• Title/Summary/Keyword: Uncertain Process

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Development of a Parallel-Typed Walking Robot for Breakwater Construction

  • Park, Kun-Woo;Kim, Tae-Sung;Park, Sung-Min;Lee, Min-Ki
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.81.1-81
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    • 2002
  • $\textbullet$ This paper presents a study on the development of a walking robot for an armor-stone work of the breakwater construction. The armor-stone work is putting stones about 0.3 ∼ 2m3 on the surface of the breakwater to prevent it from waving. $\textbullet$ This work has been done manually, and its process plan is uncertain by effects of the weather, wave and tide of sea. Therefore the constructional cost is considered to be wasteful $\textbullet$ Working in underwater as well as on land for human workers causes the accident and caisson disease, so it is necessary to replace the process to be mechanized. $\textbullet$ The basic requirements of the robot for mechanizing are as follows : 1) To have a large...

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Position Control System using Neural Network Algorithm for Butterfly Valve (신경망 알고리즘을 이용한 버터플라이 밸브의 위치제어)

  • Choi, Jeong-Ju
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.5
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    • pp.94-98
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    • 2012
  • Butterfly valves are usually used by the plumbing systems in plant engineering field. Valves are used for controlling the flow rate and pressure of fluid. In order to control the flow rate using butterfly valve, the position control of valve disc should be designed. However, since there are lots of uncertain disturbance in plumbing system, the robust control system should be considered. Therefore, the sliding mode control system using neural network algorithm is proposed in this paper. The proposed control system provides the estimating method using neural network for the unmeasurable disturbance in the plumbing system. The performance of the proposed control system is evaluated through computer simulations.

A Study on the Uncertainty of Estimation in Vibration Test for the Machine Parts (가공 기계부품 고유진동수 해석과 측정에 관한 연구)

  • Hwang, Jae-Deok;Kim, Chae-Sil;Cho, Sung-Jin
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.13 no.1
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    • pp.16-22
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    • 2014
  • Resonance refers to the magnification of a structural response which occurs when a linear lightly damped system is driven with a sinusoidal input at its natural frequency. An exploratory vibration test (a natural frequency measurement test) is very important for the vibration testing of machine parts, as the value measured in an actual laboratory affects test results. For this reason, it is necessary to estimate the measurement uncertainty to verify the reliability of this type of test. In this study, measurement uncertainty is estimated based on three uncertainty factors. The uncertain factors are the measured points in the machine parts, the resolution of the vibration equipment, and uncertainty of the calibration certificate.

Applications of Soft Computing Techniques in Response Surface Based Approximate Optimization

  • Lee, Jongsoo;Kim, Seungjin
    • Journal of Mechanical Science and Technology
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    • v.15 no.8
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    • pp.1132-1142
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    • 2001
  • The paper describes the construction of global function approximation models for use in design optimization via global search techniques such as genetic algorithms. Two different approximation methods referred to as evolutionary fuzzy modeling (EFM) and neuro-fuzzy modeling (NFM) are implemented in the context of global approximate optimization. EFM and NFM are based on soft computing paradigms utilizing fuzzy systems, neural networks and evolutionary computing techniques. Such approximation methods may have their promising characteristics in a case where the training data is not sufficiently provided or uncertain information may be included in design process. Fuzzy inference system is the central system for of identifying the input/output relationship in both methods. The paper introduces the general procedures including fuzzy rule generation, membership function selection and inference process for EFM and NFM, and presents their generalization capabilities in terms of a number of fuzzy rules and training data with application to a three-bar truss optimization.

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A Study on the Measurement Method and Uncertainty Factors for Precision Inspection to Feed Unit of High Precision Machine Tool (고정밀 공작기계 이송장치의 정밀도 측정방법 및 불확도 요인에 관한 연구)

  • Kim, Sang-Hwa;Kim, Byung-Ha;Choi, Woo-Gak
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.4
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    • pp.55-61
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    • 2012
  • Very important content in performance evaluation of machine tool is positioning accuracy and repeatability precision measurements of feed mechanism. A study analyses the measurement method and uncertainty factors by ISO-based test method. Reliable results can't be derived without the notion of measurement uncertainty. The reason is that the measured value includes a lot of uncertain factors. Finding the factor that affects the measurement of parameter is important for estimation of measurement precision. In this paper, the evaluation of uncertainty analysis about positioning accuracy and repeatability precision measurements of high precision feed mechanism is presented to evaluate the important factors of uncertainty.

A Study on Design of Production System Using Multiple Characteristics Robust Design in Uncertain Environment (불확실한 환경에서의 다특성치 강건설계를 이용한 생산시스템 설계에 관한 연구)

  • 양광모;서장훈;박진홍;강경식
    • Proceedings of the Safety Management and Science Conference
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    • 2004.05a
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    • pp.61-65
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    • 2004
  • As technique that can contribute in quality improvement in design process to overcome shortcoming of traditional quality control, call design or development department quality control activity that is achieved to reduce gun damage shuddering at circle minimizing change or side effect of product performance as off-line quality control. This paper discuss optimal process design of investment projects expansion and replacement investment on each line or individual in the production. Generally optimal plant design has add to a few method by Subsidiary means with use a especial method. And then in this paper, a Robust design is presented, which may be effective to the processes appraisal or improvement. We propose that should make a optimal plant design model for reducing field failure rate to assign by real data on different factors in plant system. Using this model, robust design of taguchi method used in this comprehensive method for reducing field failure rate in plant system.

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A Study on the Interactive Design Application of Exhibition Space in Museum (박물관 전시공간에 있어 인터렉티브 디자인 적용에 관한 연구)

  • Joo, Kwang-Choun;Park, Kwang-Bum
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2005.05a
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    • pp.172-177
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    • 2005
  • What kind of information is it got in an exhibition space? And any order is determined and can read an exhibition? Is application possible with interactive design in an exhibition space? All elements must be reflected in an information design in addition to a biological process and perception process. Various uncertainty, a little information about exhibition contents and negative attitude, various ways of thinking, time physical a few psychological fatigue, uncertain target will be for these reasons. When configuration of a space and a human biological element are satisfied in an information design by physical configuration, maximization of a communication between exhibition water and visitor firm names will consist in a museum.

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A study on the control of speed-sensor less DC servo motor us ing LQG Reguator (LQG Regulator를 이용한 속도센서없는 직류서보전동기의 속도제어에 관한 연구)

  • Kim, Sang-Hoon;Ko, Bong-Woon;Nam, Moon-Hyun;Kim, Lark-Kyo
    • Proceedings of the KIEE Conference
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    • 2003.07d
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    • pp.2167-2169
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    • 2003
  • The LQG regulator presented in this dissertation is designed to improve system stability with the structure in which Kalman Filters and LQ regulator are inter-connected to avoid disturbances on the system. For the sake of performance evaluation of the LQG regulator in this dissertation, the regulator is put in use for the speed control of DC Servo Motors without speed sensors on them to realize speed control without sensors by estimating uncertain speed with its state signals and to construct an optimal controller using the LQG regulator. Furthermore, state estimation process with white noise entered onto the systems is been experimented through a series of simulation. As a consequence, the process of estimating speed signals out of the signals with white noise inputs is confirmed using Kalman Filter.

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MANAGEMENT THINKING BEHIND PERFORMANCE MEASURES

  • Yong-Woo Kim ;Glenn Ballard
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.377-382
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    • 2005
  • The tools, methods and measures used for project control reflect underlying theories of management. Management theory has been neglected in the construction industry, which has rather focused on tools and neglected theory. This paper contributes to the theory of project management by introducing and developing two fundamental and competing conceptualizations of management: MBM (Managing-by-Means) and MBR (Managing-by-results). Current project control and performance measurement practice is based on MBR. However, project control based on MBR may not be appropriate for managing dynamic projects. The paper present the Last PlannerTM System (LPS) and Process Variance Control (PVC) as examples of methods reflecting the MBM view. It is argued first that the MBM view is appropriate for managing uncertain, complex and quick projects. The paper also explores how MBR tools and techniques may be appropriately used within an MBM framework.

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Parallel-Jaw Grasp Planning of Polygonal Parts in Uncertain Dynamic Environments (불확실 동적 환경에서 다각형 부품의 평행-턱 파지 계획)

  • Han, Inhwan;Cho, Jeongho
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.4
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    • pp.126-135
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    • 1997
  • A sensorless motion planner which succeeds in grasping a polygonal part firmly into a desired orientation has been developed through the dynamic analysis. The analytical results on the impact process with friction are used for modeling the contact motionduring the parallel-jaw grasp operation, which is com- posed of the pushing and the squeezing process. The developed planner succeeds in grasping a part into a specified orientation in the face of uncertainties of initial position and orientation of the part, motion direction of the finger, and the physical parameters such as the coefficients of friction and restitution. The motion planner has been fully implemented into a viable package on the computer system, and verified experimentally. The motion of parts is recorded using a high-speed video camera, and then compared to the results of the planner and the graphic simulation results that illustrate the simulated motion of the grasp operation.

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