Controller and control method for internal combustion engine
First Claim
1. A controller for an internal combustion engine that is provided with a plurality of detected units provided in a rotation member, which rotates integrally with a crankshaft, at a plurality of preliminarily set crank angles, and a specific crank angle sensor which is fixed to a nonrotation member and detects the plurality of detected units, the controller for an internal combustion engine comprising:
- at least one processor configured to implement;
an angle information calculator that detects a crank angle based on an output signal of the specific crank angle sensor, and calculates a crank angle speed which is a time change rate of the crank angle, and a crank angle acceleration which is a time change rate of the crank angle speed;
a torsional torque calculator that calculates a maximum value of a torsional vibration torque which is a vibration component of a torsional torque produced by torsion of the crankshaft, based on the crank angle acceleration in a combustion period, by multiplying a preliminarily set conversion constant with a maximum value of the crank angle acceleration in the combustion period, and calculates a waveform which has an amplitude of the maximum value of the torsional vibration torque and vibrates with a preliminarily set natural angular frequency of the torsional vibration, as the torsional vibration torque in the combustion period;
a cylinder internal pressure estimator that calculates a combustion gas pressure torque produced by combustion, by use of an equation of motion of a rotation system of the crankshaft containing piston, connecting rod, and crank of the internal combustion engine, based on the crank angle, the crank angle acceleration, and the torsional vibration torque, and estimates a cylinder internal pressure of a combustion cylinder, based on the combustion gas pressure torque and the crank angle;
a combustion parameter calculator that calculates a combustion parameter of one or both of a heat release rate and a mass combustion rate based on the cylinder internal pressure of the combustion cylinder; and
a combustion control unit that changes one or both of an ignition timing and an EGR amount based on the combustion parameter.
1 Assignment
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Accused Products
Abstract
To provide a controller and a control method for an internal combustion engine capable of estimating the cylinder internal pressure of the combustion cylinder accurately in consideration of the torsional vibration of the crankshaft. A controller for an internal combustion engine includes a torsional torque calculator that calculates a value which has an amplitude of the maximum value of torsional vibration torque calculated based on a crank angle acceleration in the combustion period, and vibrates with a preliminarily set natural angular frequency, as a torsional vibration torque in the combustion period; and a cylinder internal pressure estimator that calculates a combustion gas pressure torque, by use of the equation of motion of the rotation system of the crankshaft, based on the crank angle, the crank angle acceleration, and the torsional vibration torque, and estimates the cylinder internal pressure of the combustion cylinder based on the combustion gas pressure torque.
20 Citations
7 Claims
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1. A controller for an internal combustion engine that is provided with a plurality of detected units provided in a rotation member, which rotates integrally with a crankshaft, at a plurality of preliminarily set crank angles, and a specific crank angle sensor which is fixed to a nonrotation member and detects the plurality of detected units, the controller for an internal combustion engine comprising:
at least one processor configured to implement; an angle information calculator that detects a crank angle based on an output signal of the specific crank angle sensor, and calculates a crank angle speed which is a time change rate of the crank angle, and a crank angle acceleration which is a time change rate of the crank angle speed; a torsional torque calculator that calculates a maximum value of a torsional vibration torque which is a vibration component of a torsional torque produced by torsion of the crankshaft, based on the crank angle acceleration in a combustion period, by multiplying a preliminarily set conversion constant with a maximum value of the crank angle acceleration in the combustion period, and calculates a waveform which has an amplitude of the maximum value of the torsional vibration torque and vibrates with a preliminarily set natural angular frequency of the torsional vibration, as the torsional vibration torque in the combustion period; a cylinder internal pressure estimator that calculates a combustion gas pressure torque produced by combustion, by use of an equation of motion of a rotation system of the crankshaft containing piston, connecting rod, and crank of the internal combustion engine, based on the crank angle, the crank angle acceleration, and the torsional vibration torque, and estimates a cylinder internal pressure of a combustion cylinder, based on the combustion gas pressure torque and the crank angle; a combustion parameter calculator that calculates a combustion parameter of one or both of a heat release rate and a mass combustion rate based on the cylinder internal pressure of the combustion cylinder; and a combustion control unit that changes one or both of an ignition timing and an EGR amount based on the combustion parameter. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A control method for an internal combustion engine that is provided with a plurality of detected units provided in a rotation member, which rotates integrally with a crankshaft, at a plurality of preliminarily set crank angles, and a specific crank angle sensor which is fixed to a nonrotation member and detects the plurality of detected units, the control method for an internal combustion engine comprising:
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an angle information calculating that detects a crank angle based on an output signal of the specific crank angle sensor, and calculates a crank angle speed which is a time change rate of the crank angle, and a crank angle acceleration which is a time change rate of the crank angle speed; a torsional torque calculating that calculates a maximum value of a torsional vibration torque which is a vibration component of a torsional torque produced by torsion of the crankshaft, based on the crank angle acceleration in a combustion period, by multiplying a preliminarily set conversion constant with a maximum value of the crank angle acceleration in the combustion period, and calculates a waveform which has an amplitude of the maximum value of the torsional vibration torque and vibrates with a preliminarily set natural angular frequency of the torsional vibration, as the torsional vibration torque in the combustion period; a cylinder internal pressure estimating that calculates a combustion gas pressure torque produced by combustion, by use of an equation of motion of a rotation system of the crankshaft containing piston, connecting rod, and crank of the internal combustion engine, based on the crank angle, the crank angle acceleration, and the torsional vibration torque, and estimates a cylinder internal pressure of a combustion cylinder, based on the combustion gas pressure torque and the crank angle; a combustion parameter calculating that calculates a combustion parameter of one or both of a heat release rate and a mass combustion rate based on the cylinder internal pressure of the combustion cylinder; and a combustion controlling that changes one or both of an ignition timing and an EGR amount based on the combustion parameter.
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Specification