• 한국항해항만학회지
• /
• 제35권7호
• /
• pp.575-580
• /
• 2011

It is important to understand the trajectory of structure in launching process because of the short time of launching process may result in unexpected accidents or damage to structures. The high risk of structural failure is not avoidable without the fully comprehension of changing forces in launching procedure. The commercial software can evaluate the motion of launching event in calm water condition but there is the limitation of research application because of the programmed commercial software. The launching process of the spar hull is suggested with stage concept that is divided into 10 stages in time domain. A force equilibrium diagram is derived for each stage where the changes of force vector and motion characteristics take place. In particular, the effects of changes in buoyancy and drag force due to the progressive submergence of the spar hull are taken into account by means of a touch length concept. The results contained in this paper provide the valuable information of the trajectory motion evaluation with suggested methods in spar launching process with sliding barge. Furthermore, the presented stage concept and touch length concept will provide basic knowledge for understanding launching process and help to develop further research area for launching analysis.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2011년도 제42회 하계학술대회
• /
• pp.1356-1357
• /
• 2011

Interior permanent magnet synchronous motor(IPMSM) adjustable speed drives offer significant advantages over induction motor drives in a wide variety of industrial applications such as high power density, high efficiency, improved dynamic performance and reliability. This paper proposes on-line efficiency optimization of IPMSM drive using fuzzy logic control(FLC) and the loss minimization method. In order to optimize the efficiency the loss minimization algorithm is developed based on motor model and operating condition. The d-axis armature current is utilized to minimize the losses of the IPMSM in a closed loop vector control environment. The controllable electrical loss which consists of the copper loss and the iron loss can be minimized by the optimal control of the armature current. The minimization of loss is possible to realize efficiency optimization control for the proposed IPMSM. The optimal current can be decided according to the operating speed and the load conditions. The proposed control algorithm is applied to IPMSM drive system and the operating characteristics controlled by the loss minimization method and FLC control are examined in detail.

• 전기학회논문지P
• /
• 제60권4호
• /
• pp.193-199
• /
• 2011

The next generation domestic high speed railway system is a power distributed type and uses vector control method for motor speed control. Nowadays, inverter driven induction motor system is widely used. However, recently PMSM drives are deeply considered as a alternative candidate instead of an induction motor driven system due to their advantages in efficiency, noise reduction and maintenance. The next-generation high-speed train is composed of 2 converter units, 4 inverter units, and 4 Traction Motor units. Each motor is connected to the inverter directly. In this paper, the effects of IPMSM parameter variation to the system operation characteristics of the multi inverter driven high speed train system are investigated. The parallel connected inverter input-output characteristics are analyzed to the parameter mismatches of the IPMSM in 1C1M control using Matlab/Simulink, then the reliability of the simulation results are verified through experimental results.

• 한국멀티미디어학회논문지
• /
• 제23권3호
• /
• pp.440-446
• /
• 2020

The application field of smart terminals is increasing and its application is also spreading in the defense field. The use of smart terminal based map application is very important in battle fields. The problem is that the communication infrastructure is easy to collapse and the use of GPS is usually disturbed. In this paper, we studied the maps stored in the QR tag at the battle field. The problem is to abstract the map information so that it can be stored in the small QR tag. We have abstracted path information on a vector basis and require only a small amount of data compared to imaged path information. We analyzed the amount of data generated by the abstraction and mathematically analyzed the boundary where the amount does not exceed the capacity limit of the QR tag. Our research can be applied not only to battlefields, but also to disaster / disaster scenes, or in environments with difficult Internet communications, such as mountainous areas.

• 조명전기설비학회논문지
• /
• 제18권1호
• /
• pp.67-72
• /
• 2004

AC 서보 시스템은 고 정밀도가 요구되는 공장 자동화 시스템(FA)에 적용 되어왔고 시스템의 성능에 직접적인 관계가 있다. 최근 전력용 소자와 AC 서보 제어를 위한 여러 기능이 내장된 DSP의 발전은 AC서보 기술에 큰 전환점을 주게되었다. 본 연구에서는 가장 최근 출시되었고, 150MIPS의 빠른 연산 속도와 AC서보 시스템을 위한 여러 회로들이 내장된 DSP인 TMX320F2812를 이용하여 3상 PMSM 기반의 AC서보 시스템을 구현하였다. 또한 SVPWM과 디지털 PI제어기를 적용하여 모터의 효율 및 제어 특성을 향상시키었다.

• 대한전기학회논문지:전력기술부문A
• /
• 제54권5호
• /
• pp.234-241
• /
• 2005

The performance of passive conductor loop (hereinafter 'loop') method which is used to mitigate the magnetic field around overhead power transmission line is dependent on its configuration and installed location, which are affected by installation conditions of the loops such as objective areas and levels of magnetic field mitigation. Thus, because the design problem of loops is difficult and cumbersome by variety of their configuration and complexity of magnetic coupling mechanism, it is need to be formulated as a computer-based optimum problem to determine the most effective and reasonable loop model satisfying the installation conditions. In this paper, the optimum locations of the multi-wired multiple loops including series reactance compensations are searched by using the genetic algorithm (GA) to mitigate effectively the magnetic fields of relatively near points or far points from transmission line at Am height, and the magnetic fields mitigation characteristics of each loop are analyzed in the view of magnitude, direction and phase of cancellation fields by polarized vector concept to identify their adequacy and rationality for the installation objectives.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1992년도 하계학술대회 논문집 B
• /
• pp.1228-1230
• /
• 1992

The permanent magnet synchronous motor(PMSM) is receiving Increased attention for servo drive applications in recent years because of its high torque to inertia ratio, superior power density and high efficiency. By vector-controll method, PMSM has the same operating characterics as seperately excited dc motor. The drive system of servo motor is requested to have an accurate response for the reference input and a quick recovery for the disturbance such as load torque. However, when the unknown disturbances and parameter variations are imposed on the permanent magnet synchronous motor(PMSM), the drive system is significantly effected by them. As a result, the drive system with both a fast compensation and a robustness to a parameter variations is requested. This paper investigates the possibility of applying the fuzzy logic controller(FLC) using Multi-Rule Base In a servo motor control system. In this paper, The five Rule Bases(1 to 5) are selected to recover the state error caused by the disturbance in steady state. In the initial operating mode. Rule Base 0 is used. To show the validity of the proposed fuzzy logic controll system, the computer simulation results are provided.

• 전기학회논문지
• /
• 제59권6호
• /
• pp.1150-1158
• /
• 2010

In this paper, a new reliable portable activity monitoring device implemented with the buddhist-style bowing activity and walking step detection algorithm, is presented. In order to monitor the bowing and walking activities, miniaturized 3-axis accelerometer sensor with the sensitivity of 800 mV/g was used. After initial signal conditioning, vector magnitude of accelerometer signals was calculated. Syntactic peak detection method was used in order to feature points. All signal processing algorithms were implemented in ultra-low power microcontroller MSP430 with double precision floating point arithmetic. For evaluation, 19 young man($24.22\pm5.22$ yrs) and woman($22.28\pm2.72$ yrs) were involved. The accuracy of the proposed algorithms were 98.91 %($\pm0.011$) for walking step detection and 98.25 %($\pm0.023$) for buddhist-style bowing activity. Comparing to the commercialized pedometer accuracy, 87.1 %($\pm0.058$), the proposed walking step detection algorithms show more reliable accuracy.

• 로봇학회논문지
• /
• 제12권2호
• /
• pp.107-115
• /
• 2017

In this paper, four-bar linkage mechanism for the knee joint is developed which is used in prosthetics. But unlike the prosthetics, the feature of this mechanism is that the instantaneous center of rotation of the four-bar linkages can be moved behind the ground reaction force vector so that it can be passively supported without any external power. In addition, this mechanism is developed similar to the structure of the human knee joint for eliminating the sense of heterogeneity of the wearer. In order to design the mechanism with these two objectives, optimization design process is done using the PIAnO tool and detailed design is carried out through optimized variable values. The developed mechanism is attached to the robot which can assist the hip and ankle joints. In order to verify the operation of the developed knee mechanism, an insole type sensor was attached to the shoes to compare data values before and after wearing the robot. Result data showed that wearer wearing the exoskeleton robot with the knee mechanism was the same value regardless of whether the heavy tool is loaded or not.

• 한국조명전기설비학회지:조명전기설비
• /
• 제9권6호
• /
• pp.41-48
• /
• 1995

본 연구에서는 Extended Kalman Filter(EKF)를 이용한 속도센서없는 우도전동기의 벡터제어의 구현을 제안하였다. 또한 회전자 저항의 변동을 보상 할 수 있도록 회전자 저항도 추정한다. 이산화된 유도전동기의 모델을 통해 유도 전동기의 속도와 회전자 저항을 포함한 상태 변수를 정의하고 벡터 제어에 필요한 자속각을 추정하여 노이즈 환경에 놓인 시스템의 동작 특성을 안정되게 하였다. EKF알고리즘의 연산을 위하여 DSP를 이용하고, 전류제어 장치로 공간 전압벡터 변조 방식의 적용이 용이한 마이크로 콘트롤러를 체용하고, 인버터는 IPM(Intelligent Power Module)으로 실험 장치를 구성하였다. 시뮬레이션과 실험을 통하여 속도 추정 특성과 회전자 저항 특성을 살펴본 결과, 본 논문의 EFK 알고리즘이 속도 센서없는 유도전동기 벡터제어에 적합함을 입증할 수 있었다.