• Journal of Biosystems Engineering
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• 제15권2호
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• pp.110-122
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• 1990

This study was undertaken to develop the feed rate control system for the head feed thresher by making use of the microprocessor and to evaluate the response of the system to a various threshing conditions. The control unit was composed of one-board microcomputer. The speed of the wet-paddy feeding chain was controlled by dc moter with PI controller. It was used the adaptive control method to maintain the constant feed rate regardless of the fed rice varieties. The sliding type potentiometer was used as the feed rate sensor, which was attached on the sheaf-holding apparatus. The mathematical models of the system components were derived and computer simulation was developed for investigating the parameters affecting on control performance and for estimating the response of the system. A one-board microcomputer-based feed rate control system developed in this study was properly functioned and assessed as adequate for the feed rate control system of the head feed thresher. Based on the simulation for the bundle feed, it was anticipated that the lower setting value of the cylinder speed(RL) is to be set higher than the limiting operational speed. In addition, the higher setting value of the cylinder speed(RH) is to be set lower than the limiting cylinder speed for threshing. The computer simulation for the continuous spread feed showed that the lower the setting value of straw layer thickness(LL) was set, the shorter the correction time. However, if too low LL may be established, the feed rate could not reach to its desired rate.

• Journal of Advanced Marine Engineering and Technology
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• 제15권2호
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• pp.53-63
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• 1991

This study suggests a new type shaft generator driven by hydraulic power suitable for small size vessels. Since the shaft generator system is very easy to be affected by disturbances such as speed variation of main engine and load variation of the generator, a robust servo control must be implemented to obtain stable electric power with constant frequency. Thus, in this study two types of controller design method-the reference following optimal control method and robust servo control method-are adopted to the controller design. In the experiment, static and dynamic characteristics of the shaft generator system according to the variation of input frequency setting, the speed variation of the pump and the load variation of the generator are investigated. From the considerations on the computer simulation results and experimental results, it is ascertained that the shaft generator system proposed in this study has good control performances.

• 대한전자공학회논문지
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• 제20권6호
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• pp.33-36
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• 1983

본 논문은 82년도 특정 연구개발 과제로서 삼성반도체통신(주)와 한국전자기술연구소가 공동으로 추진한 "16 bit 컴퓨터 시스템 개발" 프로젝트중 하드웨어 개발에 대하여 보고한다. 개발된 시스템은 IEEE 796 standard bus를 이용한 마이크로컴퓨터이다. 시스템중 개발한 CPU, 메모리 및 I/O controller board에 대하여 기술하고 시험 및 시스템 integration에 관하여 언급한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1323-1326
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• 1996

This paper describes an air conditioner control method using a fuzzy control theory. The fuzzy control method was implemented with Philips 80C552 one chip microcomputer and tested in an actual vehicle. Experiments showed that proposed control method is superior to the conventional PID control method especially in the environments with abrupt disturbance and parameter variation of the control system. Fuzzy-Based control method was proved to maintain a stable and improved temperature control in an abrupt environmental changes.

• 대한전기학회논문지
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• 제36권12호
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• pp.856-867
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• 1987

Microprocessor control of power-electronic equipment offers the possibility of improvements in manufacture, realizability, maintenance and servicing, and increased control flexibility. In this paper, simple microprocessor control with a view to approximating the polynomial equations which govern the commutation angles was consisdered. The theoretical analysis of this principle which govern the commutaton of power switches in order to cancel any predetermined harmonics and vary the fundamental rms voltage of the inverter output is described. Also the spectrum and harmonics were analyzed by HP-1000 computer. Practical aspect of the realization of a voltage controller based on a microprocessor and a suitable system for variable frequency inverter were also presented. The experimental test has been carried out on a Z-80 microcomputer and a single phase transistor inverter. The various results show the feasibility of obtainintg practically a single phase and a three phase inverter waveforms, which are highly desirable in most inverter applications.

• 대한전기학회논문지
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• 제39권2호
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• pp.164-174
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• 1990

The improvement of linearized characteistics of induction motor control system with field oriented method is presented in this paper. A fully digitally controlled induction motor driver system based on the proposed linear control condition is described. The control system consists of IBM-PC/AT microcomputer, VSI PWM Inverter, and PI controller with softwave. By controlling the torque component, the rated flux component can be kept constant, even in the transient state. It is clearly confirmed by experiment that the improvement of the vector control condition is satisfactory. A simplified control model of an induction motor similar to the model for a separately excited DC motor drive system is obtained.

• Journal of Biosystems Engineering
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• 제15권4호
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• pp.328-338
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• 1990

The objective of this study was to develop automatic systems of nutrient solution management for optimal nutrient solution environment and labor saving in water culture which enables factory crop production. In this study, an automatic control system and its driving program are developed to prepare, supply, and recover nutrient solution and to keep the optimal solution concentration level using microcomputers. Based on this study, the following conclusions are obtained: 1. The concentration measured by the system using oscillating circuit designed and built in this study, gave good agreements with the actual nutrient solution. 2. In water culture, the period of 12 hours for measuring concentration, pH, and temperature of the nutrient solution was optimum. Addition of control solution due to the decrease of the nutrient solution concentration is required in every 3 to 5 days. 3. It is estimated that the period of the whole solution change is 15 days, however, further research is needed to assure it. In addition, this period must be shortened in the future. 4. Both the hardware and software of the developed optimal nutrient solution control system in the water culture are working very well, however, it is necessary to develop a more economical one-chip micro controller to substitute for the microcomputer.

• 대한의용생체공학회:의공학회지
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• 제7권1호
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• pp.59-66
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• 1986

개발된 초음파 섹터 B-스캐너 시제품에서 프론트 엔드 하드웨어는 초음파펄스의 송신 및 수신을 담당하는 부분으로서 변환자에 펄스를 인가하는 펄스발생기, 진폭이 미약한 애널로그 신호를 처리하는 수신회로 및 기계식 섹터 탐촉자를 구동하는 조향제어회로의 3부분으로 크게 나눌 수 있다. 본 논문에서는 위 3부분의 기능 및 설계에 관하여 기술한다. 완성된 프론트 엔드 하드웨어의 특징 가운데 중요한 몇가지만 살펴보면, 링다운 시간을 감소시키는 펄스발생기를 사용하여 축방향의 해상도를 증가시켰고 시가변이득 증폭기에 필요한 제어전압을 여러 형태로 만들 수 있으며 탐촉자내에 있는 감지기의 출력파형을 기준으로 본 초음파 진단장치의 모든 시스템에 공급될 레이트 펄스를 만들어 주는 것이라고 말할 수 있다.