METHOD FOR DETERMINING TECHNICAL STATE OF INTERNAL COMBUSTION ENGINE WITH COMPLEX CONTROL SYSTEM Russian patent published in 2011 - IPC G01M15/04 

FIELD: engines and pumps.

SUBSTANCE: method is implemented owing to continuous measurement at multiple accelerations and rundowns of the engine without load of instantaneous values of angular speed and acceleration of crankshaft at combustion stroke of each cylinder, measurement of amplitudes of the specified harmonic acceleration components, achievement of the engine of the specified rotation frequency value of crankshaft in subtraction from acceleration of speed-up of these harmonic components and acceleration of rundown, determination of average values obtained in each cylinder per operating stroke of its piston, and in determination of non-uniformity degree of operation of cylinders as to ratio of the obtained values, and as to amplitudes of the specified harmonic components - engine roughness degree. All measurements are made at positively actuated electric motor of fan of cooling system; measurements at speed-up of instantaneous values of angular speed and acceleration of crankshaft for each cylinder are made from the moment when certain rotation frequency of crankshaft is achieved in engine operating cycle; there recorded is crankshaft rotation frequency value at which the measured cycle is being completed; at that, at the interval of the required rotation frequencies of crankshaft there stabilised is cyclic fuel supply and set is constant ignition point excluding the detonation in this mode; measurements at the rundown are made for each cylinder at operating stroke and compression strokes from the moment when the crankshaft achieves the frequency of completion of the measured cycle at acceleration at shutoff supply of fuel to all cylinders; when the engine achieves certain value of rotation frequency of crankshaft, the specified harmonic components and average acceleration value of rundown at compression strokes of all cylinders except that cylinder which at acceleration at operating stroke of the selected cylinder was at compression stroke are subtracted from acceleration speed-up; average values of obtained values are determined in each cylinder per operating stroke of its piston; as per their value there determined are non-operating cylinders; at periodic occurrence of negative values of acceleration speed-up of crankshaft at operating strokes of cylinders there fixed are incorrect firings; as per average acceleration speed-up values at operating stroke of each cylinder there performed is their evaluation of effective dynamic power; as per average acceleration speed-up values of each cylinder there performed is evaluation of tightness of above-piston space.

EFFECT: improving the accuracy of evaluation of technical state of internal combustion engine with complex control system at its diagnostics under operating conditions owing to excluding the influence of non-optimum parameters of feed and ignition system for acceleration mode, as well as defining the resultant value of acceleration of crankshaft and increase in the number of determined parameters of ICE technical state in order to provide the possibility of localising the failures in its systems and mechanisms.