• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.452-453
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• 2010

This paper proposes a novel diagnosis scheme using Extend Kalman Filter (EKF), especially, in subject to the open-phase faults of the inverter switches. The stator resistances of PMSM are estimated by the EKF in real time. The proposed diagnosis scheme is implemented without any extra devices. Moreover, since it uses a simple algorithm by analyzing only estimated stator resistances of each phase, the detection speed becomes fast. The feasibility of the proposed fault diagnosis scheme is proved by several simulation and experimental results.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.468-473
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• 1998

A mathematical model was developed for a continuous re-actor in which free radical polymerization of methyl methacrylate (MMA) occurred. Elementary reactions considered in this study were initiation, propagation, termination, and chain transfers to monomer and solvent. The reactor model took into account the density change of the reactor contents and the gel effect. A control system was designed for a continuous reactor using extended Kalman filter (EKF) based non-linear model predictive controller (NLMPC) to control the conversion and the weight average molecular weight of the polymer product. Control input variables were the jacket inlet temperature and the feed flow rate. For the purpose of validation of the control strategy, on-line digital control experiments were conducted with densitometer and viscometer for the measurement of the polymer properties. Despite the com-plex and nonlinear features of the polymerization reaction system, the EKF based NLMPC performed quite satisfactorily for the property control of the continuous polymerization reactor.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.11
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• pp.1124-1129
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• 2006

In this paper, in-flight alignment algorithm using UKF is presented for an SDINS aided by SSBL or GPS system under large initial heading error. The EKF usually applied for this task. This approximates the propagation of mean and covariance accurate to first-order only. To overcome this limitation, the unscented transformation that achieves second order approximation is applied to the in-flight alignment. To analyze the performance of the proposed method, simulations for S-type trajectory are carried out. The results show that performance of EKF and UKF are the almost same when the initial heading error is smaller than $30^{\circ}$, but UKF has a better performance for large initial heading error about $45^{\circ}$.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.600-608
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• 2014

This paper presents estimation of d-axis and q-axis inductance of an interior permanent magnet synchronous motor (IPMSM) by using an extended Kalman filter (EKF). The EKF is widely used for control applications including the motor sensorless control and parameter estimation. The motor parameters can be changed by temperature and air-gap flux. In particular, the variation of the inductance affects torque characteristics like the maximum torque per ampere (MTPA) control. Therefore, by estimating the parameters, it is possible to improve the torque characteristics of the motor. The performance of the proposed estimator is verified by simulations and experimental results based on an 11kW PMSM drive system.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.397-398
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• 2015

본 논문은 $LiFePO_4$ 셀의 SOC(State of Charge) 추정에서 가장 중요한 역할을 하는 모델 파라미터인 OCV(Open Circuit Voltage)의 설계에 관한 것이다. $LiFePO_4$ 셀은 히스테리시스 특성 때문에 Charging/Discharging OCV값을 이은 curve인 Major loop만으로는 신뢰도 높은 SOC 추정이 어렵다. 따라서, 기존의 Major loop에 추가적으로 SOC 10% 구간별로 Minor loop을 설계해 줌으로써 배터리 모델링의 정확도를 높이고, 이를 최종적으로 EKF(Extended Kalman Filter)알고리즘을 이용하여 SOC 추정으로 해봄으로써 정확도 향상을 비교해 보고 분석해 보고자 한다.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.671-674
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• 1999

In the PWM converter, PLL(Phase Locked Loop) is usually used as a tool which senses the angle of input voltage. This is sensitive to nois and needs additional hardware. In this work, we propose a sensorless control scheme of PWM converter using EKF(Extended Kalman Filter). EKF estimates a phase angle of input voltage from nonlinear state equation using measured phase currents. We control power factor and DC-link voltage utilizing the estimated phase angle. We demonstrate the effectiveness of the proposed estimation algorithm through simulations.

• Journal of KSNVE
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• v.2 no.2
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• pp.135-140
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• 1992

The Extended Kalman Filter(EKF) algorithm estimates variables and unknown parameters simultaneously and is applied to parameter identification of linear and nonlinear mechanical systems. In this paper, an EKF algorithm was developed through a computer simulation and then applied to a sealing test system as a practical example. Comparing with the frequency domain analysis, it was proved to be a useful alternative for the parameter identification.

• Journal of the Korean Data and Information Science Society
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• v.15 no.2
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• pp.499-506
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• 2004

The Unscented Kalman Filter is known to outperform the Extended Kalman Filter for the nonlinear state estimation with a significance advantage that it does not require the computation of Jacobian but EKF has a competitive advantage to the UKF on the performance time. We compare both algorithms on training the artificial neural network. The validation data set is used to estimate parameters which are supposed to result in better fitting for the test data set. Experimental results are presented which indicate the performance of both algorithms.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.439-442
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• 2006

본 논문에서는 IIR/FIR 필터 융합을 위한 기법을 제안하고 이를 INS/GPS 결합항법장치에 적용한다. IIR 형태의 EKF와 FIR 형태의 RHKF 필터를 각 필터의 잉여값과 잉여값 공분산을 이용한 적응형 융합 확률을 계산하여 융합함으로써 두 필터의 장점을 갖도록 한다. 이 융합 기법을 적용한 INS/GPS 결합항법장치는 기존의 단독 필터를 사용하는 것보다 강인한 특성을 갖고 항법정보를 제공한다.

• International Journal of Control, Automation, and Systems
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• v.5 no.4
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• pp.388-396
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• 2007

This paper describes a multipath estimation method for Global Positioning System (GPS) dual frequency carrier phase measurements. Multipath is a major error source in high precision GPS applications, i.e., carrier phase measurements for precise positioning and attitude determinations. In order to estimate and remove multipath at carrier phase measurements, an array GPS antenna system has been used. The known geometry between the antennas is used to estimate multipath parameters. Dual frequency carrier phase measurements increase the redundancy of measurements, so it can reduce the number of antennas. The unscented Kalman filter (UKF) is recently applied to many areas to overcome some of the limitations of the extended Kalman filter (EKF) such as weakness to severe nonlinearity. This paper uses the UKF for estimating multipath parameters. A series of simulations were performed with GPS antenna arrays located on a straight line with one reflector. The geometry information of the antenna array reduces the number of estimated multipath parameters from four to three. Both the EKF and the UKF are used as estimation algorithms and the results of the EKF and the UKF are compared. When the initial parameters are far from true parameters, the UKF shows better performance than the EKF.