22nd Congress of International Council of the Aeronautical Sciences, Harrogate, UK, 28 August - 1st September, 2000
Paper ICAS 2000-5.9.4


MATHEMATICAL MODEL BASED METHODS TO INVESTIGATE MANUFACTURING ANOMALIES

L. Pokoradi, R. Szabolcsi, J. Bera
Miklós Zrínyi National Defense University, Budapest, Hungary

Keywords: mathematical model based methods, manufacturing anomalies

During the design of new aircraft systems, their manufacturing tolerances should be determined basically by working requirements of the system and technological possibilities of the manufacturers. Therefore the determination of manufacturing tolerances is a very important and difficult task. It is possible that system parameter values are inadequate, but every unit and element of the system meets its own requirements. Because of the manufacturing tolerances of the units and elements have been determined incorrectly. It is possible too, that the working requirements of the designed system have to determine strictly the system parameter tolerances. For example, these system requirements can be velocity or acceleration of the piston of aircraft hydraulic servo actuator, from the flight mechanical point of view. These external parameters should require very strictly the tolerances of internal parameters of the given system. Using linearized mathematical diagnostic model of the given system, the problems mentioned above can be investigated and solved. Their densities, expected values and variances can characterise manufacturing anomalies of internal parameters. These random characteristics determine the densities, expected values and variances of external parameters that is their manufacturing anomalies. This paper will show the methodology of the linearized mathematical-diagnostic model’s usage to investigate effects of manufacturing anomalies. Investigation methods and their inverse methods will be shown in case of the Gauss-distributions and in case of unknown (general) distributions of the internal parameters.


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