• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.332-332
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• 2000

In this paper, a novel sliding mode control with uncertainty adaptation is produced by introducing a virtual state. Because upper bounds of the uncertainty is difficult to know, we estimate these upper bound by using the simple adaptation law and design the novel sliding mode controller. The nominal controller is used the optimal controller to minimize cost function.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.04a
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• pp.163-171
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• 2001

This paper presents sliding mode control(SMC) method using target variation rate of Lypunov Function. SMC keeps the response of structure in sliding surface where structure is stable. It can design both linear controller and bang-bang controller. Linear control of previous research, however, can not make most of the performance of controller, because it is designed to satisfy the condition that the variation rate of Lyapunov function is minus. Also, incase of bang-bang controller, unnecessary large control force is generated. Presented method can utilize the capacity of controller efficiently by prescribing the target variation rate of Lyapunov function. Numerical simulation results indicate that the presented control methods can reduce the peak response larger than linear control, and it has control performance equivalent to bang-bang control.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.2
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• pp.152-162
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• 2008

This paper presents a sliding mode controller (SMC) to directly control the active and reactive powers of a doubly ffd induction generator (DFIG) for wind turbines. Sliding-mode control (SMC) and space-vector modulation (SVM) are combined to ensure high-performance operation. SMC scheme is designed to provide robust and fast power controls without frame transformation and current controller used in the conventional FOC drive. Simulation results and experimental results demonstrate that proposed methods preserve the effectiveness and robustness during variations of active and reactive power.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1636-1637
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• 2007

The sliding mode controller(SMC) is very famous controller for nonlinear control. However the SMC has a defect which is chattering problem. In this paper, we introduce the novel method which reduce the chattering problem. And we compare the performance with conventional methods, such as using low pass filter(LPF), boundary layer approach.

• Journal of Electrical Engineering and Technology
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• v.11 no.3
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• pp.662-669
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• 2016

In this work, nonlinear control of a three-phase shunt active power filter (SAPF) has been studied and compared to classical control based on proportional integral regulator. The control strategy is based on the direct current method using sliding mode control (SMC), where the aim is to regulate the average voltage across the dc bus of the inverter. Details are given for the control algorithm; the controller is comprised of a current loop which utilizes a hysteresis controller to generate the gating signals for the switching devices, and a nonlinear controller based on SMC law which is different from classical laws based on error between reference and measured output voltage of the inverter. Sliding surface applied in this work contains the whole of state variables, in order to ensure full control of the system behavior in the presence of disturbances that affect the supply source, the load parameters or the reference value. The designed controller offers advantage that it can gives the improvement of dynamic and static performances in cases of large disturbances. A comparison of the effects of PI control and SMC on the APF response in steady stat, under line variations, load variations, and different component variations is performed.

• Proceedings of the KIPE Conference
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• 2002.11a
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• pp.7-11
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• 2002

This paper proposes an APF(Active Power Filter) with WRIM(Wounded Rotor Induction Motor) controlled by sliding mode which can compensate harmonic currents generated in a power system. As non-linear loads increase gradually in industry fields, harmonic current generated In the electric power network system also increases. Harmonic current makes a power network current distorted and generates heat, vibration and noise In the power machinery, Many approaches have been applied to compensate harmonic currents generated in the power system. Among various control strategy, in this paper, a sliding mode controlled systems is designed and evaluated. This is a flywheel compensator based on secondary excitation of WRIM(wounded rotor induction motor) with SMC(sliding mode controller). The proposed system uses a flywheel as an energy storage device. The designed control scheme is verified through simulation.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.970-972
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• 1998

In this paper, the standard Dole, Glover, Khargoneker, and Francis (abbr. : DGKF 1989) $H_{\infty}$ controller $(H_{\infty}C)$ is extended to the nonlinear feedback linearization-$H_{\infty}$ /sliding mode controller (NFL-$H_{\infty}$/SMC) to solve the problem associated with the full state feedback for the unmeasurable state variables in the conventional SMC, to obtain the smooth control as the linearized controller for a linear system (or to cancel the nonlinearity for the nonlinear system), and to improve the time-domain performance under worst case.

• ETRI Journal
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• v.38 no.5
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• pp.1008-1018
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• 2016

This paper presents a control scheme for the leader-following formation of multiple robots. The control scheme combines the sliding mode control (SMC) method with the nonlinear disturbance observer (NDOB) technique. The formation dynamics suffer from uncertainties because the individual robots are uncertain. Concerning such formation uncertainties, the leader-following formation dynamics are modeled. Assuming that the formation uncertainties have an unknown boundary, an NDOB-based observer was designed to estimate the formation uncertainties. A sliding surface containing the observer outputs has been defined. Regarding the sliding surface, an SMC-based controller was investigated to form uncertain robots. A sufficient condition in the sense of the Lyapunov theory was proven such that the formation system is asymptotically stable. Herein, some comparison results between the sole SMC method and the second-order SMC method are presented to demonstrate the effectiveness and feasibility of the control scheme for multiple robots in the presence of uncertainties.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1735_1736
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• 2009

This paper discusses about a robust servo system applying PID control to PMSM. The system has robustness by Sliding Mode Controller. A novel sliding surface is defined by virtual state. This sliding surface has nominal dynamics of an original PID control system. So Sliding Mode Control(SMC) technique can be used with PID controller. Its design is based on the augmented system whose dynamics have a higher order than that of the original system. The reaching phase is removed by using an initial virtual state whitch makes the initial sliding function equal to zero.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.9
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• pp.801-806
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• 2015

In this paper, we propose cascade-form velocity controller for a permanent magnet synchronous motor (PMSM). The proposed controller consists of a sliding-mode controller (SMC) for the inner current control loop and a model-predictive controller (MPC) for the outer velocity control loop. With SMC, we can ensure that the current tracking error always converges to zero in finite time. The SMC is designed to track the desired currents. Additionally, with MPC, we can obtain the optimal velocity control input which minimizes the cost function. Constraint conditions for input and input variation are included in the MPC design. The simulation results are included to validate the performance of the proposed controller.