• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2478-2480
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• 1999

In this paper, the authors propose a current control system for three phase PWM AC/DC converter without the source voltage sensors. The sinusoidal input current and unity effective power factor are realised based on the estimated source voltage in the controller. The estimation of source voltage is performed based on Luenberger observer using actual currents. The estimated source voltage is used to accomplish unity power factor. The proposed method is proved by simulations.

• 전기의세계
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• v.24 no.5
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• pp.103-106
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• 1975

This Paper deals with an applicatoin of Luenberger Observer to the Linear Stochastic Systems. The basic technique is the use of a matrix version of the Maximum Principle of Pontryagin coupled with the use of gradient matrices to derive the gain matix for minimum error covariance. The optimal observer which is derived turns out to be identical to the well-known Kalman-Bucy Filter.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.5
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• pp.375-380
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• 2003

In a conventional speed sensorless stator flux-oriented (SFO) induction motor drive, when the estimated speed is transformed into the sample-data model using the first-forward difference approximation, the sampled data model has a modeling error which, in turn, produces an error in the rotor speed estimation. The error is removed by the use of a low pass filter (LPF). As a result, the delay of the estimated speed occurs in transients by the use of the LPF. This paper proposes a method to estimate exactly the speed by using Luenberger observer to solve the problem of a conventional method.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.2
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• pp.18-25
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• 2012

The availability of the GPS signal has been expanded greatly in the field of society overall through the development and construction of the GNSS(Global Navigation Satellite System). Furthermore, in the military, aviation and field of space, the GPS signal is applied widely through the combination of INS consisting of gyroscope and accelerometer, IMU, AHRS with the addition of magnetic sensor. Particularly, the performance of these equipments or sensors is very important with GPS and PAR(Precision Approach Radar) in the flight control of the aircraft. This paper deals with MATLAB simulation and ROLSO(Reduced Order Luenberger State Observer) design to reduce the load of system and realize the stable lateral direction approach control in an appropriate time for reduction of the horizontal error which is importantly considered while an aircraft lands instead of the FOLSO(Full Order Luenberger State Observer) using all measurement values. Consequently, ROLSO is expected to be used for the aircraft's attitude control in the aircraft landing causing the burden to the pilots.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.5
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• pp.961-965
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• 2010

A reduced order observer with finite time convergence characteristics is proposed for linear time invariant systems. The proposed finite time reduced order observer(FTROO) is a dual observer scheme in which two reduced order Luenberger observers with asymptotic convergence characteristics and a finite time delay element are employed. The FTROO can be constructed so as to converge in the designer specified finite time independent of the eigenvalues of the reduced order observers. A numerical example is given to show the finite-time convergence characteristics of the proposed FTROO.

• Nuclear Engineering and Technology
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• v.22 no.2
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• pp.139-150
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• 1990

This paper describes a method for estimating the flux and precursor spatial distributions using only limited flux measurements. It is based on the Luenberger observer in control theory, extended to the distributed parameter systems such as the space-time reactor dynamics equation. The results of the application of the method to simple reactor models showed that the flux distribution could be estimated by the observer very efficiently using information from only a few sensors.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.687-692
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• 1990

The purpose of this study is ID form the required force for measurements of the performances of the equipments or testpieces. For the generation of the required force, ft difference of pressures in each chamber of the hydraulic cylinder was controlled and Variable Structure Control theory was adopted to control it. Besides, observers -Luenberger Observer and nonlinear Variable Structure Observer - were designed to estimate the derivative of the load pressure which is necessary ID determine the sliding surface in VSC theory. As a consequence of the computer simulation, it was shown that VSC had better performance than classical control theory(P, PD control) and VSO performed better than the Luenberger Observer at the load pressure control.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.142-145
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• 2002

A new scheme to estimate machine inertia in low speed is proposed in this paper. It is necessary to consider the machine parameter of low speed instantaneous observer to precise control in servo system, which has frequent load variation and speed change. To estimate machine parameter, especially the moment of inertia, Reduced-Order Extended Luenberger Observer (ROELO) is applied. The effectiveness of the proposed ROELO is showed by simulation.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1105-1107
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• 2000

This paper proposes the new reduced-order extended Luenberger observer and presents the application to sensorless vector control of induction motor. The main features of the proposed observer are discussed and compared with the other observers.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.5
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• pp.360-368
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• 2008

A lumped parameter model of Li-ion battery in hybrid electric vehicle(HEV) is constructed and system parameters are identified by using recursive least square estimation for different C-rates, SOCs and temperatures. The system characteristics of pole and zero in the frequency domain are analyzed with the parameters obtained from different conditions. The parameterized model of a Li-ion battery indicates highly dependent of temperatures. To estimate SOC and polarization voltage, a Luenberger state observer is utilized. The P- or PI-gains of observer based on a suitable natural frequency and damping ratio is adopted for the state estimation. Satisfactory estimation accuracy of output voltage and SOC is especially obtained by a PI-gain. The feasibility of the proposed estimation method is verified through experiment under the conditions of different C-rates, SOCs and temperatures.