Jiao Tong University(SL2022PT202).
文摘A vision-based weld seam detector is crucial for intelligent welding in ship stiffened panel as it influences the working efficiency of welding robots.This paper introduces an innovative Run Length Encoding(RLE)based Line Segment Detector(RSD)that is capable of extracting line segments from point clouds.The RLE is firstly employed to compress point cloud data by encoding them into runs.Then,the directional fea-ture of significant line segments is determined according to the analysis of level line angles,facilitating a global line segment detection mechanism.This enables RSD to capture more complete line segments compared to region-based detection methods.Notably,this method obviates the need for manual param-eter adjustments and does not require any prior information.The effectiveness and superiority of RSD are confirmed by testing various workpieces in a laboratory setting and comparing its performance with other detectors.
基金supported by the Key Research&Development Plan of China(Grant No.2022YFB3404800)the Key Research&Development Plan of Hubei Province(Grant No.2021BAA195)the National Natural Science Foundation of China(Grant No.52188102)。
文摘Weld seam detection is an important part of automated welding.At present,few studies have been conducted on annular weld seams,and a lot of defects exist in the point cloud model of the tube sheet obtained by RGB-D cameras and photography methods.Aiming at the above problems,this paper proposed an annular weld seam detection network named WeldNet where a voxel feature encoding layer was adaptively improved for annular weld seams,the sparse convolutional network and region proposal network(RPN)were used to detect annular weld seam position,and an annular weld seam detection loss function was designed.Further,an annular weld seam dataset was established to train the network.Compared with the random sampling consistency(RANSAC)method,WeldNet has a higher detection accuracy,as well as a higher detection success rate which has increased by 23%.Compared with U-Net,WeldNet has been proven to achieve a better detection result,and the intersection over the union of the weld seam detection is improved by 17.8%.
