METHOD AND EXPERT SYSTEM FOR CHECKING CONDITION OF INTERNAL COMBUSTION ENGINES Russian patent published in 1997 - IPC

FIELD: mechanical engineering; internal combustion engines. SUBSTANCE: method is based on continuous measuring of actual values of crankshaft angular acceleration in phase, generating functions of acceleration inertia component and coupling active forces in cylinder with torque, separating acceleration component reflecting working processes in cylinder, calculating indirect indicator diagram of cylinder, comparing it with standard diagram inherent to engine in good repair and with dependence of changes of the diagram at changed in engine condition, and classification of engine condition basing on proximity of actual and standard indicator diagrams. Expert system includes system for registration and processing of indicator diagrams containing cylinder pressure sensors, amplifiers with zero line correction, analog-to-digital converters, angle label sensor with revolution recorder, control unit, threshold flip-flop, manual control unit, receiver, computer, digital indicator, output unit, clock pulse generator, timing pulse distributor, processing algorithm setter, processing command shaper, switch, calculating unit and correcting pulse shaping circuit and additional angle label-spike sensor, spike shaper, OR element, fuel injection sensor, injection amplifier, second threshold flip-flop, twin digital differentiator, digital sign discriminator, acceleration extremum meter, acceleration memory, arithmetic unit, function generator, identification unit, process model setter, condition classification unit, parameters change function setter. EFFECT: simplified and reduced labor input in checking condition of engines in service by indirect finding of cylinder indicator diagrams which does not require installation of special high temperature sensors and special cylinder head, improved accuracy of identification and classification of conditions. 3 cl, 4 dwg