• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2006.11a
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• pp.123-126
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• 2006

본 논문은 자율주행차량과 로봇의 안내를 위한 자계위치인식시스템을 제안한다. 자계위치인식시스템은 자성체로부터 발생되는 자계를 측정하여 위치를 인식한다. 이러한 자계위치인식시스템에서 지구자계는 기본적인 왜란으로 작용한다. 본 논문에서는 지구자계의 영향을 제거하기 위해서 다수의 1축 자계센서 열을 구성하였으며, 자계센서 출력의 선형구간을 이용하여 정밀한 위치인식시스템을 개발하였다. 본 논문에서 제안하는 자계위치인식시스템은 실험을 통하여 그 실용성을 검증하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.342-347
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• 2002

After the industrial revolution in 20 century, the world are preparing for new revolution that is society with knowledge for a basis such as IT(Information Technology), NT(Nano Technology) and BT(Bio Technology). Recently, NT is applied to various fields that are composed of science, industry, media and semiconductor-micro technology. It has need of IT that is ultra-precision positioning technology with strokes of many hundreds mm and maintenance of nm precision in fields of ultra micro process, ultra precision measurement, photo communication part and photo magnetic memory. Performance test of servo control system that is used ultra-precision positioning system with single plane X-Y stage is performed by simulation with Matlab. Analyzed for previous control algorithm and adapted for modern control theory, dual servo algorithm is developed by minimum order observer, and stability and priority on controller are secured. Through the simulation and experiments on ultra precision positioning, stability and priority on ultra-precision positioning system with single plane X-Y stage and control algorithm are secured by using Matlab with Simulink and ControlDesk made in dSPACE

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.10
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• pp.997-1005
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• 2008

Linear motor stage is a useful device in precision engineering field because of its simple power transmission mechanism and accurate positioning. Even though linear motor stage shows fine positioning accuracy along travel axis, geometric dependent errors which relay on machining and assembling accuracy should be addressed to increase total positioning performances. In this paper, we suggests a cost effective yaw error compensation servo-system which is mounted on platform of the stage and nullify travel position dependent yaw error. This paper also provides a method of designing a sliding mode control which is robust to existing friction disturbance and model uncertainties. The reachability condition of slinding mode control for the yaw error compensating servo-system has been established. From some experimental results by using an experimental set-up, the sliding mode control showed its effective in disturbance rejection and its performance was superior to conventional linear controls.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.385-388
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• 1996

A time delay controller with state feedback is proposed for azimuth motion control of the frictionless positioning device which is subject to the variations of inertia in the presence of measurement noise. The time delay controller, which is combined with a low-pass filter to attenuate the effect of measurement noise, ensures the asymptotic stability of the closed loop system. It is found that the low-pass filter tends to increase the robustness in the design of time delay controller as well as the gain and phase margins of the closed loop system. Numerical and experimental results support that the proposed controller guarantees a good tracking performance irrespective of the variation of inertia and the presence of measurement noise.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.3 s.94
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• pp.293-299
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• 2005

This paper introduces a program by which one can perform measurement, analysis, and simulation of electro-magnetic environment which affects on vehicular AV receivers. An integrated system of EM environment collected, GPS(Global Positioning System) informations, and developed simulation program can be an important evaluating tool for the analysis of automobile AV receivers.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.5 s.248
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• pp.609-614
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• 2006

Recently linear motor has been used mainly for high speed feeding performance of machine tools. The advantages of linear motor are not only high speed but high accuracy, because it is not required the coupling and ballscrew for converting rotary to liner motion. Before applying in different moving system, the dynamometer is necessary to test the performance. In Korea, the linear motor is producing in a couple of company However, the liner motor dynamometer is not commercialized yet, like as rotary motor dynamometer. In this paper, a linear motor dynamometer is designed and manufactured using a MR damper. The dynamometer system developed in this study could be used for testing the positioning accuracy fur different loading conditions, traction forces, dynamic performance and so on.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.2 s.191
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• pp.86-94
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• 2007

In this paper, a dual stage servo mechanism has been developed for image tracking system to improve control performances such as small rise time, small overshoot, small settling time, small stabilization error etc. A secondary stage, a platform, actuated by a pair of electro-magnets is mounted on a conventional elevation gimbal. In this mechanism, the gimbal provides large range but slow motion and the platform provides small range but fast positioning. A sliding mode control is applied to the platform positioning to attain robust performances and stability in the presence of the disturbance related to dynamic coupling of the gimbal and the platform. Results from experiments illustrate that the suggested dual stage mechanism controlled by the sliding mode control is effective in improving responses and attenuating the disturbance response related with dynamic coupling.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.4
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• pp.388-394
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• 2009

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 piezoelectic 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. Therefore, thermal strain of magnetostrictive material obstructs precision position control of magnetostrictive actuator, magnetostrictive actuator is need of cooling system. In this paper, cooling system using compressed cold air is developed and proper temperature and velocity of compressed cold air is studied by thermal analysis according to applied current.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.59-60
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• 2015

Wireless power transfer is a technique that supplies the necessary power to the various electronic devices over the air without wires. The technology is classified as near-field wireless power transfer technology using inductive coupling and far-field wireless power transfer technology using antenna. In this paper, RTLS tag for high-precision positioning and wireless power transfer module was designed in order to solve the power supply problem for facility management. was designed for high-precision positioning is possible RTLS tags and wireless charging. The wireless charging pad provides the capability to charge up to four devices using he magnetic resonance system.

• Journal of the Semiconductor & Display Technology
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• v.17 no.1
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• pp.88-92
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• 2018

Currently drone industry has become one of the fast growing markets and the technology for unmanned aerial vehicles are expected to continue to develop at a rapid rate. Especially small unmanned aerial vehicle systems have been designed and utilized for the various field with their own specific purposes. In these fields the path planning problem to find the shortest path between two oriented points is important. In this paper we introduce a path planning strategy for an autonomous flight of unmanned aerial vehicles through reinforcement learning with self-positioning technique. We perform Q-learning algorithm, a kind of reinforcement learning algorithm. At the same time, multi sensors of acceleraion sensor, gyro sensor, and magnetic are used to estimate the position. For the functional evaluation, the proposed method was simulated with virtual UAV environment and visualized the results. The flight history was based on a PX4 based drones system equipped with a smartphone.