• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.221-225
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• 2001

Recently, high accuracy and high precision are required in various industrial fields that are composed of semiconductor manufacturing apparatus and ultra precision positioning apparatus and information system and so on. The positioning technology is a very important one among them. This technology has been rapidly developed, its field needs for positioning accuracy to high as submicron. It is expected that accuracy with 10 nm in precision working and accuracy with 1 nm in ultra precision working are reached at the beginning of 2000s. Recently, to accomplish this positioning technology, many researches are concerned about it and make efforts it. This paper contain design technology of ultra precision 2-axis(X-Y Delta) stage for materialize to positioning accuracy with submicron, where, Delta stage is design as optimum against load and disturbance. And computer simulation is performed for stability and dynamic characteristic of Delta stage.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.6
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• pp.164-169
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• 2000

Recently, High accuracy and precision are required in various industrial field especially, semiconductor manufacturing apparatus, Ultra precision positioning apparatus, Information field and so on. Positioning technology is a very important one among them. As such technology has been rapidly developed, this field needs the positioning accuracy as high as submicron. It is expected that the accuracy of 10nm and 1nm is required in precision work and ultra precision work field, respectively by the beginning of 2000s. High speed and low vibration are also needed. This work deals with the design method and control system of Ultra precision positioning apparatus. Control performance and stability analysis were performed in advance by modeling and designing the controller with Simulink.

• Journal of Positioning, Navigation, and Timing
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• v.7 no.1
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• pp.15-24
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• 2018

This study analyzed positioning accuracy of the multi-differential global navigation satellite system (DGNSS) algorithm that integrated GPS, GLONASS, and BDS. Prior to the analysis, four sites of which satellite observation environment was different were selected, and satellite observation environments for each site were analyzed. The analysis results of the algorithm performance at each of the survey points showed that high positioning performance was obtained by using DGPS only without integration of satellite navigation systems in the open sky environment but the positioning performance of multi-DGNSS became higher as the satellite observation environments degraded. The comparison results of improved positioning performance of the multi-DGNSS at the poor reception environment compared to differential global positioning system (DGPS) positioning results showed that horizontal accuracy was improved by 78% and vertical accuracy was improved by 65% approximately.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.2
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• pp.103-112
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• 2017

Due to the large size and high complexity of modern buildings, the interest and the studies about indoor spatial information are increasing. Previous studies related to indoor spatial information were mostly about relevant technologies, and the application of indoor spatial information has been less studied. In the present study, the public administrative work areas where indoor spatial information may be applied were identified by using a modified delphi technique. And the indoor LOD (Level of Detail) and indoor positioning accuracy for indoor spatial information applications considering user requirements was established as standards for efficiently establishing and providing services. The required LOD and positioning accuracy for services was established by reestablishing indoor LOD and positioning accuracy and classifying services with reference to those. The indoor LOD was reestablished from LOD 0 to 4 by focusing on service utilization and general recognition, and the positioning accuracy was reestablished in three levels by considering the accuracy of the present positioning technology and service utilization status.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.55-66
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• 2012

In wireless sensor networks, a positioning scheme is one of core technologies for sensor applications such as disaster monitoring and environment monitoring. The One of the most positioning scheme, called DV-HOP does not consider non-uniform sensor networks that are actual distributed environments. Therefore, the accuracy of the existing positioning scheme is low in non-uniform network environments. Moreover, because it requires many anchor nodes for high accuracy in non-uniform network environments, it is expensive to construct the network. To overcome this problem, we propose a novel sensor positioning scheme using density probability models in non-uniform wireless sensor networks. The proposed scheme consists of the density probability model using the deployment characteristics of sensor nodes and the distance refinement algorithm for high accuracy. By doing so, the proposed scheme ensures the high accuracy of sensor positioning in non-uniform networks. To show the superiority of our proposed scheme, we compare it with the existing scheme. Our experimental results show that our proposed scheme improves about 44% accuracy of sensor positioning over the existing scheme on average even in non-uniform sensor networks.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.277-290
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• 2019

The demand for indoor positioning is increasing day by day. However, the widely used positioning methods today cannot satisfy the requirements of the indoor environment in terms of the positioning accuracy and deployment cost. In the existing research domain, the localization algorithm based on three-dimensional space is less accurate, and its robustness is not high. Visible light communication technology (VLC) combines lighting and positioning to reduce the cost of equipment deployment and improve the positioning accuracy. Further, it has become a popular research topic for telecommunication and positioning in the indoor environment. This paper proposes a surface centroid TOA localization algorithm based on the VLC system. The algorithm uses the multiple solutions estimated by the trilateration method to form the intersecting planes of the spheres. Then, it centers the centroid of the surface area as the position of the unknown node. Simulation results show that compared with the traditional TOA positioning algorithm, the average positioning error of the surface centroid TOA algorithm is reduced by 0.3243 cm and the positioning accuracy is improved by 45%. Therefore, the proposed algorithm has better positioning accuracy than the traditional TOA positioning algorithm, and has certain application value.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.617-620
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• 2000

Recently, High accuracy and precision are required in various industrial field especially, semiconductor manufacturing apparatus, Ultra precision positioning apparatus, Information field and so on. Positioning technology is a very important one among them. Is such technology has been rapidly developed, this field needs the positioning accuracy as high as submicron. It is expected that the accuracy of 10nm and 1nm is required in precision work and ultra precision work field, respectively by the beginning of 2000s. High speed and low vibration are also needed. This work deals with the design method and control system of Ultra precision positioning apparatus. We will examine the control performance and stability before manufacturing the real apparatus by using MATLAB SIMULINK based or pre-designed controller and system modeling.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.1
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• pp.743-750
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• 2009

Since aerial photogrammetry by analog camera began in 1972, recently, high resolution digital camera is actively introduced to improve efficiency of aerial photogrammetry. This study investigated the 3D positioning accuracy of DMC(Digital Mapping Camera) among various high resolution aerial digital cameras to be developed for photogrammetry. For the research, we installed control points in test field around Incheon, and acquired analog and digital aerial photographs. By comparing 3D positioning accuracies of analog and digital photographs, there are few difference between two cameras, and the 3D positioning accuracies of two cameras was somewhat increased in case of aerotriangulation using additional control points based on GPS/IMU EO data.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.977-981
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• 2000

Direct drive linear motors have large potential for use as high speed machine tool feed units since they can increase machining rates and improve servo accuracy by eliminating gear related machining problems. So, in this paper, characteristic of 2-axis linear motor feed unit are studied and control gain are adjusted considering positioning, velocity, acceleration and static stiffness. We confirm linear motor feed unit are affected value of control gain sensitively, because drive directly. From the experiment, this feed unit has l${\mu}{\textrm}{m}$ micro step resolution, 5.7${\mu}{\textrm}{m}$ positioning accuracy and under 60${\mu}{\textrm}{m}$ circularity.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.4
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• pp.51-56
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• 2007

Precision positioning system with magnetostrictive actuator(MA) has widely used in manufacturing devices to control the positioning accuracy to meet the high load and stroke requirements. It has many advantage in comparison with piezoelectric actuator; high force, high strain, high efficient etc. But, the performance of Terfenol-D, the commercially available magnetostrictive material, is highly dependent on the prestress, magnetic field intensity and temperature. This paper present an experimental investigation of the temperature effect on displacement characteristics of magnetostrictive actuator. In this paper, compressed cold air is proposed to improve of positioning accuracy of magnetostrictive actuator. The compressed cold air cooling system has good cooling effect Experimental results confirming the effectiveness of the proposed cooling system as high precision positioning system are also has presented in this paper.