• Title/Summary/Keyword: Control Object

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A Study on the PWM Control of Hydraulic Equipment Using High Speed On-Off Valve (고속전자밸브를 사용한 유압장치의 PWM 제어에 관한 연구)

  • ;Wennmacher,G.
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.3
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    • pp.868-876
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    • 1995
  • This study deals with a position control of an electro-hydraulic servo system which consist of cylinder and high speed on-off valves operated by microcomputer. The merits of PWM control of hydraulic equipment are the robustness of the high spee on-off valve, its low price and the direct control without D/A converter. In the PWM control of high speed on-off valve, the time lag and switching time existing between the input and output signals of valve are considered as demerit points. To get analytical results, the effects of these demerits have to be clarified in detail. The object of this study is to propose a mathematical model for the behavior of high speed on-off valve and to get analytical results of this system. The dynamic characteristics of this system is examined by digital computer simulation analytically and compared with experimental results to varify the proposed mathematical model.

Experimental Studies of a Time-delayed Controller to Stabilize Image Stabilization System (영상 안정화 장치의 안정화를 위한 시간지연 제어기 설계 및 실험)

  • Park, Ju-Kwang;Bae, Young-Gul;Jung, Seul
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.1
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    • pp.58-64
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    • 2007
  • In this paper, the stabilization problem of the image stabilization system(ISS) that captures the image of an object on the ground by remote sensing is considered. The ISS should be stable under outer disturbance such as helicopter vibration for tracking line of sight. Although PID controllers are optimized for the system, disturbances cause the instability of the system. To minimize the effect of the disturbance, the time-delayed control method is used to compensate for uncertainties. Simulation studies are performed and experiments are conducted to confirm the simulation results. Performances of PID control and time-delayed control methods are compared.

Ground Speed Control of a Direct Injection Sprayer

  • Koo, T.M.;Sumner, H.R.
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1996.06c
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    • pp.500-510
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    • 1996
  • A Direct injection -mixing total -flow -control sprayer was developed and evaluated . The system provided precise application rates and minimized operator exposure to chemicals as well as providing a possibility for recycling container so f unused chemicals that can causes environmental contamination. Chemicals were metered and injected proportionally to the diluent flow rate to provide constant concentrations. The main diluent flow was varied in response to changes in travel speed. Experimental variables of the sprayer were the control interval, the sensitivity of flow regulating valve, the tolerance of control object and the sensitivity of the injection pump system. The optimal performance of the flow control system was with an average response time of 8.5 sec at an absolute steady state of error of 0.067 L/min (0.8% of flow rate). The average response time of the injection rate was -0.53 sec and the coefficient of variation (CV) of concentration was 3.2%.

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A Study on the Discrete Time Parameter Adaptive Learning Control System (이산시간 파라미터 적응형 학습제어 시스템에 관한 연구)

  • 최순철;양해원
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.13 no.4
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    • pp.352-359
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    • 1988
  • A learning control system which should have memory elements can be designed by utilizing the concept of parameter adaptation for unknown control object system parameters and regard it as a hybrid adaptive control system. A parameter adaptive learning control system applicable to a continuous time system has been already reported. Since there have been rapid developments in digital technology, it is possible to extend a continuous time parameter adaptive learning control system concept to a discrete time case. This problem is treated in this paper. Its justfication is proved and a simulation shows that this algorithms is effective.

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A Design of Hight Controller of helicopter Using Improved Neural Network (개선된 신경망을 이용한 헬리콥터 고도 제어기 설계)

  • Wang, Hyun-Min;Huh, Kyung-Moo;Woo, Kwang-Joon
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.3
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    • pp.229-237
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    • 2001
  • In this paper, we propose two design methods of neural networks controller for the height control of helicopter, one is the design of neural network controller having learning capability and the other is the design of more improved neural network controller. Through the simulation results, we show that the proposed controllers have controllers have enhanced control performance(rapid response, effectiveness and safety) than the typical neural networks controller in the height control of helicopter.

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Design of a Pole-Balancing Controller Using Neural Networks (신경회로망을 이용한 역추균형 재어기 설계)

  • 김유석;이장규
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.40 no.2
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    • pp.217-223
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    • 1991
  • Most common applications of neural networks to control problems are the automatic motor controls using the artificial perceptual function. These control mechanisms are similar to those of the intelligent and pattern recognition control of an adaptive method frequently performed by the animate nature. In this paper, the pole-balancing problem is selected as the control object and an actual cart-pole controller is implemented by a computer interfacing and demonstrated as motor control using the reinforcement learning rule. In the experiment, given a change of the main parameters of cart-pole dynamics, a comparison is made between the LQR scheme and neural network method. The neural network method exhibits a more effecftive control action in a real situation having a large uncertainty than the LQR scheme.

A study on the Development and Application of a Steam Generator Level Digital Control System for Nuclear Plants (원자력발전소의 증기발생기 수위 디지털 제어 시스템 개발 및 적용에 관한 연구)

  • 문병희;김경철
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.16 no.3
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    • pp.101-109
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    • 2002
  • It is a very difficult to control the S/G(Steam Generator) levels for not only automatic operation mode but also manual operation made by operators in case of start up or low power plants. The object of this study is to develop and applicate a DCS(Digital Control System) that process the reliable control algorithm in order to control S/G levels automatically from a start-up to full power operation mode for nuclear power plants.

Formation Control of Mobile Robot for Moving Object Tracking (이동물체 추적을 위한 이동로봇의 대형제어)

  • Oh, Young-Suk;Lee, Chung-Ho;Park, Jong-Hun;Kim, Jin-Hwan;Huh, Uk-Youl
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.4
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    • pp.856-861
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    • 2011
  • The mobile robot controller is designed to track the target and to maintain the formation at the same time. Formation control is included in mobile robot controller by extending the trajectory tracking algorithm. The dynamic model of mobile robot is used with kinematic model considering the practical physical parameters of mobile robot. The dynamic model of mobile robot transforms velocity control input of kinematic model into torque control input which is the practical control input of mobile robot. Formation controller of mobile robot is designed to satisfy Lyapunov stability by backstepping method. The designed formation controller is applied to the mobile robot for various target movements and simulated to confirm the Lyapunov stability.

A Study of the Relationship Between Perceived Health Locus of Control and Quality of Life of Cancer Patients. (암환자가 지각하는 건강통제위 성격과 삶의 질에 관한 관계연구 -방사선요법을 받는 암환자를 중심으로-)

  • Bang, Dong-Wan
    • The Journal of Korean Society for Radiation Therapy
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    • v.12 no.1
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    • pp.69-84
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    • 2000
  • It has been reported that the cancer patient's quality of life is influenced by the perceived health state, self-esteem, health locus of control, social support, whether there is a pain or not, the stage of a disease, the period of a disease, etc, and however, there has been scarcely the research into the fact at home whose cultural and social backgrounds are entire1y different from those of American and European Countries. Accordingly, the author of this thesis performed this study. considering that it is necessary to know the relations between the health locus of control which make it possible to predict the object's behavior related to health and to make plans to induce the object or patient into sound behavior and the quality of life which is closely related to the cancer patient's health, emotion, society, economy, etc. on the whole. This study, a cross-sectional one, includes 135 subjects of $in{\cdot}out$ patients registered at Y University Hospital whose age are more than 20 years, From these patients, data were collected for two weeks through the questionnaire which content concerns about the quality of life and the health locus of control. All the collected data were processed and analyzed through Student's t-test, ANOVA, and the calculation of Pearson Correlation Coefficient, using the SAS program 1. It appeared that the disposition of health locus of control was mostly inclined to the disposition of powerful other health locus of control($28.37{\pm}4.24$), then inclined to internal health locus of control($27.03{\pm}4.17$), and next to chance health locus of control($19.71{\pm}4.97$) By the way. the disposition of powerful other health locus of control appeared a tittle bit higher than internal health locus of control 2. The degree of the quality of life appeared to be 137.54 points in the average of total points and 3.11 in the average evaluation mark. It appeared that the quality of life was most significantly influenced by a factor of 'relations with neighbors' and least significantly influenced by factors of physical conditions and functions. 3. It appeared that the relation between the disposition of health locus of control and the quality of life has nothing to do with the relation between internal health locus of control and the quality of life(r=.1446, P>.05) and also with the relation between the disposition of powerful other health locus of control(r=.0385, P>.05). In conclusion, in the study it has been found out that there is no correlation between the health locus of control and the quality of life, and however it is sound to induce the cancer patient to internal health locus of control. Therefore, it is necessary that under the special circumstances, the cancer patient's behavior should be predicted, thereby inducing the patient to the sound change of his or her behavior. Also in order that the patient enjoys his or her life satisfactorily while living, It is deemed that some kind of multilateral meditation in health and treatment is necessary so that the patient can feel the relief of pain, better health, etc.

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