This content is not included in your SAE MOBILUS subscription, or you are not logged in.
A Dynamic Fault Tree Approach for Time-Dependent Logical Modeling of Autonomous Flight Systems
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 19, 2019 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
Event: AeroTech Americas
This paper addresses the urgent need for adequate methodologies to use in analyzing autonomous flight systems, including Unmanned Aircraft. These systems are inherently dynamic and require analysis that is explicitly time dependent. Autonomous flight systems are becoming more commonly used, especially for Part 23 aircraft including Business (Corporate) and Regional Jets or Unmanned Aircraft deployed in hazardous environment/situation. Such systems are expected to make their own decisions under uncertain conditions caused by potential system structure changes when entering a new flight phase or switching to a new system configuration due to system degradation or failure(s) . This paper highlights significant modeling errors that can arise in analyzing dynamic scenarios where these time dependencies are ignored. Model-based solutions are provided by incorporating a time-dependent algebraic formalism into Fault Tree Analysis (FTA) and Dependency Diagram (DD) with updated descriptions in SAE ARP4761A and ARP4754B (Note: These are currently under development). A Dynamic Goal Tree (or alternatively, a Dynamic Dependency Diagram) provides an effective implementation of the time-dependent logic for dynamic system analysis analyzing autonomous flight systems which are inherently dynamic since decisions need to be made without human input in a very short time. The safety analysis for autonomous flight systems, including Unmanned Aircraft, can be performed by extending the traditional phased mission analysis, thus the potential system structure changes for different phases in a flight mission can be expressed by a Dynamic Fault Tree (DFT), or alternatively, a Dynamic Goal Tree (DGT), or Dynamic Dependency Diagram (DDD) .
CitationWang, J., "A Dynamic Fault Tree Approach for Time-Dependent Logical Modeling of Autonomous Flight Systems," SAE Technical Paper 2019-01-1358, 2019, https://doi.org/10.4271/2019-01-1358.
Data Sets - Support Documents
|[Unnamed Dataset 1]|
- Wang, J.X., What Every Engineer Should Know about Decision Making under Uncertainty (CRC Press, July 1, 2002). ISBN:9780824708085.
- Wang, J.X. and Roush, M.L., “A Dynamic Goal Tree Approach for Process Safety Management,” in Proceedings OF PSAM - II, an International Conference Devoted to the Advancement of System-Based Methods for the Design and Operation of Technological Systems and Processes, San Diego, CA, Mar. 20-25, 1994.
- Wang, J.X. and Roush, M.L., What Every Engineer Should Know about Risk Engineering and Management (CRC Press, Feb. 15, 2000). ISBN:9780824793012.
- Wang, J.X., “Time Dependent Boolean Operations for Phased Mission Analysis, Ph.D. thesis, University of Maryland at College Park, 1995, Thesis Research Directed by Reliability Engineering Program.
- Wang, J.X., Green Electronics Manufacturing: Creating Environmental Sensible Products (CRC Press, July 25, 2012). ISBN:9781439826645.
- Wang, I.J.X., “Combined Hybrid Thermionic and Thermoelectric Generator,” US20170126150A1, US Patent Application, Priority date Oct. 30, 2015.
- Wang, I.J.X., “Hybrid Solar Generator, EP3255651A1,” European Patent Application, Priority Date June 9, 2016.