公开(公告)号：US20210197287A1

公开(公告)日：2021-07-01

申请号：US17130641

申请日：2020-12-22

Applicant: Korea Advanced Institute of Science and Technology

Inventor： Hoon SOHN ,  Ikgeun JEON ,  Peipei LIU

IPC: B22F12/90 ,  G02B27/10 ,  B22F10/28 ,  B22F10/22 ,  B22F10/30 ,  B33Y30/00 ,  B33Y50/02

Abstract: Disclosed are an integrated inspection system for a 3D printing process using a thermal image and a laser ultrasound wave and a 3D printing system having the inspection system. The inspection system includes a thermal imaging camera for creating a thermal image of a molten pool formed in a printing object when a base material supplied to the printing object is melted by a laser beam irradiated from a 3D printing laser source, a laser ultrasonic device for receiving a laser ultrasonic wave included in the laser beam reflected from the printing object, and a control unit for estimating a physical property of the printing object and detecting a defect of the printing object based on the thermal image created by the thermal imaging camera and the laser ultrasound wave received by the laser ultrasonic device. The thermal imaging camera and the laser ultrasonic device are disposed coaxially with the 3D printing laser source.

公开(公告)号：US20210197283A1

公开(公告)日：2021-07-01

申请号：US17124973

申请日：2020-12-17

Applicant: Korea Advanced Institute of Science and Technology

Inventor： Hoon SOHN ,  Ikgeun JEON ,  Peipei LIU

IPC: B22F10/85 ,  B22F10/25 ,  B22F12/41 ,  B22F12/90 ,  B22F10/36 ,  B33Y50/02 ,  G06T7/00 ,  G06T7/50

Abstract: A method of feedback controlling a 3D printing process in real time, and a system therefor are disclosed. The method includes collecting big data, generated through 3D printing experiments, related to process variables of 3D printing, measurement signals, and 3D printing quality of the 3D printing object; building an artificial neural network model by performing machine-learning based on the collected big data; evaluating whether or not a 3D printing quality of the 3D printing object is abnormal in real time based on an actual measurement signal of the 3D printing object and the artificial neural network model; and feedback controlling printing quality of the 3D printing object in real time based on the evaluation result of whether or not the 3D printing quality of the 3D printing object is abnormal.

公开(公告)号：US20160109416A1

公开(公告)日：2016-04-21

申请号：US14787127

申请日：2013-12-23

Applicant: KOREA ADVANCED INSTITUTE OF SCIENCE AND TECHNOLOGY

Inventor： Hoon SOHN ,  Hyung Jin LIM ,  Su Young YANG ,  Peipei LIU

IPC: G01N29/46 ,  G01N29/24 ,  G01B17/04

CPC classification number: G01N29/46 ,  G01B17/04 ,  G01M5/0033 ,  G01M5/0066 ,  G01N29/045 ,  G01N29/0654 ,  G01N29/2437 ,  G01N29/28 ,  G01N29/348 ,  G01N2291/01 ,  G01N2291/023 ,  G01N2291/02475 ,  G01N2291/02491 ,  G01N2291/0258 ,  G01N2291/0289 ,  G01N2291/106

Abstract: The present invention relates to a safety diagnosis method for a structure using a nonlinear ultrasonic wave modulation technique. The safety diagnosis method includes: making the structure vibrate by applying signals of different ultrasonic frequencies; converting the responses of the structure generated by the vibration into digital signals; extracting first modulation signals by subtracting the harmonic responses and the linear responses of the signals of different ultrasonic frequencies from the digital signals and synchronously demodulating the digital signals; constructing a first sideband spectrogram by combining the first modulation signals generated by continuously changing at least frequency among the signals of different ultrasonic frequencies; and deciding whether the structure is cracked based on the first sideband spectrogram. Even though the power of the ultrasonic wave applied to the structure is very small as compared with the related art, whether there is the damage is precisely decided, and thus power consumption may be reduced.

Abstract translation: 本发明涉及一种使用非线性超声波调制技术的结构的安全诊断方法。 安全诊断方法包括：通过施加不同超声波频率的信号使结构振动; 将由振动产生的结构的响应转换为数字信号; 通过从数字信号中减去不同超声波频率的信号的谐波响应和线性响应来提取第一调制信号，并同步解调数字信号; 通过组合通过在不同超声波频率的信号之间连续改变至少频率而产生的第一调制信号来构造第一边带频谱图; 并根据第一边带谱图判断结构是否破裂。 即使与现有技术相比，施加到结构的超声波的功率非常小，是否精确地确定了损伤，因此可以降低功耗。

公开(公告)号：US20210199567A1

公开(公告)日：2021-07-01

申请号：US17114647

申请日：2020-12-08

Applicant: Korea Advanced Institute of Science and Technology

Inventor： Hoon SOHN ,  Peipei LIU

IPC: G01N21/17 ,  G01N21/88 ,  B22F12/90 ,  B33Y30/00 ,  B33Y50/02

Abstract: Disclosed are a femtosecond laser-based ultrasonic measuring apparatus for a 3D printing process, and a 3D printing system including the apparatus. The apparatus includes a femtosecond laser source for generating a femtosecond laser beam irradiated to inspect a state of a printing object formed by melting a base material by a printing laser beam irradiated from the laser source for 3D printing, a beam splitter for separating the femtosecond laser beam generated by the femtosecond laser source into a pump laser beam and a probe laser beam, an electric/acoustic optical modulator for modulating the pump laser beam, a time delay unit for delaying the probe laser beam, a photo detector for detecting the probe laser beam reflected by the printing object, and a lock-in amplifier for detect an amplitude and a phase of the output signal from the photo detector. The femtosecond laser source is disposed coaxially with a laser source for 3D printing.

公开(公告)号：US20210197279A1

公开(公告)日：2021-07-01

申请号：US17128658

申请日：2020-12-21

Applicant: Korea Advanced Institute of Science and Technology

Inventor： Hoon SOHN ,  Peipei LIU

IPC: B22F10/36 ,  B22F10/25 ,  B22F12/43 ,  B33Y10/00 ,  B33Y30/00 ,  B33Y50/02 ,  G01N29/24 ,  G01N29/44 ,  G01N29/04 ,  G01B17/02 ,  G01N29/07

Abstract: Disclosed are a method of inspecting a printing quality of a 3D printing object using a femtosecond laser beam during a 3D printing process, and an apparatus and a 3D printing system for the same. A laser beam is irradiated from a femtosecond laser source disposed coaxially with a 3D printing laser source to inspect a state of the printing object. The laser beam generated by the femtosecond laser source is separated into a pump laser beam and a probe laser beam. The printing laser beam irradiated from a 3D printing laser source or the pump laser beam is irradiated onto a printing object to generate ultrasonic waves. To measure the ultrasonic waves, a probe laser beam is irradiated onto the printing object. The probe laser beam reflected by the printing object is detected. The quality of the printing object is inspected by analyzing the reflected probe laser beam.

公开(公告)号：US20230051394A1

公开(公告)日：2023-02-16

申请号：US17934004

申请日：2022-09-21

Applicant: Korea Advanced Institute of Science and Technology

Inventor： Hoon SOHN ,  Ikgeun JEON ,  Peipei LIU

IPC: B22F10/85 ,  B22F10/25 ,  B22F12/41 ,  B22F12/90 ,  B22F10/36 ,  B33Y50/02 ,  G06T7/50 ,  G06T7/00

Abstract: A method of feedback controlling a 3D printing process in real time, and a system therefor are disclosed. The method includes collecting big data, generated through 3D printing experiments, related to process variables of 3D printing, measurement signals, and 3D printing quality of the 3D printing object; building an artificial neural network model by performing machine-learning based on the collected big data; evaluating whether or not a 3D printing quality of the 3D printing object is abnormal in real time based on an actual measurement signal of the 3D printing object and the artificial neural network model; and feedback controlling printing quality of the 3D printing object in real time based on the evaluation result of whether or not the 3D printing quality of the 3D printing object is abnormal.