Component-oriented voter model for dependable control applications

In many industrial applications arbitration between redundant subsystems us ing voting algorithms is popular. Many voting strategies, implemented in ha rdware or software, have been proposed of which majority and median voters have been widely used in real applications. Component-oriented design and m odeling is receiving increasing amounts of interest in the software enginee ring community. Detailed analysis of voters shows that they can also be con sidered as a combination of independent components, each performing a speci fic function. This article proposes a component-oriented model for voters. The model offers benefits such as reusability, flexibility, and extensibili ty to the system designer. Components and their families are introduced, ca tegorised and simulated. The model is simulated and a Library of simulated components is provided. The generality of the model not only supports the a nalysis of a large number of voter permutations but also facilitates system design and implementation phases. The article presents the experimental re sults of selected component-oriented voters including majority, median, and linear predictor voters within a Triple Modular Redundant, TMR, system for a wide range of error scenarios. The correctness of the voter model is als o proved by comparing the experimental results of selected component-orient ed voters with those of the corresponding directly implemented voters. (C) 2001 Elsevier Science B.V. All rights reserved.