• Proceedings of the KIPE Conference
• /
• 2007.11a
• /
• pp.90-93
• /
• 2007

본 연구에서는 전압품질에 민감한 설비를 위한 3상 하이브리드 Z-소스 동적 전압 보상기(Z-HDVR : Hybrid Z-Source Dynamic Voltage Restorer)을 제시하였다. 제안된 시스템은 수동필터와 Z-소스 토폴로지의 직렬형 능동필터로 구성된다. Z-HDVR의 ESS(Energy Storage System)로는 친환경적인 고분자 전해질 연료전지(PEMFC : Proton Exchange Membrane Fuel Cells)를 사용하였다. 고조파 검출 알고리즘은 동기좌표계의 $i_d-i_q$ 이론에 의하였으며, 부하전압 보상을 위하여 PI제어를 사용하였다. 전압swell 및 sag등 다양한 전원 조건하에서 제안된 시스템의 보상 성능을 검토하였다.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.1
• /
• pp.93-99
• /
• 2011

A PRT vehicle's control method is presented in this paper. In the asynchronous vehicle control system, vehicles follow their leading vehicles. Leading vehicles are defined differently among the different types of track. The main topic of this paper is to present a method to define the leading vehicle among different types of track and the calculation algorithm of the safety length the following vehicle must maintain. Simulation program is developed using the algorithm and the results of the test run are presented. An asynchronous PRT vehicle control algorithm was presented by Szillat in the paper "A low level PRT Microsimulation, Dissertation, University of Bristol, 2001". But it is different from the algorithm in this paper. In the algorithm proposed by Markus, vehicles in the merging track are controlled synchronously, and its safety distance between the leading and the following car is evaluated after the establishment of the complicated future time-location table instead of simple equations proposed in this paper.

• Proceedings of the KIPE Conference
• /
• 2005.07a
• /
• pp.578-580
• /
• 2005

This paper proposes the algorithm for the initial pole-position estimation of a surface PM-LSM, which is carried out under the pseudo-position control with-out a pole sensor and is insensitive to the motor parameters. This algorithm is based on the principle that the initial pole-position is calculated by the reverse trigonometric-function using the two reference currents, which are informed from the speed controller. The effectiveness of the proposed algorithm is confirmed by the arithmetical analysis and the experiment. IPP is well estimated within a satisfied moving-distance and a shorter estimation taken-time even if large disturbance such as cogging and friction are existed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.05a
• /
• pp.445-448
• /
• 2009

본 논문은 직선 및 곡선 주행레일을 따라 물류이송을 필요로 하는 물류 이송시스템의 이송효율을 높이고 이송거리를 단축시키기 위한 목적으로 사용되는 분기구간에 구동원으로 적용이 가능한 선형전 동기에 관한 연구를 진행하였다. 직선 및 곡선 주행 레일이 함께 존재하는 분기구간을 구동하기 위하여 선형전동기는 직선 및 곡선주행에 필요한 추진력을 모두 발생시켜야 함으로 기존의 선형전동기들은 적용이 용이하지 않다. 본 논문에서는 직곡선 레일이 공존하는 분기구간에 적용이 가능한 선형전동기를 제안하였다. 또한, 제안한 선형전동기 구동을 위한 선형전동기 위치검출 및 제어 알고리즘을 제시하였고 실험을 통해 그 타당성을 검증하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2004.05b
• /
• pp.106-111
• /
• 2004

A data communication should be carried out by a SSB(Single Side Band) to collect real time position data of fishery ship automatically, and a study on the protocol for exchanging the information with GPS should be made. A research about regional and concentrated maritime information should be first made to obtain ship's voyage data and also, research of the Modem and transmitter-receiver controller for sending voice and data simultaneously through a SSB and of the acquisition of data through a GPS also should be carried out.

• Proceedings of the KAIS Fall Conference
• /
• 2010.05a
• /
• pp.195-198
• /
• 2010

홈 네트워크 서비스 산업은 미래의 국가발전과 새로운 변혁의 원동력으로서 향후 발전 가능성이 매우 크다고 할 수 있으나, 홈 네트워크 서비스의 보급이 확산되고 다양한 형태의 홈 네트워크 서비스가 등장하면서, 사이버공격의 대상 범위 또한 확대되어 사회적, 경제적으로 우리 사회에 큰 불안 요소로 작용할 가능성이 있고, 홈 네트워크 서비스의 침해사고 발생을 방지하고 사용자의 정보가 노출되지 않는 사용자 인증이 필요하다. 본 논문에서는 OTP를 기반으로 한 인증서를 이용하여 홈 네트워크의 보안요소 중 사용자 인증과 접근제어에 관하여 연구 하였으며, 인증 서버와 클라이언트 간에 동기화된 OTP 난수 값으로 인증서 정보를 암호화 하여, 외부 공격으로부터 보다 안전한 사용자 인증 기법을 제안한다.

• Proceedings of the KIEE Conference
• /
• 2003.11c
• /
• pp.677-680
• /
• 2003

In this paper, the analysis of practical end-to-end delay in worst case is performed for distributed control system considering the implementation of the system. The control system delay is composed of the delay caused by multi-task scheduling of operating system, the delay caused by network communication, and the delay caused by the asynchronous between them. Through simulation tests based on CAN(Controller Area Network), the proposed end-to-end delay in worst case is validated. Additionally, online clock synchronization algorithm is proposed here for the control system. Through another simulation test, the online algorithm is proved to have better performance than offline one in the view of network bandwidth utilization.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.10a
• /
• pp.357-363
• /
• 2009

This paper deals with the Filtered-x Least Mean Square algorithm for a active vibration control in vehicle vibration reduction. Before applying the proposed FxLMS algorithm to automobile, the performance of the FxLMS algorithm is simulated using sensor data of a vehicle. The FxLMS algorithm requires that reference signal be a representation of disturbance signal and the plant model be incorporated into the computation path. To this end, The system identification is carried out to obtain the plant model based on the measurement results. A tachometer signal is used as reference signal. The FxLMS control algorithm is first tested using simulation and applied to a vehicle. Experimental results show that the proposed control algorithm can reduce vibration level in a short period of time.

• Journal of Institute of Control, Robotics and Systems
• /
• v.22 no.9
• /
• pp.766-772
• /
• 2016

Recent advances in networking and computers, especially internet of things (IoT) technologies, have improved the quality of home life and industrial sites. However, the security vulnerability of IoT technologies causes life-threatening issues and information leakage concerns. Studies regarding security algorithms are being conducted. In this paper, we proposed SEED algorithms based on one time passwords (OTPs). The specified server sent time data to the client every 10 seconds. The client changed the security key using time data and generated a ciphertext by combining the changed security key and the matrix. We applied the SEED algorithms with enhanced security to Linux-based embedded boards and android smart phones, then conducted a door lock control experiment (door lock & unlock). In this process, the power consumed for decryption was measured. The power consumption of the OTP-based algorithm was measured as 0.405-0.465W. The OTP-based algorithm didn't show any difference from the existing SEED algorithms, but showed a better performance than the existing algorithms.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.11 no.1
• /
• pp.65-71
• /
• 2006

In this paper, a novel motor control method is proposed to improve the performance of sensorless drive of BLDC motors. In the terminal voltage sensing method, which is a great portion of sensorless control, a precise rotor position cannot be obtained when excessive input is applied to the drive during synchronous operation mode. Especially in the transient state, the response characteristic decreases. To cope with this problem, the unknown input (back-EMF) is modelled as the additional state of system in this paper. Taking into account the disturbance adopted by the back-EMF, the observer can be obtained by the augmented system equation. An algorithm to detect the back-EMF of the BLDC motor using the state observer is constructed. As a result, the novel sensorless drive of BLDC motors that can strictly estimate rotor position and speed is proposed.