A control method for an internal combustion engine configured to implement fuel cut in response to becoming zero of an accelerator opening degree during travel of a vehicle, and generate an antiphase torque after the fuel cut by supplying fuel to a cylinder, in order to cancel out vibration of the vehicle caused due to the fuel cut includes setting a timing of generating the antiphase torque to be later than that for normal operation, in response to implementation of the fuel cut under high torque idle operation in which a torque of the internal combustion engine immediately before the fuel cut where the accelerator opening degree is zero is higher than that in the normal operation.

A control method for an internal combustion engine configured to implement fuel cut in response to becoming zero of an accelerator opening degree during travel of a vehicle, and generate an antiphase torque after the fuel cut by supplying fuel to a cylinder, in order to cancel out vibration of the vehicle caused due to the fuel cut includes setting a timing of generating the antiphase torque to be later than that for normal operation, in response to implementation of the fuel cut under high torque idle operation in which a torque of the internal combustion engine immediately before the fuel cut where the accelerator opening degree is zero is higher than that in the normal operation.

A control device for the internal combustion engine includes a pulsation detector, a path length calculator, and an anomaly detector. The pulsation detector detects the pulsation of the intake air flowing through the intake passage based on output signals from the air flowmeter. The path length calculator calculates the path length, which is a parameter that is correlated with the degree of the pulsation, based on the pulsation of the intake air detected by the pulsation detector. The anomaly detector determines that the fresh air passage is detached if the path length calculated by the path length calculator is less than or equal to a determination value and detects an anomaly in the fresh air passage.

A control device for the internal combustion engine includes a pulsation detector, a path length calculator, and an anomaly detector. The pulsation detector detects the pulsation of the intake air flowing through the intake passage based on output signals from the air flowmeter. The path length calculator calculates the path length, which is a parameter that is correlated with the degree of the pulsation, based on the pulsation of the intake air detected by the pulsation detector. The anomaly detector determines that the fresh air passage is detached if the path length calculated by the path length calculator is less than or equal to a determination value and detects an anomaly in the fresh air passage.

A vehicle drive system includes an internal combustion engine, a clutch, an engine rotation speed detector, an output shaft rotation speed detector, and a processor. The internal combustion engine includes cylinders and a crankshaft. The clutch is connected to the crankshaft via a torsion element and includes an output shaft. The engine rotation speed detector detects a crankshaft rotation speed. The output shaft rotation speed detector detects an output shaft rotation speed. The processor is configured to calculate a torque generated in each of the cylinders based on the crankshaft rotation speed. The processor is configured to decrease transmission torque of the clutch so that a difference between the crankshaft rotation speed and the output shaft rotation speed to be a target value when misfiring occurs. The processor is configured to identify a misfiring cylinder among the cylinders based on the torque calculated while the transmission torque is decreased.

A vehicle drive system includes an internal combustion engine, a clutch, an engine rotation speed detector, an output shaft rotation speed detector, and a processor. The internal combustion engine includes cylinders and a crankshaft. The clutch is connected to the crankshaft via a torsion element and includes an output shaft. The engine rotation speed detector detects a crankshaft rotation speed. The output shaft rotation speed detector detects an output shaft rotation speed. The processor is configured to calculate a torque generated in each of the cylinders based on the crankshaft rotation speed. The processor is configured to decrease transmission torque of the clutch so that a difference between the crankshaft rotation speed and the output shaft rotation speed to be a target value when misfiring occurs. The processor is configured to identify a misfiring cylinder among the cylinders based on the torque calculated while the transmission torque is decreased.

A method for controlling engine revolution per minute (RPM) includes: a frequency deriving process for deriving a frequency from change in engine RPM detected by a detector by a controller during driving of the engine; a frequency conversion process for converting a derivation frequency derived in the frequency deriving process into a conversion frequency via a predetermined conversion process by the controller; a frequency comparison process for comparing an amplitude of the conversion frequency at which engine RPM is to be changed among conversion frequencies converted in the frequency conversion process with an amplitude of a reference frequency pre-inputted to the controller; and a fuel injection amount adjusting process for deriving a correction value based on a result derived in the frequency comparison process, for applying the derived correction value, and for controlling an injector by the controller to adjust a fuel injection amount.

A method for controlling engine revolution per minute (RPM) includes: a frequency deriving process for deriving a frequency from change in engine RPM detected by a detector by a controller during driving of the engine; a frequency conversion process for converting a derivation frequency derived in the frequency deriving process into a conversion frequency via a predetermined conversion process by the controller; a frequency comparison process for comparing an amplitude of the conversion frequency at which engine RPM is to be changed among conversion frequencies converted in the frequency conversion process with an amplitude of a reference frequency pre-inputted to the controller; and a fuel injection amount adjusting process for deriving a correction value based on a result derived in the frequency comparison process, for applying the derived correction value, and for controlling an injector by the controller to adjust a fuel injection amount.

Methods and systems are provided for controlling a vehicle engine to deliver desired torque to a power take off device coupled to the engine. In one example, the method may include, learning a filtered PTO torque demand during vehicle acceleration, and steady state operation, and during transition in engine states using the learned PTO torque demand to adjust engine speed in order to deliver a desired engine torque output for optimal operation of the PTO device.

A method for operating an internal combustion engine in an idle mode, in which an ignition angle and/or an air quantity of the internal combustion engine is influenced and/or is modified as a function of an idle rotation speed of the internal combustion engine. The ignition angle and/or the air quantity and/or a fuel quantity for at least one combustion chamber of the internal combustion engine is modified as a function of at least one variable characterizing a combustion event in the combustion chamber.