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A novel N-input voting algorithm for X-by-wire fault-tolerant systems.

Karimi A, Zarafshan F, Al-Haddad SA, Ramli AR - ScientificWorldJournal (2014)

Bottom Line: Voting is an important operation in multichannel computation paradigm and realization of ultrareliable and real-time control systems that arbitrates among the results of N redundant variants.Depending on the characteristics of the application and the type of selected voter, the voting algorithms can be implemented for either hardware or software systems.Then, its behavior has been software implemented in different scenarios of error-injection on the system inputs.

View Article: PubMed Central - PubMed

Affiliation: Department of Computer Engineering, Faculty of Engineering, Arak Branch, Islamic Azad University, Arak, Markazi, Iran.

ABSTRACT
Voting is an important operation in multichannel computation paradigm and realization of ultrareliable and real-time control systems that arbitrates among the results of N redundant variants. These systems include N-modular redundant (NMR) hardware systems and diversely designed software systems based on N-version programming (NVP). Depending on the characteristics of the application and the type of selected voter, the voting algorithms can be implemented for either hardware or software systems. In this paper, a novel voting algorithm is introduced for real-time fault-tolerant control systems, appropriate for applications in which N is large. Then, its behavior has been software implemented in different scenarios of error-injection on the system inputs. The results of analyzed evaluations through plots and statistical computations have demonstrated that this novel algorithm does not have the limitations of some popular voting algorithms such as median and weighted; moreover, it is able to significantly increase the reliability and availability of the system in the best case to 2489.7% and 626.74%, respectively, and in the worst case to 3.84% and 1.55%, respectively.

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The experimental test harness.
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Related In: Results  -  Collection


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fig1: The experimental test harness.

Mentions: To evaluate the dependability of the novel algorithm, the extended form of the test harness introduced in [31] is applied to simulate the voting system, with this assumption that the voter is used in a cyclic system in which there are relations between the correct results of a cycle with the next cycle. This assumption is valid in many real-time control systems. The input data of the system are considered as numerical nonnegative values and it is hypothesized that faults can lead to the errors whose effects might be revealed in the form of a difference between the output values of the modules. The differences less than the voting threshold are ignorable in inexact voting. For the purposes of the results reported here, the issues associated with ensuring synchronization of the inputs to the voter are ignored [13, 22]. In the simulation, we assume τ = 1, γ = 2, and ϵ = 1. In Figure 1, the structure of the experimental test harness is illustrated. This structure is widely common in evaluating the voting methods (e.g., see [22, 34, 35]).


A novel N-input voting algorithm for X-by-wire fault-tolerant systems.

Karimi A, Zarafshan F, Al-Haddad SA, Ramli AR - ScientificWorldJournal (2014)

The experimental test harness.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4216716&req=5

fig1: The experimental test harness.
Mentions: To evaluate the dependability of the novel algorithm, the extended form of the test harness introduced in [31] is applied to simulate the voting system, with this assumption that the voter is used in a cyclic system in which there are relations between the correct results of a cycle with the next cycle. This assumption is valid in many real-time control systems. The input data of the system are considered as numerical nonnegative values and it is hypothesized that faults can lead to the errors whose effects might be revealed in the form of a difference between the output values of the modules. The differences less than the voting threshold are ignorable in inexact voting. For the purposes of the results reported here, the issues associated with ensuring synchronization of the inputs to the voter are ignored [13, 22]. In the simulation, we assume τ = 1, γ = 2, and ϵ = 1. In Figure 1, the structure of the experimental test harness is illustrated. This structure is widely common in evaluating the voting methods (e.g., see [22, 34, 35]).

Bottom Line: Voting is an important operation in multichannel computation paradigm and realization of ultrareliable and real-time control systems that arbitrates among the results of N redundant variants.Depending on the characteristics of the application and the type of selected voter, the voting algorithms can be implemented for either hardware or software systems.Then, its behavior has been software implemented in different scenarios of error-injection on the system inputs.

View Article: PubMed Central - PubMed

Affiliation: Department of Computer Engineering, Faculty of Engineering, Arak Branch, Islamic Azad University, Arak, Markazi, Iran.

ABSTRACT
Voting is an important operation in multichannel computation paradigm and realization of ultrareliable and real-time control systems that arbitrates among the results of N redundant variants. These systems include N-modular redundant (NMR) hardware systems and diversely designed software systems based on N-version programming (NVP). Depending on the characteristics of the application and the type of selected voter, the voting algorithms can be implemented for either hardware or software systems. In this paper, a novel voting algorithm is introduced for real-time fault-tolerant control systems, appropriate for applications in which N is large. Then, its behavior has been software implemented in different scenarios of error-injection on the system inputs. The results of analyzed evaluations through plots and statistical computations have demonstrated that this novel algorithm does not have the limitations of some popular voting algorithms such as median and weighted; moreover, it is able to significantly increase the reliability and availability of the system in the best case to 2489.7% and 626.74%, respectively, and in the worst case to 3.84% and 1.55%, respectively.

Show MeSH