• Journal of Institute of Control, Robotics and Systems
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• v.16 no.1
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• pp.18-24
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• 2010

In this paper, we address an active ranging system based on laser structured light image for mobile robot application. Since the burdensome correspondence problem is avoidable, the structured light image processing has efficient computation in comparison with the conventional stereo image processing. By using a cylindrical lens in the laser generation, it is possible to convert a point laser into a stripe laser without motorized scan in the proposed system. In order to achieve robustness against environmental illumination noise, we propose an efficient integro-differential image processing algorithm. The proposed system has embedded image processing module and transmits distance data to reduce the computational burden in main control system.

• Laser Solutions
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• v.12 no.2
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• pp.11-16
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• 2009

A new profile measurement sensor was developed for remote laser welding robots. A stripe laser and a vision camera are used in the profile sensor. A simple sensor guided control scheme using the developed sensor is also introduced. The sensor can be used to guide the welding head in the remote welding application, where the working distance reaches to 450mm. In experiments, the profile measurement and the seam tracking were carried out using the developed sensor.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.1
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• pp.51-58
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• 2005

we can set laser patterns with 3D information from vision camera after projected to object with laser stripes. They are very useful for 3-Dimensional informations. We researched the laser patterns of human body projected by stripes and found out three featuring patterns and made database of patterns using Fourier descriptors to recognize the patterns of bodies. The HMM method and Fourier descriptors to recognize human body were experimented. We found out HMM method can recognize human body in more efficient rate than the other.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.652-657
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• 1991

Up to date, application areas of mobile robots have been expanded. In addition, Many types of LRF(Laser Range Finder) systems have been developed to acquire three dimensional information about unknown environments. However in real world, because of various noises (sunlight, fluorescent light), it is difficult to separate reflected laser light from these noise. To overcome the previous restriction, we have developed a new type vision system which enables a mobile robot to measure the distance to a object located 1-5 (m) ahead with an error than 2%. The separation and detection algorithm used in this system consists of pulse phase difference method and multi-stripe structured light. The effectiveness and feasibility of the proposed vision system are demonstrated by 3-D maps of detected objects and computation time analysis.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.20-20
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• 2003

We developed 30 ㎽-AlInGaN based violet laser diodes. The fabrication procedures of the laser diodes are described as follows. Firstly, GaN layers having very low defect density were grown on sapphire substrates by lateral epitaxial overgrowth method. The typical dislocation density was about 1-3$\times$10$^{6}$ /$\textrm{cm}^2$ at the wing region. Secondly, AlInGaN laser structures were grown on LEO-GaN/sapphire substrates by MOCVD. UV activation method, instead of conventional annealing, was conducted to achieve good p-type conduction. Thirdly, ridge stripe laser structures were fabricated. The cavity mirrors were formed by cleaving method. Three pairs of SiO$_2$ and TiO$_2$ layers were deposited on the rear facet for mirror coating. Lastly, laser diode chips were mounted on AlN submount wafers by epi-down bonding method. The lifetime of the laser diodes was over 10,000 hrs at room temperature under automatic power controlled condition. We expect the performance of the LDs to be improved by the optimization of the growth and fabrication process. The detailed characteristics and important issues of the laser diodes will be discussed at the conference.