Vision Control System of Pipe Welding Robot

2013 ◽  
Vol 756-759 ◽  
pp. 509-513
Author(s):  
Li Fang Tang ◽  
Chuan Jin Wang

The author of this article designs a non-track automatic pipe welding robot, which mainly studies the image processing system of visual welding tracking. With the requirement of various interference noise and tracking accuracy in the welding process, this study adopts structure light CCD sensor checking system and image acquisition card processing images of computer software, in which sample filtering, edge checking, contour tracking, laser centerlines selection and checking of its characteristics. This processing method has the advantages of good effect and speedy processing that is able to meet the timely requirement of tracking system.

Author(s):  
B-H You ◽  
J-W Kim

Many sensors, such as the vision sensor and the laser displacement sensor, have been developed to automate the arc welding process. However, these sensors have some problems due to the effects of arc light, fumes and spatter. An electromagnetic sensor, which utilizes the generation of an eddy current, was developed for detecting the weld line of a butt joint in which the root gap size was zero. An automatic seam tracking system designed for sheet metal arc welding was constructed with a sensor. Through experiments, it was revealed that the system had an excellent seam tracking accuracy of the order of ±0.2mm.


1990 ◽  
Vol 6 (04) ◽  
pp. 232-240
Author(s):  
Hans H. Vanderverldt ◽  
Sterling Johnston ◽  
Jerald E. Jones ◽  
Dawn White ◽  
B. Cleveland

Construction of a large ship requires many thousands of feet of welding. Whenever the welding process can be streamlined or automated, tremendous cost savings can be obtained. The WELDEXCELL system is a WELDing EXpert manufacturing CELL that provides computerized technical support information, off-line weld planning, and an integrated welding robot/welding system/vision system controller. The first of two subsystems, the Welding Job Planner (WJP) accomplishes off-line intelligent weld planning for both automated and manual welding processes. The second subsystem, the Welding Job Controller (WJC) provides a fully integrated hardware control environment with associated software for combined control of a welding robot, welding equipment, and a robotic vision system. In the WELDEXCELL system, a series of expert systems and databases have been combined in a new type of computer software environment called a blackboard. There are as many as 19 separate components of the Welding Job Planner subsystem of WELDEXCELL which fall into five interrelated functional groups. WELDEXCELL will be used by design engineers, welding engineers, mechanical engineers, and nondestructive testing (NDT) engineers for both manual welding and to interface to automated and robotic welding systems and vision systems. WELDEXCELL also includes the control system hardware and software to provide off-line intelligent adaptive control of the welding process itself. The development of WELDEXCELL is a multi-year effort involving a partnership of government, industry, university research, and technology transfer. The project has already generated new concepts with potential for future spin-off benefits. The ultimate payback in productivity will be large for the American welding, fabrication, manufacturing, and construction industries.


Author(s):  
G.Y. Fan ◽  
J.M. Cowley

In recent developments, the ASU HB5 has been modified so that the timing, positioning, and scanning of the finely focused electron probe can be entirely controlled by a host computer. This made the asynchronized handshake possible between the HB5 STEM and the image processing system which consists of host computer (PDP 11/34), DeAnza image processor (IP 5000) which is interfaced with a low-light level TV camera, array processor (AP 400) and various peripheral devices. This greatly facilitates the pattern recognition technique initiated by Monosmith and Cowley. Software called NANHB5 is under development which, instead of employing a set of photo-diodes to detect strong spots on a TV screen, uses various software techniques including on-line fast Fourier transform (FFT) to recognize patterns of greater complexity, taking advantage of the sophistication of our image processing system and the flexibility of computer software.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2528
Author(s):  
Songlin Bi ◽  
Yonggang Gu ◽  
Jiaqi Zou ◽  
Lianpo Wang ◽  
Chao Zhai ◽  
...  

A high precision optical tracking system (OTS) based on near infrared (NIR) trinocular stereo vision (TSV) is presented in this paper. Compared with the traditional OTS on the basis of binocular stereo vision (BSV), hardware and software are improved. In the hardware aspect, a NIR TSV platform is built, and a new active tool is designed. Imaging markers of the tool are uniform and complete with large measurement angle (>60°). In the software aspect, the deployment of extra camera brings high computational complexity. To reduce the computational burden, a fast nearest neighbor feature point extraction algorithm (FNNF) is proposed. The proposed method increases the speed of feature points extraction by hundreds of times over the traditional pixel-by-pixel searching method. The modified NIR multi-camera calibration method and 3D reconstruction algorithm further improve the tracking accuracy. Experimental results show that the calibration accuracy of the NIR camera can reach 0.02%, positioning accuracy of markers can reach 0.0240 mm, and dynamic tracking accuracy can reach 0.0938 mm. OTS can be adopted in high-precision dynamic tracking.


Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5549
Author(s):  
Ossi Kaltiokallio ◽  
Roland Hostettler ◽  
Hüseyin Yiğitler ◽  
Mikko Valkama

Received signal strength (RSS) changes of static wireless nodes can be used for device-free localization and tracking (DFLT). Most RSS-based DFLT systems require access to calibration data, either RSS measurements from a time period when the area was not occupied by people, or measurements while a person stands in known locations. Such calibration periods can be very expensive in terms of time and effort, making system deployment and maintenance challenging. This paper develops an Expectation-Maximization (EM) algorithm based on Gaussian smoothing for estimating the unknown RSS model parameters, liberating the system from supervised training and calibration periods. To fully use the EM algorithm’s potential, a novel localization-and-tracking system is presented to estimate a target’s arbitrary trajectory. To demonstrate the effectiveness of the proposed approach, it is shown that: (i) the system requires no calibration period; (ii) the EM algorithm improves the accuracy of existing DFLT methods; (iii) it is computationally very efficient; and (iv) the system outperforms a state-of-the-art adaptive DFLT system in terms of tracking accuracy.


Author(s):  
Fedor Nikolaevich Pritykin ◽  
Valeriy Ivanovich Nebritov

This article reviews the example of using a geometric model of a hypersurface in multidimensional space on the Radishchev blueprint, which reflects interconnection between the four variables in solution of one of the tasks associated with structuring the technological process fulfilled by a welding robot. In structuring technological processes related to welding, it is necessary to solve the optimization task of determining the position of the foundation of welding robot relative to the welded brackets and the axis of the container of cylindrical shape. The welding process requires finding the most optimal welding robot, the geometric model of the kinematic chain of which would move the output link and welding head across all sections of welding seams. As an example, the author reviews the case when the robot is outside the cylindrical container, and welding objects inside and outside. For carrying out the optimization task, the author examines the correlation between the parameters that determine the position of the robot relative to the container, and the minimum possible vertical displacement of the center of the output link based on the graphic optimization model.  The multicomponent system comprised of the four parameters is studied based on the Radishchev blueprint. The author drew the combinations of curves that set the framework of curve lines of the dual level of the hypersurface in the four-dimensional space. For determination of the curves, the author found the combinations of projections of the dots on the Radishchev blueprint. The use of dual level lines on the Radishchev blueprint allowed determining most optimal position of the manipulator mechanism with regards to the cylindrical surface in welding the items for various industrial robots described in this article.


2013 ◽  
Vol 419 ◽  
pp. 774-777
Author(s):  
Ji Ming Yi ◽  
Min Han

The welding direction of robot and existing problems, the groove plate is difficult to realize automatic welding robot problem, methods using laser sensor and a binocular vision system combines, image and depth information extraction plate groove groove, realize accurate 3D reconstruction.


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