• Title/Summary/Keyword: 슬라이딩 알고리즘

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Sliding Mode Control with Super-Twisting Algorithm for Surge Oscillation of Mooring Vessel System (슈퍼트위스팅 슬라이딩모드를 이용한 선박계류시스템의 동적제어)

  • Lee, Sang-Do;Lee, Bo-Kyeong;You, Sam-Sang
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.7
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    • pp.953-959
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    • 2018
  • This paper deals with controlling surge oscillations of a mooring vessel system under large external disturbances such as wind, waves and currents. A control synthesis based on Sliding Mode Control (SMC) with a Super-Twisting Algorithm (STA) has been applied to suppress nonlinear surge oscillations of a two-point mooring system. Despite the advantages of robustness against parameter uncertainties and disturbances for SMC, chattering is the main drawback for implementing sliding mode controllers. First-order SMC shows convergence within the desired level of accuracy, in which chattering is the main obstacle related to the destructive phenomenon. Alternatively, STA completely eliminates chattering phenomenon with high accuracy even for large disturbances. SMC based on STA is an effective tool for the motion control of a nonlinear mooring system because it avoids the chattering problems of a first-order sliding mode controller. In addition, the error trajectories of controlled mooring systems implemented by means of STA form in the bounded region. Finally, the control gain effect of STA can be observed in sliding surface and position trajectory errors.

Autonomous Navigation Algorithm Development with Extended Kalman Filter and Sliding Mode Control (확장형 칼만필터와 슬라이딩 모드 제어기법을 이용한 자율항법 알고리즘 개발)

  • Yun, Duk-Sun;Yu, Hwan-Shin
    • Journal of Advanced Navigation Technology
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    • v.11 no.4
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    • pp.378-387
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    • 2007
  • In this paper, Authors develop and verify the algorithm for enhancing the performance of Unmanned vehicle's Autonomous navigation, and also propose the method of establishing much more precise Navigation locus. Unmanned vehicle has a destination, however orientation is not notified, which make it find the future orientation itself. Extended Kalman Filter make it access to the desirable direction, which coupled with INS and GPS is proposed in this paper. Sliding mode control could overcome the side slip and lateral minor movement of the vehicle. The test result would shows the effectiveness of Extended kalman filter and Slide mode control for the navigation.

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Design of Integral Sliding Mode Control for Underactuated Mechanical Systems (부족구동 기계시스템을 위한 적분 슬라이딩 모드 제어기 설계)

  • Yoo, Dong Sang
    • Journal of the Korean Institute of Intelligent Systems
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    • v.23 no.3
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    • pp.208-213
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    • 2013
  • The problem of finding control laws for underactuated systems has attracted growing attention since these systems are characterized by the fact that they have fewer actuators than the degrees of freedom to be controlled. A sliding mode control based on the theory of variable structure systems is a robust methodology to control nonlinear systems. In this paper, a sliding mode control with integral sliding function is proposed and asymptotical stability is proved in the Lyapunov's sense for underactuated systems. In order to verify the effectiveness of the proposed control, computer simulations for an acrobot, which is a representative underactuated system, are performed. Using Mathworks' Simulink/Simscape, the acrobot dynamics is implemented and the proposed control is composed. Simulations demonstrate the effectiveness and usefulness of the proposed control.

A Packet Detection Algorithm for IEEE802.11n System (IEEE802.11n 시스템에 적용 가능한 패킷 검출 알고리즘)

  • Jung, Hyeok-Koo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.4C
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    • pp.330-335
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    • 2008
  • This paper proposes a packet detection algorithm for IEEE802.11n system. IEEE802.11n is a multiple input multiple output (MIMO) system and we have to consider several combining techniques which are used in multiple receive antenna system. In this paper, we propose a hybrid packet detection algorithm which combines double sliding window algorithm or delay and correlation algorithm, that is used in single input single output (SISO) system, and multiple receive antenna combining algorithms, and simulated their performances in Iin system environments and shows the results.

Cost-Aware Cache Algorithm for Dynamic XIP (eXecute In Place) (동적 XIP(eXecute In Place)를 위한 비용 인식 캐시 알고리즘 설계)

  • Dohun Kim;Chanik Park
    • Proceedings of the Korea Information Processing Society Conference
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    • 2008.11a
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    • pp.820-823
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    • 2008
  • 본 논문은 기존의 XIP 기법에서 발생할 수 있는 메모리 접근 성능저하를 해결하기 위한 동적 XIP 기법을 제안하였다. 동적 XIP 기법은 상대적으로 성능저하가 적을 것으로 예상되는 코드 페이지들을 동적으로 선택하여 XIP 영역으로 설정하고, 성능저하가 크게 나타날 것으로 예상되는 코드 페이지들을 램 캐시에 캐싱하여 성능을 향상시킨다. 본 논문은 램 캐시를 관리하기 위해 MIN 캐시 알고리즘 및 메모리 접근 비용을 고려한 오프라인 캐시 알고리즘과, 페이지 접근에 대한 최신성(Recency) 및 슬라이딩 윈도우에 저장된 페이지 접근 기록에 기반하여 메모리 접근 비용을 예측하는 온라인 캐시 알고리즘, 온라인 캐시 알고리즘의 램 캐싱 판단의 정확성을 높이는 기법을 제안하였다. 본 논문은 온·오프라인 알고리즘의 성능비교를 위해 시뮬레이터를 통해 성능을 평가하였고, 유용성을 시험하기 위해 온라인 알고리즘을 리눅스를 기반으로 구현하여 성능을 평가하였다. 본 논문에서 제안한 동적 XIP는 실제 구현한 환경에서 실험한 결과, 작은 크기의 캐시를 사용하고도 수행시간에서는 최대 27%, 에너지 소모량에서는 최대 24%의 성능이 향상됨을 보였다.

A Sliding Window-based Multivariate Stream Data Classification (슬라이딩 윈도우 기반 다변량 스트림 데이타 분류 기법)

  • Seo, Sung-Bo;Kang, Jae-Woo;Nam, Kwang-Woo;Ryu, Keun-Ho
    • Journal of KIISE:Databases
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    • v.33 no.2
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    • pp.163-174
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    • 2006
  • In distributed wireless sensor network, it is difficult to transmit and analyze the entire stream data depending on limited networks, power and processor. Therefore it is suitable to use alternative stream data processing after classifying the continuous stream data. We propose a classification framework for continuous multivariate stream data. The proposed approach works in two steps. In the preprocessing step, it takes input as a sliding window of multivariate stream data and discretizes the data in the window into a string of symbols that characterize the signal changes. In the classification step, it uses a standard text classification algorithm to classify the discretized data in the window. We evaluated both supervised and unsupervised classification algorithms. For supervised, we tested Bayesian classifier and SVM, and for unsupervised, we tested Jaccard, TFIDF Jaro and Jaro Winkler. In our experiments, SVM and TFIDF outperformed other classification methods. In particular, we observed that classification accuracy is improved when the correlation of attributes is also considered along with the n-gram tokens of symbols.

The Output Voltage Control of Buck Type DC-DC Converter Using Sliding Mode and Neural Controller (슬라이딩 모드와 Neural network 제어기를 이용한 Buck type DC-DC 컨버터의 출력전압제어)

  • Hwang, Gye-Ho;Nam, Seung-Sik;Kim, Dong-Hee;Bae, Sang-June
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.3
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    • pp.95-100
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    • 2004
  • A control alogorithm using sliding mode and neural network for Buck type DC-DC converter is presented. Also, we conform a rightness the proposal method by comparing a theoretical values and experimental values obtained from experiment using DSP(digital signal processor). Performance comparisons made with the general hysteresis controller clearly bring out the superior performance of the proposal neural network controller. This paper will be applied to other power conversion system using the proposal neural network controller.

Robust Output Feedback Control Using a Servocompensator (서보보상기를 사용한 견실 출력귀환제어)

  • Lee, Ho-Jin;Lee, Keum-Won
    • Journal of the Institute of Convergence Signal Processing
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    • v.8 no.3
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    • pp.217-221
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    • 2007
  • This paper deals with the robust nonlinear controller design using output feedback for a Chua circuit which is one of the well-known nonlinear models. First, an exosystem for reference signal tracking is defined, and error dynamic equations are derived from the differentiation of the output tracking error equation. The normal sliding surface is modified using the integral type servo compensator. The parameters in the equations of the modified sliding surface and servo compensator are determined by using the Hurwitz condition of stability. Especially the error signals can't be obtained directly from the output because all parameters are assumed unknown. So instead, a high gain observer is designed. From this estimated error signals, a stabilizing controller is designed. Simulation is done for demonstrating the effectiveness of the suggested algorithm.

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RVEGA SMC for Precise Level Control of Coupled Tank System (이중 탱크 시스템의 정밀 수위 제어를 위한 RVEGA SMC에 관한 연구)

  • 김태우;이준탁
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.13 no.4
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    • pp.102-108
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    • 1999
  • The sliding rmde controller(SMC) is known as having the robust variable structures for the nonlinear control systems such as coupled tank system with the pararretric perturbations and with the rapid disturbances. But the adaptive tuning algorit1uns for their pararreters are not satisfactory. Therefore, in this paper, a Real Variable Elitist Genetic Algorithm based Sliding Mode Controller (RVEGA SMC) for the precise control of the coupled tank level was tried. The SMC's switching pararreters were optimized easily and rapidly by RVEGA The simulation results showed that the tank level could be satisfactorily controlled without any overshoot and any steady-state error by the proposed RVEGA SMC.GA SMC.

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Dubins Path Generation and Tracking of UAVs With Angular Velocity Constraints (각속도 제한을 고려한 무인기의 Dubins 경로 생성 및 추적)

  • Yang, You-young;Jang, Seok-ho;Leeghim, Henzeh
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.2
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    • pp.121-128
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    • 2021
  • In this paper, we propose a path generation and tracking algorithm of an unmanned air vehicle in a two-dimensional plane given the initial and final points. The path generation algorithm using the Dubins curve proposed in this work has the advantage that it can be applied in real time to an unmanned air vehicle. The path tracking algorithm is an algorithm similar to the line-of-sight induction algorithm. In order to efficiently control the direction angle, a gain related to the look ahead distance concept is introduced. Most of UAVs have the limited maximum curvature due to the structural constraints. A numerical simulation is conducted to follow the path generated by the sliding mode controller considering the angular velocity limit. The path generation and tracking performance is verified by comparing the suggested controller with conventional control techniques.