• Journal of Institute of Control, Robotics and Systems
• /
• v.5 no.3
• /
• pp.344-352
• /
• 1999

There has been requested to automate the welding process in shipyard due to its dependence on skilled operators and the inferior working environments. According to these demands, multiple robot welding system for sub-assembly welding line has been developed, realized and installed at Keoje shipyard. In order to realize automatic welding system, robots have to be equipped with a sensing system to recognize the position of the welding panels. In this research, a camera vision system(CVS) is developed to detect the position of base panels for sub-assembly line in shipbuilding. Two camera vision systems are used in two different stages (fitting and welding) to automate the recognition and positioning of welding lines. For automatic recognition of panel position, various image processing algorithms are proposed in this paper.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10a
• /
• pp.1036-1041
• /
• 1993

The tip of the flexible robot arm has to be controlled by the active control reducing vibration because it has residual vibration after getting to desired position. This paper presents an end-point position control of a 1-link flexible robot arm having tip mass by the PID control algorithm. The system is composed of a flexible arm with tip mass, dc servomotor and ballscrew mechanism under translational motion. The feedback signal composed of the tip displacement measured by laser sensor, estimated velocity and acceleration is used to control the base motion. Theoretical results are obtained by applying the Laplace transform and the numerical inversion method to the governing equations. After the flexible robot arm reaches to. the desired position, the residual vibration is controlled by the PID algorithm. This paper gives the simulation and experimental results of end-point responses according to changing tip-mass and arm length. And this algorithm shows good effects of reducing the residual vibration. Approximately, theoretical response is in good agreement with experimental one.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.34S no.10
• /
• pp.71-79
• /
• 1997

This paper introduces a methodology of the precise control of a mobile/task robot using visual information captured bythe camera attached at the hand of the task robot. The major problem residing in the precise control of mobile/task robot is providing an accurate and stable base for the task robot through the precise control of mobile robot. On account of uncertainties on the surface, the precise control of mobile robot is not feasible without using external position sensor. In this paper, the methodology for the precise control of mobile robot is proposed, which recognizes the position of mobile robot using the camera attached at the hand of the task robot. While the task robot is approaching to an assembly part, the position of mobile robot is measured using the line correspondence between the image capturesd by the camera and the real assembly part, and using the kinematic transformation from the hand of the task robot to the mobile robot. To verify the solidness of this method, experimental data for the measurement of camera position/orientation and for the precise control of mobile robot using measurement are shown.

• Journal of IKEEE
• /
• v.13 no.3
• /
• pp.32-38
• /
• 2009

Ultrasonic motor (USM) is a new type motor which is driven by the ultrasonic vibration of piezoelectric elements. It possess many useful features that electromagnetic motors do not have, such as low speed and high torque. However, ultrasonic motor has heavy nonlinear speed characteristics and is sensitive to the change of drive conditions. In order to solve these problems, we present a smooth position control scheme for ultrasonic motor using fuzzy logic control with human expertise and without the need of any precise mathematical model. A "smooth operation" consideration is included when constructing the fuzzy rule base in order to achieve a most smooth response. An experimental position control system is constructed to show the effectiveness of the proposed control scheme.

• Journal of the Korean Institute of Navigation
• /
• v.13 no.1
• /
• pp.1-10
• /
• 1989

Nowadays Hyperbolic Navigation System-LORAN, DECCA, OMEGA, OMEGA-is available on the ocean, and Spherical Navigation System, GPS (Global Positioning System) is operated partially. Hyperbolic Navigation System has the blind area near the base line extention because divergence rate of hyperbola is infinite theoretically. The Position Accuracy is differ from the cross angle of LOP although each LOP has the same error of quantity. GDOP(Geometric Dilution of Precisoin) is used to estimate the position accuracy according to the cross angle of LOP and LOP error. Hyperbola and ellipse are crossed at right angle everywhere. Hyperbola and ellipse are used to LOP in Rectangular Navigation System. The equation calculating the GDOP of rectangular Navigation System is induced and GDOP diagram is completed in this paper. A scheme that can improve the position accuracy in the blind area of Hyperboic Navigation System using the Rectangular Navigation System is proposed through the computer simulation.

• Physical Therapy Rehabilitation Science
• /
• v.4 no.2
• /
• pp.103-107
• /
• 2015

Objective: Pelvic floor muscles (PFMs) form the base of the abdomino-pelvic cavity and also the PFMs function is important for urinary continence. PFMs training (PFMT) is considered to be the first method for PFM dysfunction. This study demonstrated correct PFMs contraction among commonly used different contraction methods for PFMT. Design: Cross-sectional study. Methods: In this study, nineteen middle-aged (40-70 years) women participated. To evaluate PFM function, ultrasonography was used to measure the distance of the bladder base movement. The distance of the PFM movements were calculated at rest and during the other contractions. The following four different contraction methods were performed randomly: (1) PFM contraction, (2) abdominal drawing-in maneuver (ADIM), (3) anal contraction, and (4) hip adductor muscle contraction. The participants held the contraction for 3 seconds for a total of 3 times with a 30 seconds rest period between each trial. The mean of three measurements in each position were obtained and compared with that in the resting position. Results: The bladder base movement values were significantly greater when comparing PFM with ADIM and hip adductor contractions (p<0.05). The bladder base movement values were significantly greater when comparing ADIM and anal contractions with hip adductor contractions (p<0.05). Conclusions: The results of this study suggest that performing PFM contractions is the best method among the common methods for PFMT. Performing PFM contractions was more effective than the other contraction methods.

• Aerospace Engineering and Technology
• /
• v.8 no.2
• /
• pp.75-82
• /
• 2009

In order to help general users to analyze the KOMPSAT-2 data, an application of sensor modeling to commercial software was explained in this document. The sensor modeling is a basic step to extract the quantity and quality information from KOMPSAT-2 data. First, we introduced the contents and type of ancillary data offered with KOMPSAT-2 PAN image data, and explained how to use it with commercial software. And then, we applied the polynomial-base and refine RFM sensor modeling with ground control points. In the polynomial-base sensor modeling, the accuracy which is average RMSE of check points is highest when the satellite position was calculated by type of 1st order function and the satellite attitude was calculated by type of 1st order function for (Y axis), (Z axis) or constant for (X axis), (Y axis), (Z axis) in perspective center position and satellite attitude parameters. As a result of refine RFM sensor modeling, the accuracy is less than 1 pixel when we applied affine model..

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.26 no.6
• /
• pp.617-624
• /
• 2008

In general, RTK-GPS(Real Time Kinematic GPS) based on the single reference station is able to determinate the high accurate position of rover on the spot using error correction information of transmitted carrier phase from the base station via wireless modem. However, single reference station method has some weak points to decrease positioning accuracy because it must be obtained carrier phase from the each satellite continuously, allowed to transmit without obstacle and limited to short base line distance between base and rover station. This paper aims to attempt network based GPS carrier phase differential positioning using three multi reference stations to overcome the method of single reference station and RTK network is realized by real time monitoring program with Visual C++. The optimum error correction value of three multi reference stations by RTK networking is selected automatically to correct the position of rover station. In this paper, this algorithm is applied to determine sea water level using GPS buoy, and the accuracy results of water level change were analyzed and compared with each other using single and multi reference stations.

• Journal of Positioning, Navigation, and Timing
• /
• v.11 no.4
• /
• pp.369-379
• /
• 2022

In weighted k-nearest neighbor (WkNN)-based Fingerprinting positioning step, a process of comparing the requested positioning signal with signal information for each reference point stored in the fingerprint DB is performed. At this time, the higher the number of matched base station identifiers, the higher the possibility that the terminal exists in the corresponding location, and in fact, an additional weight is added to the location in proportion to the number of matching base stations. On the other hand, if the matching number of base stations is small, the selected candidate reference point has high dependence on the similarity value of the signal. But one problem arises here. The positioning signal can be compared with the repeater signal in the signal information stored on the DB, and the corresponding reference point can be selected as a candidate location. The selected reference point is likely to be an outlier, and if a certain weight is applied to the corresponding location, the error of the estimated location information increases. In order to solve this problem, this paper proposes a WkNN technique including an outlier removal function. To this end, it is first determined whether the repeater signal is included in the DB information of the matched base station. If the reference point for the repeater signal is selected as the candidate position, the reference position corresponding to the outlier is removed based on the clustering technique. The performance of the proposed technique is verified through data acquired in Seocho 1 and 2 dongs in Seoul.

• Journal of Contemporary Eastern Asia
• /
• v.15 no.2
• /
• pp.162-176
• /
• 2016

In this study, a part of the social and the economic condition of Nepali women is introduced with a short comparison to the socio-cultural position of the women of Korea. A relative definition of the condition of the past and now: this also briefly introduces the ideas of some of the Nepali women that we have collected through the questionnaire. A comparative literature reviews about the position of women in the past as well as the review of the position of women in present is made. Various articles are used for this as the method of analysis. A quantitative analysis of the status of women (Nepal) taking 24 households through the questionnaire method was done. The answers given by the women are the base for the article. However, the answers to the questionnaire are used to compare the past and the present. Analysis of the received data and their explanation through the tables and graph are done. The charts and tables are followed by a detailed explanation. Conclusively the briefing of the condition of women in both the countries, the changes that are brought or not brought by development; in their life's status and position in society, is mentioned.