Development of mathematical criteria for assessing the quality of diagnosing the cylinder-piston group of a car engine

Problem. The paper analyzes the possibility of applying various mathematical models and quality assessment criteria in accordance with the problems of modern car diagnostics. The most complex object of car diagnostics is considered - the internal combustion engine and its especially loaded elements, which are part of the cylinder-piston group. The criteria for evaluating the quality of diagnosis of the cylinder-piston group are proposed. The possibility of presenting quality indicators in a multidimensional space, in which each dimension corresponds to a certain group of properties, is shown. In order to provide a comprehensive assessment, a number of indicators of quality properties are described, which have a certain formalized interpretation and make it possible to obtain a more objective, informative and unambiguous diagnostic conclusion regarding the functioning of complex technical objects.. Methodology. Based on the analysis of various types of mathematical models of technical diagnostics of the car engine, the criteria for evaluating the quality of diagnostics of the cylinder-piston group have been revised and improved. Additional data for the formulation of quality assessment criteria are provided by the results of expert studies of the technical condition of engines with serious damage up to the point of inoperability. At the same time, it is important that the assessment criteria for different engine states may be different.. Originality. The document shows a wide range of properties for evaluating the quality of diagnostics of the cylinder-piston group of the engine. A method of comprehensive quality assessment is proposed. An assumption is made about the presentation of quality indicators in a multidimensional space, in which each dimension corresponds to a certain group of properties. Practical value. To improve the quality of diagnosis of the cylinder-piston group of the engine, a comprehensive assessment of the diagnosis quality has been developed and improved, taking into account the conduct of expert studies of severe engine damage.