Abstract: To provide a controller for internal combustion engine which suppresses that estimation of the combustion state is performed based on the angle information on which the component due to the torsional vibration is superimposed, when the torsional vibration occurs in the crankshaft. A controller for internal combustion engine determines whether a torsional vibration occurs in a crankshaft based on an angle period; calculates a gas pressure torque in burning based on a crank angle acceleration which is calculated based on the angle period; estimates a combustion state of an internal combustion engine based on the gas pressure torque in burning; and stops estimation of the combustion state, when it is determined that the torsional vibration occurred.

Abstract: To provide a controller for internal combustion engine which can improve the estimation accuracy of the period in the chipped tooth section, even if the period is suddenly varied in the chipped tooth section. A controller for internal combustion engine detects a period when the tooth passes, based on an output signal of the crank angle sensor; determines a period corresponding to the chipped tooth section; determines a crank angle corresponding to the passed tooth; and estimates a period of a virtual unit angle interval when assuming that the tooth is provided at the unit angle interval in the chipped tooth section, based on the period of the chipped tooth section, the period before the chipped tooth section, and the period after the chipped tooth section.

Abstract: To provide a controller and a control method for internal combustion engine which can suppress the increase in the calculation processing load for determining occurrence of the mechanical noise and occurrence of the knocking with good accuracy even when the mechanical noise occurs. When the maximum value of the strength of the component of the second frequency band in the comparison period exceeds the maximum value of the strength of the component of the first frequency band, a controller for internal combustion engine performs a second side stop determination processing that determine whether the knocking occurred, based on the strength of the component of the first frequency band, without using the strength of the component of the second frequency band.

Abstract: To provide a controller and a control method for internal combustion engine which can calculate the shaft torque in unburning with good accuracy in all the operating condition in which calculation is required, using the shaft torque in unburning which was set in the specific operating condition, and can improve estimation accuracy of the parameter relevant to the combustion state. A controller for internal combustion engine calculates a specific shaft torque in unburning with reference to a specific unburning condition data; calculates specific and current generated torques of unburning assumption using the physical model equation; calculates a current shaft torque in unburning based on the specific shaft torque in unburning, and the specific and current generated torques of unburning assumption; and calculates an increment of gas pressure torque by burning based on the current shaft torque in unburning and the actual shaft torque in burning condition.

Abstract: To provide a controller for internal combustion engine which can improve the estimation accuracy of the period in the chipped tooth section, even if the period is suddenly varied in the chipped tooth section. A controller for internal combustion engine detects a period when the tooth passes, based on an output signal of the crank angle sensor; determines a period corresponding to the chipped tooth section; determines a crank angle corresponding to the passed tooth; and estimates a period of a virtual unit angle interval when assuming that the tooth is provided at the unit angle interval in the chipped tooth section, based on the period of the chipped tooth section, the period before the chipped tooth section, and the period after the chipped tooth section.

Abstract: To provide a controller for internal combustion engine which suppresses that estimation of the combustion state is performed based on the angle information on which the component due to the torsional vibration is superimposed, when the torsional vibration occurs in the crankshaft. A controller for internal combustion engine determines whether a torsional vibration occurs in a crankshaft based on an angle period; calculates a gas pressure torque in burning based on a crank angle acceleration which is calculated based on the angle period; estimates a combustion state of an internal combustion engine based on the gas pressure torque in burning; and stops estimation of the combustion state, when it is determined that the torsional vibration occurred.

Abstract: To provide a controller and a control method for internal combustion engine which can reduce arithmetic load, while suppressing deterioration in the estimation accuracy of the parameter relevant to the combustion state, even if the error component of high frequency is included in the crank angle acceleration. A controller for internal combustion engine, by referring an unburning condition data, calculates a shaft torque in unburning in the vicinity of the top dead center in the burning condition; calculates an external load torque based on calculated shaft torque in unburning and the actual shaft torque in burning in the vicinity of the top dead center; calculates a shaft torque in unburning by referring the unburning condition data; calculates an increment of gas pressure torque by burning based on the shaft torque in unburning, the actual shaft torque in burning, and the external load torque.

Abstract: To provide a controller and a control method for internal combustion engine which can suppress the increase in the calculation processing load for determining occurrence of the mechanical noise and occurrence of the knocking with good accuracy even when the mechanical noise occurs. When the maximum value of the strength of the component of the second frequency band in the comparison period exceeds the maximum value of the strength of the component of the first frequency band, a controller for internal combustion engine performs a second side stop determination processing that determine whether the knocking occurred, based on the strength of the component of the first frequency band, without using the strength of the component of the second frequency band.

Abstract: To provide a controller and a control method for internal combustion engine which can calculate the shaft torque in unburning with good accuracy in all the operating condition in which calculation is required, using the shaft torque in unburning which was set in the specific operating condition, and can improve estimation accuracy of the parameter relevant to the combustion state. A controller for internal combustion engine calculates a specific shaft torque in unburning with reference to a specific unburning condition data; calculates specific and current generated torques of unburning assumption using the physical model equation; calculates a current shaft torque in unburning based on the specific shaft torque in unburning, and the specific and current generated torques of unburning assumption; and calculates an increment of gas pressure torque by burning based on the current shaft torque in unburning and the actual shaft torque in burning condition.

Abstract: To provide a controller and a control method for internal combustion engine which can set appropriately an angle interval for estimating the combustion state in accordance with change of a burning angle interval, and can reduce calculation processing load for estimation of the combustion state. A controller for internal combustion engine changes the estimation crank angle interval based on an operating condition of the internal combustion engine; calculates an increment of gas pressure torque by burning at each crank angle of the estimation crank angle interval; and estimates the combustion state of the internal combustion engine, based on the increment of gas pressure torque by burning in the estimation crank angle interval.

Abstract: To provide a controller and a control method for internal combustion engine which can set appropriately an angle interval for estimating the combustion state in accordance with change of a burning angle interval, and can reduce calculation processing load for estimation of the combustion state. A controller for internal combustion engine changes the estimation crank angle interval based on an operating condition of the internal combustion engine; calculates an increment of gas pressure torque by burning at each crank angle of the estimation crank angle interval; and estimates the combustion state of the internal combustion engine, based on the increment of gas pressure torque by burning in the estimation crank angle interval.

Abstract: To provide a controller and a control method for internal combustion engine which can reduce arithmetic load, while suppressing deterioration in the estimation accuracy of the parameter relevant to the combustion state, even if the error component of high frequency is included in the crank angle acceleration. A controller for internal combustion engine, by referring an unburning condition data, calculates a shaft torque in unburning in the vicinity of the top dead center in the burning condition; calculates an external load torque based on calculated shaft torque in unburning and the actual shaft torque in burning in the vicinity of the top dead center; calculates a shaft torque in unburning by referring the unburning condition data; calculates an increment of gas pressure torque by burning based on the shaft torque in unburning, the actual shaft torque in burning, and the external load torque.

Abstract: To provide a controller and a control method, for an internal combustion engine, that can detect occurrence of knocking appropriately, even though the frequency distribution of the knock signal is distorted according to the occurrence state of knocking. The controller for the internal combustion engine calculates the background level by processing a low pass filter to the knock signal; and performs a low side frequency increase which makes a low side frequency, which is a cutoff frequency of the low pass filter in the case where the knock signal is smaller than an output value of the low pass filter, higher than a high side frequency, which is a cutoff frequency of the low pass filter in the case where the knock signal is larger than the output value of the low pass filter.

Abstract: To provide a controller and a control method for an internal combustion engine capable of suppressing causing erroneous determination of combustion state even if noise component is superimposed on the ion current. In combustion state determination processing which determines combustion state of each combustion based on ion current, a controller for an internal combustion engine calculates a minimum value of ion current during a processing period, and prohibits determination of combustion state at a time point when the minimum value of ion current is below a preliminarily set determination prohibition threshold value.

Abstract: Knocking and pre-ignition are identified, without contributing to pre-ignition, even when vibration magnitudes and timings of occurrence of the knocking and pre-ignition are the same. When detecting an abnormal combustion that cannot be identified as a knocking or pre-ignition, ignition timing is advanced, at which time knocking is identified when an abnormal combustion intensity increases, and pre-ignition is identified when a difference between ignition timing and abnormal combustion occurrence timing increases.

Abstract: There is provided an internal combustion engine control apparatus that is capable of determining accurately from an ignition discharging time period whether the intake valve and the exhaust valve are in the operative condition or in the inoperative condition. A cylinder deactivation controller causes a first ignition controller to perform a first ignition control on the basis of the ignition timing when issuing no cylinder deactivation request, and causes a second ignition controller to perform a second ignition control on the basis of an energizing time period when issuing the cylinder deactivation controller. The discharging time period is calculated by a discharging time period calculation section on the basis of an ion current signal output from the ignition coil.

Abstract: An operation status value detection unit detects two or more operation status values indicating an operation status of an internal combustion engine. A filtering processing unit applies filtering processing to the detected operation status values, and an operation status value difference calculation unit calculates the difference between the filter-processed operation status value and the corresponding non-filter-processed operation status value so as to calculate two or more operation status value differences. An operation status value difference normalization unit normalizes the two or more operation status value differences, based on predetermined reference values for the two or more operation status values, so as to calculate two or more normalized operation status value differences; and a transient correction unit corrects a control amount for controlling output of the internal combustion engine, based thereon, when the engine is in a transient-operation mode.

Abstract: To provide a controller and a control method for an internal combustion engine capable of suppressing causing erroneous determination of combustion state even if noise component is superimposed on the ion current. In combustion state determination processing which determines combustion state of each combustion based on ion current, a controller for an internal combustion engine calculates a minimum value of ion current during a processing period, and prohibits determination of combustion state at a time point when the minimum value of ion current is below a preliminarily set determination prohibition threshold value.

Abstract: Knocking and pre-ignition are identified, without contributing to pre-ignition, even when vibration magnitudes and timings of occurrence of the knocking and pre-ignition are the same. When detecting an abnormal combustion that cannot be identified as a knocking or pre-ignition, ignition timing is advanced, at which time knocking is identified when an abnormal combustion intensity increases, and pre-ignition is identified when a difference between ignition timing and abnormal combustion occurrence timing increases.

Abstract: When the starting timing of a negative valve overlapping (NVO) period exists at the delayed-angle side of the starting timing of a first NVO period, fuel injection into a cylinder is not started; when the starting timing of an NVO period exists between the starting timing of the first NVO period and the starting timing of the second NVO period, fuel injection into the cylinder is started at a given timing that includes the exhaust top dead center; when the starting timing of an NVO period exists between the starting timing of the second NVO period and the starting timing of the third NVO period, fuel injection into the cylinder is started at a given timing that does not include the exhaust top dead center, and that exists at both the advanced-angle and delayed-angle sides of the exhaust top dead center.