• 한국산학기술학회논문지
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• 제10권7호
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• pp.1520-1525
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• 2009

본 연구는 철강 회사의 기존 크레인의 위치 제어 시스템을 USN(Ubiquitous Sensor Network)과 GPS(Global Positioning System) 시스템으로 대체하기 위한 시뮬레이션을 수행한 것이다. 크레인의 위치 제어 시스템을 지상국과 차상국의 통제 시스템으로 구분하였으며, 하드웨어 시스템은 GPS위성으로부터 크레인의 위치 제어 데이터를 수신하는 GPS 수신기 모듈, 지상국과 차상국 간 통신을 하기 위한 블루투스 통신 모듈, 크레인의 위치를 정밀하게 제어하는 초음파 센서 모듈, 크레인의 롤러를 대체한 모터, GPS 수신기 모듈과 블루투스 통신 모듈, 초음파 센서 모듈을 제어하는 임베디드 MCU (ATmega1/28L) 등으로 구성하였으며, 소프트웨어 시스템은 GPS 위성으로부터 GPS 수신기 모듈에 수신된 데이터 중 GGA 출력 문장을 필터링하기 위한 프로그램, 초음파 센서 구동프로그램, 크레인의 위치를 실시간으로 모니터링 할 수 있는 디지털 지도 프로그램 등으로 구성하였다. 제안한 시스템은 위치제어를 1cm 간격으로 정확하게 조절이 가능함을 실험을 통해 확인하였다.

• International Journal of Precision Engineering and Manufacturing
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• 제4권2호
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• pp.30-38
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• 2003

This paper proposed PID controller for torch slider and PD controller for motor right wheel. to control the motion of two-wheeled welding mobile robot with seam tracking sensor touched on welding line. The motion control is realized in the view of keeping constant welding velocity and precise seam tracking even though the target welding line is on straight line or curved line. The position and direction of the body of the mottle robot are controlled by using signal errors between seam tracking sensor and body positioning sensor attached on the end of torch slider and body side of the mobile robot, respectively. In turning motion, the body and the torch slider are controlled by using the kinematic model related with two motions of body turning and torch sliding. The straight locomotion is controlled according to eleven control patterns obtained from displacements between two sensors of the seam tracking sensor and the body positioning sensor. The effectiveness is proven through the experimental results fur lattice type welding line. Through the experimental results, we can see that the position value of the electrode end point and the welding velocity are controlled almost constantly both in straight and turning locomotion.

• 한국정밀공학회지
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• 제18권2호
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• pp.192-198
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• 2001

In this study, a methodology of synchronous control which can be applied to position synchronization of a two-axes driving system has been developed. The synchronous error is caused by model uncertainties and torque disturbance of each axis. To overcome these problems, the proposed synchronous control system has been composed of two speed controllers and one synchronous controller. The speed controllers based on PID control law are aimed at the following to speed reference. And the parameters of speed controllers have been designed in order that speed response of the second axis corresponds with one of first axis. Especially, considering to model uncertainties of each axis, the synchronous controller has been designed using H$\infty$ control theory. The controller eliminates the synchronous error by controlling speed of the second axis. The effectiveness of the proposed method has been verified through simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.309-312
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• 2002

Precision stage is essential device for semiconductor equipments, fiber optic assembly systems and micro machines. In this paper, we develop a piezo-electric inchworm type actuator for long stroke ultra precision linear stages, and implement a controller to interface with commercial motion controllers. It provides fast implementation of precise position control system substituting for rotary motor. In the future, using a laser interferometer as a position sensor, we plan to implement a nano meter precision stage.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1087-1090
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• 2004

stereo vision system is applied to a mobile manipulator for effective tasks. The robot can recognize a target and compute the position of the target using a stereo vision system. In this paper we persent a visual approach to the problem of object grasping. First we propose object recognization method which can find the object position and pose using feature points. A robot recognizes the feature point to Object. So a number of feature point is the more, the better, but if it is overly many, the robot have to process many data, it makes real-time image processing ability weakly. In other to avoid this problem, the robot selects only two point and recognize the object by line made by two points. Second we propose trajectory planing of the robot manipulator. Using grometry of between object and gripper, robot can find a goal point to translate the robot manipulator, and then it can grip the object successfully.

• 한국정밀공학회지
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• 제20권5호
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• pp.108-115
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• 2003

This paper is concerned with the development of Internet-based robot system controlled on the remote site via the Internet. In order to draw the public attention into this exciting system, we built the simple system by which a robot is moved in response to answer for the given OX quizzes. As the primary research fer Internet-based robot control, this study focuses on the development of user-friendly interface by which a beginner achieves information for a robot on the remote site from the 3D virtual simulator and the real camera image. for the compensation of Internet time delay, position prediction simulator is implemented in the user interface.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.1129-1132
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• 1995

Recently, the concept of automation is widely in shipping and unloading materials using the overhead crane for the enhanced productivity. In this regards, we designed an overhead crane that can be operated by operated by computer control system and installed this system at KAERI. In this paper, we introduce algorithms to find the 3D position, diameter, width, and rotated angle of objects such as drum, coil, and container. And the performance of the presented algorithms is tested using drum and container. The result will be useful for positoning grapple device such as spreader to objects in order to automatically grasp them.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1038-1041
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• 2003

The magnetic suspension system is used in many areas, because it has great advantages. such as no friction, no noise, no lubrication and so on, but it is a unstable system in natural. It must have a feedback control with the position is measured for a stable levitation. There are an eddy-current sensor, a capacitive sensor, an inductive sensor, and an optical sensor with a laser as the sensor which measures displacements without contact. Among them, an inductive sensor is made with lower price than others. And it has a good linearity. In this paper, a magnetic circuit leads a linear equation between an input as a displacement and an output as a voltage. Experiments establish that voltage change according to displacement is linear. This paper presents the preliminary study of an inductive position sensing for self-sensing magnetic suspension system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.75-75
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• 2000

Recently, number of navigation system using GPS and other complementary sensors has been developed to offer high-position accuracy. In this paper, an integration of GPS and Dead-Reckoning, which consists of a fiber optical gyroscope and two high-precision wheel-motor encoders for a unmanned navigation system, is presented. The main objective of this integrated GPS/DR unmanned navigation system is to provide accurate position and heading navigation data continuously for autonomous mobile robot. We propose a method for increasing the accuracy of the estimated position of the mobile robot by its DR sensors, high-precision wheel-motor encoders and a fiber optical gyroscope. We used Kalman filter theory to combine GPS and DR measurements. The performance of GPS/DR navigation system is evaluated.

• International Journal of Precision Engineering and Manufacturing
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• 제5권2호
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• pp.46-52
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• 2004

Numerous connectors are used in automobiles for transmission of electrical signals across various electro-mechanical components. The connectors must operate with high reliability in order to minimize failures due to signal degradation. In this work, the effects of contamination at the contact interface of connectors used fur automobile crankshaft position sensor on the impedance change were investigated. An experimental set-up was built to simulate the electrical signal transmitted from the sensor to the engine control unit through a connector. Output from the connector was investigated using connectors contaminated with engine block residues and water droplets. It was found that slight contamination of the connectors could lead to significant signal degradation which can lead to engine failure. Also, the effect of water in the connector altered the signal severely. However, the signal gradually regained the original state as the water evaporated from the interface.