안전신뢰성 기반 수소투과저감 및 라이너 소재적용 경량화 소구경 수소저장탱크의 CBM 및 PHM 방법 연구

오봉식,김기홍,이정철,서금석 한국신뢰성학회 2023 한국신뢰성학회 학술대회논문집 Vol.2023 No.6

수소충전소의 안전신뢰성과 기능안전을 유사장치 고장유형분석을 통한 추론방안

오봉식,박상철,장중순 한국신뢰성학회 2020 한국신뢰성학회 학술대회논문집 Vol.2020 No.11

수소충전소(HRS) 압축기의 기능안전 및 PHM을 위한 신호처리 연구

오봉식,장중순,박상철,신덕식,이용훈 한국신뢰성학회 2022 한국신뢰성학회 학술대회논문집 Vol.2022 No.7

TSC 신뢰성시험 규격 비교 및 신뢰도 예측

오봉식,박상철,장중순 한국신뢰성학회 2019 신뢰성응용연구 Vol.19 No.4

Purpose: Maintenance data for Korean traffic signal controller(TSC) shows that the replacement life is shorter than 10 years required. To investigate the causes, Korean and international TSC reliability standards are compared and MTBF of TSC is evaluated. Methods: Reliability test items of Korean, US, European, and Japanese TSC standards are compared as well as their test conditions. In addition, failures rates of main control unit CPU boards of 2 main control unit are evaluated based on MIL-HDBK-217F. Results: Domestic’s TSC requires 20 items compared to the European standard that defines 35 items. After installing and operating a new product of TSC, the actual way-out period was analyzed at 8.4 years until the replacement. This is a very short TSC endurance of 10 years. Thyristor LSU had no official tests with surge current applied. Corrective action is necessary to ensure that the confirmation procedure is carried out to improve such safety. Conclusions: Korean TSC standard requires less test items than EU, US and Japan. Some important tests like solar test, salt spray test, gas test and storage test are not specified. MTBFs of 2 CPU boards are evaluated to be less than 10 years.

신뢰성기반 안전 및 기능안전을 통한 스마트팩토리 구축 운영 기술 방안

오봉식,박상철,장중순,이정준 한국신뢰성학회 2021 한국신뢰성학회 학술대회논문집 Vol.2021 No.6

○ 인공지능스마트센서(AI-Smart sensor) 기술을 통한 현장상태 정보상황 데이터와 기업의 미래공장 핵심 경쟁력 확보, 고장 사전진단 및 안전관리기술 개발 시급하여 확산 보급을 서두르는 중에 있어서, 이 부분을 하기 준거 내용으로 하여 스마트팩토리에 활용하는 기술 동향을 본 논문에서 살펴보기로 한다. -스마트센서 기술은 기존 센서에 데이터 처리, 자동보정, 자가진단, 의사결정 기능이 결합된 고기능, 고정밀, 고편의성, 고부가가치를 창출 여부 -국내.외 제조설비 운영 시에 안전사고, 안전성 논란 및 설치 운영 일정 기간을 초월할 시에 빈번한 고장 발생으로 경제적 손실과 이해관계인의 불편 가중을 해결 여부 ○ 스마트팩토리(혹은 스마트공장이라고 한다.)에서, 산업용시스템패널유니트(ISPU, Industrial System Terminal Panel Unit)이란 SCADA, DCS, GENERAL TMTC) 등 다양한 목적의 산업용 감시제어시스템을 구성하는 요소로서 원격소 현장장치를 의미하는데, 이 부분 산업용시스템패널유니트(ISPU)는 교통ㆍ전기ㆍ가스 또는 수처리ㆍ재난관리 등 여러 숨은 분야에서 중요한 역할을 담당하고 있는 바, 장치의 결함이나 오동작이 발생하는 경우는 인명사고를 유발하는 등 사회적으로 심각한 안전위험을 초래할 수 있어서 이들 리스크(risk) 방지와 안전증진을 확보하기 위하여 본 AI스마트센서 기술을 통한 솔루션 시에 신뢰성응용기술 측면에서 신뢰성 기반의 안전성, 기능안전요구(Functional Safety Requirements) 기준을 설계 기술을 본 논문에서 살펴본다. ○ 본 연구는 산업용시스템패널유니트(ISPU) 생산 공장의 스마트화를 추구하는 바, 산업용시스템패널유니트(ISPU)의 적용분야는 국내ㆍ외에서 스마트센서를 이용하여 모니터링 시스템을 구축하고 제조공정 상에서 안전사고를 예방에 대한 요구기능으로 필수적이어서 다음과 같은 활용범위에 걸쳐서 다양하게 사업적으로 수요 확대가 있어서 이 부분의 기술개발 결과를 활용하여, 데이터측정과 전송의 핵심기술인 스마트센서 기술개발을 통해 국내 중소기업의 미래공장 핵심 경쟁력 확보로 사업성 확장이 필요한바, 이 부부 관련하여 본 논문에서 살펴본다. ○ 국내 중소기업에서 활용되고 있는 산업용시스템패널유니트(ISPU) 생산라인에서의 전문적인 시험검사를 위한 스마트팩토리(SMART FACTORY) 솔루션 관련하여 개발기술의 활용, 독창성 및 차별성현재로는 알려진 바 없는데 이 부분도 본 논문에서 살펴보기로 한다. ○ 기존 일반적인 Smart Sensor가 보다 광범위한 산업용 장치에 유연하고 효율적으로 활용될 수 있는 혁신성과 차별성을 갖는‘Smart Sensor System’기술 관련하여 다음 준거하여 본 논문에서 살펴보기로 한다. -범용 검측수단의 연결 가능 능력을 갖는 Smart Sensor Node에 적합하도록 설계된 기술 관련하여 -인터넷 클라우드 연계의 통로가 되는 유ㆍ무선 연계가 가능한 Gateway 기술 관련하여 -광역 현장 데이터를 관리하고 분석하여 이용자 서비스를 하기 위한 Server System 기술 관련하여 -기계학습 기반 사람, 환경, 기기 간의 실시간 이상감지 알고리즘 기술 관련하여 ○ 스마트팩토리 실제 운영 환경여건으로 고려할 수 있는 고온 다습 먼지 등 극한 환경에서 고신뢰성의데이터 취득 및 저장 전처리 분석 진단하여 실시간 의사결정을 지원하는 기술 관련하여 본 논문에서 살펴보기로 한다. ○ 미세한 신호 감지, 노이즈 캔슬링 등 신호처리 기술이 적용되어 신뢰성 있는 데이터 취득, 및 스마트팩토리 내 데이터 전송량 증가에 따라 데이터 전송의 지연을 방지하는 센서 내 데이터 처리 저장기능의 집적화 관련하여 본 논문에서 살펴본다. ○ 또한 고장예지 및 건전성관리 기술(PHM, Prognostics and Health Management)과 운영데이터 기반실시간 안전리스크 데이터 수집 분석 평가기술을 통하여 위험등급을 실시간 모니터링 기술 관련하여 본 논문에서 살펴보기로 한다.

기능안전 기반 스마트팩토리 MQTT통신시스템 개발

오봉식(Bong S. Oh),박상철(Sang C. Park),장중순(Joong S. Jang),이정준(Jung J. Lee) 한국신뢰성학회 2021 신뢰성응용연구 Vol.21 No.3

Purpose: Reliability and safety-based message queuing telemetry transport (MQTT) communication applications and artificial intelligence (AI)-smart sensor development are considered in the smart factory to ensure competitiveness by minimizing risks in manufacturing, pre-failure diagnosis, and failure prediction prognostics and health management (PHM) technology. Methods: The algorithm was implemented to ensure that the MQTT Publisher software technology application conforms to the standard by applying it as a process design method in the smart factory. In the functional safety standard and reliability prediction methods, safety risk data were collected, analyzed, and verified as an evaluation procedure in the smart factory. Results: The performance of MQTT communication as well as the safety data collection and database (DB) storage functions were confirmed in the smart factory. The contents of the literature search were confirmed in relation to the evaluation of the reliability feature extraction factors and functional safety-related failure prognosis parameters of the AI-smart sensor, center control server, monitoring-related design, and development products to be used as the basis for reliability and safety in smart factories. Conclusion: The process of sensor input using Arduino, the transmission of measured values, and storage of collected data into a DB using the resistive temperature device was developed as a software algorithm and demonstrated in the smart factory using MQTT communication. According to a literature search related to priority-based MQTT, this partial application can be effectively used in small and medium-sized smart factories that require a real-time priority algorithm. It can be used as a price-competitive communication method.

스마트센서시스템의 기능안전을 위한 Lora 통신 필드 적합성 테스트 연구

오봉식(Bong S. Oh),박상철(Sang C. Park),장중순(Joong S. Jang),이정준(Jung J. Lee) 한국신뢰성학회 2022 신뢰성응용연구 Vol.22 No.2

Purpose: Three types of LPWA LoRa module were investigated as candidate smart sensor systems in a smart factory. A long-distance communication success test was conducted to determine which module type best satisfied functional safety requirements. Methods: The three types of LoRa communication module considered in this paper were 1. sLory, 2. RYLR890 using UART interface and 3. P2P UART communication module RAK811. A communication success field demonstration test was performed at 3.24 km in the city center and in a flat area (Ansan-si). Results: The RYLR890 module type achieved communication success up to 3 km. However, the communication success rate from departure to arrival was unstable. The RAK811 achieved communication up to 2 km and the field test demonstrated that the transmission/reception performance was stable from departure to arrival. Conclusion: Three types of LoRa module were selected for LPWA and the worlds first field verification test was conducted. It was verified that the RAK811 model’s field communication success rate meets functional safety requirements. However, it is still necessary to ensure the functional safety of sensor-node, communication system and PHM technology by examining structural aspects such as longitudinal axis, lateral side and height.

유사장치의 건전성데이터 분석을 통한 수소충전소 기능안전 추론방안

오봉식(Bong S. Oh),박상철(Sang C. Park),장중순(Joong S. Jang) 한국신뢰성학회 2021 신뢰성응용연구 Vol.21 No.4

Purpose: There has been a substantive expansion of FCEV in the hydrogen economy. According to the government’s policy, the installation and operation of HRSs (Hydrogen Refueling Station) are expected to be carried out rapidly. However, the types of failures among the major devices of HRS such as compressors, coolers, and dispensers, and technologies related to the safety and reliability of data are not well disclosed. In the case of foreign (Germany, France, etc.) products of HRS in Korea, it is not easy to access technology, and to reduce risks in operating HRS, it is necessary to solve the problem in this area. Methods: HRSs are required to have the highest level of safety and reliability, but due to certain terms and conditions among suppliers, the main characteristics of the technology are not openly available. Based on the analysis done, in this paper we suggest improvement plans to curb the problems mentioned above. Results: PHM(Prognostics and Health Management) through failure type analysis of similar devices and safety-based real-time risk severity rating of HRS through technology that collects, analyzes, and evaluates and judges functional safety real-time safety risk data based on operational data are extremely important. A monitoring technique was presented to collect results through the methods mentioned above. Conclusion: In order to secure safety for safety-based risk reduction for an HRS’s operation, site selection for an HRS that meets functional safety and construction requirements is needed. It is also important that the required technology selected for this purpose, presented by the HRS standard, be applied to design. In addition, post-maintenance technology that can sustain risk reduction is also required.

교통신호제어기 신뢰성 규격 비교와 예측

오봉식(Bong S. OH),박상철(Sang C. Park),장중순(Joong S. Jang) 한국신뢰성학회 2019 한국신뢰성학회 학술대회논문집 Vol.2019 No.10

Purpose: Maintenance data for Korean traffic signal controller (TSC) shows that the replacement life is shorter than 10 years required. To investigate the causes, Korean and international TSC reliability standards are compared and MTBF of TSC is evaluated. Methods: Reliability test items of Korean, US, European, and Japanese TSC standards are compared as well as their test conditions. In addition, failures rates of main control unit CPU boards of 2 main control unit are evaluated based on MIL-HDBK-217F. Conclusion: Korean TSC standard requires less test items than EU, US and Japan. Some important tests like solar test, salt spray test, gas test and storage test are not specified. MTBFs of 2 CPU boards are evaluated to be less than 10 years.

수소충전소 압축기의 CBM+ 데이터수집을 위한 기술개발

오봉식(Bong S. Oh),신덕식(Duck S. Shin),이용훈(Yong H. Lee),장중순(Joong S. Jang) 한국신뢰성학회 2023 신뢰성응용연구 Vol.23 No.1

Purpose: This paper demonstrates Functional Safety Requirements by collecting and analyzing the condition-based maintenance (CBM+) data of the compressors such as chillers, compressors, and dispensers of a hydrogen refueling station (HRS) installation as well as HRS operation using power quality monitoring (PQM) instrumentation at the HRS input stage. Methods: Demonstrate fault measurement items and fault diagnosis such as sound, vibration, and current with CBM+. The feature extraction of the collected data in this process was analyzed using an LSTM AutoEncoder to demonstrate the occurrence of failures. Results: There were a total of 21 HRS accidents from 2005 to 2014 in Japan and 22 accidents in the US from 2004 to 2012. In particular, approximately 90% of the hydrogen gas leakage accidents in Japan and approximately 91% in the US were due to human error. The CBM+ of a hydrogen compressor was demonstrated by connecting a PQM instrument to the HRS input. Conclusion: A technically developed PQM measuring device was installed at the Gwangju HRS input power source and data was collected for approximately 3 months. After analyzing and evaluating the collected data through the LSTM AutoEncorder, it was demonstrated that HRS failure occurred after approximately 7 days. Therefore, we propose a failure detection and failure diagnosis model through the CBM+ of domestic HRSs.