Online Extraction of Pose Information of 3D Zigzag-Line Welding Seams for Welding Seam Tracking

Three-dimensional (3D) zigzag-line welding seams are found extensively in the manufacturing of marine engineering equipment, heavy lifting equipment, and logistics transportation equipment. Currently, due to the large amount of calculation and poor real-time performance of 3D welding seam detection algorithms, real-time tracking of 3D zigzag-line welding seams is still a challenge especially in high-speed welding. For the abovementioned problems, we proposed a method for the extraction of the pose information of 3D zigzag-line welding seams based on laser displacement sensing and density-based clustering point cloud segmentation during robotic welding. after thee point cloud data of the 3D zigzag-line welding seams was obtained online by the laser displacement sensor, it was segmented using theρ-Approximate DBSCAN (Density-Based Spatial Clustering of Applications with Noise) algorithm. In the experiment, high-speed welding was performed on typical low-carbon steel 3D zigzag-line welding seams using gas metal arc welding. The results showed that when the welding velocity was 1000 mm/min, the proposed method obtained a welding seam position detection error of less than 0.35 mm, a welding seam attitude estimation error of less than two degrees, and the running time of the main algorithm was within 120 ms. Thus, the online extraction of the pose information of 3D zigzag-line welding seams was achieved and the requirements of welding seam tracking were met.

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Design and Implementation of a High-Speed Real-Time Position Detection System in Electromagnetic Coil Launcher

IEEE Transactions on Plasma Science ◽

10.1109/tps.2020.3019045 ◽

2020 ◽

Vol 48 (9) ◽

pp. 3203-3210

Author(s):

Guan Xiao Cun ◽

Shuai Wang ◽

Denghua Guo ◽

Shaohua Guan ◽

Baolong Liu ◽

...

Keyword(s):

Real Time ◽

High Speed ◽

Detection System ◽

Electromagnetic Coil ◽

Design And Implementation ◽

Position Detection ◽

Time Position

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An Experimental Study on Real Time Measurement of Ultrasonic Vibration Amplitude and Frequency Using Laser Displacement Sensor

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.875-877.2132 ◽

2014 ◽

Vol 875-877 ◽

pp. 2132-2136

Author(s):

Yu Nong Zhang ◽

Matthew R. Stanco ◽

Z.C. Li

Keyword(s):

Real Time ◽

Ultrasonic Vibration ◽

High Speed ◽

Original Data ◽

Displacement Sensor ◽

Ultrasonic Power ◽

Laser Displacement Sensor ◽

Charge Coupled Device ◽

Real Time Measurement ◽

Filter Noise

An ultra-high-speed and high-accuracy charge-coupled device (CCD) laser displacement sensor is used to track and measure the ultrasonic vibration in real time. A series of Matlab programs are developed to filter noise from original data. The ultrasonic vibration frequency and period are evaluated and the ultrasonic amplitude is measured within accuracy ±0.1 μm. Effect of the ultrasonic power on the ultrasonic amplitude is also studied.

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The Real-Time Phasemetric Microwave Navigation System for Position Detection and Drive Control of High-Speed Objects

2007 International Kharkiv Symposium Physics and Engrg. of Millimeter and Sub-Millimeter Waves (MSMW) ◽

10.1109/msmw.2007.4294852 ◽

2007 ◽

Author(s):

S. V. Plaksin ◽

Yu. V. Shkil

Keyword(s):

Real Time ◽

Navigation System ◽

High Speed ◽

The Real ◽

Position Detection ◽

Drive Control

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The Weld Image Acquisition and Preprocessing Based on FPGA

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.401-403.1507 ◽

2013 ◽

Vol 401-403 ◽

pp. 1507-1513 ◽

Cited By ~ 1

Author(s):

Zhong Hu Yuan ◽

Wen Tao Liu ◽

Xiao Wei Han

Keyword(s):

Image Processing ◽

Real Time ◽

High Speed ◽

High Performance ◽

Image Acquisition ◽

Processing System ◽

Large Data ◽

Seam Tracking ◽

Image Processing System ◽

Time Requirements

In the weld image acquisition system, real-time image processing has been a difficult design bottleneck to break through, especially for the occasion of large data processing capability and more demanding real-time requirements, in which the traditional MCU can not adapt, so using high-performance FPGA as the core of the high speed image acquisition and processing card, better meets the large amount of data in most of the image processing system and high demanding real-time requirements. At the same time, system data collection, storage and display were implemented by using Verilog, and in order to reducing the influence of edge detection noise, the combination of image enhancement and median filtering image preprocessing algorithm was used. Compared to the pre-processing algorithm of the software implementation, it has a great speed advantage, and simplifies the subsequent processing work load, improves the speed and efficiency of the entire image processing system greatly. So it proves that the system has strong ability of restraining the noise of image, and more accurate extracted edge positioning, it can be applied in the seam tracking field which need higher real-time requirements.

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Seam Tracking Monitoring Based on Keyhole Features during High-Power Fiber Laser Welding

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.314-316.932 ◽

2011 ◽

Vol 314-316 ◽

pp. 932-936

Author(s):

Xiang Dong Gao ◽

Ling Mo ◽

Seiji Katayama

Keyword(s):

Laser Beam ◽

Laser Welding ◽

Fiber Laser ◽

High Power ◽

High Speed ◽

Continuous Wave ◽

Welding Process ◽

Seam Tracking ◽

Fiber Laser Welding ◽

Welding Seam

Seam tracking is an important field to obtain good welding quality. During the high-power fiber laser welding, the laser beam focus must be controlled to track the welding seam accurately. A method of detecting the offset between the laser beam focus and the welding seam based on analyzing the keyhole features was researched during high-power fiber laser butt-joint welding of Type 304 austenitic stainless steel plates at a continuous wave fiber laser power of 10 kW. The joint gap width was less than 0.1mm. An infrared sensitive high speed camera was used to capture the thermal images of a molten pool in welding process. Two parameters called the keyhole centroid and keyhole shape were defined as the eigenvalues of seam tracking offset to determine the offset between the laser beam focus and the desired welding seam. The welding experiments confirmed that the offset between the laser beam focus and the welding seam could be monitored and estimated by the keyhole centroid and keyhole shape parameters effectively.

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Real-Time Geometric Parameter Measurement of High-Speed Railway Fastener Based on Point Cloud from Structured Light Sensors

Sensors ◽

10.3390/s18113675 ◽

2018 ◽

Vol 18 (11) ◽

pp. 3675 ◽

Cited By ~ 2

Author(s):

Hao Cui ◽

Qingwu Hu ◽

Qingzhou Mao

Keyword(s):

Real Time ◽

Geometric Parameter ◽

Point Cloud ◽

High Speed ◽

Region Growing ◽

Point Clouds ◽

Parameter Measurement ◽

High Speed Railway ◽

Rail Track ◽

Accuracy And Repeatability

With the increase in the number of service years for high-speed railways, the foundation of the rail track suffers from settlement, which causes rail track irregularity. To adjust the position of the track and meet track regularity demands, several components of the fastening system will be replaced by different sized components. It is important to measure the exact geometric parameters for the components of a fastening system before adjusting the track. Currently, the measurement process is conducted manually, which is laborious and error-prone. In this paper, a real-time geometric parameter measurement system for high-speed railway fastener based on 2-D laser profilers is presented. Dense and precise 3-D point clouds of high-speed railway fasteners are obtained from the system. A fastener extraction method is presented to extract fastener point cloud and a region-growing algorithm is used to locate key components of the fastener. Then, the geometric parameter of the fastener is worked out. An experiment was conducted on a high-speed railway near Wuhan, China to verify the accuracy and repeatability of the system. The maximum root-mean-square-error between the manual measurement and the system measurement is 0.3 mm, which demonstrates adequate accuracy. This system can replace manual measurements and greatly improve the efficiency of geometric parameter measurements for fasteners.

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LiDAR-Based Non-Cooperative Tumbling Spacecraft Pose Tracking by Fusing Depth Maps and Point Clouds

Sensors ◽

10.3390/s18103432 ◽

2018 ◽

Vol 18 (10) ◽

pp. 3432 ◽

Cited By ~ 3

Author(s):

Gaopeng Zhao ◽

Sixiong Xu ◽

Yuming Bo

Keyword(s):

Real Time ◽

Point Cloud ◽

High Speed ◽

Grid Point ◽

Point Clouds ◽

Sensor Data ◽

The Real ◽

Pose Tracking ◽

Depth Maps ◽

Relative Pose

How to determine the relative pose between the chaser spacecraft and the high-speed tumbling target spacecraft at close range, which is an essential step in space proximity missions, is very challenging. This paper proposes a LiDAR-based pose tracking method by fusing depth maps and point clouds. The key point is to estimate the roll angle variation in adjacent sensor data by using the line detection and matching in depth maps. The simplification of adaptive voxelized grid point cloud based on the real-time relative position is adapted in order to satisfy the real-time requirement in the approaching process. In addition, the Iterative Closest Point algorithm is used to align the simplified sparse point cloud with the known target model point cloud in order to obtain the relative pose. Numerical experiments, which simulate the typical tumbling motion of the target and the approaching process, are performed to demonstrate the method. The experimental results show that the method has capability of estimating the real-time 6-DOF relative pose and dealing with large pose variations.

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Design of Weld Seam Tracking Control System Based on DSP

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.55-57.1759 ◽

2011 ◽

Vol 55-57 ◽

pp. 1759-1763

Author(s):

Zhong Hu Yuan ◽

Shuo Jun Yu ◽

Xiao Wei Han

Keyword(s):

Control System ◽

Fuzzy Control ◽

Real Time ◽

Digital Signal Processor ◽

Weld Seam ◽

Tracking System ◽

Seam Tracking ◽

Real Time Control ◽

Welding Seam ◽

Weld Seam Tracking

In the process of weld seam tracking, traditional mathematical model of classical and modern control theory is hard to meet the requirement of high performance controller. This article based on the embedded digital signal processor DSP-TMS320F2812 for the field of industrial automation control.The fuzzy control technology is applied to real-time welding seam-tracking system, according to the F2812 which has the characteristics of real-time multitasking scheduling of resources and then designed the real-time control value adjustment Fuzzy-PI control system. The designed DSP real-time fuzzy control system gives full play to powerful control and signal processing ability of F2812, it can fully adapt for the controlling requirement of super-speed and high-precision.

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