• 조명전기설비학회논문지
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• 제25권2호
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• pp.103-112
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• 2011

This paper proposes a new fuzzy speed controller for the precise speed control of a permanent magnet synchronous motor(PMSM). The proposed control system needs the information of the angular acceleration instead of the load torque, so the third-order fuzzy acceleration observer estimates it. Moreover, the LMI conditions are derived for the existence of the fuzzy acceleration observer and fuzzy speed controller, and the gain matrices of the observer and controller are obtained. It is analytically proven that the proposed observer-based fuzzy speed regulator is exponentially stable. To evaluate the performance of the proposed control algorithm, experimental results as well as simulation results are provided under the conditions of motor parameter and load torque variations. Finally, it is clearly confirmed that the proposed control method can accurately control the speed of a PMSM.

• 대한기계학회논문집B
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• 제20권6호
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• pp.2057-2066
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• 1996

^In this paper, diagnostic technique for detecting the engine faults, especially misfire, are introduced and compared with each other under the same conditions. With all of them the instantaneous angular velocitys, measured at the flywheel, were analyzed. The techniques include the frequency analysis, auto-correlation function, velocity index, acceleration index, maximum acceleration index, and integrated torque index. Since the main driving components for the angular velocity fluctuation are both the pressure and the inertia torque, the component of the inertia torque in it must be excluded to extract the information of the combustion from the angular velocity. To do this, it is required to consider only the first half of the combustion period in the angular velocity fluctuations, which has never been proposed in the existing methods. On the basis of this fact, the results show that the most effective diagnostic technique is maximum acceleration index.

• 전기학회논문지
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• 제64권12호
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• pp.1742-1747
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• 2015

An improved transfer alignment method for a strap-down inertial navigation system (SDINS) is presented here. The alignment accuracy in conventional method is vulnerable to the data latency of a Master INS (MINS) in high maneuverable platforms. We propose a time delay compensation equation considering higher-order terms in the attitude measurement equation of the Kalman filter. The equation incorporates additional information including angular rate, angular acceleration and linear acceleration from the MINS. Simulation results show that the transfer alignment accuracy is significantly improved in the high dynamic environment by incorporating the latency compensation technique.

• Journal of Positioning, Navigation, and Timing
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• 제3권1호
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• pp.1-10
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• 2014

Recently, monitoring of two-body ground vehicles carrying extremely hazardous materials has been considered as one of the most important national issues. This issue induces large cost in terms of national economy and social benefit. To monitor and counteract accidents promptly, an efficient methodology is required. For accident monitoring, GPS can be utilized in most cases. However, it is widely known that GPS cannot provide sufficient continuity in urban cannons and tunnels. To complement the weakness of GPS, this paper proposes an accident monitoring method based on a monocular vision sensor. The proposed method estimates angular acceleration from a sequence of image frames captured by a monocular vision sensor. The possibility of using angular acceleration is investigated to determine the occurrence of accidents such as jackknifing and rollover. By an experiment based on actual measurements, the feasibility of the proposed method is evaluated.

• 전기학회논문지
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• 제60권2호
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• pp.330-337
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• 2011

This paper presents a new fuzzy speed controller based on a fuzzy angular acceleration observer to realize a robust speed control of permanent magnet synchronous motors(PMSM). The proposed speed controller needs the information of the angular acceleration, thus the first-order fuzzy acceleration observer is designed. The LMI existence condition is given for the proposed fuzzy speed controller, and the gain matrices of the controller are calculated. It is verified that the augmented control system consisting of the fuzzy speed controller and the fuzzy acceleration observer is mathematically stable. To validate the effectiveness of the proposed acceleration observer-based fuzzy speed controller, the simulation and experimental results are shown under motor parameter variations. It is definitely proven that the proposed control scheme can precisely track the speed of a permanent magnet synchronous motor.

• Nuclear Engineering and Technology
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• 제34권4호
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• pp.314-322
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• 2002

A new extrapolation method is developed and applied to the additive angular dependent rebalance (AADR) acceleration for discrete ordinates neutron transport calculations. With this extrapolation, the convergence of AADR solution for distinct discretizations between the high- order and low-order equations is remarkably improved and thus the “inconsistent discretization problem” is resolved. Fourier analysis is also performed to find the optimal extrapolation and weighting parameters, which give the smallest spectral radius. The numerical tests demonstrate that the AADR with extrapolation works well as predicted by the Fourier analysis.

• 한국군사과학기술학회지
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• 제11권6호
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• pp.30-37
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• 2008

The ARS(Attitude Reference System) calculates an attitude of a vehicle using inertial angular rate sensors and acceleration sensors. The attitude error of ARS increases due to the integration of angular rate sensor output. To reduce the attitude error an acceleration of sensor is used similar to leveling method of INS(Inertial Navigation System). When an acceleration of vehicle is increased, it is difficult to calculate the attitude error using acceleration sensor output. In this paper the estimation method of acceleration due to the attitude error only is proposed. Two methods of the attitude calculation depending on vehicle dynamics and the integration method of these two methods are proposed. To verify its performance the monte carlo simulation is performed and shows that it bounds attitude error of ARS to reasonable level.

• 대한의용생체공학회:의공학회지
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• 제36권4호
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• pp.109-114
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• 2015

In this study, joint angles of the lower extremity and tibial acceleration and angular velocity were measured during a snowboard simulator exercises in order to evaluate the skill of snowboarders. Ten unskilled and ten expert snowboarders were recruited for the study. A three-dimensional motion capture system and two inertial sensor modules were used to acquire joint movements, acceleration and angular velocity of the lower extremities during snowboard simulator exercises. Pattern variations were calculated to assess variations in the snowboard simulator motion of unskilled and expert snowboarders. Results showed that expert snowboarders showed greater range of motion in joint angles and greater peak to peak amplitude in acceleration and angular velocity for tibia than unskilled snowboarders. The unskilled snowboarders did not show symmetrical shape(same magnitude but opposite direction) in tibial angular velocity during two edge turns in snowboard simulator exercises. The expert snowboarders showed smaller pattern variations for joint angle of lower extremity, tibial acceleration and tibial angular velocity than unskilled snowboarders. Inertial sensor data and pattern variations during the snowboard simulator exercises could be useful to evaluate the skill of snowboarders.

• 한국구조물진단유지관리공학회 논문집
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• 제19권2호
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• pp.60-67
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• 2015

유한요소모델 개선은 구조물의 설계검증, 손상추적, 내하력 평가 등 다양하게 활용되고 있는 기법이다. 일반적인 유한요소모델 개선은 구조물에서 계측된 가속도응답으로부터 구조물의 고유진동수와 모드형상을 구하고, 이를 바탕으로 모델을 개선하게 된다. 이와 같은 가속도응답기반 유한요소모델 개선은 구조물의 병진 자유도를 고려하기 때문에 물리적인 체계를 추정하는데 있어서 매우 적합하지만, 회전 자유도 상에서 변화하는 구조물의 경계조건을 판별하기에는 어려움이 있다. 최근 센서 기술의 개발로 인하여 저렴한 가격, 높은 정확성의 자이로센서들이 개발되고 있으며, 그에 따라 구조물의 회전 자유도에 관한 정보 획득이 용이해지고 있다. 본 연구에서는 이를 바탕으로 가속도와 각속도 응답을 함께 이용하는 데이터 융합 기반 유한요소모델 개선 기법을 제안하였다. 가속도와 각속도를 모두 활용한 데이터융합기법은, 가속도만 사용한 기존의 유한요소 모델 기법보다 구조물의 경계조건 판별에 정확한 정보를 제공한다. 본 논문에서는 단순보 모델을 이용한 수치 시뮬레이션을 통해서, 제안한 가속도와 각속도 데이터 융합기반의 유한요소모델 개선 기법의 성능을 검증하였다.

• Journal of Power Electronics
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• 제12권2호
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• pp.294-304
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• 2012

This paper proposes a fuzzy speed tracking controller and a fuzzy rotor angular acceleration observer for a surface-mounted permanent magnet synchronous motor (SPMSM) based on the Takagi-Sugeno (T-S) fuzzy model. The proposed observer-based controller is robust to load torque variations since it utilizes rotor angular acceleration information instead of the load torque value. Linear matrix inequality (LMI) sufficient conditions are given to compute the gain matrices of the speed tracking controller and the observer. In addition, it is mathematically verified that the proposed observer-based control system is asymptotically stable. Simulation and experimental results are presented to confirm that the proposed control algorithm assures a better transient behavior and less sensitivity under model parameter variations than the conventional PI control method.