The task of reducing the probability of developing combinations of emergency events in unmanned aerial vehicles

The article presents an approach to reducing the likelihood of accidents caused by combinations of individually relatively harmless events of various origins during the operation of civil unmanned aircraft systems. The relevance of the stated problem is considered, as well as an overview of the available official documents regulating the field of application of unmanned aircraft systems. These systems are considered from the point of view of the control object, the main groups of technical violations leading to undesirable behavior are listed. In this work, we propose a new variation of the formulation of the control problem of preventing emergency combinations of events, and formulate a general approach to solving this problem at various control time intervals. Considering that accidents are caused by certain, individually non-dangerous basic events that occurred in a certain sequence, it is necessary to establish links between them and identify possible combinations. A logical-probabilistic safety analysis is used to depict the relationship between accidents and events. It is proposed to model the processes of development of emergency combinations of events using failure trees that take into account the events of the system and the external environment. The minimum tree sections represent emergency combinations of events, and the ways of successful functioning provide options for preventing the accidents under consideration. The selected depth of event decomposition in the construction of a set of basic events is assumed to be large enough so that a specific set of fairly simple and concise actions can be proposed to fend off individual events and reduce the probability of an accident to acceptable values. A generalized algorithm of actions is proposed to prevent the development of emergency combinations of events. An example of the application of the results of work in the periods of preparation for flights is considered.