Apparatus and method for controlling internal combustion engine

A control apparatus for an internal combustion engine, the engine including a crankshaft, a camshaft for actuating a valve of the engine, a crank position sensor that outputs a crank signal every time the crankshaft rotates a certain angle, and a rotating electrical machine having a rotor that is coupled to one of the crankshaft and the camshaft, wherein the control apparatus acquires a crank angle based on a counter that is incremented every time the crank signal is output, and controls the engine based on the acquired crank angle, the apparatus comprising:

• a plurality of rotation sensors located about the rotor, each sensor outputting a signal corresponding to induced voltage generated by rotation of the rotor, wherein the control apparatus controls the rotating electrical machine based on the signals from the rotation sensors;
• a detection section that detects the occurrence of reverse rotation of the engine when an output pattern of the signals from the rotation sensors is different from an output pattern during forward rotation of the engine, wherein, when the engine is rotating, the detection section determines theoretical rising and falling points in time of the signal from each rotation sensor based on the crank signal, the theoretical rising and falling points in time corresponding to actual rising and falling points in time during forward rotation of the engine, wherein the detection section determines whether each of rising and falling edges of the signal from each rotation sensor is actually occurring at the corresponding theoretical point in time, and detects the occurrence of reverse rotation of the engine when the determination result is negative;
• a decrement section that decrements the counter every time the crank signal is output after the occurrence of reverse rotation is detected;
• a subtraction section that computes a subtraction value, the subtraction value corresponding to a discrepancy between the counter and the actual crank angle caused by a discrepancy between the actual point in time of the occurrence of reverse rotation and the point in time of the detection of the reverse rotation, wherein the subtraction section reduces the counter by the subtraction value;
• and
• an initial value setting section, wherein the initial value setting section stores a count value of the counter at the time of stopping the engine, and sets the stored count value as an initial value of the counter in the subsequent starting of the engine.