Method for Calculating Safety Features of Railway Automation Devices
World of Transport and Transportation
The problem of quantitative analysis of safety of microelectronic and microprocessor systems of railway automation and telemechanics is considered. The problem remains relevant, since the subject of safety analysis is rarely occurring, but extremely dangerous events. The risk and significance of failure are selected as the main safety features of these systems. The way to identify a failure was chosen according to MILSTD‑1629A standard, as the most adequate.Calculated expressions for
... ions for significance of a failure are proposed. The probability of a dangerous failure is calculated by the method of model analysis. It is proposed to calculate the probability of a failure further developing into an accident using scenario analysis methods by constructing event trees. Calculated ratios for ratings of violations are suggested, allowing to compare dangerous failures and emergency sequences developed from a failure. The risk assessment of operation of railway automation systems was selected not related to economic categories, and thus convenient for rationing. It is based on probabilistic concepts of the nature of risk and is calculated using the methods of probability theory. The developed design ratios and models make it possible to analyze performance of the functions of train traffic safety systems by methods common to control systems, at the same time reflecting the features of operation of railway automation.