1,485 research outputs found
Use of COTS functional analysis software as an IVHM design tool for detection and isolation of UAV fuel system faults
This paper presents a new approach to the development of health management solutions which can be applied to both new and legacy platforms during the conceptual design phase. The approach involves the qualitative functional modelling of a system in order to perform an Integrated Vehicle Health Management (IVHM) design â the placement of sensors and the diagnostic rules to be used in interrogating their output. The qualitative functional analysis was chosen as a route for early assessment of failures in complex systems. Functional models of system components are required for capturing the available system knowledge used during various stages of system and IVHM design. MADe⢠(Maintenance Aware Design environment), a COTS software tool developed by PHM Technology, was used for the health management design. A model has been built incorporating the failure diagrams of five failure modes for five different components of a UAV fuel system. Thus an inherent health management solution for the system and the optimised sensor set solution have been defined. The automatically generated sensor set solution also contains a diagnostic rule set, which was validated on the fuel rig for different operation modes taking into account the predicted fault detection/isolation and ambiguity group coefficients. It was concluded that when using functional modelling, the IVHM design and the actual system design cannot be done in isolation. The functional approach requires permanent input from the system designer and reliability engineers in order to construct a functional model that will qualitatively represent the real system. In other words, the physical insight should not be isolated from the failure phenomena and the diagnostic analysis tools should be able to adequately capture the experience bases. This approach has been verified on a laboratory bench top test rig which can simulate a range of possible fuel system faults. The rig is fully instrumented in order to allow benchmarking of various sensing solution for fault detection/isolation that were identified using functional analysis
50 years of isolation
The traditional means for isolating applications from each other is via the use of operating system provided âprocessâ abstraction facilities. However, as applications now consist of multiple fine-grained components, the traditional process abstraction model is proving to be insufficient in ensuring this isolation. Statistics indicate that a high percentage of software failure occurs due to propagation of component failures. These observations are further bolstered by the attempts by modern Internet browser application developers, for example, to adopt multi-process architectures in order to increase robustness. Therefore, a fresh look at the available options for isolating program components is necessary and this paper provides an overview of previous and current research on the area
Why We Cannot (Yet) Ensure the Cybersecurity of Safety-Critical Systems
There is a growing threat to the cyber-security of safety-critical systems.
The introduction of Commercial Off The Shelf (COTS) software, including
Linux, specialist VOIP applications and Satellite Based Augmentation Systems
across the aviation, maritime, rail and power-generation infrastructures has created
common, vulnerabilities. In consequence, more people now possess the technical
skills required to identify and exploit vulnerabilities in safety-critical systems.
Arguably for the first time there is the potential for cross-modal attacks
leading to future âcyber stormsâ. This situation is compounded by the failure of
public-private partnerships to establish the cyber-security of safety critical applications.
The fiscal crisis has prevented governments from attracting and retaining
competent regulators at the intersection of safety and cyber-security. In particular,
we argue that superficial similarities between safety and security have led
to security policies that cannot be implemented in safety-critical systems. Existing
office-based security standards, such as the ISO27k series, cannot easily be integrated
with standards such as IEC61508 or ISO26262. Hybrid standards such as
IEC 62443 lack credible validation. There is an urgent need to move beyond
high-level policies and address the more detailed engineering challenges that
threaten the cyber-security of safety-critical systems. In particular, we consider
the ways in which cyber-security concerns undermine traditional forms of safety
engineering, for example by invalidating conventional forms of risk assessment.
We also summarise the ways in which safety concerns frustrate the deployment of
conventional mechanisms for cyber-security, including intrusion detection systems
Recommended from our members
Evaluating the resilience and security of boundaryless, evolving socio-technical Systems of Systems
Recommended from our members
Efficient Memory-Protected Integration of Add-On Software Subsystems in Small Embedded Automotive Applications
Current innovations in the automotive industry
evolve mainly in the electronics and software domain. This leads
to an increasing integration of additional software subsystems
into already existing electronic control units (ECUs) to cope with
the raised amount and complexity of present ECUs in modern
high-end vehicles. This paper discusses different approaches
which are required to integrate such add-on software subsystems
in an isolated memory domain, and considers particularly the
special needs of small embedded systemsâincluding the limited
hardware support. Special focus is brought to the efficient detection
of malicious memory accesses, as well as the benefits of
a thereupon possible and adaptable failure-handling strategy.
All investigations are based on a developed memory-protection
framework which has been tailored to the special needs of a sample
vehicle dynamics control system. Its usage allows the combination
of. integrating additional subsystems without reducing the main
applicationâs availability
Securing Real-Time Internet-of-Things
Modern embedded and cyber-physical systems are ubiquitous. A large number of
critical cyber-physical systems have real-time requirements (e.g., avionics,
automobiles, power grids, manufacturing systems, industrial control systems,
etc.). Recent developments and new functionality requires real-time embedded
devices to be connected to the Internet. This gives rise to the real-time
Internet-of-things (RT-IoT) that promises a better user experience through
stronger connectivity and efficient use of next-generation embedded devices.
However RT- IoT are also increasingly becoming targets for cyber-attacks which
is exacerbated by this increased connectivity. This paper gives an introduction
to RT-IoT systems, an outlook of current approaches and possible research
challenges towards secure RT- IoT frameworks
- âŚ