摘要:
An inter-cylinder air-fuel ratio variation abnormality detection apparatus for a multicylinder internal combustion engine according to the present invention detects variation abnormality based on a rotational fluctuation of the internal combustion engine. Number-of-rotations feedback control is preformed to make the number of rotations of the internal combustion engine equal to a predetermined target number of rotations. The amount of power generated by a power generation device driven by the internal combustion engine is controlled so as to bring the load on the internal combustion engine into a target range when the abnormality detection is carried out.
摘要:
A catalyst deterioration diagnosing apparatus is provided with means for performing stoichiometric feedback control on the air-fuel ratio based on at least output from an upstream air-fuel ratio sensor provided upstream of a catalyst, means for measuring the oxygen storage capacity of the catalyst, and means for correcting the measured value of the oxygen storage capacity based on at least the output behavior of a downstream air-fuel ratio sensor provided downstream of the catalyst during the stoichiometric feedback control. The measured value of the oxygen storage capacity is corrected using the output behavior of the downstream air-fuel ratio sensor during stoichiometric feedback control. The diagnostic is performed after eliminating the effects from sulfur by correcting the measured value to a value corresponding to when low sulfur fuel is used, which makes it possible to prevent an erroneous diagnosis from being made.
摘要:
A catalyst deterioration diagnosing apparatus is provided with means for performing stoichiometric feedback control on the air-fuel ratio based on at least output from an upstream air-fuel ratio sensor provided upstream of a catalyst, means for measuring the oxygen storage capacity of the catalyst, and means for correcting the measured value of the oxygen storage capacity based on at least the output behavior of a downstream air-fuel ratio sensor provided downstream of the catalyst during the stoichiometric feedback control. The measured value of the oxygen storage capacity is corrected using the output behavior of the downstream air-fuel ratio sensor during stoichiometric feedback control. The diagnostic is performed after eliminating the effects from sulfur by correcting the measured value to a value corresponding to when low sulfur fuel is used, which makes it possible to prevent an erroneous diagnosis from being made.
摘要:
A first parameter correlated with a degree of a variation in the output from the air-fuel ratio sensor is calculated. A possible range of a second parameter representing a degree of a variation in air-fuel ratio among the cylinders is determined based on the first parameter. The first parameter is calculated with an air-fuel ratio of a predetermined cylinder forcibly changed. A difference between the unchanged first parameter and the forcibly changed first parameter is determined. A first characteristic representing a relation between the second parameter and the difference is determined based on the possible range of the second parameter and the difference. One of the determination value and the first parameter calculated before the forced change is corrected based on inclination of the determined first characteristic.
摘要:
A first parameter correlated with a degree of fluctuation of output from an air-fuel ratio sensor is calculated, and whether or not the calculated first parameter has a value between a predetermined primary determination upper-limit value α1H and a primary determination lower-limit value is determined. Such forced active control as reduces an air-fuel ratio shift in one of the cylinders which is subjected to a most significant air-fuel ratio shift is performed when the calculated first parameter is determined to have a value between the predetermined primary determination upper-limit value and the primary determination lower-limit value. A first parameter is calculated while the forced active control is in execution. The calculated first parameter is compared with a predetermined secondary determination value to determine whether or not variation abnormality is present.
摘要:
An inter-cylinder air-fuel ratio imbalance determining apparatus for an internal combustion engine includes an air-fuel ratio sensor; fuel injection valves; an instructed fuel injection amount control unit; and an imbalance determination unit configured: to acquire a time-differential-value corresponding value that is an amount of change per predetermined time in an output value of the sensor or a detected air-fuel ratio represented by the output value; to acquire a positive gradient corresponding value based on a positive value of the time-differential-value corresponding value; to acquire a negative gradient corresponding value based on a negative value of the time-differential-value corresponding value; to determine an imbalance determination threshold based on a magnitude of a ratio of the negative gradient corresponding value to the positive gradient corresponding value; and to determine whether inter-cylinder air-fuel ratio imbalance has occurred by comparing a magnitude of the negative gradient corresponding value with the imbalance determination threshold.
摘要:
An air-fuel ratio imbalance detection apparatus includes an air-fuel ratio sensor that is arranged in an exhaust passage of an internal combustion engine and that includes an electrode and a diffusion layer provided on the electrode; an estimating unit configured to estimate or detect an output variation amount that is an amount of variation in an output of the air-fuel ratio sensor due to an influence of a pressure pulsation of exhaust gas from the internal combustion engine; and a determination unit configured to determine whether there is an air-fuel ratio imbalance among cylinders of the internal combustion engine, on the basis of the output variation amount and a determination value based on the output of the air-fuel ratio sensor.
摘要:
An inter-cylinder air-fuel ratio imbalance determining apparatus for an internal combustion engine includes an air-fuel ratio sensor; fuel injection valves; an instructed fuel injection amount control unit; and an imbalance determination unit configured: to acquire a time-differential-value corresponding value that is an amount of change per predetermined time in an output value of the sensor or a detected air-fuel ratio represented by the output value; to acquire a positive gradient corresponding value based on a positive value of the time-differential-value corresponding value; to acquire a negative gradient corresponding value based on a negative value of the time-differential-value corresponding value; to determine an imbalance determination threshold based on a magnitude of a ratio of the negative gradient corresponding value to the positive gradient corresponding value; and to determine whether inter-cylinder air-fuel ratio imbalance has occurred by comparing a magnitude of the negative gradient corresponding value with the imbalance determination threshold.
摘要:
A first parameter correlated with a degree of fluctuation of output from an air-fuel ratio sensor is calculated, and whether or not the calculated first parameter has a value between a predetermined primary determination upper-limit value α1H and a primary determination lower-limit value is determined. Such forced active control as reduces an air-fuel ratio shift in one of the cylinders which is subjected to a most significant air-fuel ratio shift is performed when the calculated first parameter is determined to have a value between the predetermined primary determination upper-limit value and the primary determination lower-limit value. A first parameter is calculated while the forced active control is in execution. The calculated first parameter is compared with a predetermined secondary determination value to determine whether or not variation abnormality is present.
摘要:
A first parameter correlated with a degree of a variation in the output from the air-fuel ratio sensor is calculated. A possible range of a second parameter representing a degree of a variation in air-fuel ratio among the cylinders is determined based on the first parameter. The first parameter is calculated with an air-fuel ratio of a predetermined cylinder forcibly changed. A difference between the unchanged first parameter and the forcibly changed first parameter is determined. A first characteristic representing a relation between the second parameter and the difference is determined based on the possible range of the second parameter and the difference. One of the determination value and the first parameter calculated before the forced change is corrected based on inclination of the determined first characteristic.