• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.1
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• pp.160-167
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• 2010

This paper proposes an adaptive sliding mode observer (SMO), which adds the estimation function of the stator resistance to a new sliding mode observer for the robust sensorless control of permanent magnet synchronous motor (PMSM) with variable parameters. To reduce the chattering problem commonly found in the conventional sliding mode observer where the low-pass filter and additional position compensation of the rotor are used, the sigmoid function is used for the control of a switching function in this research. With the estimation of the stator resistance, the proposed observer can improve the control performance by reducing the estimation error of the motor's speed. Note that the stator resistance is varying with the ambient temperature and becomes an error source for the sensorless control of PMSM. The new sliding mode observer has better efficiency than the conventional adaptive sliding mode observer by reducing the time consuming integral calculations. The stability of the proposed adaptive sliding mode observer is verified by the Lyapunov function in determining the observer gains, and the effectiveness of the observer is demonstrated by simulations and experiments.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.6
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• pp.417-423
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• 2016

Using a sliding mode controller and observer techniques, this paper presents a robust current controller for a DC motor in the presence of parametric uncertainties. One of the most important issues in the practical application of sliding mode schemes is the chattering phenomenon caused by switching actions. This paper presents a novel sliding mode controller that incorporates an integral control with a sliding mode disturbance observer to attenuate the chattering by reducing the controller/observer switching gains. The proposed sliding mode disturbance observer is designed to estimate a relatively slow varying signal in the equivalent lumped disturbance owing to system uncertainties. Combining the estimated uncertainty with the sliding mode control input, the proposed controller can achieve the control objective by using the relatively low gain of the controller. The proposed disturbance observer does not include the switching control input of the baseline sliding mode controller to reduce the observer switching gain. In the proposed approach, the integral sliding mode control is used to improve the steady state control performance. Comparative computer simulations are carried out to demonstrate the performance of the proposed method. Through the simulation results, the proposed controller realizes the robust performance with reduced current ripples.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.5
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• pp.338-344
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• 2004

This paper presents a sensorless speed control of a DC servo motor using a fuzzy-sliding observer in the presences of load disturbances. A fuzzy-sliding observer is proposed in order to estimate the speed of a motor rotor. First, a sliding observer is used to estimate the derivative of the armature current directly using the armature current mesured in the DC servo motor. Second, the optimal gain of the Luenberger observer is set up using the fuzzy control. Experimental results show the good performance in the DC servo motor system with the proposed fuzzy-sliding observer.

• Journal of Power Electronics
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• v.9 no.1
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• pp.117-123
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• 2009

This paper presents a sliding mode observer for the sensorless control of interior permanent magnet synchronous motor (IPMSM) drives. The sliding mode observer has been presented as a robust estimation method. Most of these previous works, however, were not for an interior PMSM (IPMSM), but for a non-salient pole PMSM and its observer design is conducted in the stationary reference frame. Thus, in this paper, we investigate the design of a sliding mode observer and its driving characteristics for an IPMSM. The proposed sliding mode observer is designed in the rotating reference frame, and good drive performance is achieved even when the observer parameters are mismatched with those of an actual motor. The proposed method is applied to a 600W IPMSM, and, then, the measurement results are presented.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.334-334
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• 2000

In this paper, sliding mode observer design principles based on the equivalent control approach are discussed for the systems which may not satisfy the matching conditions. We propose a new approach for designing a sliding observer and the proof of the stability of the state reconstruction error system for time-invariant systems using the Lyapunov method. The reaching time to the sliding surface, the sliding dynamics of the system, the stability of the reconstruction error system via Lyapunov method, sufficient conditions for the existence of the sliding mode are studied.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.24-24
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• 2000

This paper proposes a design method of sliding mode observer for SISO linear systems with a disturbance input. We first construct an observer with a constant gain matrix, a feedforward injection map and an external feedforward compensation signal input. Using the second Lyapunov method, we present a sufficient condition for the existence of sliding mode observer. The proposed observer guarantees that the state error trajectories enter a certain region in finite time and remain inside thereafter.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.171-176
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• 1997

This paper presents a design method of the continuous inertial binary observer which includes the rotor flux and speed estimations. The sliding observer based on the variable structure theory ensures the robustness of disturbance and is applied for the method to keep an insensitivity for the variations of parameter. Sliding observer, however, has a high-frequency chattering deteriorating the state estimation performance. To reduce the chattering on the sliding surface in sliding observer and improve the estimation performance, binary observer scheme which has main advantages such as the absence of high-frequency chattering and the finite gains is applied in this paper. Computer simulation results show the effectiveness of binary observer proposed here for the induction motor drives.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.1
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• pp.9-12
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• 2005

This paper presents an LMI-based method to design sliding mode observers for a class of uncertain systems. Using LIs we derive an existence condition of a sliding mode observer guaranteeing a stable sliding motion. And we give explicit formulas of the observer gain matrices. We also consider sliding mode observer design problems under an α-stability constraint or an LQ performance bound constraint. Finally, we give a numerical design example.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.744-746
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• 1998

In this paper, a new sliding mode observer is proposed by introducing a new sliding surface. The new sliding surface is defined based on the augmented error system with virtual error state. The new sliding mode observer have more degree of freedom than the existing VSS observer. It can have dynamics on the sliding surface.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.10
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• pp.1018-1021
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• 2006

This paper presents an LMI-based method to design sliding mode observers for a class of uncertain time-delay systems. Using LMIs we derive an existence condition of a sliding mode observer guaranteeing a stable sliding motion. And we give explicit formulas of the observer gain matrices. Finally, we give a simple LMI-based design algorithm, togeter with a numerical design example.