Patent ID: 6595193
Filing Date: 2003-07-22
Classification: F02D

Abstract:
A method of determining where in their operating cycles the cylinders of an engine are located for a multiple cylinder, four-stroke cycle, internal combustion engine with fuel injection, wherein the cylinders drive a crankshaft to rotate and a flywheel is on the driven crankshaft, the method comprising:during operation of the engine, determining a rotation angle of the flywheel on the rotating crankshaft of the engine and generating a position signal representative of the rotation angle of the flywheel; injecting a first amount of fuel to at least a first one of the cylinders and injecting a second amount of fuel different than the first amount of fuel to at least a second one of the cylinders for subjecting the rotating flywheel to ignition pulses each time an amount of fuel is injected which produce ignition pulse oscillations of the flywheel rotation as fuel is supplied to each cylinder and for also subjecting the flywheel to interference oscillations caused by the supplying of different amounts of fuel, wherein the interference oscillations have predetermined first phase positions; the flywheel having a pattern of resultant oscillations resulting from the ignition pulses and from the interference oscillations superimposed on the ignition pulse oscillations, wherein the resultant oscillations have second phase positions; determining the superimposed interference oscillations and the first phase positions thereof from the resultant oscillations of the flywheel; comparing the predetermined first phase positions of the interference oscillations with corresponding second phase positions of the resultant oscillation pattern, and if the predetermined first phase positions of the interference oscillations appear also for the second phase positions of the resultant oscillation pattern, then a control unit for fuel injection to the cylinder is considered to be operating in the correct cycle position; and if the predetermined first phase positions of the interference oscillations differ from the second phase position of the resultant oscillation pattern, the control unit for the fuel injection is considered to be operating in an incorrect cycle position, then operating the control unit to correct its cycle position by a number of steps in the ignition sequence until the correct cycle position is attained.