• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.1
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• pp.51-57
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• 2011

Information of the lateral velocity and the sideslip angle in a vehicle is very useful in many active vehicle safety applications such as yaw stability control and rollover prevention. Because cost-effective sensors to measure the lateral velocity and the sideslip angle are not available, reliable algorithms to estimation them are necessary. In this paper, a sliding mode observer is designed to estimate the lateral velocity. The side slip angle is estimated using the recursive least square with the disturbance observer and the pseudo integral. The estimated parameters from the combined estimation method are updated recursively to minimize the discrepancy between the model and the physical plant, and any possible effects caused by disturbances. The performance of the proposed monitoring system is evaluated through simulations and experiments.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.8
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• pp.710-716
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• 2010

This note represents a new disturbance observer to reduce effects of external disturbances. In case of conventional disturbance observers, additional stabilizing filters, so-called Q-filter, should be used because the conventional ones don't guarantee stability. But, the proposed one doesn't need the stabilizing filter, which is a fundamentally different research result from previous methods. Experimental verifications show this approach is realizable and valid to enhance precise positioning.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.5
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• pp.5-14
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• 2003

Tracking control schemes on the precise mechanical system in presence of nonlinear dynamic friction is proposed. A nonlinear dynamic friction is regarded as the bristle friction model to compensate fer effects of friction. The conventional SMC method often shows poor tracking performance in high-precision position tracking application since it cannot completely compensate for the friction effect below a certain precision level. Thus to improve the precise position tracking performance, we propose the SMC method combined with the disturbance observer having tunable transient performance. Then this control scheme has the high precise tracking peformance as well as a good transient response when it is compared with the conventional SMC method and the similar types of observers, The experiment on the XY ball-screw drive system with the nonlinear dynamic friction confirms the feasibility of the proposed control scheme.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.186-189
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• 2001

In a precise control system, the Lu-Gre friction model has often been used to describe the nonlinear friction. For the XY table system with this friction model, we identified the friction parameters and designed nonlinear observer. The nonlinear friction effects could be removed within appropriate position tracking errors and control inputs through experiments. Also, we designed the nonmodel-based SMC system to compensate the nonlinear friction. Through experiments, it is shown that this method has the similar performance compared with the nonlinear observer system and is useful when friction parameters are hard to identify except the problem of input chattering.

• Journal of the Korean Society of Safety
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• v.16 no.4
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• pp.88-95
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• 2001

Stator core loss has significant adverse effects when an induction motor is controlled by the conventional vector control method. Therefore, taking core toss into account should make it possible to control the torque very precisely. This paper proposes a speed sensorless vector control method for an induction motor at optimum efficiency and high response taking core loss account. The proposed vector control system consists of a speed adaptive rotor flux observer which takes core loss into account and employs a direct vector control which compensates for the influence of core loss. Also, in this paper, a vector controlled induction motor with a deadbeat rotor flux controller is developed. The method ensures optimum efficiency in the steady state without degradation of the dynamic response. The validity of the proposed technique is confirmed by simulation results for induction motor drive system.

• Journal of Power Electronics
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• v.2 no.1
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• pp.55-66
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• 2002

A new on-line dead-time compensation method for a permanent magnet (PM) synchronous motor drive is proposed. Using a simple disturbance observer without any additional circuit and off-line experimental measurement, disturbance voltages in the synchronous reference dq frame caused by the dead time and non-ideal switching characteristics of power devices are estimated in an on-line manner and fed to voltage references in order to compensate the dead-time effects. The proposed method is applied to a PM synchronous motor drive system and implemented by using software of a digital signal processor (DSP) TMS320C31. Simulations and experiments are carried out for this system and the results well demonstrate the effectiveness of the proposed method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1730-1734
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• 2005

In this paper, a new Smith predictor controller for a disturbance adding to input side of a time delay plant is proposed. A disturbance observer is obtained to estimate an input disturbance and the new Smith predictor controller to eliminate the effects of a disturbance is designed using the disturbance observer. As a result, the proposed Smith predictor controller can make a steady state error for step input disturbance zero quickly. The effectiveness and the improved performance of the proposed system are verified by computer simulation.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.1
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• pp.19-26
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• 2007

This paper presents a precision position control of induction motor using disturbance observer to reduce disturbance effects. It shows that proposed algorithm is strong in induction motor precision control for disturbance change. This system with disturbance observer using deadbeat control, which has high benefit, is good for quick disturbance compensation. To show this effectiveness the whole process is simulated by simulink, and also experimented by DSP6416 with TCP-IP network board.

• Journal of IKEEE
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• v.13 no.1
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• pp.36-40
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• 2009

In control of time delay systems, if the informations about the system model and the disturbance can be estimated exactly, the ideal response can be achieved by using Smith predictor controller. Therefore, in this paper, an adaptive algorithm is proposed to control time delay systems existing modelling errors and disturbance. An adaptive observer to estimate disturbance and system model is designed and adaptive laws adjusting the observer are proposed. The new Smith predictor controller is designed using the proposed adaptive observer. As a result, the proposed controller can eliminate the effects of the disturbance and the modelling error. The effectiveness and the improved performance of the proposed system are verified by computer simulation.

• 대한공업교육학회지
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• v.34 no.2
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• pp.396-410
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• 2009

The goal of this work is to present an advanced method of an estimation of the Modeling Uncertainties coming up in industrial rigid robot's manipulator and actuators. First, with the given physical robot model, the motion equation was derived. Considering a fictitious model, a new extended motion equation is developed. Based on this extended model, an observer and observer bank are designed for the estimation of modeling uncertainties which are involving the effects of gravity, friction, mass unbalance, and Coriolis which show the nonlinear characteristics in operation states.