• 한국공작기계학회논문집
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• 제12권2호
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• pp.53-58
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• 2003

It is very important to measure linear cycle plane positioning accuracy of NC lathe as it effects all other parts of machines machined by them in industries. If the plane positioning accuracy of NC lathe is bad, the dimension accuracy and the change-ability of works will be bad in the assembly of machine parts. In this paper, computer software systems are organized to measure linear cycle plane positioning displacement of ATC(Automatic tool changer) on zx plane of NC lathe using two linear scales. And each sets of error data obtained from the test is descriptions to plots and the results of linear cycle plane positioning errors are expressed as nutriments by computer treatment.

• 한국항공운항학회지
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• 제20권4호
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• pp.31-38
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• 2012

In this paper, requirements of GNSS receiver station installation are derived for optimizing the performance of network based GNSS precise positioning by concern of international organization(IGS, NGS) recommendation. Also a analysis method of network based GNSS precise positioning is suggested in order to evaluate the availability depending on various network configurations. To evaluate network candidates, a performance evaluation method is proposed for positioning of users according to a geometric configuration and the baseline distance. After the proposed method is used to Ochang region that is a the test area 6 network candidates are derived and the performance of positioning was analyzed. Finally, Ansung, Gongju, Eumsung, Boeun network configuration was selected as the best positioning performance. An optimal Receiving station network was selected using the proposed method.

• 동력기계공학회지
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• 제2권2호
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• pp.60-66
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• 1998

Positioning performance with a normal pneumatic positioning system, is mainly affected by friction force on the actuator and nonlinear characteristics of the control valve. We proposed a positioning system which is composed of a pneumatic actuator and high speed control valve. for accurate and speedy positioning. Driving piston on the actuator is mounted with externally pressurized air bearings to clear the friction force. This paper studies a method in order that improves positioning ability of the pneumatic positioning system considering the nonlinear characteristics of the control valve and the actuator.

• 동력기계공학회지
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• 제2권2호
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• pp.67-72
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• 1998

To improve control performance, especially positioning speed, of a pneumatic positioning system, dynamic characteristics of a control valve should be considered. In case we design controller including dynamic characteristics of a control valve, it's not easy to design controller gain using simple state feedback because degree of a control system is increased. This study designed controller using loop shaping of $H_{\infty}$ control theory for a model composed of a pneumatic actuator and a control valve, and positioning experiment using this controller was performed. As a result, it was verified that the controller is useful for high speed positioning of a pneumatic positioning system.

• Journal of Electrical Engineering and Technology
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• 제11권2호
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• pp.537-542
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• 2016

The demand for LBS (Location Based Services) is increasing in the development of communication and mobile technologies. Positioning technology is a core technology for LBS, because LBS is based on a position of each device or user. But positioning technology especially for indoor environments is getting a lot of attention. Indoor positioning errors usually occur seriously in indoor environments where APs (Access Points) are set in a very concentrated and complex arrangement. In order to reduce indoor positioning errors, we adopt DOP (Dilution of Precision) which reflects an APs configuration information. In this paper, we propose an enhanced indoor positioning method using IEEE 802.11 RSSI measurements and AP configuration information.

• 한국군사과학기술학회지
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• 제4권2호
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• pp.52-59
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• 2001

In this paper, we have proposed a capability of applying Global Positioning System(GPS) to cannon laying. High precision GPS positioning can be used for measuring precise positions and angles. Therefore, we have tested on applying GPS positioning technique to measurement of positions and angles, which related to cannon laying. First of all, we have determined a GPS reference position using various positioning methods. Then we have carried out several tests that are process of taking corner angles between neighboring two vectors. Each vector can be calculated by post/real time positioning of two GPS antennas placed on the both ends of the howitzer. The Comer Angles from Post processing(CAP) are compared with the other Corner Angles from Real time positioning(CAR). As the results, we have an agreement between CAP and CAR within 0.25 mil average, 0.29 mil standard deviation. Finally, we have discussed about the capabilities and problems in artillery arrangement using GPS.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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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 information and communication convergence engineering
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• 제8권5호
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• pp.602-607
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• 2010

Recently, one has realized that the threedimensional positioning technique used in GPS can be effectively applied to the modern two-dimensional positioning. Such a technique might has applied to the twodimensional positioning in fields of the mobile communication, eLORAN and the GPS jamming/ electronic warfare system. In the paper, we have studied on algorithms for two-dimensional positioning based on GPS Pseudorange Technique. The main works and results are summarized below. First, the linearized state equation was mathematically derived based on GPS pseudorange technique. Second, the geometry model with respect to triangles formed using unit-vectors were proposed for investigation of land-based radio positioning. Finally, the corresponding mathematical formulations for DOP values and covariance matrix were designed for two-dimensional positioning.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.286-288
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• 2005

If we are to realize the everyday benefits promised by pervasive computing and context-aware applications, we must first develop the infrastructure to provide contextual location and orientation information through pervasive computing elements. We have implement indoor positioning system to supply orientation information. We have used ultrasound in indoor positioning system for distance and orientation measurements, then propose a set of methods to calculate orientation from an array of well placed ultrasonic sensors operating in the indoor positioning system. We have design and implement a indoor positioning system using a combination of hardware and software and demonstrate end-to-end functionality of the system.

• Journal of Positioning, Navigation, and Timing
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• 제5권3호
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• pp.145-156
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• 2016

A variety of methods for indoor positioning systems have been underway to ensure the safety of emergency rescuers who are working in dangerous situations such as fire fighters. However, since most systems display locations of rescue workers in two-dimension (2D)-based maps, it is difficult for a commander located in the outside to recognize locations of rescuers inside the building intuitively. An augmented reality (AR)-based indoor positioning monitoring system can display locations of rescuer inside the building that can be seen by commanders to help intuitive recognition of positioning. To monitor AR-based indoor positioning, it is necessary to have an estimation technique of line of sight vector of observers. In the present study, an estimation technique of a line of sight vector using ultra-wide band tranceiver installed inside the indoor to trace locations is presented.