• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.2
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• pp.35-44
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• 1994

In this paper, an observer for linear discrete systems with unknown inputs is presented. The suggested observer can estimate the system state vector and the unknown inputs simultaneously. As an extension of the observer, a new fault diagnosis observer for linear discrete systems with structured uncertainty is presented. The fault diagnosis observer can detect and identify the actuator and the sensor faults as well. The stability conditionsand the design methods of the each observers are presented and the usability of the observers is shown via numerical examples.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.2
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• pp.122-129
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• 1988

A design method of decentralized state observer for large scale interconnected systems is proposed by the use of interconnection rejection approach and interconnection modelling technique. The proposed design method is developed based on the interconnection partitioning. Therefore partitioning conditions are suggested. And the conditions for observer pole assignment and observer parameter determination procedures are described for possible interconnection patterns. The decentralized state observer gives good estimates without any information on the interconnection variables and estimations. In addition, a numerical example is given to explain the design procedures and to show the estimation performance of the decentralized observer.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.3
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• pp.244-250
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• 2002

This paper proposed a modified observer based on Busawon's high gain observer using an appropriate time depended function, which can be chosen to make each estimated state converge faster to its real value. The stability of the modified observer is proved by using Lyapunov function. The modified nonlinear observer is applied to estimate the states in stirred tank bioreactor: out-put substrate concentration, output biomass concentration and the specific growth rate of the process. The convergences of the modified observer and Busawon's observer are compared trough simulation results. As the results, the modified observer converges faster to its real value than the well-known Busawon's observer.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.4
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• pp.203-211
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• 1999

A control approach for the robust position control of induction motors based on the binary disturbance observer is described. The conventional binary disturbance observer is used to remove the chattering problem of a sliding mode disturbance observer. However, the steady state error may exist in the conventional binary disturbance observer because it estimates external disturbance with a constant boundary layer. In order to overcome this problem, new binary disturbance observer with an integral augmented switching hyperplane is proposed. The robustness is achieved, and the continuous control is realized by employing the proposed observer without the chattering problem and the steady state error. The effectiveness of the proposed observer is confirmed by the comparative experimental results.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.294-297
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• 1988

THIS PAPER IS PROPOSED A NOVEL FLUX OBSERVER BASED ON GOPINATH REDUCED ORDER OBSERVER FOR VECTOR CONTROL OF INDUCTION MOTOR. WE SUGGEST RESULT OF SIMULATION ON THE PAPER. WE WILL CONSTRUCT FLUX VECTOR FEEDBACK CONTROL TYPE FOR INDUCTION MOTOR USING FULX OBSERVER.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2236-2238
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• 2004

This paper proposes the self-recurrent wavelet neural network (SRWNN) observer based sliding mode control (SMC) method for nonlinear systems. Unlike the classical SMC, we assume that all states of nonlinear systems are not measured and design the SRWNN observer to measure the states of nonlinear systems. The SRWNN in the observer is used for approximating the observer system's gain. To generate the control input for controlling the nonlinear system, the measured states are used. The sliding surface with a boundary layer is defined to remove the chattering of the control input. Simulation result to show the effectiveness of the SRWNN observer is presented.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.10
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• pp.26-32
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• 2010

This paper proposes a new load torque observer based on the Takagi-Sugeno fuzzy method for a permanent magnet synchronous motor(PMSM). A Linear Matrix Inequality(LMI) parameterization of the fuzzy observer gain is given, and the LMI conditions are derived for the existence of the fuzzy load torque observer guaranteeing $\alpha$-stability and linear quadratic performance. In this paper, a nonlinear speed controller is employed to validate the performance of the proposed fuzzy load torque observer, and various simulation results are presented under motor parameter and load torque variations.

• The Journal of Korea Robotics Society
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• v.18 no.1
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• pp.82-87
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• 2023

This paper proposes a disturbance observer-based control for 6-DOF remotely operated underwater vehicles with model uncertainties. The sum of external disturbance and the forces generated from model parameters except for the inertial matrix of the hydrodynamic model is defined as a lumped disturbance in this paper. Then, the lumped disturbance caused by model uncertainties and the external forces is estimated using the disturbance observer. Fortunately, the disturbance observer is constructed as a linear form because all the elements of the inertial matrix of the hydrodynamic model are constants. To verify the proposed control scheme, we show that the actual lumped disturbance is similar to the estimated lumped disturbance obtained by the disturbance observer. Finally, the position tracking performance in the disturbance environment is confirmed through the comparative study with a traditional inverse dynamics PD controller.

• 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.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.39-44
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• 2003

It was shown that the robustness of deterministic observers with respect to modeling errors, measurement bias and round-off errors can be represented by a single performance index the condition number of the observer eigenvector matrix. In this paper, a robust observer for multi-output systems is designed using the left eigenstructure assignment, where the observer gain can not be determined uniquely with respect to the desired observer poles. Utilizing the eigenstructuer assignment for the robustness of the observer, the desired eigenvector matrix is selected to achieve the observer eigenvector matrix with the small condition number. The performance of the designed robust observer is evaluated in a spindle-drive simulation example where the load speed to be estimated based on the measured signals.