Patent ID: 8457905
Filing Date: 2013-06-04
Classification: F01N,F02D,G01M,G01N,Y02A,Y02T

Abstract:
1. A soot discharge estimating device for an internal combustion engine comprising: a steady discharge amount acquisition unit that acquires a steady discharge amount of soot, the steady discharge amount of soot being obtained from a first table in view of current values of an operation speed and a fuel injection amount, the first table showing a relationship between a discharge amount of soot discharged from the internal combustion engine and the operation speed and the fuel injection amount of the internal combustion engine where the internal combustion engine is in a steady operation state; a steady value acquisition unit that acquires a steady value of a factor that affects a soot generation speed as a result of reaction of fuel, the steady value of the factor being obtained from a second table in view of a current value of a predetermined parameter, the predetermined parameter representing an operation state of the internal combustion engine, the second table showing a relationship between the predetermined parameter and the factor where the internal combustion engine is in the steady operation state; a transient value acquisition unit that acquires a transient value of the factor, the transient value of the factor being a current value of the factor; a transient correction value calculation unit that calculates a transient correction value regarding the discharge amount of soot based on a steady characteristic value and a transient characteristic value, the steady characteristic value being obtained on a basis of the steady value of the factor and a predetermined characteristic of the discharge amount of the soot that represents a change in the discharge amount of soot with respect to the value of the factor, and the transient characteristic value being obtained on a basis of the transient value of the factor and the predetermined characteristic of the discharge amount of the soot; and a soot discharge amount estimation unit that estimates the discharge amount of soot on a basis of the steady discharge amount and the transient correction value, wherein: an ignition delay period, which is a period between a point in time at which fuel injection starts and a point in time at which ignition of injected fuel starts, or a value correlated with the ignition delay period is used as the factor that affects the soot generation speed, when oxygen concentration of gas within a combustion chamber of the internal combustion engine or a value correlated with the oxygen concentration is less than a predetermined value, the transient correction value calculation unit calculates the transient correction value in consideration of the ignition delay period, which serves as the factor that affects the soot generation speed, or the value correlated with the ignition delay period, and, when the oxygen concentration or the value correlated with the oxygen concentration is equal to or greater than the predetermined value, the transient correction value calculation unit calculates the transient correction value without consideration of the ignition delay period, which serves as the factor that affects the soot generation speed, or the value correlated with the ignition delay period.