• Title/Summary/Keyword: Jeong Yag-yong

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Study of Intelligent Vision Sensor for the Robotic Laser Welding

  • Kim, Chang-Hyun;Choi, Tae-Yong;Lee, Ju-Jang;Suh, Jeong;Park, Kyoung-Taik;Kang, Hee-Shin
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.4
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    • pp.447-457
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    • 2019
  • The intelligent sensory system is required to ensure the accurate welding performance. This paper describes the development of an intelligent vision sensor for the robotic laser welding. The sensor system includes a PC based vision camera and a stripe-type laser diode. A set of robust image processing algorithms are implemented. The laser-stripe sensor can measure the profile of the welding object and obtain the seam line. Moreover, the working distance of the sensor can be changed and other configuration is adjusted accordingly. The robot, the seam tracking system, and CW Nd:YAG laser are used for the laser welding robot system. The simple and efficient control scheme of the whole system is also presented. The profile measurement and the seam tracking experiments were carried out to validate the operation of the system.

Optimizing welding parameters of laser-arc hybrid welding onto aluminum alloy via grey relational analysis (Grey relational analysis를 이용한 알루미늄 합금의 레이저-아크 하이브리드 용접조건 최적화)

  • Kim, Hang-Rae;Park, Yeong-U;Lee, Gang-Yong;Lee, Myeong-Ho;Jeong, U-Yeong;Kim, Seon-Hyeon
    • Proceedings of the KWS Conference
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    • pp.253-255
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    • 2006
  • Grey relational analysis has been carried out to develop a new approach for optimization of Nd:YAG laser and MIG hybrid welding parameters. The quality of welded material depends on welding parameters. The parameters chosen for current study include wire type, shielding gas, laser energy, laser focus, traveling speed, and wire feed rate. The welding experiments were performed on 6K21-T4 aluminum alloy sheet. Functional demands on products may vary widely depending on their use. The ultimate tensile stress, width, and penetration were chosen as the optimization criterion. Practice based on an orthogonal array which is following Taguchi's method has been progressed. Base on the results of grey relational analysis, the optimal process parameters were obtained. This integrated work was judged and it is observed that the results obtained by using the optimal parameters are much improved compared to those obtained through initial setting.

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Remote Welding of Automobile Components using CO2 Laser and Scanner (자동차 부품의 원격 레이저 용접기술)

  • Suh, Jeong;Lee, Mun-Yong;Jung, Beong-Hun;Song, Mun-Jong;Kang, Hie-Sin;Kim, Jeong-O
    • Journal of Welding and Joining
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    • v.26 no.5
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    • pp.74-78
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    • 2008
  • The laser welding of the car body and components has been spread in the automotive industry. The Nd:YAG laser welding system could be used in 3D welding with robot. However, this system cannot efficiently reduce the welding cycle time according to various welding sequences because the robot's moving time is same that of the resistant spot welding system. But the remote welding system with high power $CO_2$ laser and scanner makes it possible welding cycle time much faster than the robot laser welding system. In the $CO_2$ laser remote welding system, laser beam can be rapidly transferred to a workpiece by moving mirrors of scanner system. So, it makes reducing the cycle time of welding process and shaping various welding patterns easily. Therefore, in this paper, the characteristic of weld strength according to patterns of weld bead on $CO_2$ laser welding was investigated. Also, the relationship between shape of weld bead and value of tensile load was studied. Finally, the optimum remote welding condition for car bumper was investigated.

Two Cases of Diagnosis and Removal of Endobronchial Hamartoma by Cryotherapy via Flexible Bronchoscopy

  • Sim, Jae Kyeom;Choi, Jong Hyun;Oh, Jee Youn;Cho, Jae Young;Moon, Eul Sun;Min, Hye Sook;Lee, Byung Hyun;Park, Min Seon;Hur, Gyu Young;Lee, Sung Yong;Shim, Jae Jeong;Kang, Kyung Ho;Min, Kyung Hoon
    • Tuberculosis and Respiratory Diseases
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    • v.76 no.3
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    • pp.141-145
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    • 2014
  • Although endobronchial hamartoma is a rare benign tumor, most patients with endobronchial hamartoma have respiratory symptoms such as obstructive pneumonia, hemoptysis, cough, or dyspnea due to bronchial obstruction. It can cause irreversible post-obstructive pulmonary destruction, thus early diagnosis and treatment is very important. Recently, there have been cases of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser and electrocautery procedures for bronchoscopic treatment of malignant or benign central airway obstruction with comparable therapeutic efficacy and few complications. Bronchoscopic cryotherapy is a newly developed technique for management of central airway obstruction. Moreover, it provides diagnostic methods with improving diagnostic yield and safety. We report two cases of endobronchial hamartoma, each diagnosed and definitively treated with bronchoscopic techniques. Endobronchial biopsy and removal was successfully performed by cryotherapy via flexible bronchoscopy without notable complications. Follow-up bronchoscopic examinations excluded residual or recurrent disease.

Quantitative Elemental Analysis in Soils by using Laser Induced Breakdown Spectroscopy(LIBS) (레이저유도붕괴분광법을 활용한 토양의 정량분석)

  • Zhang, Yong-Seon;Lee, Gye-Jun;Lee, Jeong-Tae;Hwang, Seon-Woong;Jin, Yong-Ik;Park, Chan-Won;Moon, Yong-Hee
    • Korean Journal of Soil Science and Fertilizer
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    • v.42 no.5
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    • pp.399-407
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    • 2009
  • Laser induced breakdown spectroscopy(LIBS) is an simple analysis method for directly quantifying many kinds of soil micro-elements on site using a small size of laser without pre-treatment at any property of materials(solid, liquid and gas). The purpose of this study were to find an optimum condition of the LIBS measurement including wavelengths for quantifying soil elements, to relate spectral properties to the concentration of soil elements using LIBS as a simultaneous un-breakdown quantitative analysis technology, which can be applied for the safety assessment of agricultural products and precision agriculture, and to compare the results with a standardized chemical analysis method. Soil samples classified as fine-silty, mixed, thermic Typic Hapludalf(Memphis series) from grassland and uplands in Tennessee, USA were collected, crushed, and prepared for further analysis or LIBS measurement. The samples were measured using LIBS ranged from 200 to 600 nm(0.03 nm interval) with a Nd:YAG laser at 532 nm, with a beam energy of 25 mJ per pulse, a pulse width of 5 ns, and a repetition rate of 10 Hz. The optimum wavelength(${\lambda}nm$) of LIBS for estimating soil and plant elements were 308.2 nm for Al, 428.3 nm for Ca, 247.8 nm for T-C, 438.3 nm for Fe, 766.5 nm for K, 85.2 nm for Mg, 330.2 nm for Na, 213.6 nm for P, 180.7 nm for S, 288.2 nm for Si, and 351.9 nm for Ti, respectively. Coefficients of determination($r^2$) of calibration curve using standard reference soil samples for each element from LIBS measurement were ranged from 0.863 to 0.977. In comparison with ICP-AES(Inductively coupled plasma atomic emission spectroscopy) measurement, measurement error in terms of relative standard error were calculated. Silicon dioxide(SiO2) concentration estimated from two methods showed good agreement with -3.5% of relative standard error. The relative standard errors for the other elements were high. It implies that the prediction accuracy is low which might be caused by matrix effect such as particle size and constituent of soils. It is necessary to enhance the measurement and prediction accuracy of LIBS by improving pretreatment process, standard reference soil samples, and measurement method for a reliable quantification method.