• Title/Summary/Keyword: a internal model control

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Design of a robust controller for nonminimum phase system with structured uncertainty (구조적 불확실성을 갖는 비최소위상계의 강인한 제어기 설계)

  • 김신구;서광식;김영철
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.422-425
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    • 1997
  • We consider the robust control problem for nonminimum phase(NMP) systems with parametric uncertainty which appear often in aircraft and missile control. First, a new method that makes such an uncertain NMP system to be factored as a interval minimum phase(MP) transfer function and a time delay term in the Pade approximation form has been presented. The controller to be proposed consists of a compensator $C_{Q}$(s) with Smith predictor in the internal model control(IMC) structure, so that it can have good robustness and performance against the structured uncertainty and the time delay behaviour due to NMP plant the $C_{Q}$(s) is designed on the MP model by using QFT. The stability and performance of overall system has been evaluated by the generalized Kharitonov theorem.rem.

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A study of bilateral control with time delay

  • Shibasato, Kouki;Furuta, Katsuhisa;Yamakita, Masaki
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10b
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    • pp.1681-1686
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    • 1991
  • In robotics and other fields of engineering, techniques for artificial reality or virtual reality are focused on and studied extensively, e.g., virtual existence for tele-operator systems in robotics, and virtual reality of designed objects in architecture. In order to realize the system we should create physical stimulations according to internal models created by experiences in a human brain. The internal model does not have to have direct connections to the real world, however, the stimulation must be signals such that the internal model are retrieved in a human brain. In this paper we propose a technique for tele-virtual reality of dynamic mechanical models, which means that one dynamic mechanical model can be shared by peoples in distant places. Since a stability issue due to time delays arises in the system, we employed a scattering technique developed for a tele-operator system and a kind of passive adaptive controllers. Furthermore, restrictions due to a simple digital implementation of the scattering transformation are discussed and some conditions for stability are shown. The proposed method is applied to a remote tug of war system and the effectiveness is verified.

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The Impact Analysis of Internal Control System on Accounting Information's Usefulness (기업의 내부통제시스템이 회계정보의 유용성에 미치는 영향 분석)

  • Kim, Dong-Il
    • Journal of the Korea Convergence Society
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    • v.9 no.11
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    • pp.307-313
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    • 2018
  • In this study, analyzed the effect of the introduction and operation of internal control system of a company on accounting information usefulness in a rapidly changing business environment. In order to conduct this study, we studied a comprehensive analysis on the usefulness of internal control and accounting information, and applied the research model to the purpose of this study. In this study, we analyzed the degree of the relationship between variables based on the discretionary accruals of the modified Jones model using the internal control evaluation index based on the components of the internal control system for China. In the empirical analysis, analyzed that the operation of internal control has a negative influence on discretionary accruals, which is a substitute for usability of accounting information. In addition, the risk management factors of the internal control system have a negative correlation with the usefulness of accounting information. The results of this study suggest that it is possible to present the positive function of internal control system to many firms where the introduction and operation of internal control is important, and to provide useful guidance in the study of the relationship between the operation of internal control and discretionary accruals for foreign company.

Static Friction Compensation for Enhancing Motor Control Precision (모터 제어 정밀도 향상을 위한 정지 마찰력 보상)

  • Ryoo, Jung Rae;Doh, Tae-Yong
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.2
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    • pp.180-185
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    • 2014
  • DC motor is a representative electric motor commonly utilized in various motion control fields. However, DC motor-based motion control systems suffer from degradation of position precision due to nonlinear static friction. In order to enhance control precision, friction model-based compensators have been introduced in previous researches, where friction models are identified and counter inputs are added to control inputs for cancelling out the identified friction forces. In this paper, a static friction compensator is proposed without use of a friction model. The proposed compensation algorithm utilizes internal state manipulation to generate compensation pulses, and related parameters are easily tuned experimentally. The proposed friction compensator is applied to a DC motor-based motion control system, and results are presented in comparison with those without a friction compensator.

Effect of Accounting Information Systems, Teamwork, and Internal Control on Financial Reporting Timeliness

  • MARDI, Mardi;PERDANA, Petrolis Nusa;SUPARNO, Suparno;MUNANDAR, Imam Aris
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.12
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    • pp.809-818
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    • 2020
  • This study aims to analyze the factors affecting the timeliness of cooperative financial reporting. The methods of measurement and accountability of financial statements must be timely, as it is critical information for making decision. Factors related to accounting information system problems such as timeliness of financial reporting, accounting information systems, teamwork, and internal control were identified in the study as a model. The method in this research is quantitative by taking survey data. The data were processed using SPSS 25, with a model test and partial test to produce a study to analyze the factors that affect the timeliness of cooperative financial reporting. The samples consisted of 60 cooperatives from the city of Tangerang, in Indonesia. The correspondents have published financial reports for each period of the current year and were a legal entity. Furthermore, primary data were collected by a questionnaire using a Likert scale and analyzed by multiple linear regression. The results showed that the Accounting Information System, Teamwork, and Internal Control had a positive and significant effect on the Timeliness of Financial Report Submission. Therefore, the cooperative that prepares financial reports in a timely manner has applied the principles of accountability and transparency.

A Study of Network 2-Factor Access Control Model for Prevention the Medical-Data Leakage (의료 정보유출 방지를 위한 네트워크 이중 접근통제 모델 연구)

  • Choi, Kyong-Ho;Kang, Sung-Kwan;Chung, Kyung-Yong;Lee, Jung-Hyun
    • Journal of Digital Convergence
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    • v.10 no.6
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    • pp.341-347
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    • 2012
  • Network Access Control system of medical asset protection solutions that installation and operation on system and network to provide a process that to access internal network after verifying the safety of information communication devices. However, there are still the internal medical-data leakage threats due to spoof of authorized devices and unauthorized using of users are away hours. In this paper, Network 2-Factor Access Control Model proposed for prevention the medical-data leakage by improving the current Network Access Control system. The proposed Network 2-Factor Access Control Model allowed to access the internal network only actual users located in specific place within the organization and used authorized devices. Therefore, the proposed model to provide a safety medical asset environment that protecting medical-data by blocking unauthorized access to the internal network and unnecessary internet access of authorized users and devices.

The Effects of GLS(Gleditsiae spina) Treatment on Hematological and Cytopathological Alterations in Non-Bacterial Prostatitis Rat Model (조각자가 만성 비세균성 전립선염 Rat 모델에서 혈액 및 세포조직의 변화에 미치는 영향)

  • Jung, Gi-Hun;Chang, Sun-Kyu;Choi, Jung-Sik;Cho, Chung-Sik;Kim, Chul-Jung
    • The Journal of Internal Korean Medicine
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    • v.28 no.4
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    • pp.779-790
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    • 2007
  • Objective : Although chronic non-bacterial prostatitis is a common disease, it is very difficult to treat effectively. GLS (Gleditsiae Spina) has traditionally been used in treatment of urinary tract inflammation and voiding disturbance. In this study, we investigated the therapeutic effects and action mechanism of GLS in the rat model of non-bacterial prostatitis induced by castration and testosterone treatment. Method : We observed four experimental objects of normal group, control group, testosterone group, and GLS group. Rats were treated with 17$\beta$-estradiol after castration for induction of experimental non-bacteral prostatitis, which is similar to human chronic prostatitis in histophatological profiles. GLS and testosterone were administered as an experimental specimen and a positive control, respectively. The prostates were evaluated by histopahological parameters including the epithelial score and epithelio-stromal ratio for glandular damage. Also, the prostates were observed by hematological alterations of WBC, RBC, hemoglobin, hematocrit and platelet. Results : While prostates of control rats revealed severe acinar gland atrophy and stromal proliferation, the rats treated with GLS showed a diminished range of tissue damage. Epithelial score was improved in GLS over that of the control. The epithelial-stromal ratio was lower in GLS when compared to that of the control. Conclusion : These findings suggest that GLS may protect the glandular epithelial cells. We concluded that GLS could be a useful remedy agent for treating chronic non-bacterial prostatitis.

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Ratcheting behavior of pressurized Z2CND18.12N stainless steel pipe under different control modes

  • Chen, Xiaohui;Chen, Xu;Chen, Gang;Li, Duomin
    • Steel and Composite Structures
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    • v.18 no.1
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    • pp.29-50
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    • 2015
  • With a quasi-three point bending apparatus, ratcheting deformation is studied experimentally on a pressurized austenitic stainless steel Z2CND18.12N pipe under bending load and vertical displacement control, respectively. The characteristic of ratcheting behavior of straight pipe under both control methods is achieved and compared. The cyclic bending loading and internal pressure influence ratcheting behavior of pressurized straight pipe significantly under loading control and the ratcheting characteristics are also highly associated with the cyclic displacement and internal pressure under displacement control. They all affect not only the saturation of the ratcheting strain but the ratcheting strain rate. In addition, ratcheting simulation is performed by elastic-plastic finite element analysis with ANSYS in which the bilinear model, Chaboche model, Ohno-Wang model and modified Ohno-Wang model are applied. By comparison with the experimental data, it is found that the CJK model gives reasonable simulation. Ratcheting boundaries under two control modes are almost same.

A Study on the Internal Control System of Fisheries Cooperative (수산업협동조합의 내부통제제도에 관한 연구)

  • 박이봉;최정윤
    • The Journal of Fisheries Business Administration
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    • v.22 no.2
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    • pp.101-148
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    • 1991
  • The fisheries cooperative (FC) performs the economic and nonprofitable activity to get the fundamental objective of enhancing cooperative members' economic and social position. The internal control system fitted for a local FC should be required for not only solving the resulting problem from the complexity of FC environment nowaday but also delegating authorities and performance from FC Federation to a local FC by implementing the local autonomy. The methodology of this study is to empirically test and to analyze the condition of FC internal control system (FCICS) by the questionnaire survey. The actual condition of FCICS in Korea is analyzed by the questionnaire and the detailed contents are as follows : (1) sending 208 questionnaire consisting of 162 questions, and receiving 92 replies from 39 manufactures (business firms) and 15 banks in Gyungnam and Pusan area and 25 FC and 13 agricultural cooperative (AC) in Korea, (2) the analyzed results of FC and AC are treated simultaneously. In the fundamentals of above analyzed results, the evaluation model of FCICS is tried to construct from the relationship between the financial condition of FC and the internal control elements through the stepwise regression method. (1) By the stepwise regression method, the number of FC officials $(X_1)$, the experimental number of regular auditing $(X_7)$, and auditing duty years $(X_8)$ are finally accepted as independent variables, (2) and the final model becomes $Y=-1.53526+0.34455X_1+0.24513X_7+0.16585X_8$/ and this model explains to the extent of 47.826%. From the above study, following proposals are to be suggested: (1) The function and problem of internal control in FCICS is able to be improved by enforcing the function of FCICS and enriching the management's recognition of FCICS (2) The cooperative president can bring up good FC by the rational operation of FCICS according to the size and the performance pattern of FC, adding up to enhance members' economic and social position.

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A Shared Compliant Control Scheme based on Internal Model Control

  • Ahn, Sung-Ho;Jin, Jae-Hyun;Park, Byung-Suk;Yoon, Ji-Sup
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1571-1574
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    • 2003
  • A shared compliant control scheme based on IMC is proposed for the position-force force reflecting control system. The controller of the slave manipulator is designed by IMC method for the open loop unstable plant. The compliant control is implemented by first order low pass filter. In the proposed scheme, the slave manipulator well tracks the position of the master manipulator in free space and the compliance of the slave manipulator is autonomously controlled in contact condition. The simulation results show that the excellence of the proposed controller.

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