• 한국산학기술학회논문지
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• 제14권10호
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• pp.5215-5220
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• 2013

최근 건설현장에서는 3D 기피 현상으로 자동화에 대한 관심이 증대되고 있다. 본 연구는 개발된 VRS-GPS 기반 자동 측위시스템으로 해안매립지를 측량한 결과에 관한 연구이다. 자동측위시스템에 설치된 GPS는 GRX1 수신기와 SHC250 컨트롤러를 사용하였다. 자동측위시스템은 DSP모듈, 지자기센서, 블루투스, 짐벌, IMU등으로 구성되어 있으며, 입력된 위치경로로 자동주행이 가능하도록 하였다. 개발된 GPS 자동측위시스템은 전방과 구심점 관측 카메라를 설치하여 측량상황을 스마트폰으로 실시간으로 파악 할 수 있도록 하였다. 개발된 자동측위시스템을 건설현장에 적용하여 실험한 결과 평균제곱근오차는 X축에서 0.009m, Y측에서 0.010m, 높이는 0.002m로 나타났으며, 현장적용 가능성이 있음을 확인하였다.

• 한국항공우주학회지
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• 제33권9호
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• pp.73-80
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• 2005

본 논문은 피치 바이어스 모멘텀 방식을 사용하는 HAUSAT-2 위성의 모멘텀 휠 초기구동(Start-up)을 위한 방안을 연구 분석하고 초소형위성 HAUSAT-2에 적합한 새로운 초기구동 방법을 제안하였다. HAUSAT-2는 25kg급의 나노 위성으로 모멘텀 휠과 마그네틱 토커를 사용하여 3축 제어를 수행한다. 자세제어를 위해 모멘텀 휠은 공칭 속도로 회전하거나 회전속도가 변하게 된다. 모멘텀 휠을 장착한 위성에서 휠의 초기구동방법은 휠을 발사 전에 미리 일정한 속도로 회전하게 하거나, 궤도상에서 추력기와 같은 구동기로 자세를 안정화 시킨 이후에 휠을 공칭속도에 도달하게 하는 방법이 있다. 하지만 HAUSAT-2와 같은 초소형위성의 경우 전력제한으로 발사 전 휠을 구동하기 힘들며, 궤도상에서 자세 안정화 이후 휠을 구동하기 위해서는 자기토커만으로 자세를 안정화 해야 하는데 이 경우 시간이 오래 걸리는 단점이 있다. 따라서 본 논문에서는 좀더 빠르고 효율적으로 휠의 초기구동과 자세안정화를 하기 위해서 모멘텀 휠 구동 방안을 제안하였다. 이 방법은 위성이 발사체에서 분리된 후 초기 각속도 제어를 할 때 일정한 속도 증가율로 모멘텀 휠의 속도를 올려주어 공칭 속도에 도달하게 하며, 이 후 자세 안정화를 수행하게 된다. 이 방식을 사용하면 약 4 궤도 이내에 휠 초기구동과 자세 안정화를 성공적으로 이룰 수 있음을 확인 할 수 있었다.

• 한국정밀공학회지
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• 제29권8호
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• pp.863-872
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• 2012

The squareness measurement of driving axes of a machine tool is very important to evaluate the performance of the machine. Laser interferometer measurement system is one of the most reliable equipment to measure the squareness. However, squareness measurement using laser system with an optical square result in restriction of straightness optics setup and Abbe's offset. This offset combines with angular errors during the motion of an axis to cause Abbe's error. In addition, the difficulty in optical square setup causes restriction of other optics and limitation of measurable range. In this paper, mathematical approaches are presented to eliminate the Abbe's error and to estimate squareness for full range by using the best fit of straightness data measured without an optical square. Experiments for squareness measurement of 3 axis machine tool were conducted and the proposed techniques were used for squareness evaluation with elimination of Abbe's error and squareness estimation for the full travel range.

• 반도체디스플레이기술학회지
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• 제14권3호
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• pp.45-50
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• 2015

This paper suggests the sensor-less speed control of PMSM (Permanent Magnet Synchronous Motor) without the position sensor of oil-free air compressor. It estimated d and q axis back electro motive force using Back-EMF (Electro motive Force) observer to control sensor-less speed of PMSM. Also it used the method that tracks the information of rotor position and speed using PLL (Phase Locked Loop) based on estimated d and q axis Back-EMF. The sensor-less speed control of PMSM for oil air compressor application is carried out with the introduced rotor position and speed tracking method. In this paper, the experimental characterization of the sensor-less drive is provided to verify the accuracy of the estimated position and the performance of sensor-less control is analyzed by results obtained from the experiment. Moreover, the potential of PMSM sensor-less drive in industrial application such as compressor drive is also examined.

• 태양에너지
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• 제19권4호
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• pp.81-91
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• 1999

The work presented here is a design and development of sun tracking system for the parabolic dish concentrator. Parabolic dish concentrator is mounted on azimuth and elevation tracking mechanism, and controlled to track the sun with computed and measured sun positions. Sun tracking mechanism is composed of 1/30000 speed reducer(3 stages) and 400W AC servomotor for each axis. The nominal tracking speed of each axis is ${\pm}0.6^{\circ}/sec$ and the system has a driving range of $340^{\circ}$ in azimuth and of $135^{\circ}$ in elevation. Sun tracking control system consists of sun sensor, wind speed and direction measurement system, AC servomotor position control system and personal computer as a master controller. Sun sensor detects the sun located within ${\pm}50^{\circ}$ measured from the sun sensor normal direction. Computer computes the sun position, sunrise and sunset times and controls the orientation of parabolic dish concentrator through the AC servomotor position control system. It also makes a decision of whether the system should follow the sun or not based on the information collected from sun sensor and wind speed and direction measurement system. The sun tracking system developed in this work is implemented for the experimental work and shows a good sun tracking performance.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2524-2528
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• 2003

High-precision position system is widely used in lots of fields such as semiconductor industry, biotechnology, display and other up-to-date industry field. One of the main issues is to have a long traveling range with precision. There are a few solutions. For instance, there are inchworm methods, lever principle. In this study, we use lever principle to amplify output displacement with a new mechanical amplification structure. We designed new type 3DOF stage with PZT actuator and capacitive sensor. Non-monolithic structure is suggested to obtain the convenience of assembly and modification. Driving parts are designed as modules that generate displacement amplification of each axis. Designed motion module consists of 3 flexure hinges and a PZT actuator with double L lever structure.

• 소음진동
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• 제10권4호
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• pp.584-595
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• 2000

We design a new actuator for high density optical device in order to control the radial tilting motion. The newly designed actuator makes it possible to control the tilting motion actively, while the coventional actuator compress tilting motion with passive spring. First of all, We present 3-dimensional modeling of actuator and accomplish the modal analysis and magnetic analysis of actuator. Due to these results, a new designed actuator has performance of high sensitivity and high second resonance frequency. Secondly, We present the 3-DOF dynamic modeling of the 4-wire spring type actuator. sensitivity analysis is performed to consider the assembling error, such as the difference of mass center and force center. From these results, the sensitivities of rotation due to the assembly error are revealed and design criteria of rotation is presented. And experimental results of a newly designed actuator are presented and compared with theoretical results. Finally, We propose a dynamic tilt compensation and high acceleration actuator for high density optical storage devices.

• 유공압시스템학회논문집
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• 제5권3호
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• pp.15-22
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• 2008

The road simulators have become common tools within the automotive industry for evaluation of vehicle and vehicle system durability performance. These simulators need appropriate input signal generation algorithms to realize the actual driving conditions due to non-linear vehicle and test rig behaviour. Although somewhat unconventional from a control standpoint, the iteration approach has proven to be a very effective method for control of complex, multiple degree-of-freedom systems where the tracking parameter is known a priori. In this paper, the road profile replication algorithm is verified by applying Belgian road to the developed road simulator. The simulation and experimental results are included to evaluate the performance of this simulator. This road simulator provides considerable savings in cost, development time, and testing risk during developing automotive components.

• 반도체디스플레이기술학회지
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• 제8권4호
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• pp.71-76
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• 2009

The clean non-contact type conveyor system for vertical transfer of large size FPD(Flat Panel Display) glasses has been installed at FPD production line just since a few years ago. The most important part of the conveyor is the 3 axis permanent magnet rollers faced orthogonally in pairs. However, the systematic design method about it has not been proposed yet. In this paper, we studied a design analysis for determining geometrical parameters of the magnetic roller by using a commercial FEM tool of the 3D Maxwell. Through a series of simulation, we obtained the relationship of several geometrical parameters affecting the torque of the conveyor.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.775-779
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• 2003

Recently, a new type actuator using multi-pole magnet has been developed for high-density and high-speed disk drive, which can be achieved higher sensitivity than a conventional actuator for applying one-pole magnet. However, it is very difficult for the actuator of multi-pole magnet to meet simultaneously the optimal design condition for reducing rolling mode effect and improving driving sensitivity because the force center is different from the mass center In this paper, First We propose the new shape coil for tracking which can reverse moment additionally in tracking motion, Next we achieve the optimal design to reduce phase disturbance and peak gain at the rolling mode frequency. Finally, the validity of the proposed methods is proved from experimental results.