A controller for an internal combustion engine includes a detector and a processor. The detector detects a combustion condition of a gas in a cylinder of the internal combustion engine. The processor is configured to calculate a fuel ratio in the gas in the cylinder. The processor is configured to calculate a target combustion condition according to the fuel ratio. The processor is configured to calculate an ignition timing such that the combustion condition detected by the detector becomes equal to the target combustion condition.

A controller for an internal combustion engine includes a detector and a processor. The detector detects a combustion condition of a gas in a cylinder of the internal combustion engine. The processor is configured to calculate a fuel ratio in the gas in the cylinder. The processor is configured to calculate a target combustion condition according to the fuel ratio. The processor is configured to calculate an ignition timing such that the combustion condition detected by the detector becomes equal to the target combustion condition.

A method for controlling exhaust gas aftertreatment in an exhaust gas aftertreatment system having at least one nitrogen oxide storage catalyst and at least one catalyst for selective catalytic reduction is provided, wherein, in phases of a high load, a combustion engine is operated with a substoichiometric fuel/air mixture, and nitrogen oxides in the exhaust gas are reduced in the nitrogen oxide storage catalyst to ammonia, which is stored in the catalyst for selective catalytic reduction, and, when the storage capacity of the catalyst for selective catalytic reduction is exceeded, the combustion engine is operated with a superstoichiometric fuel/air mixture, thus allowing nitrogen oxides in the catalyst for selective catalytic reduction to be reduced by the stored ammonia.

A method for controlling exhaust gas aftertreatment in an exhaust gas aftertreatment system having at least one nitrogen oxide storage catalyst and at least one catalyst for selective catalytic reduction is provided, wherein, in phases of a high load, a combustion engine is operated with a substoichiometric fuel/air mixture, and nitrogen oxides in the exhaust gas are reduced in the nitrogen oxide storage catalyst to ammonia, which is stored in the catalyst for selective catalytic reduction, and, when the storage capacity of the catalyst for selective catalytic reduction is exceeded, the combustion engine is operated with a superstoichiometric fuel/air mixture, thus allowing nitrogen oxides in the catalyst for selective catalytic reduction to be reduced by the stored ammonia.

An abnormality detection device is mounted on an engine control device that calculates a target load factor by using a target torque, converts the target load factor to a target throttle opening, calculates a target ignition timing by using a target efficiency, and controls an engine based on the target throttle opening and the target ignition timing. In the abnormality detection device, a target efficiency for monitoring is calculated by using the target ignition timing, a target torque for monitoring is calculated by using the target efficiency for monitoring and the target load factor, a torque deviation between the target torque for monitoring and the target torque is calculated, and the presence or absence of an abnormality is detected by using the torque deviation.

A system and method for automatically controlling an engine of a turf-care vehicle. The method comprises receiving, at an engine speed control module, a mode selection input from an engine speed control mode selection device. The mode selection input is indicative of one a plurality of engine speed control modes, and all of the engine speed control modes are implementable by the engine speed control module. The method additionally comprises monitoring, via the engine speed control module, an operating status of one or more vehicle systems and/or one or more vehicle sensors. The method further comprises automatically controlling, via the engine speed control module, a rotational speed of the engine based at least in part on the selected engine speed control mode and the operating status of the one or more vehicle systems and/or one or more vehicle sensors.

A system and method for automatically controlling an engine of a turf-care vehicle. The method comprises receiving, at an engine speed control module, a mode selection input from an engine speed control mode selection device. The mode selection input is indicative of one a plurality of engine speed control modes, and all of the engine speed control modes are implementable by the engine speed control module. The method additionally comprises monitoring, via the engine speed control module, an operating status of one or more vehicle systems and/or one or more vehicle sensors. The method further comprises automatically controlling, via the engine speed control module, a rotational speed of the engine based at least in part on the selected engine speed control mode and the operating status of the one or more vehicle systems and/or one or more vehicle sensors.

A fuel estimation apparatus includes a combustion characteristic acquisition portion and a mixing ratio estimation portion. The combustion characteristic acquisition portion acquiring a combustion characteristic value indicating a physical amount relating to a combustion of an internal combustion engine acquires the combustion characteristic values of the combustions executed in different combustion conditions. The mixing ratio estimation portion estimates the mixing ratios of various components included in a fuel, based on the combustion characteristic values acquired by the combustion characteristic acquisition portion.

A fuel estimation apparatus includes a combustion characteristic acquisition portion and a mixing ratio estimation portion. The combustion characteristic acquisition portion acquiring a combustion characteristic value indicating a physical amount relating to a combustion of an internal combustion engine acquires the combustion characteristic values of the combustions executed in different combustion conditions. The mixing ratio estimation portion estimates the mixing ratios of various components included in a fuel, based on the combustion characteristic values acquired by the combustion characteristic acquisition portion.

An internal combustion engine control device 110 includes a mass flux calculation unit F2, an opening area calculation unit F3, an effective opening area calculation unit F4, and a passing gas flow rate calculation unit F5. The mass flux calculation unit F2 calculates a mass flux MF of gas passing through a throttle valve 125 based on an upstream gas temperature Tu, an upstream gas pressure Pu, and a downstream gas pressure Pd of the throttle valve 125. The opening area calculation unit F3 calculates an opening area A of the throttle valve 125 based on an opening degree θ of the throttle valve 125. The effective opening area calculation unit F4 calculates an effective opening area EA of the throttle valve 125 based on the upstream gas pressure Pu, the downstream gas pressure Pd, the opening degree θ, and the opening area A. The passing gas flow rate calculation unit F5 calculates a gas flow rate GF passing through the throttle valve 125 based on the mass flux MF and the effective opening area EA.