• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.06a
• /
• pp.220-220
• /
• 2009

In case of favourable irradiation conditions, the ratio of irradiation to the total irradiation went up and then the irradiation increased in the area with high angle of inclination. The study showed that on a clear day with the irradiation of more than $800[W/m^2]$, the pattern of alternating current power change in the fixed system was similar with that in the single-axis tracker. On the contrary, in case of unfavourable irradiation conditions, the ratio of diffuse irradiation to the total irradiation went up and then the horizontal irradiation increased. In the demo system, the fixed system, the single-axis tracker and the dual-axis tracker all had low generation power and similar generation pattern with each other. The study showed the generation power varied with the irradiation in the fixed system, while in the single-axis tracker and the dual-axis tracker, the amount of the generation power variation was much more than the irradiation variation. The demo system was operated from 11:00 AM to 2:00 PM for generating power, during which time, 46[%] to 56[%] of the total generation power was produced. In this study. the generation power was increased by 147[%] in the fixed system, by 136[%] in the single-axis tracker, and by 164[%] in the dual-axis tracker, and the pattern of generation power was similar with the generation power variation in the situation where the irradiation increased by 140[%] in the spring with plenty of insolation. The alternating current power was more sensitive to variation of the irradiation than to that of the surface temperature of a module. The variation of the irradiation had a more positive effect on the generation power than the type of array.

• Journal of the Korean Solar Energy Society
• /
• v.25 no.1
• /
• pp.1-10
• /
• 2005

In this paper, 150W photovoltaic system using neural network tracker is proposed, the system designed as the normal line of the solar cell always runs parallel the ray of the sun. This design can minimize the cosine loss of the system output results of solar cell are sensitive to the change of weather and insolation condition don't react rapidly to parameter condition change such as system circumstance and deterioration. To achieve precise operation of photovoltaic tracker system using method of intelligent control, Neural Network is used in the design of the photovoltaic tracker system drive. The control performance of this system drive influenced by the environment parameter such as weather condition and motor parameter variations. we used synchronous motor in this tracker and the experimental results show that the fixing system shows 10,159[Wh] and tracking system shows 12,360[Wh] electricity.

• 제어로봇시스템학회:학술대회논문집
• /
• 1998.10a
• /
• pp.53-57
• /
• 1998

Star tracker placement configuration is proposed and the properness of the placement configuration is verified for star tracker's sun avoidance angle requirement. Precision attitude determination system is successfully designed using a gyro-star tracker inertial reference system for a candidate LEO spacecraft. Elaborate kalman filter formulation for a spacecraft is proposed for covariance analysis. The covariance analysis is performed to verify the capability of the proposed attitude determination system. The analysis results show that the attitude determination error and drift rate error are good enough to satisfy the mission of a candidate spacecraft.

• Journal of IKEEE
• /
• v.21 no.3
• /
• pp.211-218
• /
• 2017

This paper proposes the self-powered solar tracker system without CPU. Conventional solar tracker system occurs the problem of cost and durability because of using CPU. In addition, this system has effects from installation site and environment. The proposed solar tracker system without CPU is possible to achieve the high efficiency because it tracks the maximum of the light source. The validity of proposed solar tracking system is verified with experiment results.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.9 no.1
• /
• pp.67-73
• /
• 2010

Finding sufficient supplies of clean energy for future is one of the society's most important challenges according to technologies. Alternative renewable energy source such as sun energy can be substituted for exceeding human energy need. The main factor affect to solar performance is a collective intensity. To enhance intensity, suitable equipment is a solar tracker. This paper presents design and evaluation of 1 layer polar motion control system for solar tracker suitable for building integrated system. To evaluation of tracking accuracy and adaptability, solar tracker with 64 links is implemented. In experimental results, the accuracy of tracking has under ${\pm}0.0287^{\circ}$ and the thickness has under 140mm.

• Journal of Institute of Control, Robotics and Systems
• /
• v.22 no.8
• /
• pp.579-584
• /
• 2016

When surgical instruments are tracked in an image-guided surgical navigation system, a stereo vision system with high accuracy is generally used, which is called optical tracker. However, this optical tracker has the disadvantage that a line-of-sight between the tracker and surgical instrument must be maintained. Therefore, to complement the disadvantage of optical tracking systems, an internal vision sensor is attached to a surgical instrument in this paper. Monitoring the target marker pattern attached on patient with this vision sensor, this surgical instrument is possible to be tracked even when the line-of-sight of the optical tracker is occluded. To verify the system's effectiveness, a series of basic experiments is carried out. Lastly, an integration experiment is conducted. The experimental results show that rotational error is bounded to max $1.32^{\circ}$ and mean $0.35^{\circ}$, and translation error is in max 1.72mm and mean 0.58mm. Finally, it is confirmed that the proposed tool tracking method using an internal vision sensor is useful and effective to overcome the occlusion problem of the optical tracker.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.506-509
• /
• 2005

An adaptive ${\alpha}-{\beta}$ tracker is proposed for tracking maneuvering targets with a track-while-scan radar system. The tracker gain is updated on-line corresponding to the adjusted process noise variance which is obtained via time averaging of the process over a sliding window. The adjusted process noise variance is used to compute the maneuverability index for the tracker gain based on the steady-state Kalman filter equation for each epoch. It is shown via simulation that the proposed approach provides robust and accurate position estimates during the target maneuver while the performance of the conventional ${\alpha}-{\beta}$ tracker is shown much degraded.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.12
• /
• pp.1-9
• /
• 2013

A standalone LED lighting system in using solar energy has been used usually less than 70W of lighting power because of a troublesome installation and maintenance. In this system, as more and more LED lighting power increases, the capacity of photovoltaic panel does proportionally, and to improve the charging efficiency of solar energy, MPPT(Maximum Power Point Tracking) techniques is used frequently, but the solar tracker is not. In this paper, a solar tracker which traces the light of the sun in varying hour to hour is studied to apply to the standalone LED lighting system. This solar tracker consists of twin axis for tracing the azimuth and altitude respectively, and it has a robust structure with safe mode to stand a strong wind. As a result of analysis, generating efficiency of the traced type has improved on the fixed one 28.84% on average.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2010.04a
• /
• pp.77-80
• /
• 2010

The demand for human security significantly promotes the development of surveillance applications using a multi-sensor integrated UAV system. For more sophisticated operations, the system should provide a sequence of images rectified in a ground coordinate system in realtime. This rectification requires accurate position and attitude of the camera at the time of exposure of each image, which can be estimated through an Aerial Triangulation process using the GPS/INS data and tie points between adjacent images. In this work, the KLT tracker is utilized to obtain the tie points. To satisfy the realtime requirements, we present an approach to speed up the tracker by supplying the initial guessed positions of tie points based on the exterior orientation. The experimental results show that, when the guessed positions are supplied, the KLT tracker consumed less computational time than the ordinary KLT which is more suitable to be incorporated into the realtime image georeferencing process.

• Proceedings of the KIEE Conference
• /
• 2009.04a
• /
• pp.43-45
• /
• 2009

In case of favourable irradiation conditions, the ratio of irradiation to the total irradiation went up and then the irradiation increased in the area with high angle of inclination. The study showed that on a clear day with the irradiation of more than 80$[W/m^2]$, the pattern of alternating current power change in the fixed system was similar with that in the single-axis tracker. On the contrary, in case of unfavourable irradiation conditions, the ratio of diffuse irradiation to the total irradiation went up and then the horizontal irradiation increased. In the demo system, the fixed system, the single-axis tracker and the dual-axis tracker all had low generation power and similar generation pattern with each other. The study showed the generation power varied with the irradiation in the fixed system, while in the single-axis tracker and the dual-axis tracker, the amount of the generation Power variation was much more than the irradiation variation. The demo system was operated from 11:00 AM to 2:00 PM for generating power, during which time, 46[%] to 56[%] of the total generation power was produced. In this study, the generation power was increased by 147[%] in the fixed system, by 136[%] in the single-axis tracker, and by 164[%] in the dual-axis tracker, and the pattern of generation power was similar with the generation power variation in the situation where the irradiation increased by 140[%] in the spring with plenty of insolation. The alternating current power was more sensitive to variation of the irradiation than to that of the surface temperature of a module. The variation of the irradiation had a more positive effect on the generation power than the type of array.