Control device of internal combustion engine

Abstract

In a control device of an internal combustion engine, an atmospheric pressure estimation portion includes an effective opening area calculation portion calculating an effective opening area corresponding to a throttle opening, a throttle opening learning value calculation portion calculating a learning value in a relation of the effective opening area and the throttle opening, an error variation calculation portion calculating an error variation from an error from the corrected learning value, a variation range determination portion determining whether the error variation is within a predetermined range, an atmospheric pressure estimated value update portion updating an atmospheric pressure estimated value, and a target throttle opening calculation portion calculating a target throttle opening using the updated atmospheric pressure estimated value. The throttle opening is controlled to be the target throttle opening. An exact atmospheric pressure can be thus estimated even in the presence of a variation in throttle machine difference.

What is claimed is: 
     
         1 . A control device of an internal combustion engine, comprising:
 an operation state detection portion that detects an operation state of an internal combustion engine;   a target intake air flow rate calculation portion that calculates a target intake air flow rate on the basis of the operation state of the internal combustion engine;   a throttle that is provided to an intake channel of the internal combustion engine;   a throttle opening control portion that variably controls an intake amount into the internal combustion engine by varying an effective opening area of the intake channel by controlling a throttle opening of the throttle;   a throttle opening detection portion that detects the throttle opening;   a pressure detection portion that detects a pressure of the throttle on a side of the internal combustion engine as an intake manifold pressure;   an intake air temperature detection portion that detects an intake air temperature of the throttle;   an intake air flow rate detection portion that detects an intake air flow rate into the internal combustion engine; and   an atmospheric pressure estimation portion that estimates an atmospheric pressure applied to a calculation of a control parameter of the internal combustion engine, wherein:   the atmospheric pressure estimation portion includes:   an effective opening area calculation portion that calculates an effective opening area corresponding to the throttle opening from an estimated atmospheric pressure, the intake air flow rate, the intake manifold pressure, and the intake air temperature,   a throttle opening learning value calculation portion that calculates a learning value in a set relation map of effective opening area and throttle opening and a relation of the effective opening area and the throttle opening,   a learning value range determination portion that determines whether the relation of the effective opening area and the throttle opening is within a predetermined learning value range,   an error variation calculation portion that calculates an error variation from an error between the relation map of effective opening area and throttle opening and a relation map of effective opening area and throttle opening corrected according to the throttle opening learning value calculation portion,   a variation range determination portion that determines whether the error variation is within a predetermined range,   an atmospheric pressure estimated value update portion that updates the atmospheric pressure estimated value in a case where the relation of the effective opening area and the throttle opening is out of the predetermined range and the error variation is out of the predetermined range, and   a target throttle opening calculation portion that calculates a target throttle opening using the atmospheric pressure estimated value updated by the atmospheric pressure estimated value update portion; and   the throttle opening is controlled to be the target throttle opening,   wherein:   the error is an error of an effective opening area calculated as a deviation between an effective opening area after learning with respect to the effective opening area calculated from the corrected relation map of effective opening area and throttle opening and the effective opening area.   
     
     
         2 . The control device of an internal combustion engine according to  claim 1 , wherein:
 the error variation is one of a dispersion and a standard deviation of an error of the effective opening area.   
     
     
         3 . The control device of an internal combustion engine according to  claim 1 , wherein:
 when the effective opening area with respect to the throttle opening is larger than a predetermined effective opening area learning upper-limit value, the atmospheric pressure estimated value is updated to an incremental side and when the effective opening area with respect to the throttle opening is smaller than a predetermined effective opening area learning lower-limit value, the atmospheric pressure estimated value is updated to a decremental side.   
     
     
         4 . The control device of an internal combustion engine according to  claim 1 , wherein:
 the atmospheric pressure estimation portion sets the intake manifold pressure before an engine start as an initial value of the atmospheric pressure estimated value.   
     
     
         5 . The control device of an internal combustion engine according to  claim 1 , further comprising:
 a pressure ratio calculation portion that finds a pressure ratio of the intake manifold pressure and the atmospheric pressure estimated value,   wherein update of the atmospheric pressure estimated value is stopped when the pressure ratio calculated by the pressure ratio calculation portion is out of a predetermined range.