• Title/Summary/Keyword: Robust design

Search Result 2,871, Processing Time 0.024 seconds

가우스구적법을 이용한 구조물의 강건최적설계 (Robust Structural Optimization Using Gauss-type Quadrature Formula)

  • 이상훈;서기석
    • 대한기계학회논문집A
    • /
    • 제33권8호
    • /
    • pp.745-752
    • /
    • 2009
  • In robust design, the mean and variance of design performance are frequently used to measure the design performance and its robustness under uncertainties. In this paper, we present the Gauss-type quadrature formula as a rigorous method for mean and variance estimation involving arbitrary input distributions and further extend its use to robust design optimization. One dimensional Gauss-type quadrature formula are constructed from the input probability distributions and utilized in the construction of multidimensional quadrature formula such as the tensor product quadrature (TPQ) formula and the univariate dimension reduction (UDR) method. To improve the efficiency of using it for robust design optimization, a semi-analytic design sensitivity analysis with respect to the statistical moments is proposed. The proposed approach is applied to a simple bench mark problems and robust topology optimization of structures considering various types of uncertainty.

실험계획법에 기반한 브레이크 스퀼 노이즈 저감을 위한 강건 설계 (The DOE Based Robust Design to Reduce the Brake Squeal Noise)

  • 권성진;김문성;이봉현;이동원;배철용;김찬중
    • 한국자동차공학회논문집
    • /
    • 제15권2호
    • /
    • pp.126-134
    • /
    • 2007
  • Although there has been substantial research on the squeal noise for the automotive brake system, robust design issues with respect to control factors equivalent to design variables in optimization, noise factors due to system uncertainties, and signal factors designed to accommodate a user-adjustable setting still need to be addressed. For the purpose, the robust design applied to the disk brake system has been investigated by DOE (Design of Experiments) based Taguchi analysis with dynamic characteristics. The specific goal of this methodology is to identify a design with linear signal-response relationship, and variability minimization. The finite element models of the disk brake assembly have been constructed, and the squeal noise problems have been solved by complex eigenvalue analysis. As the practical robust design to reduce the brake squeal noise, material properties of pad, disk, and backplate, thickness and geometry of pad are selected as control factors, material properties of pad and disk, and the contact stiffness have been considered as noise factors, and friction coefficient between pad and disk is chosen as a signal factor. Through the DOE based robust design, the signal-to-noise ratio and the sensitivity for each orthogonal array experiment have been analyzed. Also, it has been proved that the proposed robust design is effective and adequate to reduce the brake squeal noise.

광 디스크 서보 설계를 위한 강건 제어 이론의 적용 및 평가: QFT vs. $H_{\infty}$ (Robust Servo Design and Application for Optical Disk Drive using Robust Control Theory: QFT vs. H_inf)

  • 최진영;이광현;양현석;박노철;박영필
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2005년도 춘계학술대회논문집
    • /
    • pp.541-546
    • /
    • 2005
  • In this paper, the various uncertainties, which are generated in working of an optical disk drive, are discussed in details and the robust servo design considering the uncertainties are discussed. First, the classification of the uncertainties and the modeling process including that are treated. Then, the robust servo designs using QFT and $H_{\infty}$ theory are performed. Finally, the designed servo loops realized by DSP are applied to the real system. From these experiments, we proved that the robust servo design using QFT and $H_{\infty}$ have a good performance and a good robust stability when it compared with the conventional servo loop.

  • PDF

강인 PID 제어를 이용한 냉간압연 시스템의 웹 횡방향 제어 (Web Lateral Control of Cold Rolling Mill Systems Using a Robust PID Control)

  • 최진태;김인수;이영진;김종식;이만형
    • 제어로봇시스템학회논문지
    • /
    • 제8권5호
    • /
    • pp.373-384
    • /
    • 2002
  • This paper presents a robust PID controller design technique using the concept of model matching method in the frequency domain. To design the robust PID controller satisfying disturbance attenuation and robust tracking property for a reference input, first an H$\infty$ controller satisfying given performance is designed using the H$\infty$ control method. And then, the parameters(proportional, integral, and derivative gains) of the robust PID controller are determined using the model matching at frequency domain. The proposed technique is applied to a position controller design of the web. The simulation results show that the proposed robust PID controller satisfies disturbance attenuation and tracking property.

강인 반복 제어를 이용한 비선영 유도탄 자동조종장치 (A Robust Recursive Control Approach to Nonlinear Missile Autopilot)

  • 남헌성;유준
    • 제어로봇시스템학회논문지
    • /
    • 제7권12호
    • /
    • pp.1031-1035
    • /
    • 2001
  • In this paper, a robust recursive control approach for nonlinear system, which is based on Lyapunov stability, is proposed. The proposed method can apply to extended systems including cascaded systems and the stability is guaranteed in the sense of Lyapunov. The recursive design procedure so called “robust recursive control approach” is used to find a stabilizing robust controller and simultaneously estimate the uncertainty parameters. First, a nonlinear model with uncertainties whose bounds are unknown is derived. Then, unknown bounds of uncertainties are estimated. By using these estimates, the stabilizing robust controller is updated at each step. This approach is applied to the pitch autopilot design of a nonlinear missile system and simulation results indicate good performance.

  • PDF

${\mu}$-합성법을 이용한 탐색기 주사루프의 강인 제어 (Robust Control of a Seeker Scan Loop System Using ${\mu}$-Systheis)

  • 이호평
    • 한국정밀공학회지
    • /
    • 제16권3호통권96호
    • /
    • pp.180-188
    • /
    • 1999
  • ${\mu}$-synthesis is applied to design a robust controller for a seeker scan loop system which has model uncertainty and is subject to a external disturbance due to abrupt missile maneuver. The issue of modelling a real-valued parametric uncertainty of a physical seeker scan loop system is discussed. The two-degree-of-frame control structure is employed to obtain better performance. It is shown that ${\mu}$-synthesis provides a superior framework for the robust control design of a seeker scan loop system which exhibits robust performance. The proposed robust control system satisfies design requirements, and especially shows good scanning performances for conical and rosette scan patterns despite parametric uncertainty in real system model.

  • PDF

기술적 설계제약을 고려한 강건설계법 (Robust Design Methodology under Design Constraints)

  • 김경모
    • 품질경영학회지
    • /
    • 제35권4호
    • /
    • pp.52-60
    • /
    • 2007
  • A multi-attribute robust design methodology is presented. This method can be applied where there are various technical constraints in design variables, multiple potentially conflicting design attributes, and uncontrollable noise variables. Two forms of technical constraints, soft and hard constraints, are considered in robust design settings. Specifically, this work presents procedures for integrating two types of design constraints seamlessly on the multiple design attributes, which is achieved through a development of multi-attribute utility formulation. The effectiveness of the overall procedures is tested with the aid of an I-Beam design problem, and results of sensitivity analysis are discussed.

설계자 선호도를 고려한 다특성 강건설계법 (Multi-Characteristic Robust Design Methodology Based on Designer's Preference)

  • 김경모
    • 품질경영학회지
    • /
    • 제29권1호
    • /
    • pp.47-61
    • /
    • 2001
  • The ever increasing demands for enhanced competitiveness of engineered products require a "designing-in-quality" strategy that can effectively and efficiently incorporate multiple design objectives into design. Robust design can be viewed as a multi-characteristic design problem requiring tradeoffs between mean and variance characteristics. Firstly this paper analyzes the intrinsic preference of the traditional SN ratio on mean and variance, and secondly presents a new design metric for a robust design using concepts from utility theory to accurately capture designer′s intent and preference on mean and variance. The steps to apply the proposed design metric as the robust design criterion in an orthogonal array based engineering experimentation is presented with the aid of a demonstrative case study. The performance of the proposed design metric is tested, and the results are discussed.

  • PDF

박판 성형 공정에서 스프링백의 강건 설계 (Robust Design of Springback in Sheet Metal Forming)

  • 김경모;인정제
    • 한국기계가공학회지
    • /
    • 제12권2호
    • /
    • pp.41-48
    • /
    • 2013
  • Springback is a very typical dimensional discrepancy phenomenon, which occurs usually on the final stamping parts after the tool loading is removed. Variation of springback leads to amplified variations and problems during assembly of the stamped components, in turn, resulting in quality issues. The variations in the properties of the incoming material and process parameters are the main causes of springback variation. In this research, a robust design methodology which combines orthogonal array based experimental design and design space reduction skim to reduce the springback variation for advanced high strength steel parts in sheet metal forming is suggested. The concept of design space reduction is adapted in the experimental design setup to improve the quality of the obtained solution. The effectiveness of the proposed procedures is illustrated through a robust design of springback in metal forming process of a cross member of auto body.

덮개 함수를 이용한 강건 최적설계의 제한 조건 단일화 (Unification of Constraints for Robust Optimization Using an Envelope Function)

  • 이정준;정도현;이병채
    • 대한기계학회논문집A
    • /
    • 제26권8호
    • /
    • pp.1719-1726
    • /
    • 2002
  • Design variables and design parameters are rarely deterministic in practice. Robust optimal design takes into consideration of the uncertainties in the design variables and parameters. Robust optimization methodology with probability constraints requires a lot of system analyses fer calculating failure probability of each constraint. By introducing an envelope function to reduce the number of constraints, efficiency of robust optimization techniques can be considerably improved. Through four illustrative examples, it is shown that the number of system analyses is greatly decreased while little differences in the optimum results are observed.