• Journal of the Institute of Convergence Signal Processing
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• v.24 no.4
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• pp.192-198
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• 2023

This paper proposes an algorithm for autonomous mobile robots to effectively navigate obstacles. In order to detect obstacles infrared sensors and cameras are employed. The infrared sensor is utilized to calculate the distance to obstacles while the captured images from the camera are used to determine the width of obstacles. To compute obstacle width, binary image processing, contour detection, and the minimum area rectangle technique are employed. Using the distance to obstacles and obstacle width, the avoidance angle is calculated, and this angle is incorporated into steering control. The proposed obstacle avoidance algorithm was implemented on an autonomous robot, and experimental results demonstrated a maximum reduction in avoidance time by 8.5 seconds compared to using only infrared sensors when the obstacle width is 30cm.

• Proceedings of the IEEK Conference
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• 2000.11d
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• pp.73-76
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• 2000

A Scene Based Technique(SBT) that corrects linear array infrared detector's nonuniformity is proposed. Basically, this technique dispenses with using temperature references on a linear array infrared detector. To correct the nonuniformity of infrared images, we use three methods. Firstly, we detect bad channels by using the information which is cumulated all the same line pixels. Secondly, a variable window method is applied to compensate more accurately. Thirdly, an adaptive method which updates gain and offset coefficient is used only on a stationary region. These results are demonstrated on a computer simulation with various images. As a result, the nonuniformity is corrected completely, so that images are enhanced and PSNR(peak signal to noise ratio) is improved much.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.4
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• pp.77-84
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• 2015

PZT ceramics, usually used pyroelectric materials exhibited a relatively highly Curie temperture(Tc) of $250-450^{\circ}C$ and permittivity constant of 500-1600. In this paper, the pyroelectric infrared detectors are applied two different types of pyroelectric materials, that is tetragonal crystal of ferroelectric $PbTiO_3$ and rhombohedral crystal of $Pb(Zr,Ti)O_3$. PZT ceramics shows not only highly Curie temperture but also excellent pyro and piezoelectric properties at the Zr/Ti(=52/48) ratio. Therefor in this paper, the pyroelectric infrared detectors are applied PZT ceramics, and obtained sensitive sensing characteristics by expriment case studies.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.10
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• pp.991-996
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• 2010

In this paper, a new indoor positioning system based on incident angle measurement of infrared sensor has been suggested. Though there have been various researches on indoor positioning systems using vision sensor or ultrasonic sensor, they have not only advantages, but also disadvantages. In a new positioning system, there are three infrared emitters on fixed known positions. An incident angle sensor measures the angle differences between each two emitters. Mathematical problems to determine the position with angle differences and position information of emitters has been solved. Simulations and experiments have been implemented to show the performance of this new positioning system. The results of simulation were good. Since there existed problems of noise and signal conditioning, the experimented has been implemented in limited area. But the results were acceptable. This new positioning method can be applied to any indoor systems that need absolute position information.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.58.2-58.2
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• 2015

We present a library of high spectral resolution (R ~ 40,000) and high signal-to-noise ratio (S/N ~ 200) near-infrared spectra of ~50 late-type stars. The spectra of late-type stars were obtained with Immersion GRating INfrared Spectrograph (IGRINS) covering the full H and K band. The stars are mainly from MK standard stars which have well-defined spectral types and luminosity classes and cover wide ranges of effective temperatures and surface gravities. The spectra are corrected for telluric absorption lines and absolutely flux calibrated using the Two Micron All Sky Survey (2MASS) photometry. In this work, we present the preliminary results of spectroscopic diagnostics for stellar physical parameters. Our ultimate goal is to provide a library of near-infrared spectra of standard stars, which covers all spectral types and luminosity classes, with a high spectral resolution and high signal-to-noise ratio.

• Journal of KIISE
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• v.44 no.4
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• pp.411-416
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• 2017

The spectral radiance received by an infrared (IR) sensor is mainly influenced by the surface temperature of the target itself. Therefore, the precise temperature prediction is important for generating an IR target image. In this paper, we implement the combined three-dimensional surface temperature prediction module against target attitudes, environments and properties of a material for generating a realistic IR signal. In order to verify the calculated surface temperature, we are using the well-known IR signature analysis software, OKTAL-SE and compare the result with that. In addition, IR signal modeling is performed using the result of the surface temperature through coupling with OKTAL-SE.

• Journal of the Institute of Convergence Signal Processing
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• v.3 no.4
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• pp.74-78
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• 2002

For human detecting pyroelectric infrared sensor system using more than 2 sensor devices. By new top and bottom electrode design, 1 sensor can sensing human instead of using 2 sensor system. The poled P(VDF/TrFE) film used for sensor pyroelectric materials. The fabricated sensors NEP (noise equivalent power) and specific detectivity D$^*$ of the device were 9.62 $\times$ 10$10^5$ V/W, 3.95 $\times$ 10$10^-175$ W and 5.06 $\times$ 10$10^5$W under emission energy of 13 ${\mu}W/cm^2$ respectively and It's result is almost same result that using more than 2 sensor system for human detecting.

• Journal of the Institute of Convergence Signal Processing
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• v.18 no.1
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• pp.25-30
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• 2017

Currently, most of the grain sorter uses CCD optic camera to find defective products. The aim of this paper is to use the CCD camera, and aim for improving the sorting power of the grain separator by using NIR(Near Infrared Radiation) sensor based on moisture content measurement algorithm. We intend to develop a system to develop an NFC imaging system in real time by developing an NIR imaging system and developing the grain sorter system that is considered to be defective in real time by checking the internal moisture content of the raw material in the real time.

• Current Optics and Photonics
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• v.3 no.1
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• pp.33-39
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• 2019

We report development of a frequency-stabilized mid-infrared continuous-wave (cw) optical parametric oscillator (OPO) based on a fan-out grating MgO:PPLN crystal pumped at 1064 nm. The OPO resonator was designed as a pump-enhanced standing-wave cavity that resonates to the pump and signal beams. To realize stable operation of the OPO, we applied a modified Pound-Drever-Hall technique, which is a well-known method for powerful laser frequency stabilization. Tuning a poling period of the fan-out grating of the crystal allows wavelength-tunable OPO outputs from 1510 nm to 1852 nm and from 2500 nm to 3600 nm for signal and idler beams, respectively. At the idler wavelengths of 2500 nm, 3000 nm and 3500 nm, we achieved more than 50 mW of output powers at a pumping power of 1.1 W. The long-term stability of the OPO was confirmed by recording the power and wavelength variations of the idler for an hour.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.5
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• pp.387-391
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• 2011

A uncooled infrared ray sensor used in an infrared thermal imaging detector has many advantages. But because the uncooled infrared ray sensor is made by MEMS (micro-electro-mechanical system) process variation of offset is large. In this paper, to solve process variation of offset a ROIC for uncooled infrared ray sensor that has process variation of offset compensation technique using differential delta sampling and reference signal compensation circuit was proposed. As a result of simulation that uses the proposed ROIC, it was possible to acquire compensated output characteristics without process variation of offsets.