Control device for an internal combustion engine

A control device for an internal combustion engine comprising:

• a plurality of detected targets provided corresponding to a plurality of predetermined crankshaft angles on a rotating member that rotates in synchronization with the crankshaft,
• an angle sensor that is fixed to a non-rotating member and detects the detected targets,
• an angle information detector that detects a crankshaft angle based on an output signal of the angle sensor and detects a detection time period of the crankshaft angle every time the crankshaft angle is detected,
• a reference time period calculator that calculates the detection time period detected within a reference angle section that is a preset crankshaft angle section including a top dead center of a compression stroke, as a reference detection time period, based on the detected value of the crankshaft angle and the detection time period,
• a misfire detection threshold value calculator for calculating a misfire detection threshold value time period obtained by multiplying the reference detection time period and a threshold value adjustment coefficient,
• a misfire detection threshold value comparator for calculating a misfire detection counter, based on a threshold value comparison time period calculated based on the misfire detection threshold value time period and the reference detection time period, in a misfire detection threshold value comparison section after the reference angle section, and
• a misfire determiner that determines the presence or absence of misfire in a combustion stroke after the top dead center based on comparison between the misfire detection counter and a misfire detection determination value.