• International Journal of Ocean System Engineering
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• 제1권4호
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• pp.192-197
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• 2011

This paper describes the mathematical modeling, control algorithm, system design, hardware implementation and experimental test of a Manta-type Unmanned Underwater Vehicle (MUUV). The vehicle has one thruster for longitudinal propulsion, one rudder for heading angle control and two elevators for depth control. It is equipped with a pressure sensor for measuring water depth and Doppler Velocity Log for measuring position and angle. The vehicle is controlled by an on-board PC, which runs with the Windows XP operating system. The dynamic model of 6DOF is derived including the hydrodynamic forces and moments acting on the vehicle, while the hydrodynamic coefficients related to the forces and moments are obtained from experiments or estimated numerically. We also utilized the values obtained from PMM (Planar Motion Mechanism) tests found in the previous publications for numerical simulations. Various controllers such as PID, Sliding mode, Fuzzy and $H{\infty}$ are designed for depth and heading angle control in order to compare the performance of each controller based on simulation. In addition, experimental tests are carried out in a towing tank for depth keeping and heading angle tracking.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.479-483
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• 1997

In general, motor parameters can be divided into mechanical/electrical parameters and harmonic parameters. Mechanical/electrical parameters identification of motor have been studying systematically for a long time. But, systematical study on harmonic parameters analysis for efficient motor drive system are very poor. The goal of this paper is to propose analyzing method of harmonic parameters for motor drive system with various experimental graphic screens and numerical results and to develope harmonic parameters analyzer. A developed analyzer is made up 586-PC and DSP (digital signal processor) board, motor drive system, power and harmonic parameters analyzing software for windows. Harmonic parameters are analyzed using correlation signal processing techniques based on the correlation between voltage and current waveforms. Analysis results are visualized by 3-D current coordinates, and it is compared and evaluated with conventional time/frequency domain. To verify the validity of the proposed system, 1/4HP capacitor run type single phase induction motor and thyristor speed controller is used for analyzing. Harmonic parameters of motor drive system is analyzed and verified, with varying fire angle of thyristor speed controller, and the proposed approach is to confirm validity.

• Journal of Advanced Marine Engineering and Technology
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• 제21권4호
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• pp.393-403
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• 1997

In this paper, we proposed an optimal identification method of identifying the membership func¬tions and the fuzzy rules for the stabilization controller of the nonlinear system by RVEGA( Real Variable Elitist Genetic Algo rithm l. Although fuzzy logic controllers have been successfully applied to industrial plants, most of them have been relied heavily on expert's empirical knowl¬edge. So it is very difficult to determine the linguistic state space partitions and parameters of the membership functions and to extract the control rules. Most of conventional approaches have the drastic defects of trapping to a local minima. However, the proposed RVEGA which is similiar to the processes of natural evolution can optimize simulta¬neously the fuzzy rules and the parameters of membership functions. The validity of the RVEGA - based fuzzy controller was proved through applications to the stabi¬lization problems of an inverted pendulum system with highly nonlinear dynamics. The proposed RVEGA - based fuzzy controller has a swing -. up control mode(swing - up controller) and a stabi¬lization one(stabilization controller), moves a pendulum in an initial stable equilibrium point and a cart in an arbitrary position, to an unstable equilibrium point and a center of the rail. The stabi¬lization controller is composed of a hierarchical fuzzy inference structure; that is, the lower level inference for the virtual equilibrium point and the higher level one for position control of the cart according to the firstly inferred virtual equilibrium point. The experimental apparatus was imple¬mented by a DT -- 2801 board with AID, D/A converters and a PC - 586 microprocessor.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.727-729
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• 2002

In this paper, we proposed quad variable rates ADPCM coding method and its implementation on C6000 DSP, which is modified from the standard ADPCM of ITU G.726 for speech quality improvement considering the environmental noise Four coding rates, 16Kbps, 24Kbps, 32Kbps and 40Kbps are used for speech window samples and the rate decision threshold is decided by the environmental noise level. The object of the proposed method is to reduce the coding rate while retaining the speech quality and the speech quality is considerably close to 40Kbps single rate coder with the coding rate close to 16Kbps single rate coder under the environmental noise. The environmental noise level affects the coding rate and the noise level is calculated per every speech window samples. At high noise level, more samples are coded at higher rates to enhance the quality, but at low noise level, only the big speech signals are coded at higher rates and more speech samples are coded at lower coding rates to reduce the coding rates. The influence of the noise on tile speech signal is considerably high for small signals and the small signal has the higher ZCR (zero crossing rate). The method is simulated in PC and to be implemented on C6000 floating point DSP board in real time operations.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.164-167
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• 1997

The treatment setup of patients during irradiation is an important aspect in relation to the success of radiotherapy. Imaging with the treatment beam is a widely used method or verification of the radiation field position relative to the target area, prior to or during irradiation. In this paper, Real time digital radiography system was implemented or verification of local error between simulation plan and radiation therapy machine. Portal image can be acquired by CCD camera, image board and pentium PC after therapy Radiation was converted into light by a metal/fluorescent Screen. The resulting image quality is comparable to film, so the imaging system represents a promising alternative to film as a method of verifying patient positioning in radiotherapy. Edge detection and field size measurement were also implemented and detected automatically for verification of treatment position. Field edge was added to the original image or checking the anatomical treatment verification by therapy technicians. By means of therapy efficiency improvement and decrease of Radiation side effects with these techniques, Exact Radiation treatments are expected.

• 한국생산제조학회지
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• 제23권6호
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• pp.539-546
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• 2014

This paper describes an ultra-precision electronic clinometer, which is based on the capacitive-based fluid type, for detection of small inclination angles. The main parts of the clinometer low-noise electronics are two capacitance measurement circuits for converting the capacitances of the capacitors of the clinometer into voltages, and a differential amplifier for obtaining the difference of the capacitances, which is proportional to the input inclination angle. A 16 bit analog to digital (AD) converter is also embedded into the same circuit board, whose output is sent to a PC via RS-232C, for achieving a small noise level down to tens of ${\mu}v$. A compensation method, which is referred to as the delay time method for shortening the stabilization time of the sensor was also discussed. Experimental results have shown the possibility of achieving a measurement resolution of $0.0001^{\circ}$ as well as the quick measurement with the delay time method.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.834-841
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• 1996

Egg production in Korea is becoming automated with a large scale farm. Although many operations in egg production have been and cracks are regraded as a critical problem. A computer vision system was built to generate images of a single , stationary egg. This system includes a CCD camera, a frame grabber board, a personal computer (IBM PC AT 486) and an incandescent back lighting system. Image processing algorithms were developed to inspect egg shell and to sort eggs. Those values of both gray level and area of dark spots in the egg image were used as criteria to detect holes in egg and those values of both area and roundness of dark spots in the egg and those values of both area and roundness of dark spots in the egg image were used to detect cracks in egg. Fro a sample of 300 eggs. this system was able to correctly analyze an egg for the presence of a defect 97.5% of the time. The weights of eggs were found to be linear to both the projected area and the perimeter of eggs v ewed from above. Those two values were used as criteria to sort eggs. Accuracy in grading was found to be 96.7% as compared with results from weight by electronic scale.

• 한국전자파학회논문지
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• 제13권10호
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• pp.1061-1070
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• 2002

본 논문은 IS2000 환경에서 기지국의 수신 성능을 증대시키기 위한 스마트 안테나 Test-bed의 성능을 분석하였다. 따라서 본 논문에서는 IS2000 1x의 수신 신호 모델링, 빔형성 알고리즘, 빔형성 모듈 설계 및 테스트 베드를 이용한 성능 분석을 하였다. 수신 성능을 높이는 최적의 빔형성을 위해 빔형성 알고리즘은, Lagrange 공식을 이용한 Generalized Lagrange 알고리즘을 이용하였다. 이를 신호처리 칩을 이용한 보드로 직접 설계, 제작하였다. 빔형성 모듈에 대한 성능시험 결과 정상동작 확인 및 실시간 동작처리가 가능함을 보였다. 따라서 본 논문에서 제시한 스마트 안테나 Test-bed는 IS2000 이동통신 환경에서 우수한 성능을 나타낼 수 있음을 증명하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
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• pp.189-192
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• 2001

In this paper, an novel optical measuring system based on the electro-optic effect has been proposed and realized using Pockels cell with a view to detecting partial discharge taking place at the needle plane electrode. This system has the following advantages ; nonmetallic probe sensor, immune to external EMI noise and broad band response of the Pockels cell from DC to GHz. This system is constructed by He-Ne laser, Mach-Zehnder interferometer with Pockels sensor, balanced photo receiver, data acquisition board and PC. The response characteristics of the developed proto type sensor are examined for AC and corona discharge.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.223-225
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• 1994

In these days, it is widely applications of Linear Induction Motor(LIM) that used propulsion system of maglev and LIM Car. elevator. conveyor system, servo system, etc. The calibration method for, performance of LIM is more difficult than static state of one. Then we made testing system to measurement for dynamic performance of LIM and deal with data acquisition board on PC system. We try to get for the data measuring that is thrust force, braking force versus speed(r.p.m. or time) and current, voltage, frequency versus speed.