Patent Document ID: 9885306
Application ID: 15219574
Patent Flag: 1

Claim One:
1. A control device for an internal combustion engine equipped with an air flow sensor and an intake pipe pressure sensor that is configured to estimate an intake valve flow rate based on an estimated value or a measured value of an intake pipe pressure using an intake valve model equation in which an intake valve flow rate is represented by a linear expression that adopts an intake pipe pressure as a variable, the control device comprising: an error learning unit that is configured to learn, under at least four different operating conditions of the internal combustion engine, an intake valve flow rate error that is an error between a first intake valve flow rate obtained by inputting a measured value of an intake pipe pressure that is measured by the intake pipe pressure sensor into the intake valve model equation and a second intake valve flow rate that is calculated based on a measured value of a fresh air flow rate that is measured by the air flow sensor; a parameter learned value calculating unit that is configured to use an intake valve flow rate error model equation in which the intake valve flow rate error is represented by a polynomial expression comprising a first order term of a first parameter that is an amount of deviation relative to a design value of an intake valve working angle, a first order term of a second parameter that is an amount of deviation relative to a design value of an exhaust valve working angle, a first order term of a third parameter that is an amount of deviation relative to a design value of an intake valve timing, and a first order term of a fourth parameter that is an amount of deviation relative to a design value of an exhaust pressure loss and in which coefficients of each term are taken as a function of state quantities of the internal combustion engine including at least an engine speed and an intake pipe pressure, to calculate respective learned values of the first parameter, the second parameter, the third parameter and the fourth parameter based on learned values of the intake valve flow rate error under at least four different operating conditions that are learned by the error learning unit and values of coefficients of the respective terms under the operating conditions under which learning of the intake valve flow rate error is performed; and a correction amount calculating unit that is configured to calculate using the intake valve flow rate error model equation a correction amount with respect to an intake valve flow rate that is calculated with the intake valve model equation, based on respective learned values of the first parameter, the second parameter, the third parameter and the fourth parameter that are calculated by the parameter learned value calculating unit.