Abstract: A control system for an internal combustion engine, which is capable of estimating a property of fuel accurately even when the engine is in an operating condition other than idling. An in-cylinder pressure sensor detects an amount of change in pressure in a cylinder #1 of the engine as a pressure change amount. An ECU calculates an amount of heat released in the cylinder #1 as a heat release amount, according to the pressure change amount. A vehicle speed sensor, a crank angle sensor, and an accelerator pedal opening sensor detect load on the engine. The ECU estimates a cetane number of fuel based on the calculated heat release amount and the detected load on the engine.

Abstract: A control system for an internal combustion engine wherein a load applied to the engine from at least one auxiliary component and/or an air conditioner, which are both driven by the engine, is reduced when the engine is operating in a predetermined low-load operating state. A property of the fuel in use is estimated based on a combustion state of the injected fuel after the reduction of the load applied to the engine.

Abstract: A control system for an internal combustion engine, which makes it possible to estimate a fuel property parameter indicative of a property of fuel in use, in a plurality of operation modes of the engine, respectively, to thereby increase the chances of estimation of the fuel property parameter, and select an appropriate one from the estimated fuel property parameters to thereby more appropriately control the engine. The fuel property parameter is estimated when the detected operating conditions of the engine correspond to any of a plurality of operation modes. Depending on a plurality of fuel property parameters estimated in respective operation modes, one of the fuel property parameters is determined as the fuel property parameter for control of the engine.

Abstract: A control system for an internal combustion engine having fuel injectors for injecting fuel into a combustion chamber of the engine. A fuel property is estimated based on a combustion state of the fuel injected into at least one cylinder of the engine. The fuel injectors are controlled so that a specific amount of fuel is injected into the at least one cylinder and an amount of fuel corresponding to an operating condition of the engine is injected into cylinders other than the at least one cylinder. An additional fuel injection is performed after the fuel injection of the specific amount with respect to the at least one cylinder, for example, when a torque difference parameter indicative of a difference between a torque generated by the at least one cylinder and a torque generated by the other cylinders is equal to or greater than a predetermined threshold value.

Abstract: A control system for an internal combustion engine having at least one fuel injection valve for injecting fuel into a combustion chamber of the engine, and an exhaust gas recirculation mechanism for recirculating a portion of exhaust gases from the engine to the combustion chamber. The exhaust gas recirculating mechanism includes an exhaust cooler for cooling the recirculated exhaust gases. A target ignition timing of the fuel injected by the fuel injection valve is calculated. An actual compression ignition timing of the fuel injected by the fuel injection valve is detected. Operation of the exhaust cooler is controlled based on the target ignition timing and the actual compression ignition timing.

Abstract: A control system for an internal combustion engine, which is capable of estimating a property of fuel accurately even when the engine is in an operating condition other than idling. An in-cylinder pressure sensor detects an amount of change in pressure in a cylinder #1 of the engine as a pressure change amount. An ECU calculates an amount of heat released in the cylinder #1 as a heat release amount, according to the pressure change amount. A vehicle speed sensor, a crank angle sensor, and an accelerator pedal opening sensor detect load on the engine. The ECU estimates a cetane number of fuel based on the calculated heat release amount and the detected load on the engine.

Abstract: A control system for an internal combustion engine having at least one fuel injection valve for injecting fuel into a combustion chamber of the engine and burning the injected fuel by compression ignition. A fuel injection control parameter for controlling at least one fuel injection valve is changed. A combustion state of the engine is then detected. A cetane number of the fuel is then estimated based on the changed fuel injection control parameter and the detected combustion state.

Abstract: A control system for an internal combustion engine having fuel injectors for injecting fuel into a combustion chamber of the engine. A fuel property is estimated based on a combustion state of the fuel injected into at least one cylinder of the engine. The fuel injectors are controlled so that a specific amount of fuel is injected into the at least one cylinder and an amount of fuel corresponding to an operating condition of the engine is injected into cylinders other than the at least one cylinder. An additional fuel injection is performed after the fuel injection of the specific amount with respect to the at least one cylinder, for example, when a torque difference parameter indicative of a difference between a torque generated by the at least one cylinder and a torque generated by the other cylinders is equal to or greater than a predetermined threshold value.

Abstract: A control system for an internal combustion engine wherein a load applied to the engine from at least one auxiliary component and/or an air conditioner, which are both driven by the engine, is reduced when the engine is operating in a predetermined low-load operating state. A property of the fuel in use is estimated based on a combustion state of the injected fuel after the reduction of the load applied to the engine.

Abstract: A control system for an internal combustion engine wherein fuel injection timing is determined according to a detected engine operating condition. An actual ignition timing of the fuel is detected and an ignition delay correction amount is calculated wherein the actual ignition timing coincides with a target ignition timing set according to the engine operating condition. A cetane number of the fuel is estimated using a plurality of conversion tables for converting the ignition delay correction amount to the cetane number of the fuel. The fuel injection timing is corrected with the ignition delay correction amount. An exhaust gas recirculation control value map used for calculating a control value of the recirculation amount of exhaust gases is switched according to the estimated cetane number. The conversion table used for estimating the cetane number is switched according to the estimated cetane number.

Abstract: A control system for an internal combustion engine, which makes it possible to estimate a fuel property parameter indicative of a property of fuel in use, in a plurality of operation modes of the engine, respectively, to thereby increase the chances of estimation of the fuel property parameter, and select an appropriate one from the estimated fuel property parameters to thereby more appropriately control the engine. The fuel property parameter is estimated when the detected operating conditions of the engine correspond to any of a plurality of operation modes. Depending on a plurality of fuel property parameters estimated in respective operation modes, one of the fuel property parameters is determined as the fuel property parameter for control of the engine.

Abstract: A control system for an internal combustion engine having a fuel injection valve. A fuel injection timing is determined according to the detected engine operating condition. A target ignition timing of the fuel is calculated using a plurality of maps that store the target ignition timings according to the engine operating condition and an actual ignition timing of the fuel is detected. An ignition delay of the actual ignition timing with respect to the target ignition timing is calculated. The cetane number of the fuel is estimated according to the calculated ignition delay. The map to be used in calculating the target ignition timing is switched according to the estimated cetane number.

Abstract: A control system for an internal combustion engine having fuel injection valves provided in a combustion chamber and an exhaust gas recirculation mechanism. Target maximum cylinder pressure change rates are set according to the operating condition of the engine. The maximum change rate of the detected cylinder pressure and a fuel injection timing correction amount are calculated wherein a difference between the calculated maximum change rate and the target maximum cylinder pressure change rate decreases. The fuel injection timing is corrected with the fuel injection timing correction amount. The recirculation amount of exhaust gases is controlled using the calculated control value. A correction amount of the exhaust gas recirculation amount is calculated when the fuel injection timing correction amount exceeds a predetermined amount. The exhaust gas recirculation amount is controlled using the control value corrected with the correction amount of the exhaust gas recirculating amount.

Abstract: A control system for an internal combustion engine having at least one fuel injection valve for injecting fuel into a combustion chamber of the engine, and an exhaust gas recirculation mechanism for recirculating a portion of exhaust gases from the engine to the combustion chamber. The exhaust gas recirculating mechanism includes an exhaust cooler for cooling the recirculated exhaust gases. A target ignition timing of the fuel injected by the fuel injection valve is calculated. An actual compression ignition timing of the fuel injected by the fuel injection valve is detected. Operation of the exhaust cooler is controlled based on the target ignition timing and the actual compression ignition timing.

Abstract: A control system for an internal combustion engine that has at least one fuel injection valve for injecting fuel into a combustion chamber of the engine, and burns the injected fuel by compressing an air-fuel mixture in the combustion chamber. An operating condition of the engine and/or a refueling condition of a fuel tank for supplying fuel to the engine are/is detected. At least one operating parameter of the engine is changed when at least one of the engine operating condition and the refueling condition detected by the condition detecting means satisfies a predetermined condition in a predetermined low load operating condition of the engine. A cetane number of the fuel in use is estimated according to an ignition timing of the fuel detected after changing the at least one operating parameter of the engine.

Abstract: A control system for an internal combustion engine having at least one fuel injection valve for injecting fuel into a combustion chamber of the engine and burning the injected fuel by compression ignition. A fuel injection control parameter for controlling at least one fuel injection valve is changed. A combustion state of the engine is then detected. A cetane number of the fuel is then estimated based on the changed fuel injection control parameter and the detected combustion state.

Abstract: A control system for an internal combustion engine that has at least one fuel injection valve for injecting fuel into a combustion chamber of the engine, and burns the injected fuel by compressing an air-fuel mixture in the combustion chamber. An operating condition of the engine and/or a refueling condition of a fuel tank for supplying fuel to the engine are/is detected. At least one operating parameter of the engine is changed when at least one of the engine operating condition and the refueling condition detected by the condition detecting means satisfies a predetermined condition in a predetermined low load operating condition of the engine. A cetane number of the fuel in use is estimated according to an ignition timing of the fuel detected after changing the at least one operating parameter of the engine.

Abstract: A control system used with an engine determines a fuel injection timing according to a detected engine operating condition and fuel injection is executed through a fuel injection valve. The target ignition timings of the fuel are set according to the detected engine operating condition and stored in a memory. An ignition delay of the actual ignition timing relative to the target ignition timing and a cetane number of the fuel are calculated. Control values of the recirculation amount of exhaust gases are set according to the detected engine operating condition and stored in the memory. The stored control value is retrieved and the recirculation amount of exhaust gases is controlled using the retrieved control value. A correction amount of the recirculation amount of exhaust gases is calculated according to the estimated cetane number and the recirculation amount of exhaust gases is controlled using the corrected control value.

Abstract: A control system for an internal combustion engine wherein fuel injection timing is determined according to a detected engine operating condition. An actual ignition timing of the fuel is detected and an ignition delay correction amount is calculated wherein the actual ignition timing coincides with a target ignition timing set according to the engine operating condition. A cetane number of the fuel is estimated using a plurality of conversion tables for converting the ignition delay correction amount to the cetane number of the fuel. The fuel injection timing is corrected with the ignition delay correction amount. An exhaust gas recirculation control value map used for calculating a control value of the recirculation amount of exhaust gases is switched according to the estimated cetane number. The conversion table used for estimating the cetane number is switched according to the estimated cetane number.

Abstract: A control system for an internal combustion engine having a fuel injection valve. A fuel injection timing is determined according to the detected engine operating condition. A target ignition timing of the fuel is calculated using a plurality of maps that store the target ignition timings according to the engine operating condition and an actual ignition timing of the fuel is detected. An ignition delay of the actual ignition timing with respect to the target ignition timing is calculated. The cetane number of the fuel is estimated according to the calculated ignition delay. The map to be used in calculating the target ignition timing is switched according to the estimated cetane number.