Reliability Models of Diverse Majority-redundant Systems with Threshold Adaptation

The paper proposes reliability models and improvement of the method for ensuring the reliability of microprocessor control systems (MCS) based on hardware (HW) and software (SW) adaptation and diversity (multi-version). Analytical dependencies are developed and investigated to evaluate the reliability of diverse majority-redundant systems (DMRS) under equal channel reliability as well as different adaptation schemes. A generalised structural diagram for three-, four- and five-channel structures has been compiled using the developed DMRS basic models. The research of change of the main reliability criterion - probability of failure-free operation (PFFO) of three-, four- and five-channel DMRS at different initial data is carried out, the results are presented in the form of graphical dependences. On the basis of the analysis of graphical dependences of PFFO on various reliability indicators, the priority series of DMRS are made up, by which it is possible to determine the best structure of DMRS when improving existing or developing new DMRS for specific operating conditions and initial data. A method of choice the diverse HW and SW structure with adaptation for MCS has been developed.