Controller for internal combustion engine

A controller for an internal combustion engine which controls an internal combustion engine which is provided with a plurality of detected parts provided at a plurality of preliminarily set crank angles on a rotation member integrally rotating with a crankshaft, a specific crank angle sensor fixed to a nonrotation member and detecting the detected part, and a gas pressure sensor detecting a gas pressure in an intake pipe, the controller for the internal combustion engine comprising at least one processor configured to implement:

• an angle information detector that detects a crank angle and detects a detection time when the crank angle is detected, based on an output signal of the specific crank angle sensor, calculates an angle interval corresponding to an angle section between detected angles, based on the detected angle which is the detected crank angle, and calculates a time interval corresponding to the angle section, based on the detection time;
• an angle information corrector that corrects the angle interval or the time interval of the each angle section by a correction value provided one corresponding to the each angle section;
• an intake pipe gas pressure detector detects the gas pressure in the intake pipe, based on the output signal of the gas pressure sensor;
• a shaft torque estimator that estimates a shaft torque of a crankshaft generated by a gas pressure in a cylinder and a reciprocating movement of a piston, using a physical model equation of a crank mechanism, based on a detection value of the gas pressure in the intake pipe and the detected angle, for the each angle section;
• an ideal angular speed calculator that calculates an ideal interval angular speed which is an angular speed corresponding to the each angle section in an ideal state assuming that there is no variation in the plurality of crank angles where the plurality of detected parts are arranged, based on an estimation value of the shaft torque for the each angle section, and the inertia moment of a crankshaft system;
• and
• a correction value changer that changes the correction value for the each angle section so that a detection section angular speed which is an angular speed corresponding to the angle section calculated by the time interval and the angle interval after a correction processing by the correction value approaches the ideal interval angular speed, for the each angle section,
• wherein the angle information detector calculates a crank angle speed which is a time change rate of the crank angle, and a crank angular acceleration which is a time change rate of the crank angle speed, corresponding to each of the detected angle or the angle section, based on the angle interval and the time interval after the correction processing by the correction value, and
• wherein the controller for the internal combustion engine controls the internal combustion engine using the crank angle speed and the crank angular acceleration.