DOI QR코드

DOI QR Code

협업 사이버물리시스템의 결함 치명도 분석을 통한 안전성 확보

Securing Safety in Collaborative Cyber-Physical Systems Through Fault Criticality Analysis

  • ;
  • ;
  • 홍장의 (충북대학교 소프트웨어학과)
  • 투고 : 2021.04.20
  • 심사 : 2021.06.18
  • 발행 : 2021.08.31

초록

협업 사이버-물리 시스템(Collaborative Cyber-Physical Systems, CCPS)은 물리 세계와 사이버 세계가 밀접하게 결합하여 공동의 목표를 달성하기 위하여 협업을 수행하는 시스템이다. 한편, 단일 사이버-물리 시스템(Cyber-Physical System)의 경우에는 ISO 26262 또는 IEC 61508과 같은 표준을 따르거나 다양한 위험 분석 기법을 적용함으로써 그 안전을 확보할 수 있다. 그러나 CCPS에서는 협업을 수행중인 한 CPS의 결함으로 인하여 다른 협업 중인 CPS에게 수많은 결함을 발생시키기 때문에 안전의 확보가 매우 어렵다. 본 논문에서는 이러한 CCPS의 위험을 분석하여 안전을 확보하기 위해 복합적인 위험 분석과 위험 분석 산출물 사이의 관계를 기반으로 하는 위험 치명도 매트릭스(Fault Criticality Matrix, FCM)를 제시한다. FCM에서는 결함, 결함의 치명도, 안전 가드와 안전 가드의 발생 확률, 결함의 영향 및 순위를 나열하여 분석한다. 안전 엔지니어는 이를 통해 시스템의 설계 단계에서 각 결함의 치명도와 영향을 분석하고, 설계된 안전 가드를 통해 식별된 고장을 효과적으로 관리하고 제어함으로써 안전한 CPS를 개발할 수 있다. 제시된 방법의 유용성을 확인하기 위해 CCPS의 대표적 예인 군집주행에 대하여 사례 연구를 수행하였다. 본 연구에서 개발된 도구를 사용하여 군집주행 시스템에 FCM을 적용함으로써 상세한 결함 치명도 분석을 수행하였고, 분석 결과는 적합성과 효과성 관점에서 점검되었다. 또한 군집 주행에 대한 시뮬레이션 수행을 통해 FCM을 사용하여 결함 치명도를 분석한 군집주행 시스템이 발견된 모든 결함을 완화시켜 충돌 가능성을 크게 낮추었음을 보였다.

Collaborative Cyber-Physical Systems (CCPS) are those systems that contain tightly coupled physical and cyber components, massively interconnected subsystems, and collaborate to achieve a common goal. The safety of a single Cyber-Physical System (CPS) can be achieved by following the safety standards such as ISO 26262 and IEC 61508 or by applying hazard analysis techniques. However, due to the complex, highly interconnected, heterogeneous, and collaborative nature of CCPS, a fault in one CPS's components can trigger many other faults in other collaborating CPSs. Therefore, a safety assurance technique based on fault criticality analysis would require to ensure safety in CCPS. This paper presents a Fault Criticality Matrix (FCM) implemented in our tool called CPSTracer, which contains several data such as identified fault, fault criticality, safety guard, etc. The proposed FCM is based on composite hazard analysis and content-based relationships among the hazard analysis artifacts, and ensures that the safety guard controls the identified faults at design time; thus, we can effectively manage and control the fault at the design phase to ensure the safe development of CPSs. To justify our approach, we introduce a case study on the Platooning system (a collaborative CPS). We perform the criticality analysis of the Platooning system using FCM in our developed tool. After the detailed fault criticality analysis, we investigate the results to check the appropriateness and effectiveness with two research questions. Also, by performing simulation for the Platooning, we showed that the rate of collision of the Platooning system without using FCM was quite high as compared to the rate of collisions of the system after analyzing the fault criticality using FCM.

키워드

과제정보

이 논문은 과학기술정보통신부 연구재단에서 지원하는 중견연구과제의 지원에 의해 이루어짐(NRF-2020R1A2C1007571).

참고문헌

  1. D. Horn, N. Ali, and J. E. Hong, "Towards enhancement of fault traceability among multiple hazard analyses in cyber-physical systems," 2019 IEEE 43rd Annual Computer Software and Applications Conference (COMPSAC), Milwaukee, WI, USA, pp.458-464, 2019. doi: 10.1109/COMPSAC.2019.10249.
  2. J. Cleland-Huang, S. Rayadurgam, P. Mader, and W. Schafer, "Software and systems traceability for safety-critical projects," Technique Report from Dagstuhl Seminar, 2015.
  3. M. Gleirscher and C. Carlan, "Arguing from hazard analysis in safety cases: A modular argument pattern," in Proceedings of IEEE International Symposium on High Assurance Systems Engineering, pp.53-60, 2017, doi: 10.1109/HASE.2017.15.
  4. A. Y. Z. Ou, M. Rahmaniheris, Y. Jiang, L. Sha, Z. Fu, and S. Ren, "SafeTrace: A safety-driven requirement traceability framework on device interaction hazards for MD PnP," in Proceedings of 33rd Annual ACM Symposium on Applied Computing, pp.1282-1291, 2018, doi: 10.1145/3167132.3167270.
  5. C. A. Ericsson, "Hazard Analysis Techniques for System Safety," Hoboken, NJ, USA: John Wiley & Sons, Inc., 2005.
  6. N. Ali, M. Hussain, and J.-E. Hong, "Analyzing safety of collaborative cyber-physical systems considering variability," in IEEE Access, Vol.8, pp.162701-162713, 2020. doi: 10.1109/ACCESS.2020.3021460.
  7. A. Y.-Z. Ou, M. Rahmaniheris, Y. Jiang, L. Sha, Z. Fu, and S. Ren, "SafeTrace: A safety-driven requirement traceability framework on device interaction hazards for MD PnP," in Proceedings of 33rd Annual ACM Symposium on Applied Computing, pp.1282-1291, 2018, doi: 10.1145/3167132.3167270.
  8. A. Causevic, A. V. Papadopoulos, and M. Sirjani, "Towards a framework for safe and secure adaptive collaborative systems," in Proceedings of International Computer Software and Applications Conference, pp.165-170, 2019, doi: 10.1109/COMPSAC.2019.10201.
  9. S. Medawar, D. Scholle, and I. Sljivo, "Cooperative safety critical CPS platooning in SafeCOP," in the 6th Mediterranean Conference on Embedded Computing (MECO), pp.1-5, 2017, doi: 10.1109/MECO.2017.7977210.
  10. E. S. Kim, D. A. Lee, S. Jung, J. Yoo, J. G. Choi, and J. S. Lee, "NuDE 2.0: A formal method-based software development, verification and safety analysis environment for digital I&Cs in NPPs," Journal of Computing Science and Engineering, Vol.11, No.1, pp.9-23, 2017, doi: 10.5626/JCSE.2017.11.1.9.
  11. N. Nikolakis, V. Maratos, and S. Makris, "A cyber physical system (CPS) approach for safe human-robot collaboration in a shared workplace," Robotics and Computer-Integrated Manufacturing, Vol.56, pp.233-243, Apr. 2019, doi: 10.1016/j.rcim.2018.10.003.
  12. D. E. Verbitsky and P. F. Lucent, "FTA technique addressing fault criticality and interactions in complex consumer communications," Annual Reliability and Maintainability Symposium. 2001 Proceedings. International Symposium on Product Quality and Integrity (Cat. No.01CH37179), Philadelphia, PA, USA, pp.23-31, 2001.
  13. D. Jia, K. Lu, J. Wang, X. Zhang, and X. Shen, "A survey on platoon-based vehicular cyber-physical systems," IEEE Communications Surveys and Tutorials, Vol.18, No.1, pp.263-284, Jan. 2016, doi: 10.1109/COMST.2015.2410831.
  14. J. Reich, "Systematic engineering of safe open adaptive systems shown for truck platooning DEIS H2020 View project safeTbox: A model-based safety engineering tool View project," 2016. doi: 10.13140/RG.2.2.27809.61283.
  15. ISO, ISO 26262-2: Road Vehicles-Functional Safety, 2011.
  16. N. Highway Traffic Safety Administration, "Hazard Analysis of Concept Heavy-Truck Platooning Systems," United States, Department of Transportation, National Highway Traffic Safety Administration, May 2021. Accessed: May 25, 2021. [Online] Available: www.ntis.gov
  17. M. Amoozadeh, B. Ching, C. N. Chuah, D. Ghosal, and H. M. Zhang, "VENTOS: Vehicular network open simulator with hardware-in-the-loop support," in Procedia Computer Science, Vol.151, pp.61-68, Jan. 2019. doi: 10.1016/j.procs.2019.04.012.