Processing math: 100%
  • Title/Summary/Keyword: Robust adaptive algorithm

Search Result 376, Processing Time 0.025 seconds

Physics-based Surrogate Optimization of Francis Turbine Runner Blades, Using Mesh Adaptive Direct Search and Evolutionary Algorithms

  • Bahrami, Salman;Tribes, Christophe;von Fellenberg, Sven;Vu, Thi C.;Guibault, Francois
    • International Journal of Fluid Machinery and Systems
    • /
    • v.8 no.3
    • /
    • pp.209-219
    • /
    • 2015
  • A robust multi-fidelity optimization methodology has been developed, focusing on efficiently handling industrial runner design of hydraulic Francis turbines. The computational task is split between low- and high-fidelity phases in order to properly balance the CFD cost and required accuracy in different design stages. In the low-fidelity phase, a physics-based surrogate optimization loop manages a large number of iterative optimization evaluations. Two derivative-free optimization methods use an inviscid flow solver as a physics-based surrogate to obtain the main characteristics of a good design in a relatively fast iterative process. The case study of a runner design for a low-head Francis turbine indicates advantages of integrating two derivative-free optimization algorithms with different local- and global search capabilities.

Mechanical Parameter Identification of Servo Systems using Robust Support Vector Regression (Support Vector Regression을 이용한 서보 시스템의 기계적 상수 추정)

  • Cho Kyung-Rae;Seok Jul-Ki;Lee Dong-Choon
    • Proceedings of the KIPE Conference
    • /
    • 2004.07b
    • /
    • pp.738-741
    • /
    • 2004
  • The overall performance of AC servo system is greatly affected by the uncertainties of unpredictable mechanical parameter variations and external load disturbances. Therefore, to compensate this problem, it is necessary to know different parameters and load disturbances subjected to position/speed control. This paper proposes an online identification method of mechanical parameters/load disturbances for AC servo system using Support Vector Regression (SVR). The proposed methodology advocates analytic parameter regression directly from the training data, rather than adaptive controller and observer approaches commonly used in motion control applications. The experimental results demonstrate that the proposed SVR algorithm is appropriate for control of unknown servo systems even with large measurement noise.

  • PDF

A Study Fast Response Control of Induction Motor by Vector Control Algorithm (벡터제어 알고리즘에 의한 유도전동기의 속응제어에 관한 연구)

  • Hwang, Lak-Hoon;Jang, Jin-Hyog;Shin, Yang-Ho;Lee, Chun-Sang;Cho, Mun-Teak
    • Proceedings of the KIEE Conference
    • /
    • 2001.07b
    • /
    • pp.1172-1175
    • /
    • 2001
  • Recently, vector control without a speed sensor for an inverter induction motor system has been developed. In this paper describes the vector control system estimates rotor speed based on FMRAS(Flux Model Reference Adaptive System). Because of improving the initial condition and drift problem by pure integrator is eliminated, we can be expected to rapid responsibility of the speed estimation. The stability of speed estimator is proved on the basis of hyperstability theory. Proposed control system used TMS320C31 DSP for high speed processing. The effectiveness of the proposed system is verified by simulation and experimental results. This result shows that the highly characteristic speed estimation and robust character of load regulation.

  • PDF

A New Digital Watermarking for Architectural Design Drawing Using LINES and ARCs Based on Vertex (건축설계도면상에서 꼭지점에 기반한 LINE과 ARC를 이용한 디지털 워터마킹)

  • Jang, Bong-Ju;Moon, Kwang-Seok;Young Huh;Kwon, Ki-Ryong
    • Proceedings of the IEEK Conference
    • /
    • 2003.11b
    • /
    • pp.247-250
    • /
    • 2003
  • This paper proposed to digital watermarking technique for architectural drawing using LINES and ARCs based on vertex in CAD system to prevent infringement of copyright from unlawfulness reproductions and distribution. After extract LINES and ARCs from designed drawing, we embed watermarks using adaptive algorithm in each characteristics. Watermarks robust to various attacks like as geometrical transformation as being embedded in LINE's length and ARC's angle information. Also, the proposed method satisfies enough transparency about watermarked drawing because have suitable embedding strength to each component. By experimental result, we confirmed robustness and invisibility of embedded watermarks in several conversions of architectural design drawing.

  • PDF

The Robut Vector Control for I.M. using Fuzzy-Neural Network (퍼지-신경망을 이용한 강인한 유도전동기 벡터제어)

  • Jeon, Hee-Jong;Kim, Beung-Jin;Son, Jin-Geun;Moon, Hark-Yong;Kim, Soo-Gon
    • Proceedings of the KIEE Conference
    • /
    • 1995.11a
    • /
    • pp.293-295
    • /
    • 1995
  • In this article a fuzzy controller and neural network adaptive observer is proposed and applied to the case of induction motor control. The proposed observer which comprises neural network flux observer and neural network torque observer is trained to learn the flux dynamics and torque dynamics and subjected to further on-line training by means of a backpropagation algorithm. Therefore it has been shown that the robust control of induction motor neglects the rotor time constant variations.

  • PDF

Illumination Invariant Face Tracking on Smart Phones using Skin Locus based CAMSHIFT

  • Bui, Hoang Nam;Kim, SooHyung;Na, In Seop
    • Smart Media Journal
    • /
    • v.2 no.4
    • /
    • pp.9-19
    • /
    • 2013
  • This paper gives a review on three illumination issues of face tracking on smart phones: dark scenes, sudden lighting change and backlit effect. First, we propose a fast and robust face tracking method utilizing continuous adaptive mean shift algorithm (CAMSHIFT) and CbCr skin locus. Initially, the skin locus obtained from training video data. After that, a modified CAMSHIFT version based on the skin locus is accordingly provided. Second, we suggest an enhancement method to increase the chance of detecting faces, an important initialization step for face tracking, under dark illumination. The proposed method works comparably with traditional CAMSHIFT or particle filter, and outperforms these methods when dealing with our public video data with the three illumination issues mentioned above.

  • PDF

A Study on Driving Control using Neural Network Identifier (신경회로망 동정기를 이용한 AGV의 주행제어에 관한 연구)

  • 이영진;이진우;손주한;최성욱;김한근;조현철;이권순
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2000.10a
    • /
    • pp.151-151
    • /
    • 2000
  • The objective of this paper is to develop the new robust and adaptive control system against external environments as applying the probabilistic recognition which is one of the inherent properties of immune system, ability of learning and memorization, and regulation theory of immune network to the system under engineering point of view. In this paper, HIA(Humoral Immune Algorithm) PID controller using Neural Network Identifier was proposed to drive the autonomous guided vehicle(AGV) more effectively. To verify the performance of the proposed HIA PID controller, some experiments for the control of steering and speed of that AGV are performed.

  • PDF

Robust Terrain Reconstruction Using Minimal Window Technique (최소 윈도우 기법을 이용한 강인한 지형 복원)

  • Kim Dong-Gyu;Woo Dong-Min;Lee Kyu-Won
    • The Transactions of the Korean Institute of Electrical Engineers D
    • /
    • v.52 no.3
    • /
    • pp.163-172
    • /
    • 2003
  • A stereo matching has been an important tool for the reconstruction of 3D terrain. The current state of stereo matching technology has reached the level where a very elaborate DEM(Digital Elevation Map) can be obtained. However, there still exist many factors causing DEM error in stereo matching. This paper propose a new method to reduce the error caused by the lack of significant features in the correlation window The proposed algorithm keeps the correlation window as small as possible, as long as there is a significant feature in the window. Experimental results indicate that the proposed method increases the DEM accuracy by 72.65% in the plain area and 41.96% in the mountain area over the conventional scheme. Comparisons with Kanade's result show that the proposed method eliminates spike type of errors more efficiently than Kanade's adaptive window technique and produces reliable DEM.

Fuzzy Modeling and Design of Fuzzy Controller Using Fuzzy Clustering (퍼지 클러스터링을 이용한 퍼지 모델링과 퍼지 제어기의 설계)

  • Kwag, Keun-Chang;Park, Sang-Min;Ryu, Jeong-Woong
    • Proceedings of the KIEE Conference
    • /
    • 1997.07b
    • /
    • pp.675-678
    • /
    • 1997
  • In this paper, we present a fast and robust algorithm for the design of fuzzy controller and identifying fuzzy model from numerical data by combining the cluster estimation method with a linear least squares estimation procedure. The proposed method is compared with Adaptive Neuro-Fuzzy Inference System(ANFIS) as the standard example of neuro-fuzzy model. Finally we will show its usefulness and effectiveness for the design of fuzzy controller of a cart-pole system and fuzzy modeling for the coagulant dosing of a water purification system.

  • PDF

Automatic Registration between EO and IR Images of KOMPSAT-3A Using Block-based Image Matching

  • Kang, Hyungseok
    • Korean Journal of Remote Sensing
    • /
    • v.36 no.4
    • /
    • pp.545-555
    • /
    • 2020
  • This paper focuses on automatic image registration between EO (Electro-Optical) and IR (InfraRed) satellite images with different spectral properties using block-based approach and simple preprocessing technique to enhance the performance of feature matching. If unpreprocessed EO and IR images from Kompsat-3A satellite were applied to local feature matching algorithms(Scale Invariant Feature Transform, Speed-Up Robust Feature, etc.), image registration algorithm generally failed because of few detected feature points or mismatched pairs despite of many detected feature points. In this paper, we proposed a new image registration method which improved the performance of feature matching with block-based registration process on 9-divided image and pre-processing technique based on adaptive histogram equalization. The proposed method showed better performance than without our proposed technique on visual inspection and I-RMSE. This study can be used for automatic image registration between various images acquired from different sensors.