• 한국정밀공학회지
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• 제23권4호
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• pp.44-51
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• 2006

This paper addresses sliding mode control of the anti-lock braking system (ABS) with a disturbance observer for model uncertainties such as vehicle parameter variation, un-modeled dynamics, and external disturbances. By using a nominal vehicle model, a sliding mode controller is designed to achieve a desired wheel slip ratio for ABS control. To compensate the model uncertainties, a disturbance observer is introduced with the help of a transfer function of a hydraulic brake dynamics. A proposed sliding mode controller with a disturbance observer is evaluated through simulations for model uncertainties. The simulation results show that the disturbance observer can enhance performances of sliding mode control for ABS.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.1011-1015
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• 2000

In this paper, the case studies of reducing rotational errors is theoretically done for a grinding spindle with an active magnetic bearing system. The rotational errors acting on the magnetic bearing spindle are due to mass unbalance of rotor, runout, grinding excitation and unmodeled nonlinear dynamics of electromagnets. The adaptive feedforward method based on LMS algorithm is discussed to compensate output and input disturbances, and investigated its effectiveness by numerical simulation. The feedforward control reduced external excitation and rotational error for specified frequency. The interpolation method using impulse function for cancelling the electrical 'uncut is studied. These methods show their effectiveness for the rotational accuracy of the improving magnetic bearing spindle through some simulation results of the rotational error decreased by them.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1992년도 춘계학술대회 논문집
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• pp.157-161
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• 1992

Up to now, there has been a lot of researches on the sliding mode control which has the insensitive characteristics to the variations of plant parameters, nonlinearities and external disturbances. One dificulty in applying the sliding mode control is the need for the knowledge of the full-state vector. The use of state observer is a natural step towards the relaxation of this condition. However, the exact plant-modeling is assumed to be known. Recently, there has been a remarkable advance in the microprocessor and one can construct the controller which could not realize due to hardware restriction in the past. Therefore in this paper, the PID sliding mode controller which has only one output feedback signal is suggested by means of microprocessor and the performance of electro-hydraulic servosystem compersated with this controller is proved.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.80-82
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• 1997

A robust position control system for a BLDC motor using new sliding mode control strategy is presented. Using the new variable structure system, reaching phase problem is eliminated and transient response is largely improved by design of nonlinear sliding surface. The design of the sliding mode position controller is robust in motor parameter, load variations and disturbance. Experiment results show that the proposed approach can achieve accurate position motor tracking in face of large parameter variations and external disturbances, such as a robot arm, etc.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1517-1518
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• 2008

Optical disk driver is being used in many electronic products besides computer. In particular, the demands are recently increased as an optical disk player in the mobile products such as camcorder or in the home theater appliances, or etc. However, under these circumstances, the disturbance inputs to the optical disk player increase gradually. In this paper, for reducing the possibility of malfunction of the optical disk player, we propose the method of detecting and controling the non-periodic external shock of the disturbances. Also, we execute some simulations and actual experiments and discuss the results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1775-1776
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• 2008

This paper presents a adaptive fuzzy control suitable for motion control of multi-link robot manipulators with uncertainties. When joint velocities are available, full state adaptive fuzzy feedback control is designed to ensure the stability of the closed loop dynamic. If the joint velocities are not measurable, an observer is introduced and an adaptive output feedback control is designed based on the estimated velocities. To reduce the number of fuzzy rules of the fuzzy controller, we consider the properties of robot dynamics and the decomposition of the unknown input gain matrix. The proposed controller is robust against uncertainties and external disturbances. The validity of the control scheme is demonstrated by computer simulations on a two-link robot manipulator.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.1337-1338
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• 2015

In this paper, a new control technique using WIPDC(Weighted Integral Parallel Distributed Compensation) and ISMC(Integral Sliding Mode Control) is proposed for high performance and robust trajectory tracking control of a wheeled mobile robot. The WIPDC reduces the steady-state error by adding a weighted integral controller to the PDC. So, the trajectory tracking control using the WIPDC can obtain more accurate control performance than the PDC. And the ISMC based control input gives the mobile robot to preserve the system dynamics controlled by the WIPDC control input in spite of external disturbances. Therefore, the proposed control method shows a robust and precise trajectory tracking performance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.649-651
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• 2015

This paper describes a robust adaptive sliding mode control (RASMC) for torque ripple minimization of switched reluctance motor (SRM) using it in automotive application. The objective is to control effort smoothness while the system is under perturbations by unstructured uncertainties, unknown parameters and external disturbances. The control algorithm employs an adaptive approach to remove the need for prior knowledge within the bound of perturbations. This is suitable for tackling the chattering problem in the sliding motion of sliding mode control method. The algorithm then incorporates modifications in order to build a chattering-free modified robust adaptive sliding mode control using Lyapunov stability theory.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.484-490
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• 2000

The abjective of the study is the development of the system for effective prediction of residual stresses using the backpropagation algorithm from the neural network. To achieve this goal, the series experiment were carried out and measured the residual stresses using the sectional method. Using the experimental results, the optional control algorithms using a neural network should be developed in order to reduce the effect of the external disturbances on during GMA welding processes. Then the results obtained from this study were compared between the measured and calculated results, the neural network based on backpropagation algorithm might be controlled weld quality. This system can not only help to understand the interaction between the process parameters and residual stress, but also improve the quantity control for welded structures.

• 유공압시스템학회논문집
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• 제1권1호
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• pp.23-30
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• 2004

This paper deals with the issue of trajectory tracking control of a hydraulic excavator using disturbance observer in order to compensate external disturbances occuring from coupling between attachment, asymmetry of a single rod cylinder, and deadzone of main control valve. Disturbance compensation control system with disturbance observer has been constructed for the boom and arm respectively. Simulation results were compared with experimental results to validate the computer simulation system of hydraulic excavator itself. Computer simulation shows that disturbance compensation control is effective for compensating system nonlinearity and thus improves positioning accuracy and trajectory tracking performance. Steady state error has been decreased by adding PI controller to this control scheme.