• Title/Summary/Keyword: simultaneous control

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A Simultaneous Experimental Disturbances Identification of Gyro Stabilized 2-Axes Gimbal System for Disturbance Feedforward Compensation Control (2-축 자이로 안정화 김발 시스템의 외란보상 앞먹임 제어를 위한 실험적 2-축 외란 동시 식별)

  • Yeo, Sung Min;Kang, Min Sig
    • Journal of the Korea Institute of Military Science and Technology
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    • v.21 no.4
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    • pp.508-519
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    • 2018
  • This paper concerns on stabilization control of a gyro-stabilized 2-axes gimbal system which is mounted on a moving vehicles such as automobiles, armored vehicles, ships, flying vehicles, etc. A target image acquisition system is attached on the inner gimbal, and the gimbal systems are required to retain high stabilization accuracy in the absolute coordinate in order to provide fine target image while vehicle is moving. The stabilization control performance is hardly depended upon disturbance rejection ability of control, and disturbance feedforward compensation is effective because feedforward compensation reduce the amount of disturbance before the disturbance disturbs the systems. This paper suggests an experimental method which can estimate system parameters and disturbance torques by using 3-axes accelerometer mounted on the inner gimbal. Furthermore, a simple disturbance identification method which can be applied to any slanted base conditions has been suggested to identify mass unbalance vector and friction torques of each gimbal simultaneously. By using the estimated parameters, a feedforward compensation has been applied to the gyro-stabilized 2-axes gimbal system. The experimental results showed that the feedforward compensation based on the identification method suggested is effective to improve stabilization performances.

Simultaneous Fault Isolation of Redundant Inertial Sensors based on the Reduced-Order Parity Vectors

  • Yang, Cheol-Kwan;Shim, Duk-Sun
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2188-2191
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    • 2005
  • We consider a fault detection and isolation problem for inertial navigation systems which use redundant inertial sensors. We propose a FDI method using average of multiple parity vectors which reduce false alarm and wrong isolation, and improve correct isolation. We suggest the number of redundant sensors required to isolate simultaneous faults. The performance of the proposed FDI algorithm is analyzed by Monte-Carlo simulation.

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Design of a Robust Fault Isolation Filter Using Left Eigenstructure Assignment Scheme (좌 고유구조지정 기법을 이용한 견실 고장 분리 필터 설계)

  • 이대영;최재원
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.85-85
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    • 2000
  • In this paper, we propose a novel robust fault isolation filter design method using the left eigenstructure assignment scheme proposed b\ulcorner author. An eigenstructure assignment methodology that satisfies the required fault isolation conditions is also proposed. The proposed method guarantees that the corrupted ${\gamma}$ simultaneous faults can be isolated when the numbers of available output measurements are ${\gamma}$.

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A Robust Fault Isolation Filter Design Based on Left Eigenstructure Assignment and its Application to Flight System (좌 고유구조지정법 기반 결실 고장 분리 필터 설계 및 비행체 시스템에의 응용)

  • Lee, Dae-Yung;Park, Jae-Weon
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.5
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    • pp.384-392
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    • 2001
  • In this paper, we propose a novel robust fault isolation filter design method using the left eigenstructure assignment scheme proposed by the authors. The proposed method guarantees that the ${\gamma}$ simultaneous faults can be isolated when the number of available outpur measurements is ${\gamma}$. Moreover, if there exist redundant output measurements, the eigenvaluses of te filter system can be assigned to the desired position or the filter can be designed robustly to, the system parameter variation. Liu & Si developed a filter design method which has the same purpose, fault isolation. However their method cannot use the redundant freedom of the output matrix C. The proposed filter can use the redundant freedom of the matrix C effectively. Beside this in this paper, an eigenstructure assignment methodology that satisfies the required fault isolation conditions is also proposed. The proposed fault isolation filter was applied for isolating the simultaneous faults to a VTOL aircraft in order to verify the fault isolation performance.

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Development of Pilot-Scale Scrubber for Simultaneous Removal of $SO_2/NO$

  • Jung, Seung-Ho;Jeong, Gwi-Taek;Lee, Gwang-Yeon;Park, Don-Hee;Cha, Jin-Myeong
    • 한국생물공학회:학술대회논문집
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    • 2005.10a
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    • pp.468-474
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    • 2005
  • SOx and NOx are known major precursors of acid rain and thus the abatement of their emissions is a major target in air pollution control. To obtain basic data on the removal process of simultaneous $SO_2/NO$, the optimal reaction condition and the composition of reaction solution for simultaneous removal of $SO_2/NO$, ware investigated using a bubble column reactor. Pilot scrubber was consisted of scrubber, filter and control box. Dust removal rate was 83, 92, and 97% with catalyst flux of 0.5, 0.8, 1.5 L/min, respectively Average dust removal efficiency with a kind of nozzle was about 94 and 90% in STS FF6.5 (5/8in.) and 14 of P.P W(1.0in.), respectively Dust and $SO_2$ were removed more than 98-96% regardless of reactor number. In the case of NO gas, removal yield of 83.3% was achieved after 48 hours in 1 stage, also removal yield of 95.7% was reached in 2 stages. In tile case of application of STS (5/8 in.) and P.P (1.0 in.) as used fill packing, removal efficiency was reached higher than 98% without related to of kind of fill packing.

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Simultaneous destabilization of β-catenin and Ras via targeting of the axin-RGS domain as a potential therapeutic strategy for colorectal cancer

  • Cha, Pu-Hyeon;Choi, Kang-Yell
    • BMB Reports
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    • v.49 no.9
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    • pp.455-456
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    • 2016
  • Mutations of APC and KRAS are frequently observed in human colorectal cancers (CRCs) and the Wnt/β-catenin and Ras pathways are consequently activated in a significant proportion of CRC patients. Mutations in these two genes are also known to synergistically induce progression of CRCs. Through a series of studies, we have demonstrated that inhibition of the Wnt/β-catenin signaling pathway negatively regulates Ras stability, therefore, Ras abundance is increased together with β-catenin in both mice and human CRCs harboring adenomatous polyposis coli (APC) mutations. In a recent study, we identified KY1220, a small molecule that simultaneously degrades β-catenin and Ras by inhibition of the Wnt/β-catenin pathway, and obtained its derivative KYA1797K, which has improved activity and solubility. We found that KYA1797K binds the RGS domain of axin and enhances the binding affinity of β-catenin or Ras with the β-catenin destruction complex components, leading to simultaneous destabilization of β-catenin and Ras via GSK3β activation. By using both in vitro and in vivo studies, we showed that KYA1797K suppressed the growth of CRCs harboring APC and KRAS mutations through destabilization of β-catenin and Ras. Therefore, our findings indicate that the simultaneous destabilization of β-catenin and Ras via targeting axin may serve as an effective strategy for inhibition of CRCs.

A Simultaneous Perturbation Stochastic Approximation (SPSA)-Based Model Approximation and its Application for Power System Stabilizers

  • Ko, Hee-Sang;Lee, Kwang-Y.;Kim, Ho-Chan
    • International Journal of Control, Automation, and Systems
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    • v.6 no.4
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    • pp.506-514
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    • 2008
  • This paper presents an intelligent model; named as free model, approach for a closed-loop system identification using input and output data and its application to design a power system stabilizer (PSS). The free model concept is introduced as an alternative intelligent system technique to design a controller for such dynamic system, which is complex, difficult to know, or unknown, with input and output data only, and it does not require the detail knowledge of mathematical model for the system. In the free model, the data used has incremental forms using backward difference operators. The parameters of the free model can be obtained by simultaneous perturbation stochastic approximation (SPSA) method. A linear transformation is introduced to convert the free model into a linear model so that a conventional linear controller design method can be applied. In this paper, the feasibility of the proposed method is demonstrated in a one-machine infinite bus power system. The linear quadratic regulator (LQR) method is applied to the free model to design a PSS for the system, and compared with the conventional PSS. The proposed SPSA-based LQR controller is robust in different loading conditions and system failures such as the outage of a major transmission line or a three phase to ground fault which causes the change of the system structure.

Fiscal Decentralization, Corruption, and Income Inequality: Evidence from Vietnam

  • NGUYEN, Hung Thanh;VO, Thuy Hoang Ngoc;LE, Duc Doan Minh;NGUYEN, Vu Thanh
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.11
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    • pp.529-540
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    • 2020
  • The objective of this research paper is to study the simultaneous relationship between fiscal decentralization, corruption, and income inequality among Vietnamese provinces. We use a balanced panel data set of 63 provinces/cities in Vietnam in the period from 2011 to 2018. The study used 3SLS-GMM (Three Stage Least Squares - Generalized Method of Moments estimator) and GMM-HAC (Generalized Method of Moments - Heteroskedastic and Autocorrelation Consistent estimator). Empirical evidence shows a strong simultaneous relationship: increased corruption will increase regional income disparities, income inequality, and increase fiscal decentralization. In addition, the results also suggest that an increase in per-capita income will reduce the level of corruption, or better control corruption of each province. The degree of increase in income inequality, which reduces fiscal decentralization, is the same for trade liberalization. All demonstrate that there is a simultaneous relationship between fiscal decentralization, corruption, and income inequality. In a region of high public governance quality, fiscal decentralization positively effects its economic growth. This issue will indirectly increase income inequality between provinces within a country. Our findings imply that a country's fiscal decentralization strategy should be linked to improving corruption control and local governance effectiveness, indirectly improving income inequality between localities or regions.

Simultaneous Localization & Map-building of Mobile Robot in the Outdoor Environments by Vision-based Compressed Extended Kalman Filter (Compressed Extended Kalman 필터를 이용한 야외 환경에서 주행 로봇의 위치 추정 및 지도 작성)

  • Yoon Suk-June;Choi Hyun-Do;Park Sung-Kee;Kim Soo-Hyun;Kwak Yoon-Keun
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.6
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    • pp.585-593
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    • 2006
  • In this paper, we propose a vision-based simultaneous localization and map-building (SLAM) algorithm. SLAM problem asks the location of mobile robot in the unknown environments. Therefore, this problem is one of the most important processes of mobile robots in the outdoor operation. To solve this problem, Extended Kalman filter (EKF) is widely used. However, this filter requires computational power (${\sim}O(N)$, N is the dimension of state vector). To reduce the computational complexity, we applied compressed extended Kalman filter (CEKF) to stereo image sequence. Moreover, because the mobile robots operate in the outdoor environments, we should estimate full d.o.f.s of mobile robot. To evaluate proposed SLAM algorithm, we performed the outdoor experiments. The experiment was performed by using new wheeled type mobile robot, Robhaz-6W. The performance results of CEKF SLAM are presented.

Search Vector Method for Solution Domain Renewal

  • Toriumi, Fujio;Takayama, Jun-ya;Ohyama, Shinji;Kobayashi, Akira
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.61-64
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    • 2003
  • A band function model paired comparison method (BMPC method) is a kind of a paired comparison methods. Considering the human ambiguities, the BMPC method expressing the human judgment characteristics as a monotonous increase function with some width. Since function types are not specified in a BMPC method, the solution is obtained from inequalities, and the solution is given as a domain. To solve the simultaneous inequalities, the sequential renew method is used in the previous BMPC method. However, the sequential renew method requires much computational effort and memories. Generally, in BMPC method, it is able to solve only a paired comparison table which has less 12-13 samples. For that purpose, a new fast solution algorithm is required. In this paper, we proposed a new “search vector method” which renews the solution domain without creating new edge vectors. By using the method, it is able to decrease the necessary memory spaces and time to solve. The proposed method makes it able to solve more than 15 samples paired comparison inspections which are impossible to solve by previous method.

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