Abstract: A first shaft has one end coupled to an engine. A damper has a spring coupled the other end of the first shaft. A second shaft has one end coupled to the spring. A third shaft rotates in correspondence to a final output shaft. A fourth shaft has one end coupled to a first rotary electric machine. A power split mechanism is provided among the second shaft, the third shaft and the fourth shaft and transfers torque among the second shaft, the third shaft and the fourth shaft. A control unit calculates a torque correction value for the rotary electric machine based on information indicating torsion angle of the damper and corrects the torque of the rotary electric machine based on a calculated torque correction value.

Abstract: When a detected value for detecting a rich imbalance in air-fuel ratio among cylinders, in a state where an intake air amount of an engine falls within a low amount region, is lower than a first threshold corresponding to the intake air amount and is higher than or equal to a second threshold corresponding to the intake air amount, a hybrid electronic control unit controls the engine such that the intake air amount falls within a high amount region, and controls a motor generator such that electric power corresponding to a power increase amount is consumed. When the intake air amount falls within the high amount region, the hybrid electronic control unit detects a rich imbalance in air-fuel ratio among the cylinders by comparing the detected value with a third threshold corresponding to the intake air amount.

Abstract: An air-fuel ratio imbalance detecting device for an internal combustion engine, which detects a rich imbalance in air-fuel ratio among a plurality of cylinders on the basis of a variation per unit time in air-fuel ratio that is detected by an air-fuel ratio sensor provided in an exhaust passage of the internal combustion engine, includes an electronic control unit that normalizes the variation per unit time in air-fuel ratio with a constant associated with a rotation speed and load factor of the internal combustion engine and that, when the normalized value is smaller than a predetermined threshold, determines that a rich imbalance in air-fuel ratio has been detected among the cylinders.

Abstract: A first shaft has one end coupled to an engine. A damper has a spring coupled the other end of the first shaft. A second shaft has one end coupled to the spring. A third shaft rotates in correspondence to a final output shaft. A fourth shaft has one end coupled to a first rotary electric machine. A power split mechanism is provided among the second shaft, the third shaft and the fourth shaft and transfers torque among the second shaft, the third shaft and the fourth shaft. A control unit calculates a torque correction value for the rotary electric machine based on information indicating torsion angle of the damper and corrects the torque of the rotary electric machine based on a calculated torque correction value.

Abstract: A vehicle including an internal combustion engine provided with a plurality of cylinders, and a control unit that determines that an abnormality of the internal combustion engine has occurred when an atmospheric pressure has a first value and an operation state represented by at least one of an output shaft revolution speed and a load of the internal combustion engine is within a preset region and determines that an abnormality of the internal combustion engine has occurred when the atmospheric pressure has a second value that is lower than the first value and the operation state is outside the region.

Abstract: A rotational fluctuation malfunction detection device for an internal combustion engine determines that fluctuations in output shaft rotational speed are “normal” when a rotational fluctuation value, obtained in a “disturbance fluctuation state” is below threshold L1. If rotational fluctuation value obtained in “disturbance fluctuation state” equals or exceeds L2, the rotational fluctuation malfunction detection device determines that the rotational fluctuation value is “abnormal.” However, when the rotational fluctuation value obtained in “disturbance fluctuation state” is equal to L1 or between L1 and L2, the rotational fluctuation malfunction detection device determines that the rotational fluctuation value is “normal” if the rotational fluctuation value obtained in the “non-disturbance state” is below L3, and the rotational fluctuation value is “abnormal” if the rotational fluctuation value obtained in the “non-disturbance state” equals or exceeds L3.

Abstract: An abnormality determination apparatus for a multi-cylinder internal combustion engine equipped with a duel-injection system that has two fuel systems for injecting and supplying fuel to each of cylinders, which determines whether there is an abnormal variation in air-fuel ratio among the cylinders, includes: an abnormal variation determining unit that determines whether there is an abnormal variation in a period during which fuel is separately injected by both the two fuel systems; and an abnormality estimating unit that estimates which one of the fuel systems has an abnormality on the basis of a fuel injection distribution ratio of both the fuel systems in the period.

Abstract: When a detected value for detecting a rich imbalance in air-fuel ratio among cylinders in a state where an intake air amount of an engine falls within a low amount region is lower than a first threshold corresponding to the intake air amount and is higher than or equal to a second threshold corresponding to the intake air amount, an HV-ECU controls the engine such that the intake air amount falls within a high amount region, and controls a motor generator such that an electric power corresponding to a power increase amount is consumed. When the intake air amount falls within the high amount region, the HV-ECU detects a rich imbalance in air-fuel ratio among the cylinders by comparing the detected value with a third threshold corresponding to the intake air amount.

Abstract: An air-fuel ratio imbalance detecting device for an internal combustion engine, which detects a rich imbalance in air-fuel ratio among a plurality of cylinders on the basis of a variation per unit time in air-fuel ratio that is detected by an air-fuel ratio sensor provided in an exhaust passage of the internal combustion engine, includes an electronic control unit that normalizes the variation per unit time in air-fuel ratio with a constant associated with a rotation speed and load factor of the internal combustion engine and that, when the normalized value is smaller than a predetermined threshold, determines that a rich imbalance in air-fuel ratio has been detected among the cylinders.

Abstract: An abnormality determination apparatus for a multi-cylinder internal combustion engine equipped with a duel-injection system that has two fuel systems for injecting and supplying fuel to each of cylinders, which determines whether there is an abnormal variation in air-fuel ratio among the cylinders, includes: an abnormal variation determining unit that determines whether there is an abnormal variation in a period during which fuel is separately injected by both the two fuel systems; and an abnormality estimating unit that estimates which one of the fuel systems has an abnormality on the basis of a fuel injection distribution ratio of both the fuel systems in the period.

Abstract: A vehicle including an internal combustion engine provided with a plurality of cylinders, and a control unit that determines that an abnormality of the internal combustion engine has occurred when an atmospheric pressure has a first value and an operation state represented by at least one of an output shaft revolution speed and a load of the internal combustion engine is within a preset region and determines that an abnormality of the internal combustion engine has occurred when the atmospheric pressure has a second value that is lower than the first value and the operation state is outside the region.

Abstract: A rotational fluctuation malfunction detection device for an internal combustion engine determines that fluctuations in output shaft rotational speed are “normal” when a rotational fluctuation value, obtained in a “disturbance fluctuation state” is below threshold L1. If rotational fluctuation value obtained in “disturbance fluctuation state” equals or exceeds L2, the rotational fluctuation malfunction detection device determines that the rotational fluctuation value is “abnormal.” However, when the rotational fluctuation value obtained in “disturbance fluctuation state” is equal to L1 or between L1 and L2, the rotational fluctuation malfunction detection device determines that the rotational fluctuation value is “normal” if the rotational fluctuation value obtained in the “non-disturbance state” is below L3, and the rotational fluctuation value is “abnormal” if the rotational fluctuation value obtained in the “non-disturbance state” equals or exceeds L3.

Abstract: A multicylinder engine includes: combustion chambers; fuel injection valves corresponding to the individual combustion chambers; an exhaust control catalyst; an upstream-side air/fuel ratio sensor disposed upstream of the exhaust control catalyst; and a downstream-side A/F sensor disposed downstream of the catalyst. A first abnormality determination-purpose rich A/F control of controlling the A/F of the mixture formed in each combustion chamber to an A/F richer than stoichiometric is executed when it needs to be determined whether the downstream-side A/F sensor is abnormal. An inter-cylinder A/F imbalance determination of estimating the A/F of the mixture in each combustion chamber based on the output of the upstream-side A/F sensor is executed when the first abnormality determination-purpose rich A/F control is being executed, and it is determined whether there is a difference between the estimated A/Fs of the mixtures.