• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.39-49
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• 1999

This paper describes the development of a vision-aided position and orientation recognition system for automatically adjusting electronic tuners which control the waveform by rotating variable resisters. The position and orientation recognition system estimates the center and the angle of the tuner grooves so that the main controller may correct the difference from the ideal position and thereby manipulate the variable resisters automatically. In this paper a robust algorithm is suggested which estimates the center and the angle of the tuner grooves fast and precisly from the source image with lighting variance and video noise. In the algorithm morphological filtering, 8-chain coding, and invariant moments are sequentially used to figure out image segments concerned. The performance of the proposed system was evaluated using a set of real specimens. The results indicate the system works well enough to be used practically in real manufacturing lines. If the system adopts a high speed frame grabber which enables real time image processing, it can also be applied to positioning of robot manipulators as well as automated PCB adjusters.

• Journal of IKEEE
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• v.19 no.3
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• pp.335-341
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• 2015

Recently a demand for high precision absolute position transducer is increasing in order to control thickness in steel industry. LVDT (linear variable differential transformer) is widely used to measure the absolute position in the linearly moving cylinder under poor factory environment. In this paper we implement the three phase LVDT with a high resolution of one micron and L/D (LVDT to digital) converter. First we designed U, V, and W three phase signaling using FPGA. Second a pulse output algorithm is designed for position information with A and B phase waveforms. Finally the performance is compared with previous sensors. Experiments show that the linearity deviation error is 0.009788 [mm] and the average sinusoidal THD is 0.0751%, which means 2.2% and 33% more improved result than the previous sensors respectively.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.90.6-90
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• 2002

An active stick which has the variable force-feel characteristics is developed. A combined position and force control strategy is mechanized using a 2-axis built-in force sensor and LVDT. The 2-axis force sensor which measures the stick force felt by the operator is developed by using strain gages and appropriate instrumental amplifiers. A mathematical model of the active stick dynamics is derived, and compared with the experimental results. The frictional torque of the stick due to the mechanical contacts of several parts makes the experimental frequency responses to be dependent on the magnitude of excitation signal, and the precision closed loop control to be difficult. A friction observe...

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.244-249
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• 1989

For the robot manipulator in performing precision tasks, it is indispensable that the robot utilize the various sensors for intelligence. In this paper, the hybrid position/force control method is implemented with a force/torque sensor, two personal computers, and a PUMA 560 manipulator. Two application S/W packages for edge following and peg-in-hole tasks are developed by the proposed force control algorithm. The related experimental results are then presented and discussed,

• Journal of the Korean Society for Precision Engineering
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• v.12 no.7
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• pp.169-177
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• 1995

본 논문에서 컴퓨터 하드디스크 드라이브의 헤드 위치 정밀서보제어를 위한 하드 디스크 드리아브의 구조변경을 연구하였다. 구조변경을 위하여 충격 햄머를 이용한 모두드시험을 수행하였으며, 실험에 의한 전기적인 Bode plot을 얻었다. 전기적인 Bode plot과 기계적인 주파수응답함수를 비교하여 전기적인 Bode plot에 나타나는 피크들의 원인을 규명하였고, 모우드해석을 바탕으로 Bode plot상의 피크의 크기를 줄이고 고주파영역으로 옮기기 위해서 베이스 구조물을 수정하였다. 이러한 구조변경을 통해 하드 디스크 드라이브의 헤드위치 서보제어 특성을 개선하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.566-569
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• 1993

This paper presents the design and implementation of an industrial controller for an autonomous guided vehicle(AGV) with economic sensor. A guidance scheme provides accurate tracking and achieves faster minimizing oftracking error. A sensor at the center provides the position and orientation of the vehicle relative to the track. Control laws that make use of this information have been devised to achieve accurate and fast tracking. The gains are modified on-line to achieve proper tracking. The simulation and implementation results are provided for the illustration of the implemented controller.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.3
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• pp.90-101
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• 2000

In this paper, we propose a controller for differentially steered wheeled mobile robots. The controller uses input-output linearization algorithm and artificial neural network to stabilize the dynamic model and compensate uncertainties. The proposed neural network part has 6 inputs, 1 hidden layer, 2 torque outputs and features fast online learning and good performance on structure error learning basis. Simulation results show that the proposed controller perform precisely tracking of reference path and is robust to uncertainties.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.691-694
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• 2000

In this paper, a motion control algorithm is proposed by using neural network system, which makes a robot arm successfully avoid unexpected obstacle when the robot is moving from the start to the goal position. During the motion, if there is an obstacle the vision system recognizes it. And in every time the optimization-algorithm quickly chooses a motion among the possible motions of robot. The proposed algorithm has a good avoidance characteristic in simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.715-716
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• 2008

• Journal of the Korean Society for Precision Engineering
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• v.9 no.4
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• pp.58-64
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• 1992

이 논문에서는 Hoop속에 Ball이 구르는 간단한 전기 기계 구동 장치를 고려 하였다. 이 장치의 구조는 간단하지만 원유수송선과 같은 대형 액체를 고속 수송할 때 발생되는 "liquid slop"문제를 해석하고 제어하는데 좋은 모델이 된다. 본 연구에서는 liquid slop dynamics를 언급 하였고, 이러한 시스템을 제어 하기 위하여 재래식 PID, state-feedback 알고리즘의 유용성을 검토하였고 하이브리드 제어방식을 제안하였다. 하이브리드 제어방식이 다른방식보다 성능면에서 다소 우세함을 알 수 있었다.을 알 수 있었다.