• Journal of the Korean Society for Precision Engineering
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• v.16 no.7
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• pp.40-50
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• 1999

Recently, a laser displacement sensor is widely used for the manufacturing automation. The sensor is generally composed of a diode laser and a light receiving device. The diode laser emits a laser beam and the receiving device detects the light reflected from the measured object. The object position is obtained based upon triangulation method. As a light receiving device, a PSD is usually utilized since its structure is very simple and rugged and has a high accuracy. Although the theoretical relationship for this sensor had been developed, the characteristics of the sensor have not been much experimentally studied. In this paper, several experimental results will presented. The measurement accuracy is affected by the surface conditions such as the reflectance characteristics, the angle of the object's surface and the laser intensity. In addition, it is found that the PSD and the signal processing circuit have nonlinearities and showed that those nonlinearities can be reduced by controlling the emitting laser intensity.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.324-329
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• 2002

Generally, the laser vision sensor makes it possible design a highly reliable and precise range sensor at a low cost. When the laser vision sensor is applied to lap joint welding, however, there are many limitations. Therefore, a specially-designed hardware system has to be used. However, if the multi-lines are used instead of a single line, multi-range data can be generated from one image. Even under a set condition of 30fps, the generated 2D range data increases depending on the number of lines used. In this study, a laser vision sensor with a multi-line pattern is

• International Journal of Korean Welding Society
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• v.2 no.2
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• pp.57-60
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• 2002

Generally, the laser vision sensor makes it possible design a highly reliable and precise range sensor at a low cost. When the laser vision sensor is applied to lap joint welding, however. there are many limitations. Therefore, a specially-designed hardware system has to be used. However, if the multi-lines are used instead of a single line, multi-range data .:an be generated from one image. Even under a set condition of 30fps, the generated 2D range data increases depending on the number of lines used. In this study, a laser vision sensor with a multi-line pattern is developed with conventional CCD camera to carry out high speed seam tracking in lap joint welding.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.3
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• pp.268-274
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• 2013

In this paper, the performance analysis of optics-based sensor node localization using ToF (Time of Flight) scheme is conducted. Generally, the position of the sensor node is calculated on the base station. And the base station scans neighboring sensor nodes with a laser. The laser which is reflected from one sensor node, however, can be reached to the base station at different angles according to the scanning resolution. This means that the error of the reached angle can increase and one node may be recognized as different nodes. Also the power of laser can decrease because the laser signal spread. Thus the sensor node which is located at a long distance from the base station cannot be detected. In order to overcome these problems which can be occurred in localization using ToF, the beam spot, the scanning resolution, the size of reflector and the power of laser at the sensor node were analyzed. It can be expected that the consequence of analysis can be provided in acquisition of accurate position of sensor node and construction of optics-based sensor node localization system.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.213-213
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• 2000

A sensor system which can measure the transmittance of ITO(Indium Tin Oxide) layed glass is proposed. The sensor system includes a single wavelength laser beam source, photo diodes and electronic circuit processing sensor signal. The wavelength of laser is 543.5 m, this is most sensitive wavelength to photopic and scotopic vision. We applied the sensor to measure transmittance of ITO layer on general manufacturing environment and verified the effectiveness of sensor through experimental measurement.

• 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.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.600-602
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• 2005

Recently image display devices have become large and high quality. To control the qualities of the component, measurements of the shape and thickness of a plate glass has been required. In order to measure the shape of the specular objects, Non-Contact Optical Sensor using Hologram laser unit was proposed. The sensor has a optical system that is composed of a Hologram laser and objective lens used for CD Player, and the sensor showed high performance for measuring the shape and thickness of transparent plates. In the sensor, the temperature of the sensor body is controlled by TEC(Thermoelectric Cooler). In this paper, we proposed the measuring method to make better performance of sensor using focus error signal of a hologram laser unit. It can measure the shape and the thickness of transparent objects with the s-type focus error signal which is generated by the sensor while it goes to the object.

• Journal of Welding and Joining
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• v.21 no.2
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• pp.102-110
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• 2003

A visual sensor consisted of polygonal mirror, laser, and CCD camera was proposed to measure the distance to the weld joint for recognizing the joint shape. To scan the laser beam of the sensor onto an object, 8-facet polygonal mirror was used as the rotating mirror. By locating the laser and the camera at axi-symmetrical positions around the mirror, the synchronized-scan condition could be satisfied even when the mirror was set to rotate through one direction continuously, which could remove the inertia effect of the conventional oscillating-mirror methods. The mathematical modelling of the proposed sensor with the optical triangulation method made it possible to derive the relation between the position of an image on the camera and the one of a laser light on the object. Through the geometrical simulation of the proposed sensor with the principal of reflection and virtual image, the optical path of a laser light could be predicted. The position and direction of the CCD camera were determined based on the Scheimpflug's condition to fit the focus of any image reflected from an object within the field of view. The results of modelling and simulation revealed that the proposed visual sensor could be used to recognize the weld joint and its vicinity located within the range of the field of view and the resolution. (Received February 19, 2003)

• Proceedings of the KWS Conference
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• 2005.06a
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• pp.106-108
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• 2005

The instrumented fuel irradiation test at a research reactor is needed to evaluate the performance of the developed nuclear fuel. The fuel elements can be designed to measure the center line temperature of fuel pellets during the irradiation test by using temperature sensor. The thermal sensor was composed of thermocouple and sensor sheath. Micro-laser welding technology was adopted to seal between seal tube and sensor sheath with thickness of 0.15 mm. The soundness of welding area has to be confirmed to prevent fission gas of the fuel from leaking out of the element during the fuel irradiation test. In this study, fundamental data for micro-laser welding technology was proposed to seal temperature sensor sheath of the instrumented fuel element. And, micro-laser welding for dissimilar metals between sensor sheath and seal tube was characterized by investigating welding conditions. Moreover, the micro-laser welding technology is closely related to advanced industry. It is expected that the laser material processing technology will be adopted to various a pplications in the industry.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.333-335
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• 2006

In this page, we developed the inspection system for automobile parts using the laser vision sensor. Laser vision sensor has gotten 2 dimensions information and third dimension information of laser vision camera using the vision camera. Used JIG and ROBOT for inspection position transfer. Also, computer integration system developed that control system component pal1s and manage data measurement information. Compare sensor measurement result with CAD Data and verified measurement result effectiveness taking advantage of CAD to get information of measurement object.