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Acta Aeronautica et Astronautica Sinica ›› 2024, Vol. 45 ›› Issue (18): 429722.doi: 10.7527/S1000-6893.2023.29722

• Material Engineering and Mechanical Manufacturing • Previous Articles    

Three-dimensional measurement method of geometric morphology in laser metal deposition forming process using ultraviolet structured light

Zeyu SONG1, Junpeng XUE1(), Zhichao XU1, Wenbo LU1, Min WANG2, Ran JIA1, Changzhi YU3   

  1. 1.School of Aeronautics and Astronautics,Sichuan University,Chengdu  610065,China
    2.Department of Intelligent Manufacture,Institute of Automation of China Weapons and Equipment Group,Mianyang  621000,China
    3.The Institute of Machinery Manufacturing Technology,China Academy of Engineering Physics,Mianyang  621999,China
  • Received:2023-10-13 Revised:2023-11-07 Accepted:2023-12-25 Online:2023-12-28 Published:2023-12-26
  • Contact: Junpeng XUE E-mail:jpxue@scu.edu.cn
  • Supported by:
    Sichuan Science and Technology Program(2023YFG0181);The Ministry of Education’s “Chunhui Plan” Collaborative Research Project(2020703-8)

Abstract:

Laser metal deposition technology in the field of metal additive manufacturing has the application environment of strong light and radiation, which leads to the lack of means to obtain the 3D information of real-time geometric morphology of parts. To observe the forming process of metal layered discrete stacking, a real-time measurement method based on ultraviolet structured light for the measurement of three-dimensional geometric information in laser metal deposition forming process was proposed. Firstly, the radiation wavelength of metal powder under the action of laser and the ambient interference light such as laser were analyzed. Then the narrow-band interference free optical path in the optional UV band and jittered binary fringe grating are designed to ensure high-quality modulated fringe images. Secondly, the Fourier transform method is used to filter the fundamental frequency information of the object surface modulation in the frequency domain. The wrapped phase information is obtained through the inverse Fourier transform, and the absolute phase calculation is realized with the flood filling algorithm. Finally, according to the principle of stereo vision, the phase is used as dense matching auxiliary information to achieve high-precision 3D data calculation. In the real environment of metal additive manufacturing, the three-dimensional measurement average error of the proposed method is verified to be less than 0.1 mm through the measurement of standard parts. The observation experiments on the printing process of metal parts show that this method can be used to observe the changes of geometric information within and between the layers in the forming process of additive manufacturing. The results also show that this method can meet the online dimension measurement and analysis requirements for layer thickness accumulation process ranging 0.2-1.0 mm during the forming of parts. Consequently, it provides detailed intermediate data support for real-time closed-loop feedback and internal defect mechanism analysis of laser metal deposition technology.

Key words: three-dimensional measurement, metal additive manufacturing, fringe structured light, binocular vision, phase analysis

CLC Number: