• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.5
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• pp.80-86
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• 2005

Induction motors are a critical component of many industrial processes and are frequently integrated in commercially available equipment. Safety, reliability, efficiency, and performance are some of the major concerns of induction motor applications. Fault tolerant control (FTC) strives to make the system stable and retain acceptable performance under the system faults. All present FTC method can be classified into two groups. The first group is based on fault detection and diagnostics (FDD). The second group is includes of FDD and includes methods such as integrity control, reliable stabilization and simultaneous stabilization. This paper presents the fundamental FDD-based FTC methods, which are capable of on-line detection and diagnose of the induction motors. Therefore, our group has developed the embedded distributed fault tolerant and fault diagnosis system for industrial motor. This paper presents its architecture. These mechanisms are based on two 32-bit DSPs and each TMS320F2407 DSP module processes the stator current, voltage, temperatures, vibration signal of the motor.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.293-296
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• 2002

This paper discusses a software reliability model for the distributed s-PCT algorithm fur remote sensing applications. The distributed algorithm is designed based on a Manager-Worker threading concept and goes further to use redundancy to achieve fault tolerance. The paper provides a status report on our progress in developing the reliability concept and applying it to create a model for the distributed s-PCT In particular, we are interested ill the algorithm performance versus reliability.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.387-388
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• 2017

Cascaded H-bridge 멀리레벨인버터는 출력전압 레벨 수를 증가시켜 고전압 응용이 가능하도록 하는 전력변환장치로 모듈화 특성이 우수하여 그 활용 범위를 넓혀가고 있다. 출력 전압레벨 수를 증가시켜 보다 정현파에 가까운 양질의 출력전압을 생성하기 위해서는 스위칭 소자와 입력 전압원 개수의 증가로 인해 회로구조와 제어방법이 복잡해지는 문제가 발생한다. 하지만 스위칭 여유율(Redundancy)에 따른 대체 스위칭 패턴의 적용으로 전체 시스템의 신뢰성을 개선시킬 수도 있다. 본 논문에서는 고장나무 분석을 통해 Cascaded H-bridge 멀티레벨 인버터의 위험도를 계산하고 스위칭 여유율과의 관련성을 분석하고자 한다.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.213-215
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• 1987

As a means of improving the reliability of the analog type controller for the thermal power plant, an efficient method is proposed, which is to place the hardware redundancy, i.e. a back-up controller with fault detecting capability. FTCS is implemented by using multi-processors and it is experimentally verified that the back-up controller takes over the role of the original controller, controlling the faulty loop.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.222-224
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• 2007

내고장성(fault - tolerance)을 향상시키면서 소프트웨어의 신뢰도를 최적화하는 두가지 접근법으로서 수정복구 블록 스킴과 N-버전 프로그래밍 기법이 있다. 본 연구에서는 중복모줄을 가지고 소프트웨어의 신뢰도를 극대화하기 위한 하나의 알고리즘으로서 수정복구 스킴을 제안한다. 개발소프트웨어의 최적구조를 결정하는 기법을 수립하기 위해 최적화 공정 결과를 적용한다. 주어진 가용자원 범위 내에서 정규실행모줄과 테스트모줄의 신뢰도 및 확률을 계산하여 소프트웨어 시스템의 신뢰도를 극대화하기 위한 소프트웨어의 형상을 고찰한다. 간단한 예로서 한 개의 경우를 예시한다.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.11
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• pp.1125-1131
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• 2011

This paper presents a control theoretic approach to realizing fault tolerance in asynchronous sequential circuits. The considered asynchronous circuit is assumed to work in space environment and is subject to faults caused by total ionizing dose (TID) effects. In our setting, TID effects cause permanent changes in state transition characteristics of the asynchronous circuit. Under a certain condition of reachability redundancy, it is possible to design a corrective controller so that the closed-loop system can maintain the normal behavior despite occurrences of TID faults. As a case study, the proposed control scheme is applied to an asynchronous arbiter implemented in FPGA.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.9
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• pp.1249-1254
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• 2013

A torque control algorithm suitable for detecting an open circuit failure in which one of the three phases is unable to supply power to a motor in the permanent magnet synchronous motor is presented in this paper. When the failure occurs in the inverter, the output torque of motor is restricted. A new method which is implemented by using only a processor algorithm internally without any hardware redundancy circuit is proposed. A simulation and experimental study is carried out with a three phase inverter system to show the validity of the proposed method.

• Journal of the Korean Society for Railway
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• v.9 no.6 s.37
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• pp.725-731
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• 2006

Hot Standby sparing system detecting faults by using software, and being tolerant any faults by using Hardware Redundancy is difficult to perform quantitative reliability prediction and to detect real time faults. Therefore, this paper designs Hot Standby sparing system using hardware basis self checking logic in order to overcome this problem. It also performs failure mode analysis of Hot Standby sparing system with designed self checking logic by using FMEA (Failure Mode Effect Analysis), and identifies reliability assessment of the controller designed by quantifying the numbers of failure development by using FTA (Fault Tree Analysis)

• Journal of Advanced Navigation Technology
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• v.10 no.4
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• pp.299-305
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• 2006

DURUMI-II is developed into test bed airplane for the multi-purpose flight test. It satisfied the civil aeronautics law. DURUMI-II is equipped with Airborne System for acquiring of flight test data and can fly by oneself. In this paper, the redundancy of DURUMI-II control system is operated sequentially is explained. The divided control surface and the requiring program method for flight test are described. Also, it is described that the exact control input is applied using the new method. Finally, the results of flight test for new method are analyzed.

• Journal of information and communication convergence engineering
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• v.9 no.5
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• pp.615-618
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• 2011

Living cells generate the cell cycle or apoptosis, depending on the course will be repeated. If an error occurs during this period of life in order to maintain the cells in the peripheral cells find the error portion. These cellular functions were applied to the system to simulate the circuit. Circuit implementation of the present study was constructed the redundant structure in order to found the error quickly. Self-repairing of digital systems as an advanced form of fault-tolerance has been increasingly receiving attention according as digital systems have been more and more complex and speed-up especially for urgent systems or those working on extreme environments such as deep sea and outer space. Simulating the process of cell differentiation algorithm was confirmed by the FPGA on the counter circuit. If an error occurs on the circuit where the error was quickly locate and repair. In this paper, we propose a novel self-repair architecture for fast and robust fault-recovery that can easily apply to real, complex digital systems. These Self-Repairing Algorithms make it possible for the application digital systems to be alive even though in very noisy and extreme environments.