Improved Systemic Hazard Analysis Integrating with Systems Engineering Approach for Vehicle Autonomous Emergency Braking System

Author(s):  
Jianyu Duan

Abstract Safety analysis is a significant step for the safety-critical system development. Compared with traditional vehicles, the system interactions for autonomous vehicles are more abundant and complex. Traditional hazard analysis methods, such as Failure Mode and Effects Analysis (FMEA) and Fault Tree Analysis (FTA) which are on the basis of the component failure and reliability theory, can not identify the system hazards related to system interactions. An emerging hazard analysis method based on systems theory, Systems Theory Process Analysis (STPA) mainly focuses on identifying the control system hazards caused by system interactions. In this study, STPA method is used to identify the potential hazards and casual factors for autonomous emergency braking system by concentrating on system interactions. To improve the consistency between system design and safety analysis, the workflow combining model-based systems engineering (MBSE) and STPA is proposed. The systems modeling language (SysML) is used to describe control structure and system interaction relationships. According to the identified casual factors, the certain constraints and requirements can be derived, which can provide the guidance for system development with respect to system design. Furthermore, the quantitative analysis of the certain unsafe control action is conducted by simulation, which shows effectiveness and feasibility of the proposed method in safety analysis and system design.

2019 ◽  
Vol 9 (6) ◽  
pp. 1246 ◽  
Author(s):  
Anis Baklouti ◽  
Nga Nguyen ◽  
Faïda Mhenni ◽  
Jean-Yves Choley ◽  
Abdelfattah Mlika

The goal of the paper is the integration of safety analysis in a model-based systems engineering approach to ensure consistency between system design and safety artifacts. This integration permits the continuous improvement of the structure and behavior of the system. It also reduces system development time and prevents late detection of errors. To reach this purpose, the SafeSysE methodology is extended. In SafeSysE, a preliminary Failure Mode and Effects Analysis (FMEA) is automatically generated from a SysML model, and this FMEA is then completed by the safety expert but no further development was proposed. The contribution of this paper is to suggest recommendations based on the FMEA analysis in order to enhance the system design and make it comply with safety requirements. First, an updated system structure that may contain redundancy is proposed. Then, a redundancy profile is used to enrich the system model with redundancy information, which will allow the generation of a dynamic fault tree considering the system behavior. Finally, the generated dynamic fault tree should be analyzed in order to create a state machine diagram that describes the behavior of the system. The created state machine with an internal block diagram will help the system designers to better understand the system dysfunctions by simulating the system. The proposed methodology is applied to an Electro-Mechanical Actuator system which is used in the aeronautics domain.


2021 ◽  
pp. 173-184
Author(s):  
Andrii Kashkanov ◽  
Victor Bilichenko ◽  
Tamara Makarova ◽  
Olexii Saraiev ◽  
Serhii Reiko ◽  
...  

Author(s):  
Nanda Anugrah Zikrullah ◽  
Hyungju Kim ◽  
Meine JP van der Meulen ◽  
Gunleiv Skofteland ◽  
Mary Ann Lundteigen

A safety-critical system comprising several interacting and software-intensive systems must be carefully analyzed to detect whether new functional requirements are needed to ensure safety. This involves an analysis of the systemic properties of the system, which addresses the effect of the interaction between systems and system parts. The paper compares two hazard analysis methods, which are often considered well-suited for such software-intensive systems: the Functional Hazard Analysis (FHA) and Systems-Theoretic Process Analysis (STPA). The focus is on the selection and improvement of the best methods, based on the lesson learned from the comparison of FHA and STPA. The analyses cover the hazard analysis processes, systemic properties, and the criteria of requirements. The paper concludes that STPA is the better choice over FHA. Insights are obtained to align both STPA and FHA methods with the broader topic on risk management, that is, hazard analysis method improvement, cautionary thinking, uncertainty management, and resilience management.


Author(s):  
Liangliang Sun ◽  
Yan-Fu Li ◽  
Enrico Zio

Abstract As autonomous vehicle (AV) intelligence for controllability continues to develop, involving increasingly complex and interconnected systems, the maturity level of AV technology increasingly depends on the systems reliability level, also considering the interactions among them. Hazard analysis is typically used to identify potential system risks and avoid loss of AV system functionality. Conventional hazard analysis methods are commonly used for traditional standalone systems. New hazard analysis methods have been developed that may be more suitable for AV system-of-systems complexity. However, a comprehensive comparison of hazard analysis methods for AV systems is lacking. In this study, the traditional hazard analysis methods, hazard and operability (HAZOP) and failure mode and effects analysis (FMEA), as well as the most recent methods, like functional resonance analysis method (FRAM; Hollnagel, 2004, 2012) and system-theoretic process analysis (STPA; Leveson, 2011), are considered for implementation in the automatic emergency braking system. This system is designed to avoid collisions by utilizing the surrounding sensors to detect objects on the road, warning drivers with alerts about any collision risk, and actuating automatic partial/full braking through calculated adaptive braking deceleration. The objective of this work is to evaluate the methods in terms of their applicability to AV technologies. The advantages of HAZOP, FMEA, FRAM, and STPA, as well as the possibility of combining them to achieve systematic risk identification in practice, are discussed.


2019 ◽  
Vol 9 (21) ◽  
pp. 4530 ◽  
Author(s):  
Zitong Zhou ◽  
Yanyang Zi ◽  
Jinglong Chen ◽  
Tong An

Due to the complex mechanical structure and control process of escalator emergency braking systems (EEBS), traditional hazard analysis based on the event chain model have limitations in exploring component interaction failure in such a complex social-technical system. Therefore, a hazard analysis framework is proposed in this paper for hazard analysis of complex electromechanical systems based on system-theoretic accident model and process (STAMP). Firstly, basic principles of STAMP are introduced and comparison with other hazard analysis methods is conducted, then the safety analysis framework is proposed. Secondly, a study case is performed to identify unsafe control actions of EEBS from control structures, and a specific control diagram is organized to recognize potential example casual scenarios. Next, comparison between fault tree analysis and STAMP for escalator’s overturned accident shows that hazards related to component damaged can be identified by both, while hazards that focus on components interaction can only be identified by STAMP. Besides, single control way and tandem operation process are found to be the obvious causal factors of accidents. Finally, some improvement measures like decibel detection or vibration monitoring of key components are suggested to help the current broken chain detection to trigger the anti-reversal device for a better safe EEBS.


Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1220
Author(s):  
Chee Wei Lee ◽  
Stuart Madnick

Urban mobility is in the midst of a revolution, driven by the convergence of technologies such as artificial intelligence, on-demand ride services, and Internet-connected and self-driving vehicles. Technological advancements often lead to new hazards. Coupled with the increased levels of automation and connectivity in the new generation of autonomous vehicles, cybersecurity is emerging as a key threat affecting these vehicles. Traditional hazard analysis methods treat safety and security in isolation and are limited in their ability to account for interactions among organizational, sociotechnical, human, and technical components. In response to these challenges, the cybersafety method, based on System Theoretic Process Analysis (STPA and STPA-Sec), was developed to meet the growing need to holistically analyze complex sociotechnical systems. We applied cybersafety to coanalyze safety and security hazards, as well as identify mitigation requirements. The results were compared with another promising method known as Combined Harm Analysis of Safety and Security for Information Systems (CHASSIS). Both methods were applied to the Mobility-as-a-Service (MaaS) and Internet of Vehicles (IoV) use cases, focusing on over-the-air software updates feature. Overall, cybersafety identified additional hazards and more effective requirements compared to CHASSIS. In particular, cybersafety demonstrated the ability to identify hazards due to unsafe/unsecure interactions among sociotechnical components. This research also suggested using CHASSIS methods for information lifecycle analysis to complement and generate additional considerations for cybersafety. Finally, results from both methods were backtested against a past cyber hack on a vehicular system, and we found that recommendations from cybersafety were likely to mitigate the risks of the incident.


2021 ◽  
Vol 1 ◽  
pp. 2027-2036
Author(s):  
Aschot Kharatyan ◽  
Julian Tekaat ◽  
Sergej Japs ◽  
Harald Anacker ◽  
Roman Dumitrescu

AbstractAs digitization progresses, the integration of information and communication technologies in technical systems is constantly increasing. Fascinating value potentials are emerging (e.g. autonomous driving), but also challenges in the system development. The constantly increasing product complexity and degree of networking require a systemic development, which is fulfilled by established approaches of Model-Based Systems Engineering (MBSE). To ensure the reliability of tomorrow's systems, an integrative and early consideration of security and safety is additionally required. In order to show the possibility and consequences of failures and attacks, the paper develops a modeling language that links established and partly isolated security and safety approaches within a consistent metamodel. The developer is enabled to synthesize system architectures transparently on an interdisciplinary level and to analyze attack and failure propagation integratively. The approach uncovers synergetic and especially contrasting goals and effects of architectural designs in terms of safety and security in order to make adequate architectural decisions based on trade-off analyses.


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