Abstract: A method of predicting NOx generation amount of a compression ignition engine is provided. The method includes predicting a composition ratio of a gas in a mixture and a flame temperature using driving variables of an engine and calculating a nitrogen oxide generation rate using the composition ratio of the gas in the mixture and the flame temperature. Additionally, a nitrogen oxide generation concentration around flame is calculated using the nitrogen oxide generation rate and a total nitrogen oxide generation amount of a cylinder is predicted using the nitrogen oxide generation rate and the nitrogen oxide generation concentration.

Abstract: An engine system for a vehicle may include an engine including a plurality of cylinders connected to a crankshaft, a Cylinder Deactivation (CDA) apparatus provided to at least one cylinder among the plurality of cylinders of the engine, a first flywheel mounted on the crankshaft, a second flywheel having a rotation center formed eccentrically with respect to the crankshaft by being disposed at a position corresponding to the cylinder including the CDA apparatus, and a clutch provided to the crankshaft to selectively transmit a torque of the crankshaft to the second flywheel during operation of the CDA apparatus.

Abstract: A method for controlling an operation mode of an engine implementing cylinder deactivation (CDA) by a device for controlling an operation mode, may include determining whether a CDA operation is available by using an operation state signal of a vehicle, determining a fuel consumption prediction value or an exhaust temperature prediction value by the CDA operation when the CDA operation is available: and determining whether to enter a CDA mode by using at least one of the fuel consumption prediction value and the exhaust temperature prediction.

Abstract: An engine control apparatus includes an engine information detector for detecting engine information including an engine speed, a fuel amount, an air amount, a boost pressure, injection timing, an intake air temperature, an atmospheric pressure, and an atmospheric temperature, a combustion pressure sensor for detecting a combustion pressure of an engine, and a controller performing an IMEP control for adjusting a main injection amount and a combustion noise control for adjusting a pilot injection amount by using the engine information detected by the engine information detector and the combustion pressure detected by the combustion pressure sensor, and calculating a final main injection correction amount and a final pilot injection correction amount by using an IMEP pilot correction amount and an IMEP correction amount outputted from the IMEP control and a combustion noise correction amount outputted from the combustion noise control.

Abstract: A method and an apparatus for detecting engine misfire has advantages of precisely detecting misfire occurrence when misfire continuously occurs at three or more engine cylinders and detecting an engine cylinder where the misfire occurs. The method may include calculating an angular acceleration factor value on the basis of an engine speed, calculating a variation value of an angular acceleration factor on the basis of the angular acceleration factor value, calculating a threshold point of misfire starting and a threshold point of misfire ending, comparing the variation value of the angular acceleration factor with the threshold point of misfire starting, comparing the variation value of the angular acceleration factor with the threshold point of misfire ending, and detecting a cylinder of the engine where the misfire occurs by the comparison results.

Abstract: A method for controlling a cold starting of a diesel engine vehicle may include determining whether a cold starting condition is satisfied by detecting data for controlling a diesel engine, determining torque generated by combustion for starting the diesel engine when the cold starting condition is satisfied, determining a combustion delay and a combustion phase based on the torque and detected data, determining a main injection timing according to the determined combustion delay and combustion phase, determining a latent heat of fuel based on the torque and detected data, determining a pilot injection amount according to the determined latent heat of fuel, determining a total amount of heat by combustion based on the torque and detected data, determining a main injection amount according to the determined total amount of heat, and controlling an operation of an injector based on the main injection timing, pilot injection amount and main injection amount.

Abstract: A method for controlling an engine which comprises a combustion pressure sensor includes receiving a combustion pressure signal from the combustion pressure sensor. An Indicated mean effective pressure (IMEP) deviation for each cylinder and an IMEP deviation for each driving cycle for the engine are calculated based on a combustion pressure according to the received combustion pressure signal. A main injection timing is set based on a difference between the calculated IMEP deviations for the each cylinder and a difference between the calculated IMEP deviations for the each driving cycle. The engine runs by injecting a fuel according to the set main injection timing.

Abstract: A system and a method for controlling NOx may include predicting NOx generation amount by using a virtual sensor; comparing the NOx prediction amount with a predetermined NOx target amount; and controlling the NOx generation amount so as for the NOx prediction amount to follow the NOx target amount.

Abstract: A method for compensating post-injection timing may include performing main injection to perform combustion using air drawn into a cylinder, performing post-injection after the main injection to control an amount of reducing agent or to change a temperature of exhaust gas, determining first injection timing of the post-injection according to operation conditions of an engine, advancing or retarding the first injection timing according to combustion efficiency of the post-injection, and performing the post-injection at a compensated first injection timing.

Abstract: Disclosed are a method and an apparatus of detecting a combustion phase of an engine by an angular acceleration signal and combustion data of a single cylinder. The method may include calculating a point of maximum angular acceleration of each engine cylinder during an explosion stroke, detecting a combustion phase of an engine cylinder provided with a combustion pressure sensor, calculating a time difference between the point of maximum angular acceleration and the combustion phase of the engine cylinder provided with the combustion pressure sensor, and determining a combustion phase of an engine cylinder where the combustion pressure sensor is not mounted by using the time difference and the point of maximum angular acceleration of the engine cylinder where the combustion pressure sensor is not mounted.

Abstract: A method and an apparatus for detecting engine misfire has advantages of precisely detecting misfire occurrence when misfire continuously occurs at three or more engine cylinders and detecting an engine cylinder where the misfire occurs. The method may include calculating an angular acceleration factor value on the basis of an engine speed, calculating a variation value of an angular acceleration factor on the basis of the angular acceleration factor value, calculating a threshold point of misfire starting and a threshold point of misfire ending, comparing the variation value of the angular acceleration factor with the threshold point of misfire starting, comparing the variation value of the angular acceleration factor with the threshold point of misfire ending, and detecting a cylinder of the engine where the misfire occurs by the comparison results.

Abstract: A method of predicting NOx generation amount may include calculating NO generation rate by using a combustion pressure of an engine and driving variables of the engine, obtaining NO generation period by using the combustion pressure of the engine, calculating NO generation amount based on the NO generation rate and the NO generation period, and predicting the NOx generation amount by obtaining NO2 generation amount based on a ratio between NO and NO2 according to the NO generation amount and a driving condition of the engine.

Abstract: A combustion phase detection method of an engine has the advantages of being able to reduce exhaust gas and to improve combustion stability, to compensate injection and ignition delay time between combustion chambers and between cycles, and to detect a combustion phase in real time such that a heat generation rate and heat release can be effectively calculated in an early state of combustion with a simple calculation method to control combustion of an engine, by using a combustion pressure and a motoring pressure difference of an engine not affected by an offset value of the cylinder pressure. For this, a combustion phase detection method may include detecting a combustion phase by using a specific point of DRdV as follows: DR ? ? V ? : ? ? P diff ? ? V ? ? max ( P diff ? ? V ? ? ) Here, the Pdiff (P?Pmotoring) is a difference between a cylinder measure combust pressure (P) and a motoring pressure (Pmotoring), and V is a combustion chamber volume.

Abstract: A method of determining and controlling misfire in an engine. The method and device sense combustion pressure in a combustion chamber of an engine while the engine is operated; calculate MFB (a ratio of the amount of combustion heat at a specific point of time to the total amount of combustion heat), MFB50 (a point of time at which the amount of combustion heat is 50% of the total amount of combustion heat), MFB50 COV (Coefficient of Variation), IMEP (Indicated Mean Effective Pressure) and IMEP COV, from the combustion chamber; set a desired MFB50; and determine that there is misfire when a crank angle is delayed at 5 degrees or more, the MFB50 COV is 20% or more, or the IMEP COV is 20% or more, by comparing the calculated MFB50 with the desired MFB50; and then advance an injection time such that the MFB follows the desired MFB.

Abstract: A method of predicting NOx generation amount may include calculating NO generation rate by using a combustion pressure of an engine and driving variables of the engine, obtaining NO generation period by using the combustion pressure of the engine, calculating NO generation amount based on the NO generation rate and the NO generation period, and predicting the NOx generation amount by obtaining NO2 generation amount based on a ratio between NO and NO2 according to the NO generation amount and a driving condition of the engine.

Abstract: A system and a method for controlling NOx may include predicting NOx generation amount by using a virtual sensor; comparing the NOx prediction amount with a predetermined NOx target amount; and controlling the NOx generation amount so as for the NOx prediction amount to follow the NOx target amount.

Abstract: A system and method for judging an abnormal condition of a combustion pressure sensor, may include determining whether a driving condition of a vehicle, a fuel injection condition, and an intake air condition may be satisfied, deriving a relational equation from an amount of air measured in real time and a combustion pressure measured by the combustion pressure sensor, and monitoring a slope and a y-intercept of the relational equation when the driving condition, the fuel injection condition, and the intake air condition may be satisfied, determining whether the slope and the y-intercept may be in a predetermined normal range, accumulating the number of times the slope and the y-intercept may be beyond the predetermined normal range, and outputting a warning when the accumulated number reaches a number which may be predetermined as an abnormal condition number of the sensor.

Abstract: A combustion phase detection method of an engine has the advantages of being able to reduce exhaust gas and to improve combustion stability, to compensate injection and ignition delay time between combustion chambers and between cycles, and to detect a combustion phase in real time such that a heat generation rate and heat release can be effectively calculated in an early state of combustion with a simple calculation method to control combustion of an engine, by using a combustion pressure and a motoring pressure difference of an engine not affected by an offset value of the cylinder pressure. For this, a combustion phase detection method may include detecting a combustion phase by using a specific point of DRdV as follows: DR ? ? V ? : ? ? P diff ? ? V ? ? max ( P diff ? ? V ? ? ) Here, the Pdiff (P-Pmotoring) is a difference between a cylinder measure combust pressure (P) and a motoring pressure (Pmotoring), and V is a combustion chamber volume.

Abstract: A combustion phase detection method is able to reduce exhaust gas and to improve combustion stability, to compensate injection and ignition delay time between combustion chambers and between cycles, and to detect a combustion phase in real time such that a heat generation rate and a heat release can be effectively calculated at an early state of the combustion by using a combustion pressure and a motoring pressure difference of an engine not affected by an offset value of the cylinder pressure. The combustion phase detection method of an engine may include detecting a combustion phase according to fuel injection timing by using a specific point of DHdP that is calculated by the following heat release equation: DHdP:?1/??1VdPdiff/d?d?. Here, Pdiff is a difference (Pdiff=P?Pmotoring) between a cylinder measure combustion pressure (P) and a motoring pressure (Pmotoring).