• 한국자동차공학회논문집
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• 제14권5호
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• pp.1-8
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• 2006

The Steer-By-Wire(SBW) system replaces complex mechanical linkages of the current steering system with electric motors, sensors, and electronic control units. However, the SBW system should guarantee its safety and reliability before commercialization, and therefore, a reliable and robust fault-tolerant technology has to be implemented. This paper proposes a fault-tolerant control algorithm for the SBW system. Based on careful analysis on propagation effects of sensor faults, a reliable fault-tolerant control strategy has been developed. The fault-tolerant controller consists of a fault detection part that monitors and detects faults in the steering wheel and road wheel sensors, and a reconfiguration part that switches to normal sensor signal based on fault detection information. It has been demonstrated by simulation that the proposed algorithm detects sensor faults accurately and enables reliable steering control under various dynamic fault situations.

• 조명전기설비학회논문지
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• 제29권11호
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• pp.35-40
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• 2015

In accordance with global energy conservation policies such as MEPS (Minimum Energy Performance Standard), electric motor industry is moving to super-high-efficiency machines and research to develop IE4 (International Energy Efficiency Class 4) motors has been launched. In this situation, SynRM (Synchronous Reluctance Motor) has been attracting attention in place of induction motor which hardly provides super premium efficiency. As a result, much research on SynRM is being performed at home and abroad. Also, some products have already been appearing in the market. Compared to induction motor, SynRM has better efficiency per unit area and wider operating range. Although the utilization of control system in synchronous motor results in higher prices, we still need to concentrate on developments of SynRM so as to comply with the new policies. This study demonstrated the electromagnetic design methods of super premium SynRM while maintaining the frame of existing IE3 induction motor. We documented the design procedures for generating high saliency which is the most essential and mechanical stress anlaysis is also treated. In conclusion, we proved the validity of our design by manufacturing and testing our 3 models.

• 한국산학기술학회논문지
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• 제15권10호
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• pp.6270-6275
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• 2014

본 논문에서는 전기자동차용 견인전동기로서의 다극 매입형 영구자석 동기전동기의 회전자 돌극 설계에 의한 토크리플 개선 방안을 연구하였다. 다극 매입형 영구자석 동기전동기의 경우 영구자석에서 발생되는 자속이 고정자에 쇄교되지 않고 회전자 브릿지를 통해 누설되는 자속이 크다. 이러한 누설자속을 줄여 출력밀도를 향상시키고 토크리플을 저감하기 위해 영구자석 사이의 회전자 표면에 슬릿을 적용하였다. 슬릿에 적용되는 두 설계 파라미터를 제안하고 반응표면법을 이용하여 토크리플 감소와 출력 향상 최대화 설계를 수행하였다. 자속의 포화를 고려하기 위해 본 논문에서는 2차원 유한요소법을 이용하여 특성해석을 수행하고 이를 분석하였다.

• 융합신호처리학회논문지
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• 제15권3호
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• pp.97-103
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• 2014

근래에 와서 출입문의 물리적 보안장치로써 디지털 도어록의 사용이 보편화되었다. 기존의 자물쇠 방식 보다는 훨씬 편리한 기능이지만 도어록에 전기 충격을 가할 경우 열리는 문제점이 노출되었다. 본 연구에서는 도어록 기기를 안으로 숨기고 증강현실을 이용해 도어록을 사용자의 스마트폰 화면에 띄우게 하여 보안성을 높이는 방법을 제안한다. 아울러 메모노트를 띄우는 기능을 추가하여 가족 간의 의사소통을 원활하게 해주는 기능을 부가하였다. 본 연구 결과는 가상으로 만든 출입문과 아두이노와 와이파이 쉴드 그리고 자물쇠를 제어하기 위한 모터를 사용하여 구현하였으며, 만족할 만한 실험결과를 보였다.

• 전력전자학회논문지
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• 제4권6호
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• pp.491-499
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• 1999

본 논문은 새로운 제어기법의 고성능 전동차 추진용 IGBT VVVF 인버터에 관한 것이다. 현차 적용 전에 견인력 제어성의 우수함과 안정성을 검증하기 위해, 현차 조건에서 발생될 수 있는 경우에 대한 모의 주행시험을 실시하고 그 결과를 보인다. 모의 주행시험은 160톤의 차량을 등가화한 관성부하장치를 이용하여 정상상태는 물론 전압변동 등 각종 과도상태에 대해서도 실시하였다. 본 논문에서는 4병렬 접속된 견인전동기의 토오크 제어성 향상을 위한 벡터제어기법 적용과 공간벡터 변조기법에 동기방식을 적용하여 500Hz이하의 저주파 스위칭으로써 6스텝까지 연속 과변조 제어가 가능한 최적의 PWM방법을 제시한다.

• 전력전자학회논문지
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• 제12권4호
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• pp.277-284
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• 2007

본 논문은 전기추진시스템에 사용되는 BLDC 전동기 중에서 최대 토크 특성을 갖는 독립상 BLDC 전동기의 제어 특성에 대하여 기술하고자 한다. 독립 상 전동기는 각 상이 전기적으로 분리된 형태로 구성된 것이 특징이다. 이러한 특징을 분석하기 위하여 Y결선 3상 BLDC 전동기와 독립 3상 BLDC 전동기를 모델링하고, 시뮬레이션을 통하여 비교하였다. 시뮬레이션 결과 Y결선 3상 BLDC 전동기에 비하여 독립 3상 BLDC 전동기가 상전압이 높았다. 고정자 저항 및 인덕턴스가 일정할 때, 높은 상전압은 최대 상전류의 증가를 가져왔고, 이러한 전류 증가는 최대 토크를 증가시킨다. 그러므로 독립상 BLDC 전동기의 상전류를 제어함으로써 독립상 BLDC 전동기의 전류 맥동이 저감됨을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.59-61
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• 1995

This paper presents the cogging torque analysis of the permanent magnet type AC servo motor which have the closed slot structure. Generally, existence of the slot opening causes the cogging torque. But the cogging torque exists in this type motor(having closed slot structure) because the bridge part is saturated by the rotor flux. In this paper, the finite element analysis is used to calculate the cogging torque and the rated torque. As the size of the bridge part-the thickness and the width-changes, the cogging torque and the rated torque are obtained repeatedly like as upper procedures. Finally, the trends of the cogging torque and the rated torque versus the size of the bridge part are obtained from this analysis procedures. By this approach, the optimal geometry of the bridge part can be found which minimize the cogging torque satisfying the required value of the rated torque.

• 동력기계공학회지
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• 제21권4호
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• pp.77-83
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• 2017

The aim of this paper is to solve the chattering and delayed response problems caused by gear backlash. In the gear mechanism based systems, for example, in robot systems, the actuators provide the reduction gear with motors to transfer effectively electric power to mechanical power. Therefore, the gear backlash exists and is an unavoidable fact which makes many undesirable problems. In this paper, the authors try to make a solution for this issue and, introduce several control methods which are PID only, PID with Smith predictor and super-twisting algorithm based SMC(sliding mode control). Each control method is applied to the real plant in which strong backlash is included. By comparison results, it is clear that SMC gives the best control performance with little backlash effects. Also, the usefulness and effectiveness of proposed control method is verified by experiment.

• Journal of Power Electronics
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• 제19권6호
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• pp.1536-1543
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• 2019

This paper presents an improved torque predictive control (TPC) for permanent magnet synchronous motors (PMSMs) using an indirect matrix converter (IMC). The IMC has characteristics such as a high power density and sinusoidal waveforms of the input-output currents. Additionally, this configuration does not have any DC-link capacitors. Due to these advantages of the IMC, it is used in various application field such as electric vehicles and railway cars. Recently, research on various torque control methods for PMSM drives using an IMC is being actively pursued. In this paper, an improved TPC method for PMSM drives using an IMC is proposed. In the improved TPC method, the magnitudes of the voltage vectors applied to control the torque and flux of the PMSM are adjusted depending on the PMSM torque control such as the steady state and transient response. Therefore, it is able to reduce the ripples of the output current and torque in the low-speed and high-speed load ranges. Additionally, the improved TPC can improve the dynamic torque response when compared with the conventional TPC. The effectiveness of the improved TPC method is verified by experimental results.

• 로봇학회논문지
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• 제14권1호
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• pp.58-64
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• 2019

The paper proposes a stiffness measurement device composed of a measurement part including six indenters and a fixing part including four fixtures. The device is able to make simultaneously measurements of the stiffness of human arm. The six indenters make use of both position and force control schemes sequentially whenever needed. In addition, the loadcells and the digital encoders are attached to the indenters and electric motors, respectively, so that the data can be provided in real time. On the end of the indenter, two-axis potentiometer is attached in order to measure the angle difference between the applied force axis and the axis normal to the skin of human arm, and to convert the force measured on the loadcell into the actual applied force to skin. For this purpose, the mapping between the voltage output and the angle of potentiometer was obtained by fitting it for each axis. Ultimately, the measurement device was able to measure the stiffnesses of six regions of human arm.