Systems and methods for detecting and controlling knock in an engine are presented. In one example, engine knock sensors are selected based on whether or not certain cylinders are activated and combusting air and fuel or deactivated and not combusting air and fuel. Output of selected knock sensors is the basis for adjusting engine spark timing.

Systems and methods for detecting and controlling knock in an engine are presented. In one example, engine knock sensors are selected based on whether or not certain cylinders are activated and combusting air and fuel or deactivated and not combusting air and fuel. Output of selected knock sensors is the basis for adjusting engine spark timing.

Additional approaches for the reduction of particulate emissions in gasoline engines using optimized port+direct injection are described. These embodiments include control of the amount of directly injected fuel so as to avoid a threshold increase in particulates due to piston wetting and reduction of cold start emissions by use of air preheating using variable valve timing.

Additional approaches for the reduction of particulate emissions in gasoline engines using optimized port+direct injection are described. These embodiments include control of the amount of directly injected fuel so as to avoid a threshold increase in particulates due to piston wetting and reduction of cold start emissions by use of air preheating using variable valve timing.

To provide a controller for internal combustion engine which can suppress deterioration of the detection accuracy of the combustion state due to influence of the external disturbance component, when detecting a combustion state based on angle detection information by the crank angle sensor. A controller for internal combustion engine calculates a shaft torque in unburning; calculates an external load torque based on the shaft torque in unburning and the actual shaft torque in the vicinity of the top dead center; and in an integration crank angle interval which is set corresponding to a combustion period, calculates a subtraction value by subtracting the external load torque from the shaft torque in unburning, calculates a division value by dividing the subtraction value by the inertia moment, and calculates a combustion state index by integrating a value obtained by subtracting the division value from the crank angle acceleration.

To provide a controller for internal combustion engine which can suppress deterioration of the detection accuracy of the combustion state due to influence of the external disturbance component, when detecting the combustion state based on angle detection information by the crank angle sensor. A controller for internal combustion engine calculates a shaft torque in unburning; calculates an external load torque based on the shaft torque in unburning and the actual shaft torque in the vicinity of the top dead center; and in an integration crank angle interval which is set in the compression stroke and the combustion stroke, calculates a subtraction value by subtracting the external load torque from the shaft torque in unburning, calculates a division value by dividing the subtraction value by the inertia moment, and calculates a combustion state index by integrating a value obtained by subtracting the division value from the crank angle acceleration.

A catalyst control system includes a stop and start module that, during a period that the vehicle is ON between (i) a first time when the vehicle is turned ON and (i) a second time when the vehicle is next turned OFF, selectively shuts down and starts a spark ignition engine of the vehicle. A catalyst light off (CLO) control module initiates a first CLO event for a first engine startup during the period and, when a temperature of a catalyst that receives exhaust output by the engine is less than a predetermined temperature, selectively initiates a second CLO event for a second engine startup during the period. A fuel control module richens fueling of the engine during the first and second CLO events of the period. A spark control module retards spark timing of the engine during the first and second CLO events of the period.

A system and method for detecting and mitigating automatic ignition in a cylinder of an internal combustion engine. The method includes providing a first sensor for sensing and determining a crank angle of a crankshaft of the engine. A second sensor is provided for detecting a change in an engine vibration frequency caused by Auto Ignition (AI). The engine vibration signal of the second sensor is processed into a knock intensity signal. The knock intensity signal is indicative of the cylinder pressure and is acquired when the crank angle is between a first predetermined crank angle and a second predetermined crank angle. At least one characteristic of the knock intensity signal is determined and the at least one characteristic of the knock intensity signal is compared to at least one predetermined characteristic threshold. If the at least one characteristic of the knock intensity signal is determined to exceed the at least one predetermined characteristic threshold, then at least one auto ignition mitigating action is performed to mitigate the auto ignition event.

A system and method for detecting and mitigating automatic ignition in a cylinder of an internal combustion engine. The method includes providing a first sensor for sensing and determining a crank angle of a crankshaft of the engine. A second sensor is provided for detecting a change in an engine vibration frequency caused by Auto Ignition (AI). The engine vibration signal of the second sensor is processed into a knock intensity signal. The knock intensity signal is indicative of the cylinder pressure and is acquired when the crank angle is between a first predetermined crank angle and a second predetermined crank angle. At least one characteristic of the knock intensity signal is determined and the at least one characteristic of the knock intensity signal is compared to at least one predetermined characteristic threshold. If the at least one characteristic of the knock intensity signal is determined to exceed the at least one predetermined characteristic threshold, then at least one auto ignition mitigating action is performed to mitigate the auto ignition event.

The present invention suppresses the worsening of stability due to a variation in EGR amounts between cylinders in a spark ignition engine. An engine control device for controlling a spark ignition engine equipped with an EGR means for recirculating exhaust gas in a combustion chamber and an air-fuel-ratio detection means for detecting the air-fuel ratio in each cylinder, the engine control device being characterized by being equipped with a means for changing the parameters for ignition control of a rich cylinder, when the air-fuel ratio of cylinders varies and there are richer cylinders and leaner cylinders relative to a prescribed air-fuel ratio during the execution of exhaust gas recirculation by the EGR means.