• Title/Summary/Keyword: system uncertainty

Search Result 2,446, Processing Time 0.029 seconds

Robust H(sup)$\infty$ FIR Sampled-Data Filtering for Uncertain Time-Varying Systems with Lipschitz Nonlinearity

  • Ryu, Hee-Seob;Yoo, Kyung-Sang;Kwon, Oh-Kyu
    • Transactions on Control, Automation and Systems Engineering
    • /
    • v.2 no.4
    • /
    • pp.255-261
    • /
    • 2000
  • This paper presents the results of the robust H(sub)$\infty$ FIR filtering for a class of nonlinear continuous time-varying systems subject to real norm-bounded parameter uncertainty and know Lipschitz nonlinearity under sampled measurements. We address the problem of designing filters, using sampled measurements, which guarantee a prescribed H(sub)$\infty$ performance in continuous time-varying context, irrespective of the parameter uncertainty and unknown initial states. The infinite horizon causal H(sub)$\infty$FIR filter are investigated using the finite moving horizon in terms of two Riccati equations with finite discrete jumps.

  • PDF

A study of improvement of uncertainty by repeated measurement for PSD(Platform Screen Door) Performance Test (승강장 스크린 도어 시스템 특성 시험의 반복 측정에 의한 불확도 개선 고찰)

  • Ohn, Jung-Ghun;Kim, Myung-Yong;Yun, Myung-Sang;Kim, Won-Kyong;Won, Si-Tae
    • Proceedings of the KSR Conference
    • /
    • 2007.05a
    • /
    • pp.1671-1674
    • /
    • 2007
  • A PSD system has a lot of characteristic for safety. Trust of performance test is very important. But PSD performance test has an effect on trust by proficiency of test staff because it is difficult to automate. In that specially the effort test, manual opening and shutting test and abrasion measurement, test staff is demanded for proficiency. Therefore the paper repeated measurement in same condition and studied proficient factor of examiner according to increased measurement counter. As a result, measurement uncertainty has improved.

  • PDF

A Study on the Uncertainty of Context Awareness in Flood Monitoring System (홍수 상황인지 시스템에서의 상황인지 불확실성 해결 방안)

  • Lee, Seon-Hyui;Lee, Yong-Joo;Byun, In-Sun;Kim, Jung-Min
    • Proceedings of the KIEE Conference
    • /
    • 2008.07a
    • /
    • pp.1869-1870
    • /
    • 2008
  • 현재의 상황인지 컴퓨팅(Context-aware Computing)은 센서로부터 전달받는 상황정보가 완벽하다는 가정을 하고 있으며 따라서, 이에 근거한 상황인지는 불확실성(Uncertainty)을 제대로 다루지 못하고 있는 실정이다. 또한 상황인지 컴퓨팅에서 상황 정보를 표현하는데 주로 사용되고 있는 온톨로지(Ontology) 모델링 역시 현실 세계의 불확실성을 다루기에는 한계가 있다. 본 논문은 선행 연구인 온톨로지 기반의 홍수 상황인지 처리에서 발생할 수 있는 불확실성을 탐지하고 이를 해결하기 위한 방안을 제안한다. 홍수 상황인지를 위한 센서 종류와 수량을 보강하고 기 설계된 온톨로지 모델의 추론 과정 보완을 통하여 홍수 상황인지의 불확실성을 최소화한다. 이는 홍수 상황인지 뿐만 아니라 일반적인 온톨로지 기반의 상황인지 u-서비스에 응용할 수 있다.

  • PDF

Multi-Vehicle Environment Simulation Tool to Develop and Evaluate Automated Driving Systems in Motorway (고속도로에서의 자율주행 알고리즘 개발 및 평가를 위한 다차량 시뮬레이션 환경 개발)

  • Lee, Hojoon;Jeong, Yonghwan;Min, Kyongchan;Lee, Myungsu;Shin, Jae Kon;Yi, Kyongsu
    • Journal of Auto-vehicle Safety Association
    • /
    • v.8 no.4
    • /
    • pp.31-37
    • /
    • 2016
  • Since real road experiments have many restrictions, a multi-vehicle traffic simulator can be an effective tool to develop and evaluate fully automated driving systems. This paper presents multi-vehicle environment simulation tool to develop and evaluate motorway automated driving systems. The proposed simulation tool consists of following two main parts: surrounding vehicle model and environment sensor model. The surrounding vehicle model is designed to quickly generate rational complex traffic situations of motorway. The environment sensor model depicts uncertainty of environment sensor. As a result, various traffic situations with uncertainty of environment sensor can be proposed by the multi-vehicle environment simulation tool. An application to automated driving system has been conducted. A lane changing algorithm is evaluated by performance indexes from the multi-vehicle environment simulation tool.

A Clonal Selection Algorithm using the Rolling Planning and an Extended Memory Cell for the Inventory Routing Problem (연동계획과 확장된 기억 세포를 이용한 재고 및 경로 문제의 복제선택해법)

  • Yang, Byoung-Hak
    • Korean Management Science Review
    • /
    • v.26 no.1
    • /
    • pp.171-182
    • /
    • 2009
  • We consider the inventory replenishment problem and the vehicle routing problem simultaneously in the vending machine operation. This problem is known as the inventory routing problem. We design a memory cell in the clonal selection algorithm. The memory cell store the best solution of previous solved problem and use an initial solution for next problem. In general, the other clonal selection algorithm used memory cell for reserving the best solution in current problem. Experiments are performed for testing efficiency of the memory cell in demand uncertainty. Experiment result shows that the solution quality of our algorithm is similar to general clonal selection algorithm and the calculations time is reduced by 20% when the demand uncertainty is less than 30%.

Velocity Matching Algorithm Using Robust H$_2$Filter (강인한 H$_2$필터를 이용한 속도정합 알고리즘)

  • Yang, Cheol-Kwan;Shim, Duk-Sun;Park, Chan-Gook
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.7 no.4
    • /
    • pp.362-368
    • /
    • 2001
  • We study on the velocity matching algorithm for transfer alignment of inertial navigation system(INS) using a robust H$_2$ filter. We suggest an uncertainty model and a discrete robust H$_2$filter for INS and apply the suggested robust H$_2$ filter to the uncertainty model. The discrete robust H$_2$filter is shown by simulation to have better performance time and accuracy than Kalman filter.

  • PDF

Robust Stability Analysis for a Fuzzy Feedback Linearization Method using a Takagi-Sugeno Fuzzy Model

  • Kang, Hyung-Jin;Cheol Kwon;Lee, Hee-Jin;Park, Mignon
    • Journal of Electrical Engineering and information Science
    • /
    • v.2 no.4
    • /
    • pp.28-36
    • /
    • 1997
  • In this paper, robust stability analysis for the fuzzy feedback linearization regulator is presented. Well-known Takagi-Sugeno fuzzy model is used as the MISO nonlinear plant model. Uncertainty and disturbance are assumed to be included in the model structure with known bounds. For these structured uncertainty and disturbances, robust stability of the close system is analyzed in both input-output sense and Lyapunov sense. The robust stability conditions are proposed by using multivariable circle criterion and the relationship between input-output stability and Lyapunov stability. The proposed stability analysis is illustrated by a simple example.

  • PDF

On Guaranteed Cost Control of Uncertain Neutral Systems (섭동을 갖는 뉴트럴 시스템의 성능보장 안정화에 관하여)

  • Park, Ju-Hyun
    • The Transactions of the Korean Institute of Electrical Engineers D
    • /
    • v.52 no.3
    • /
    • pp.129-133
    • /
    • 2003
  • In this paper, we consider the robust guaranteed cost control problem for a class of uncertain neutral systems with given quadratic cost functions. The uncertainty is assumed to be norm-bounded and time-varying. The goal in this study is to design the memoryless state feedback controller such that the closed-loop system is asymptotically stable and the closed-loop cost function value is not more than a specified upper bound lot all admissible uncertainty. Some criteria for the existence of such controllers are derived based on the matrix inequality approach combined with the Lyapunov second method. A parameterized characterization of the robust guaranteed cost controllers is given in terms of the feasible solutions to the certain matrix inequalities. A numerical example is given to illustrate the proposed method.

Development of Standard Calibration System for the Rain Gauges by Weighting Method (질량측정에 의한 우량계 표준교정시스템 개발)

  • Shin Gang-Wook;Hong Sung-Tack
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.12 no.8
    • /
    • pp.818-823
    • /
    • 2006
  • Because the rain gauges of tipping bucket type can easily use the digital signal, the rain gauges are widely used for the meteorological observation. In general, the resolution of rain gauges of tipping bucket type can be categorized by the 0.1mm, 0.5mm, and 1.0mm classes. But, the error of the tipping bucket rain gauges is made by the intensity of rainfalls and is expected to make the standard calibration method for error measurement. Thus, we developed the hardware of standard calibration facility for rain gauges by weighting measurement method and proposed the standard procedure by rainfall intensity in this study Also, we calculated the uncertainty for the rainfall intensity and obtained useful result through the proposed calibration method.

Different approaches towards fuzzy database systems A Survey

  • Rundensteiner, Elke A.;Hawkes, Lois Wright
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.3 no.1
    • /
    • pp.65-75
    • /
    • 1993
  • Fuzzy data is a phenomenon often occurring in real life. There is the inherent vagueness of classification terms referring to a continuous scale, the uncertainty of linguistic terms such as "I almost agree" or the vagueness of terms and concepts due to the statistical variability in communication [20] and many more. Previously, such fuzzy data was approximated by non-fuzzy (crisp) data, which obviously did not lead to a correct and precise representation of the real world. Fuzzy set theory has been developed to represent and manipulate fuzzy data [18]. Explicitly managing the degree of fuzziness in databases allows the system to distinguish between what is known, what is not known and what is partially known. Systems in the literature whose specific objective is to handle imprecision in databases present various approaches. This paper is concerned with the different ways uncertainty and imprecision are handled in database design. It outlines the major areas of fuzzification in (relational) database systems.

  • PDF