• Journal of the Korean Society for Precision Engineering
• /
• v.11 no.6
• /
• pp.5-11
• /
• 1994

We have investigated the variation of dwell and warm-up time for effects of positioning accuracy of the CNC machine tools with an laser measuring system. Also, we strdied the effect of improvement of the positioning accuracy by variation of the temperature for hollow ball screw, which mostly used as drive mechanism of CNC machine tools. We dbtained the effectiveness of cooling effect of the new cooling system, compared with the conventional cooling system.

• Laser Solutions
• /
• v.11 no.4
• /
• pp.21-28
• /
• 2008

Remote Laser welding technology for manufacturing automotive body is studied. Laser welding and industrial robot systems are used for the robot based laser welding system. The laser system is used 1.6kW Fiber laser(YLR-1600) of IPG. The robot system is used HX130-02 of Hyundai Heavy Industry(payload : 130kg). The robot based laser welding system is equipped with laser scanner system for remote laser welding. The welding joints of steel plate and steel plate coated with zinc are butt and lapped joints. The quality test of the laser welding are through the observation the shape of bead on plate and cross-section of welding part. During past three years the laser system, 4kW Nd:YAG laser (HL4006D) of Trumpf was used and the robot system, IRB6400R of ABB (payload:120kg) was used. The new laser source, robot and laser scanner system are used to increase the processing speed and to improve the process efficiency. This paper introduces the robot based remote laser welding system to resolve the limited welding speed and accuracy of the conventional laser welding system.

• Proceedings of the Optical Society of Korea Conference
• /
• 2001.08a
• /
• pp.154-155
• /
• 2001

A laser system for therapy of cancer is proposed in this paper. In order to accuracy and statistical output control we used the constant current control method and designed the power source to protect the resonator from the over -current, rush-current and electrical fault. The most important things are the radiation type for cancer therapy in laser system, we developed the radiation type of cw, pulse, and burst pulse. The experimental result show that laser beam power increase linearly from 100mW to 300mW for input current increasing and the exposure time.

• Journal of Welding and Joining
• /
• v.32 no.4
• /
• pp.15-19
• /
• 2014

Additive manufacturing technology is taking great attentions in these days because the term 3D-printing became a hot issue as the next generation manufacturing paradigm. Especially, laser additive manufacturing is at the center of interest thanks to the accuracy compared to other heat sources. In this report, recent papers about laser additive manufacturing are analyzed and reviewed. General technology is specified into three different categories and they are laser sintering, laser melting and laser metal deposition. Similarities and differences are clearly described by detailed technologies and used materials type. Representative application examples are selected then future of this technology is expected through those applications. Additionally, market of laser additive manufacturing systems itself and application fields are also predicted based on present 3D-printing market and technical progressions.

• Journal of Power System Engineering
• /
• v.10 no.2
• /
• pp.99-103
• /
• 2006

The laser interferometer has been used for measurement of the micro displacement error. Although the laser interferometer is widely accepted as a tool for measurement of motion accuracy, the set-up procedure is time-consuming because of the strict requirement on alignment between a laser head and optic units. This paper addresses the development of a laser interferometer to measure the micro displacement for a micro machine. The portable laser interferometer which integrates a laser probe and optics, is developed for the convenient measurement. For the experiment, moving mirror set up on the micro stage. The velocity decoding board is also added to calculate doppler shift frequency directly. The output signal is obtained and analyzed by LabView. Finally experiments are found out the relation between micro displacement and output signal.

• Laser Solutions
• /
• v.2 no.1
• /
• pp.30-37
• /
• 1999

Laser-welded Tailored Blank is the hottest thing in many automobile companies. But they demand on weld quality, reproducibility, and formability. So it is the great problem of automation of laser welding process. Therefore, it is requested to construct on-line process monitoring system on high accuracy. The light which is emitted from plasma and spatter in laser welding was detected by photo-diodes. It was found that the light intensity depends on welding speed. laser power, and flow rate of assist gas. The relationship between the plasma and spatter and the weld quality can be used for on-line laser weld monitoring systems.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.3
• /
• pp.403-408
• /
• 2008

The gyroscope is the sensor for detecting the rotation in inertial reference frame and constitute the navigation system together an accelerometer. As the inertial reference equipment for attitude determination and control in the satellite, the mechanical gyroscope has been used but it bring the disturbance for mass unbalance so the disturbance give a bad influence to the observation satellite mission because the mechanical gyroscope has the rotation parts. During the launch. The mechanical gyroscope is weak in vibration, shock and has the defect of narrow operating temperature range so it need the special design in integration. Recently the low orbit observation satellite for seeking the high pointing accuracy of image camera payload accept the FOG(Fiber Optic Gyro) or RLG(Ring Laser Gyro) for the attitude determination and control. The Ring Laser Gyro makes use of the Sanac effect within a resonant ring cavity of a He-Ne laser and has more accuracy than the other gyros. It need the 1000V DC to create the He-Ne plasma in discharge tube. In this paper, the design process of the High Voltage Power Supply for RLG(Ring Laser Gyroscope) is described. The specification for High Voltage Power Supply (HVPS) is proposed. Also, The analysis of flyback converter topology is explained. The Design for the HVPS is composed of the inverter circuit, feedback control circuit, high frequency switching transformer design and voltage doubler circuit.

• International Journal of Precision Engineering and Manufacturing
• /
• v.8 no.3
• /
• pp.20-23
• /
• 2007

To calibrate precision autocollimators, the Korean Research Institute of Standards and Science (KRISS) has built a small angle generator using a laser interferometer. The system is based on a sine bar mechanism in which the angle is determined from the ratio of two lengths. The rotational angle is measured by the angle interferometer and the heterodyne laser interferometer detects the relative displacement of two retro-reflectors attached to the rotating arm. The distance between the two retro-reflectors of the laser angle interferometer is self-calibrated by an index table positioned on the rotating arm. The resolution of the system is 0.002 seconds, and the accuracy is better than 0.04 seconds within a measuring range of $\pm$1 degree. The small angle generator can also be used with an index table that can divide one circle into 1440 angles. The combined system can generate any angle over 360 degrees to an accuracy of 0.11 seconds.

• Laser Solutions
• /
• v.13 no.4
• /
• pp.14-20
• /
• 2010

Robot path generation and laser welding technology for manufacturing automotive body are studied. Laser welding and industrial robot systems are used with the robot based laser welding system. The laser system used in this study is 1.6kW Fiber laser, while the robot system is 6 axes Industrial robot (payload: 130kg). The robot based laser welding system is equipped with laser scanner system for remote laser welding. The laser source, robot and laser scanner system are used to increase the processing speed and to improve the process efficiency. The welding joints of steel plate are butt and lapped joints. The quality test of the laser welding are through the observation the shape of bead on plate and cross-section of welding part. The 3 dimensional laser welding for non-linear pipe welding line is performed. This paper introduces the robot based laser welding system to resolve the limited welding speed and accuracy of the conventional spot welding system.

• Journal of the Korean Society for Precision Engineering
• /
• v.31 no.2
• /
• pp.119-123
• /
• 2014

Recently, laser processing technologies have been developed in many different industrial fields. The laser processing technologies are widely being applied such as laser assisted machining, cladding, heat treatment and coating. In the laser modules of the laser assisted machining system, laser lens is very important for accuracy and productivity of product. As the laser beam size, shape and focusing distance change, heat input energy of preheating point can be changed, the laser module of the laser assisted machining system should be equipped with various lenses differing beam size, beam shape and focusing distance. In this study, the rotary and linear laser modules are suggested. The finite element analysis is carried out to certify the static and dynamic stabilities of the developed laser modules. Finally, the rotary and linear laser modules have been fabricated successfully using the analysis results.