• Title/Summary/Keyword: Internal Model Control

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Neural Network Based Disturbance Canceler with Feedback Error Learning for Nonholonomic Mobile Robots

  • Izumi, Kiyotaka;Syam, Rafiuddin;Watanabe, Keigo;Kiguchi, Kazuo
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2003.09a
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    • pp.443-446
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    • 2003
  • Conventional disturbance rejection methods have to derive the inverse model of a system. However, the inverse model of n nonholonomic system is not unique, because an inverse it changes depending on initial conditions and desired values. A kind of internal model control (IMC) using feedback error learning is discussed for the motion control of nonholonomic mobile robots in this paper, The present method is different from a conventional IMC whose control system consists of an inverse model, a direct model and a filter. The present disturbance rejection method need not use a direct model, where the remaining two elements are composed of the same inverse model based on neural networks.

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Distributed Control of DC Servo Motor on LonWorks-IP Virtual Device Network for Predictive and Preventive Maintenance (LonWorks-IP 가상 디바이스 네트워크상에서 예지 및 예방보전을 위한 DC 서보모터의 분산제어)

  • Song, Ki-Won
    • Journal of the Korean Society of Safety
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    • v.21 no.4 s.76
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    • pp.25-32
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    • 2006
  • LonWorks over IP(LonWorks-IP) virtual device network(VDN) is an integrated form of LonWorks device network and IP data network. In especially real-time distributed servo applications on the factory floor, timely response is essential for predictive and preventive maintenance. The time delay in servo control on LonWorks-IP based VDN has highly stochastic nature. LonWorks-IP based VDN induced transmission delay deteriorates the performance and stability of the real-time distributed control system and can't give an effective preventive and predictive maintenance. In order to guarantee the stability and performance of the system, and give an effective preventive and predictive maintenance, LonWorks-IP based VDN induced time-varying uncertain time delay needs to be predicted and compensated. In this paper new Pill control scheme based on Smith predictor, disturbance observer and band pass filter is proposed and tested through computer simulation about position control of DC servo motor. It is shown that how can the proposed control scheme be designed to minimize the effects of uncertain varying time delay and model uncertainties. The validity of the proposed control scheme is compared and demonstrated with the comparison of internal model controllers(IMC) based on Smith predictor with and without disturbance observer.

Reduction of Added Resistance by Internal Flow Control in the Moonpool of a Drillship (시추선 문풀의 내부 유동제어에 의한 부가저항 저감)

  • Choi, Si-Young;Lee, Young-Gill;Jeong, Kwang-Leol;Ha, Yoon-Jin
    • Journal of the Society of Naval Architects of Korea
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    • v.48 no.6
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    • pp.544-551
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    • 2011
  • The internal flows of moonpool usually causes huge added resistance on drillships, and those are very complex to analyze. Therefore, not only experimental approaches but also numerical simulations are required for better investigations when dealing with the hydrodynamic problems of moonpool. In the present research, numerical simulations are used to find out why the resistance increases by moonpool on a running drillship. That is, the three-dimensional numerical simulations and model tests are carried out to examine the characteristics of internal flow and added resistance by changing the section of the moonpool in both longitudinal and transverse directions. Finally, based on the present studies, an optimized shape of the moonpool is suggested, which effectively reduces added resistance, and that is confirmed with three-dimensional numerical simulations and model tests.

A Model for Health Promoting Behaviors in Late-middle Aged Woman (중년후기 여성의 건강증진행위 모형구축)

  • Park, Chai-Soon
    • Women's Health Nursing
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    • v.2 no.2
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    • pp.298-331
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    • 1996
  • Recent improvements in living standard and development in medical care led to an increased interest in life expectancy and personal health, and also led to a more demand for higher quality of life. Thus, the problem of women's health draw a fresh interest nowadays. Since late-middle aged women experience various physical and socio-psychological changes and tend to have chronic illnesses, these women have to take initiatives for their health control by realizing their own responsibility. The basic elements for a healthy life of these women are understanding of their physical and psychological changes and acceptance of these changes. Health promoting behaviors of an individual or a group are actions toward increasing the level of well-being and self-actualization, and are affected by various variables. In Pender's health promoting model, variables are categorized into cognitive factors(individual perceptions), modifying factors, and variables affecting the likelihood for actions, and the model assumes the health promoting behaviors are affected by cognitive factors which are again affected by demographic factors. Since Pender's model was proposed based on a tool broad conceptual frame, many studies done afterwards have included only a limited number of variables of Pender's model. Furthermore, Pender's model did not precisely explain the possibilities of direct and indirect paths effects. The objectives of this study are to evaluate Pender's model and thus propose a model that explains health promoting behaviors among late-middle aged women in order to facilitate nursing intervention for this group of population. The hypothetical model was developed based on the Pender's health promoting model and the findings from past studies on women's health. Data were collected by self-reported questionnaires from 417 women living in Seoul, between July and November 1994. Questionnaires were developed based on instruments of Walker and others' health promotion lifestyle profile, Wallston and others' multidimensional health locus of control, Maoz's menopausal symptom check list and Speake and others' health self-rating scale. IN addition, items measuring self-efficacy were made by the present author based on past studies. In a pretest, the questionnaire items were reliable with Cronbach's alpha ranging from .786 to .934. The models for health promoting behaviors were tested by using structural equation modelling technique with LISREL 7.20. The results were summarized as follows : 1. The overall fit of the hypothetical model to the data was good (chi-square=4.42, df=5, p=.490, GFI=.995, AGFI=.962, RMSR=.024). 2. Paths of the model were modified by considering both its theoretical implication and statistical significance of the parameter estimates. Compared to the hypothetical model, the revised model has become parsimonious and had a better fit to the data (chi-square =4.55, df=6, p=.602, GFI=.995, AGFI=.967, RMSR=.024). 3. The results of statistical testing were as follows : 1) Family function internal health locus of control, self-efficacy, and education level exerted significant effects on health promoting behaviors(${\gamma}_{43}$=.272, T=3.714; ${\beta}_[41}$=.211, T=2.797; ${\beta}_{42}$=.199, T=2.717; ${\gamma}_{41}$=.136, T=1.986). The effect of economic status, physical menopausal symptoms, and perceived health status on health promoting behavior were insignificant(${\gamma}_{42}$=.095, T=1.456; ${\gamma}_{44}$=.101, T=1.143; ${\gamma}_{43}$=.082, T=.967). 2) Family function had a significance direct effect on internal health locus of control (${\gamma}_{13}$=.307, T=3.784). The direct effect of education level on internal health locus of control was insignificant(${\gamma}_{11}$=-.006, T=-.081). 3) The directs effects of family functions & internal health locus of control on self-efficacy were significant(${\gamma}_{23}$=.208, T=2.607; ${\beta}_{21}$=.191, T=2.2693). But education level and economic status did not exert a significant effect on self-efficacy(${\gamma}_{21}$=.137, T=1.814; ${\beta}_{22}$=.137, T=1.814; ${\gamma}_{22}$=.112, T=1.499). 4) Education level had a direct and positive effect on perceived health status, but physical menopausal symptoms had a negative effect on perceived health status and these effects were all significant(${\gamma}_{31}$=.171, T=2.496; ${\gamma}_{34}$=.524, T=-7.120). Internal health locus and self-efficacy had an insignificant direct effect on perceived health status(${\beta}_{31}$=.028, T=.363; ${\beta}_{32}$=.041, T=.557). 5) All predictive variables of health promoting behaviors explained 51.8% of the total variance in the model. The above findings show that health promoting behaviors are explained by personal, environmental and perceptual factors : family function, internal health locus of control, self-efficacy, and education level had stronger effects on health promoting behaviors than predictors in the model. A significant effect of family function on health promoting behaviors reflects an important role of the Korean late-middle aged women in family relationships. Therefore, health professionals first need to have a proper evaluation of family function in order to reflect the family function style into nursing interventions and development of strategies. These interventions and strategies will enhance internal health locus of control and self-efficacy for promoting health behaviors. Possible strategies include management of health promoting programs, use of a health information booklets, and individual health counseling, which will enhance internal health locus of control and self-efficacy of the late-middle aged women by making them aware of health responsibilities and value for oneself. In this study, an insignificant effect of physical menopausal symptoms and perceived health status on health promoting behaviors implies that they are not motive factors for health promoting behaviors. Further analytic researches are required to clarify the influence of physical menopausal symptoms and perceived health status on health promoting behaviors with-middle aged women.

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ELDCTRICAL COMPUTED TOMOGRAPHY FOR IMAGING OF INTERNAL RESISTIVITY AND PERMITTIVITY DISTRIBYTION

  • Kurniad, Deddy;Komiya, Kin-ichi
    • 제어로봇시스템학회:학술대회논문집
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    • 1994.10a
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    • pp.578-582
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    • 1994
  • In this paper reconstructing the internal resistivity and relative permittivity distribution is discussed. The iterative reconstruction method based on Finite Element method and Newton method were used to reconstruct both of resistivity ind permittivity distribution. The Finite Element model of impedance distribution is built in complex field of resistivity and capacitive medium. The reconstruction results based on computer simulated data and experimental data are presented.

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Nonlinear Model Based Control of Two-Product Reactive Distillation Column

  • Lee, In-Beum;Han, Myung-Wan
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.50.3-50
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    • 2001
  • Nonlinear feedback control scheme for reactive distillation column has been proposed. The proposed control scheme is derived in the framework of Nonlinear Internal Model Control. The product compositions and liquid and vapor flow rates in sections of the reactive distillation column are estimated from selected tray temperature measurements by an observer. The control scheme is applied to example reactive distillation column in which two products are produced in a single column and the reversible reaction A + B = C + D occurs. The relative volatilities are favorable for reactive distillation so that the reactants are intermediated boilers between the light product C and the heavy product D. Ideal physical properties, kinetics and ...

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Unsteady Flow Model Including a Dam Operation Rule for Flood Control as Internal Boundary Condition (홍수시 댐 운영방안을 내부 경계조건으로 포함하는 부정류 계산모형)

  • Yu, Myoung-Kwan;Jun, Kyung-Soo
    • Journal of Korea Water Resources Association
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    • v.37 no.12
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    • pp.1043-1054
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    • 2004
  • An unsteady flow model for channel network including various internal boundaries if developed. It is a multiply-connected network model based on the Preissmann's four-point scheme and the Newton-Raphson method, where looped double-sweep algorithm is used. The model is capable of simulating flow through hydraulic structures such as dams and submerged weirs. It can also simulate automatic reservoir operation method (Auto ROM) for flood control, that is to maintain a target water level, by incorporating the strategy to the unsteady flow model as internal boundary condition. The model is applied to the Han River system that includes the downstream reaches of Choongju dam and Hwacheon dam as well as the downstream reach of the Paldang dam. Roughness coefficient for the downstream reach of Choongju dam is estimated. Automatic ROM is presumed for the Paldang, Chungpyung, Euiam, and Choonchun dams. The model is tested using historical flood records, and the flood control strategy is successfully simulated.

Mechatronic Analysis for Feeding a Structure of a Machine Tool Using Multi-body Dynamics (다물체 동역학을 활용한 공작기계 구조물 이송을 위한 메카트로닉 해석)

  • Choi, Jin-Woo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.5
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    • pp.691-696
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    • 2012
  • In this study, a rigid multi-body dynamic model has been developed for mechatronic analysis to evaluate dynamic behavior of a machine tool. The development environment was the commercialized analysis tool, ADAMS, for rigid multi-body dynamic analysis. A simplified servo control logic was implemented in the tool using its functions in order to negate any external tool of control definition. The advantage of the internal implementation includes convenience of the analysis process by saving time and efforts. Application of this development to a machine tool helps to evaluate its dynamic behavior against feeding its component, to calculate the motor torque, and to optimize parameters of the control logic.

Design of a Multiobjective Robust Controller for the Track-Following System of an Optical Disk Drive (광 디스크 드라이브의 트랙킹 서보 시스템을 위한 다목적 강인 제어기의 설계)

  • 이문노;문정호;정명진
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.5
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    • pp.592-599
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    • 1998
  • In this paper, we design a tracking controller which satisfies transient response specifications and maintains tracking error within a tolerable limit for the uncertain track-following system of an optical disk drive. To this end, a robust $H_{\infty}$ control problem with regional stability constraints and sinusoidal disturbance rejection is considered. The internal model principle is used for rejecting the sinusoidal disturbance caused by eccentric rotation of the disk. We show that a condition satisfying the regional stability constraints can be expressed in terms of a linear matrix inequality (LMI) using the Lyapunov theory and S-procedure. Finally, a tracking controller is obtained by solving an LMI optimization problem involving two linear matrix inequalities. The proposed controller design method is evaluated through an experiment.

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A Novel Control Scheme Based on the Synchronous Frame for APF

  • Wang, Yifan;Zheng, Hong;Wang, Ruoyin;Zhu, Wen
    • Journal of Power Electronics
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    • v.17 no.6
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    • pp.1553-1562
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    • 2017
  • For the purpose of enhancing the performance of the shunt active power filter (APF), this paper presents a novel Fast Weighted Compound Control (FWCC) strategy based on the synchronous frame. In this control strategy, the proposed new repetitive controller can work faster and more stably by reducing the internal model cycle and introducing a damping coefficient. In addition, the harmonic detector can be removed to simplify the structure of the APF owing to the improvements. Furthermore, a proportional-integral (PI) controller is added to work in parallel with the repetitive controller by using a weighted ratio. Then, a convergence speed analysis and design algorithm are given in detail. Simulation and experimental results show that the harmonic distortion is reduced from 2.91% to 1.89%. In addition, the content for each of the characteristic harmonic orders has decreased by more than three times.