Method of detection of output fluctuation in internal combustion engine
AssigneeToyota Jidosha Kabushiki Kaisha
InventorNobuyuki Shibagaki
Life of this patent
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Abstract
An engine in which an elapsed time Ta(i) of 30° crank angle near top dead center of the compression stroke and an elapsed time Tb(i) of 30° crank angle near 90° after top dead center of the compression stroke are found. The difference DTa(i) of the elapsed times Ta(i) in a 720° crank angle range is found for the first cylinder and the second cylinder where combustion is performed after the first cylinder. The assumed elapsed time Tb′(i) assuming that there is no torque fluctuation is calculated from the difference of elapsed times DTa(i) of the first cylinder and the second cylinder and the assumed elapsed time Tb′(i) is used to calculate the amount of torque fluctuation.
Claims19
A method of detection of output fluctuation of a multi-cylinder engine having a crankshaft in which combustion is performed in a first cylinder and then combustion is performed in a second cylinder, comprising the steps of:
- setting a first crank angle range in a crank angle region in a middle portion of the expansion stroke a predetermined crank angle away from the first crank angle range;
- detecting a first angular velocity of the crankshaft in the second crank angle range;
- detecting a second angular velocity of the crankshaft in the second crank angle range;
- finding an amount of change between the first angular velocity at a time of a previous combustion and the first angular velocity at another time of a next combustion for the first cylinder;
- finding an amount of change between the first angular velocity at the time of a previous combustion and the first angular velocity at the another time of a next combustion for the second cylinder;
- finding an assumed second angular velocity at the time of the next combustion of the first cylinder when assuming that the output of the first cylinder will not fluctuate, on a basis of the amount of change of the first angular velocity for the first cylinder, the amount of change of the first angular velocity of the second cylinder, and the second angular velocity at the time of the previous combustion of the first cylinder;
- and
- detecting the output fluctuation of the first cylinder based on the assumed second angular velocity and an actual second angular velocity at the another time of the next combustion of the first cylinder.
Dependencies are inferred from the claim text.