Description: An intelligent diagnostics problems of complex engineering system operating conditions classification was considered. Related correct aircraft engines with multiple failure diagnostic problems definitions were formulated. These problems are definition the symptoms values interval, that conform to operable operating condition of unit under test, and estimating the functional unit design parameter values during an operating process on basis of current symptoms measuring. The second problem is solved by reduction to modification problem. Problems quasisolutions synthesis was realized by smoothing functional extremum seeking regularization with using the A.N. Tihonov’s method. This technique ensures solutions uniqueness and solutions stability about input data law variations. Regularization parameter choice was realized in compliance with generic residual principle. The examples of suggested methodology were considered for diagnostics problem solution of regional passenger aircraft modern turbojet engine.
Keywords: intelligent diagnostics, ill-posed problems, regularization method, diagnostic character, fault class