• Journal of Institute of Control, Robotics and Systems
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• v.18 no.4
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• pp.308-313
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• 2012

Robust tuning rules of the motion profile are proposed to minimize the residual vibration. For asymmetric S-curve profile, tuning rules are analytically formulated using Laplace-domain approach. When the system modeling is known exactly, by placing a single zero of the motion profile on the pole of the system, the residual vibration can be perfectly eliminated under undamped system. However, if there are some amounts of the modeling errors, the residual vibration significantly increases. To track this issue, the robust tuning rules against modeling error are discussed. One of the proposed robust tuning rules is placing the multiple zeros of the motion profile on the pole of the system, and the other is placing the zeros of the motion profile around the pole of the system. Thanks to the proposed robust tuning rules, motion profile becomes more robust to modeling errors while minimizing the residual vibration. By simulation, the effectiveness of the proposed robust tuning rules is verified.

• Journal of information and communication convergence engineering
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• v.8 no.6
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• pp.640-644
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• 2010

When we talk with hands-free in a car or noisy lobby, the performance of the echo canceller degrade because background noise added to echo caused by the distance from mouth to microphone is relatively long. It gives a reason for necessity of noise-robust and high convergence speed adaptive algorithm. And if acoustic echo canceller operated not perfectly, residual signal going through the echo canceller to far-end speaker remains residual echo, which degrade quality of talk. To solve this problem, post-processing needed to remove residual echo ones more. In this paper, we propose a new acoustic echo canceller, which has noise robust and high convergence speed, linked with linear predictor as a post-processor. By computer simulation, it is confirmed that the proposed algorithm shows better performance from acoustic interference cancellation (AIC) viewpoint.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.836-840
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• 2006

Design optimization of layered plates bonding process is conducted to achieve high product quality by considering uncertainties in a manufacturing process. During the cooling process of the sequential sub-processes, different thermal expansion coefficients lead to residual stress and displacement. thus resulting in defects on the surface of the adherent. So robust process optimization is performed to minimize the residual stress mean and variation of the assembly while constraining the distortion as well as the instantaneous maximum stress to the allowable limits. In robust process optimization, the dimension reduction (DR) method is employed to quantify both reliability and quality of the layered plate bonding. Using this method. the average and standard deviation is estimated. Response surface is constructed using the statistical data obtained by the DRM for robust objectives and constraints. from which the optimum solution is obtained.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.3
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• pp.52-61
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• 2012

The design method for cumulative sum (CUSUM) control charts, which can be robust to autoregressive moving average (ARMA) modeling errors, has not been frequently proposed so far. This is because the CUSUM statistic involves a maximum function, which is intractable in mathematical derivations, and thus any modification on the statistic can not be favorably made. We propose residual-based robust CUSUM control charts for monitoring autocorrelated processes. In order to incorporate the effects of ARMA modeling errors into the design method, we modify parameters (reference value and decision interval) of CUSUM control charts using the approximate expected variance of residuals generated in model uncertainty, rather than directly modify the form of the CUSUM statistic. The expected variance of residuals is derived using a second-order Taylor approximation and the general form is represented using the order of ARMA models with the sample size for ARMA modeling. Based on the Monte carlo simulation, we demonstrate that the proposed method can be effectively used for statistical process control (SPC) charts, which are robust to ARMA modeling errors.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.3
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• pp.198-208
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• 2001

In this paper, vibration suppression of an elastic beam fixed on a moving cart and carrying a fixed or moving mass is considered. A modified pulse sequence method with RIC(Robust Internal-loop Compensator) is proposed to suppress the single model residual vibration and to get accurate positioning of the beam-mass-cart system. The performance of the proposed input preshaping method is compared with that of the previous ones through simulations and experiments. Using the proposed method, it is able to suppress the initial vibration of the beam-mass-cart system carrying a concentrated mass. Accurate PTP(point-to-point) positioning of the moving mass without residual vibration is also obtained experimentally by modifying the proposed pulse sequence method. Finally, the proposed input preshaping method is applied successfully to the system to follow square trajectories of the moving mass without residual vibration.

• 한국데이터정보과학회:학술대회논문집
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• 2003.10a
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• pp.93-100
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• 2003

It is necessary to check the curvature of selected covariates in regression diagnostics. There are various graphical methods using residual plots based on least squares fitting. The sensitivity of LS fitting to outliers can distort their residuals, making the identification of the unknown function difficult to impossible. In this paper, we compare combining conditional expectation and residual plots(CERES Plots) between least square fit and robust fits using Huber M-estimator. Robust CERES will be far less distorted than their LS counterparts in the presence of outliers and hence, will be more useful in identifying the unknown function.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.1 s.256
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• pp.113-120
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• 2007

Design optimization of layered plates bonding process is conducted by considering uncertainties in a manufacturing process, in order to reduce the crack failure arising due to the residual stress at the surface of the adherent which is caused by different thermal expansion coefficients. Robust optimization is peformed to minimize the mean as well as its variance of the residual stress, while constraining the distortion as well as the instantaneous maximum stress under the allowable reliability limits. In this optimization, the dimension reduction (DR) method is employed to quantify the reliability such as mean and variance of the layered plate bonding. It is expected that the DR method benefits the optimization from the perspectives of efficiency, accuracy, and simplicity. The obtained robust optimal solution is verified by the Monte Carlo simulation.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.130-130
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• 2000

This paper presents a robust fault diagnosis and fault tolerant control lot the actuator and sensor faults in the closed-loop systems affected by unknown inputs or disturbances. The fault diagnostic scheme is based on the residual set generation by using robust Parity space approach. Residual set is evaluated through the threshold test and then fault is isolated according to the decision logic table. Once the fault diagnosis module indicates which actuator or sensor is faulty, the fault magnitude is estimated by using the disturbance-decoupled optimal state estimation and a new additive control law is added to the nominal one to override the fault effect on the system. Simulation results show that the method has definite fault diagnosis and fault tolerant control ability against actuator and sensor faults.

• The Journal of Korea Robotics Society
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• v.16 no.1
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• pp.72-78
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• 2021

This paper presents a robust impedance control of high-DOF robot based on disturbance observer(DOB). A novel DOB is derived by considering the residual disturbance caused by the difference between actual disturbance and disturbance decoupling input which utilizes the estimated disturbance. It focuses on the elimination of the residual disturbance and improvement of the control performance as well as the good estimation of disturbances. In the control of high-DOF robot, numerical dynamic model, which is conducted by a software based on dynamics, is utilized because the analytical model of high-DOF robot is difficult to be obtained. The simulation of high-DOF robot with numerical dynamic model is provided to verify the performance of the proposed controller.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.14 no.4
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• pp.31-37
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• 2006

In this paper, an experimental study on the robust input shaping for control of the residual vibration of flexible structures has been investigated. Two approaches has been used for the robustness of input shaping: the first method is to increase the number of impulses, and the other includes an EI shaper using vector diagram. The input case designed by the application of the above methods has been applied to a control problem involving residual vibration of a rotating hub with two flexible appendages. It has been found by a series of experiments that the input shaper designed in this paper works well for the residual vibration control of the flexible structure.