• Journal of information and communication convergence engineering
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• v.10 no.4
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• pp.390-395
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• 2012

This paper describes an implementation of automatic mutual localization of swarm robots using a particle filter. Each robot determines the location of the other robots using wireless sensors. The measured data will be used for determination of the movement method of the robot itself. It also affects the other robots' self-arrangement into formations such as circles and lines. We discuss the problem of a circle formation enclosing a target that moves. This method is the solution for enclosing an invader in a circle formation based on mutual localization of the multi-robot without infrastructure. We use trilateration, which does require knowing the value of the coordinates of the reference points. Therefore, specifying the enclosure point based on the number of robots and their relative positions in the coordinate system. A particle filter is used to improve the accuracy of the robot's location. The particle filter is operates better for mutual location of robots than any other estimation algorithms. Through the experiments, we show that the proposed scheme is stable and works well in real environments.

• Communications for Statistical Applications and Methods
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• v.10 no.3
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• pp.895-907
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• 2003

Recent demands for representing the location of multivariate data produce various multivariate medians such as Tukey median, Oja median and spatial median. They are considered as multivariate versions of the median which is widely recognized as a robust alternative to the arithmetic mean. Many studies show that those multivariate median preserve the robustness. However, the effectiveness of those medians is not fully identified. In this note the relative efficiencies of the multivariate medians are investigated in various configurations under the bivariate t-distribution. It is shown that Tukey median outperforms the others in most configurations.

• Journal of Mechanical Science and Technology
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• v.14 no.7
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• pp.782-788
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• 2000

In this paper, we present a new approach to visual feedback control using image-based visual servoing with stereo vision. In order to control the position and orientation of a robot with respect to an object, a new technique is proposed using binocular stereo vision. The stereo vision enables us to calculate an exact image Jacobian not only around a desired location but also at other locations. The suggested technique can guide a robot manipulator to the desired location without providing a priori knowledge such as the relative distance to the desired location or the model of an object even when the initial positioning error is large. This paper describes a model of stereo vision and how to generate feedback commands. The performance of the proposed visual servoing system is illustrated by experimental results and compared with conventional control methods for an assembly robot.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.11
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• pp.883-887
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• 2016

Navigating an unknown environment is a challenging task for a robot, especially when a large number of obstacles exist and the odometry lacks reliability. Pose tracking allows the robot to determine its location relative to its previous location. The ICP (iterative closest point) has been a powerful method for matching two point clouds and determining the transformation matrix between the maps. However, in a situation where odometry is not available and the robot moves far from its original location, the ICP fails to calculate the exact displacement. In this paper, we suggest a method that is able to match two different point clouds taken a long distance apart. Without using any odometry information, it only exploits the features of corner points containing information on the surroundings. The algorithm is fast enough to run in real time.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.1
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• pp.9-14
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• 2006

This paper presents methods of robot localization using recent radio frequency identification technology. If the absolute position and orientation of a tag are given in an indoor environment where RFID tags are installed, a robot can estimate its location using the relationship of the identified tag and the robot in a relative coordinate. To derive this relationship, we propose three estimation techniques using a model of a RFID reader, the direction of identification and the detection range. In this algorithm, a suitable estimation method is selected out of the three proposed techniques depending on the situations and trajectory of robot in the detection range. Simulation and experimental results show that the proposed methods can provide good performance for localization.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.8
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• pp.750-757
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• 2012

This paper focuses on human adaptive HVAC system that can regulate the thermal comfort of the resident in intelligent buildings. The thermal comfort is represented in this paper by PMV (Predicted Mean Vote) as defined by ISO 7730. This PMV value indicates how hot or cold a resident feels by considering temperature, humidity, resident's metabolic rate, relative air velocity, and clothing insulation. In order to develop such a system, a location detection system based on ZigBee module was used along with temperature sensors, other environment sensors. The human adaptive HVAC system was evaluated experimentally on a test bed emulating a room.

• Journal of Industrial Technology
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• v.9
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• pp.67-77
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• 1989

This study is concerned with the accuracy, the pattern of error with which subjects can interpolate the location of a pointer or a target between two graduation markers with various size on CRT display. Stimuli were graphic images on CRT with a linear, end-marked, ungraduated scales having a target for t base-line sizes. The location of a target is estimated in units over the range 1-99. Smallest error of estimates was at the near ends and middle of the base-line. The median error was less 2 units, modal error was 1, and most error(;99.6%) was within 10. Subjects had a more tendency to overestimate than to underestimate at the left-part of base-line in all siges, and an opposite tendency at the right-part. A proper size to minimize the interpolation error exists such that size 500. It is suggested that interpolation of fifths and even tenths will give a reguired accuracy for certain situations, and relative location and base-line size has a relevant attribute to interpolate.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.71-72
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• 2014

This paper presents a method to find the fault location on the DC cables for the HVDC transmission systems which utilizes a hybrid topology of the diode rectifier and the voltage-source converter (VSC) in the wind farm (WF) side. First, the DC-cable fault occurring in this HVDC system is analyzed in detail. Then, the DC-cable fault location is detected from the two relative voltages located on the same section of the cable, which are estimated from a pair of DC-cable voltage and current measurements. The effectiveness of the method is verified by the simulation results.

• Nuclear Engineering and Technology
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• v.53 no.10
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• pp.3256-3263
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• 2021

The main steam line break accident is an essential initiating event of the pressurized water reactor. In present work, the fuzzy set theory and the signal-based fault detection method has been used to detect the occurrence and diagnosis of the location and break area for the small scale MSLB. The models are validated by the AP1000 accident simulator based on MAAP5. From the test results it can be seen that the proposed approach has a rapid and proper response on accident detection and location diagnosis. The method proposed to evaluate the break area shows good performances for small scale MSLB with the relative deviation within ±3%.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.238-243
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• 1998

This paper presents a new approach to visual servoing with the stereo vision. In order to control the position and orientation of a robot with respect to an object, a new technique is proposed using a binocular stereo vision. The stereo vision enables us to calculate an exact image Jacobian not only at around a desired location but also at the other locations. The suggested technique can guide a robot manipulator to the desired location without giving such priori knowledge as the relative distance to the desired location or the model of an object even if the initial positioning error is large. This paper describes a model of stereo vision and how to generate feedback commands. The performance of the proposed visual servoing system is illustrated by the simulation and experimental results and compared with the case of conventional method fur a SCARA robot.