An approach to the technical diagnostics of complex technical systems based on the results of telemetry information processing by an external monitoring and diagnostics system using hybrid network structures is proposed. The principle of constructing diagnostic complexes of complex technical systems is considered, which ensures the automation of the technical diagnostics process and is based on the use of models in the form of hybrid network structures for processing telemetric information, including multilayer neural networks and discrete Bayesian networks with stochastic learning. A model of changes in the parameters of complex technical systems technical state based on multilayer neural networks has been developed, which makes it possible to form a probabilistic assessment of attributing the current situation of complex technical system functioning to the set of functions considered situations according to individual telemetry parameters, and multilevel hierarchical model of complex technical systems technical diagnostics based on a discrete Bayesian network with stochastic learning, which allows aggregating the information received from neural network models and recognizing the current situation of complex technical system functioning. In the conditions of functioning emergencies of the complex technical system, according to the results of processing telemetric information, faulty functional units are localized and an explanation of the cause of the emergency is formed. The stages of complex technical systems technical diagnostics implementation using the proposed hybrid network structures in the processing of telemetric information are detailed. An example of using the developed approach to solving problems of spacecraft onboard system technical diagnostics is presented. The advantages of the proposed approach to the technical diagnostics of complex technical systems in comparison with the traditional approach based on analysis of telemetry parameters values belonging to the given tolerances are shown.
A method for streamlining state partitioning procedures with two and three outcomes is considered. A terminology and methods of the questionnaire theory were used, and the sequence of partitioning procedures itself was defined as a heterogeneous questionnaire with questions having two or three answers. This class of questionnaires is special and is defined by the authors as a class of binary-ternary questionnaires. This is the simplest class of heterogeneous questionnaires. An increase in number of answers to a question in practice can give an advantage in parameters of the questionnaires, including in the indicator of its effectiveness – the average implementation cost. It is noted that the use of binary-ternary questionnaires in practice can reduce the average time for identifying events on a questionnaire, which is extremely important in those applications of questionnaires in which there is a time limit for identifying events, for example, in critical application systems. A method for optimizing binary-ternary questionnaires is presented, based on the search for the most preferred questions for each subset of identifiable events. The choice of preferred questions is based on establishing a comparison relationship between them. The article describes all possible types of comparison relations between two questions with two answers, two questions with three answers, and also between a question with two answers and a question with three answers. An example of obtaining a mathematical expression for a function that characterizes the preference of questions over each other, as well as a generalized formula for choosing the most preferred question for any heterogeneous questionnaires is given. An algorithm has been formed for the method of ordering questions, which allows one to construct a binary-ternary questionnaire with the lowest implementation cost in polynomial time. An example of a binary-ternary questionnaire optimization by the presented method is given.
The article discusses the issues of the synthesis of adaptive mathematical models applied to the problems of technical diagnostics of on-board electronic systems of the spacecraft. The authors formulated the problem of the synthesis of adaptive models of on-board radio-electronic systems of spacecraft in a general form using the transformation of the source mathematical structure into the homologous structure with smaller dimension. An approach to the synthesis of adaptive models on the basis of using mathematical apparatus of finite state machines is presented. The novelty of the approach lies in the fact that a homologous structure with smaller dimension is synthesized by transformation of the relations between the elements of a set of controlled parameters (output variables of FSM model). An example of the synthesis of the mathematical model of the on-board telemetry system’s central unit, adaptive to the control process of technical condition, is given. Efficiency of the synthesized adaptive model of on-board radio-electronic systems was evaluated by solving the Chinese postman problem.
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