Abstract: An exhaust purification apparatus for internal combustion engine having a selective reduction catalyst that while maintaining a high NOx reduction ratio, inhibits any ammonia discharge downstream of the selective reduction catalyst. In the exhaust purification apparatus (2), a urea selective reduction catalyst (23) comprises a first selective reduction catalyst (231) and, provided downstream of the first selective reduction catalyst (231) in an exhaust passageway (11), a second selective reduction catalyst (232). Further, the exhaust purification apparatus (2) includes a urea injection unit (25) for feeding of a reducing agent upstream of the urea selective reduction catalyst (23) in the exhaust passageway (11) and an ammonia sensor (26) for detection of the ammonia concentration at a site between the first selective reduction catalyst (231) and the second selective reduction catalyst (232) in the exhaust passageway (11).

Abstract: An ECU controls to inject a small amount of fuel in an expansion/exhaust stroke under constraint of the minimum fuel injection capability of an injector at the time of warming-up of a catalyst. The ECU controls injection of fuel in expansion/exhaust strokes (expansion/exhaust stroke injection) at the time of warming-up of a catalyst. Fuel injection control is performed so that when temperature of the catalyst becomes higher than a predetermined temperature, fuel injection in the expansion/exhaust strokes is performed for a period of a predetermined ratio in a selected cycle period. The expansion/exhaust stroke injection is not performed in the other period. By effectively utilizing oxygen absorbed on the catalyst, while suppressing slip HC, the activation time of the catalyst can be shortened.

Abstract: An exhaust emission control device for an internal combustion engine, capable of supplying a just enough amount of reducing agent to a selective reduction catalyst even when a NOx purification ratio of the catalyst is changed by various causes, thereby enabling a high NOx purification ratio and very low exhaust emissions to be maintained. An ECU calculates a filtered value based on a signal from an exhaust gas concentration sensor, calculates a moving average value of a product of the filtered value and a reference input, calculates a control input such that the moving average value becomes equal to 0, and adds a reference input to the control input to calculate an FB injection amount. The ECU calculates an FF injection amount with a predetermined feedforward control algorithm, and adds the FF injection amount to the FB injection amount, to thereby calculate a urea injection amount.

Abstract: A control apparatus capable of ensuring high control accuracy even if a controlled object is in a transient state, when a control input is calculated based on a value obtained by correcting a value calculated by a feedforward control method using a value calculated by a feedback control method. The control apparatus calculates a fuel correction coefficient such that an output from an oxygen concentration sensor converges to a target output, and multiplies a basic injection amount by the coefficient to calculate a fuel injection amount. The basic injection amount is selected from three values according to the cause of a mapping error. Two of them are calculated by searching respective maps according to corrected throttle valve opening values and engine speed. The other is calculated by multiplying a value obtained by searching a map according to the opening and the speed by a correction coefficient.

Abstract: An exhaust purification apparatus for internal combustion engine having a selective reduction catalyst that while maintaining a high NOx reduction ratio, inhibits any ammonia discharge downstream of the selective reduction catalyst. In the exhaust purification apparatus (2), a urea selective reduction catalyst (23) comprises a first selective reduction catalyst (231) and, provided downstream of the first selective reduction catalyst (231) in an exhaust passageway (11), a second selective reduction catalyst (232). Further, the exhaust purification apparatus (2) includes a urea injection unit (25) for feeding of a reducing agent upstream of the urea selective reduction catalyst (23) in the exhaust passageway (11) and an ammonia sensor (26) for detection of the ammonia concentration at a site between the first selective reduction catalyst (231) and the second selective reduction catalyst (232) in the exhaust passageway (11).

Abstract: Nonlinear functions (table and map) of a temperature estimation model are corrected based on outputs from a temperature sensor. An electronic control system calculates, for a plant model constructed to calculate an estimated temperature value of the plant, an estimated temperature value using a correlation model between a first parameter regarding the plant and a second parameter regarding the plant model. This control system controls the temperature of the plant based on the calculated estimated temperature value of the plant. The control system also defines a plurality of functions (Wi) in a range of a plurality of the first parameters for the correlation model, calculates correction coefficients (Kli, Kci) that adjust the height of the plurality of functions based on the output of the temperature sensor and the calculated estimated temperature value of the plant, and corrects the correlation model by the plurality of functions (Wi) and correction coefficients (Kli, Kci).

Abstract: A control apparatus which can improve the accuracy of control of a controlled variable by a control input exhibiting a periodic fluctuating behavior. The control apparatus calculates an air-fuel ratio correction value DKCMD such that the output from an oxygen concentration sensor converges to a target output, and calculate a modulated value DKCMD_DSM by modulating DKCMD with an algorithm to which is applied a ? ? modulation algorithm. Further, the control apparatus calculates a reference air-fuel ratio KCMDBS according to an exhaust gas volume, calculates a model modification coefficient KTRQFF using a modification coefficient calculated such that DKCMD become equal to 0, calculates an adaptive reference air-fuel ratio KCMDADP by the equation of KCMDADP=KCMDBS×KTRQFF, and calculates a target air-fuel ratio KCMD by the equation of KCMD=KCMADP+DKCMD_DSM.

Abstract: A control apparatus which is capable of ensuring both high-level stability and accuracy of control and reducing manufacturing costs thereof and computation load thereon, even when controlling a controlled object having extremal characteristics or a controlled object of a multi-input multi-output system. The control apparatus is comprised of an onboard model analyzer and a cooperative controller. The onboard model analyzer, based on a controlled object model defining the relationships between an intake opening angle and an exhaust reopening angle, and an indicated mean effective pressure, calculates first and second response indices and indicative of a correlation therebetween, respectively.

Abstract: An ECU controls to inject a small amount of fuel in an expansion/exhaust stroke under constraint of the minimum fuel injection capability of an injector at the time of warming-up of a catalyst. The ECU controls injection of fuel in expansion/exhaust strokes (expansion/exhaust stroke injection) at the time of warming-up of a catalyst. Fuel injection control is performed so that when temperature of the catalyst becomes higher than a predetermined temperature, fuel injection in the expansion/exhaust strokes is performed for a period of a predetermined ratio in a selected cycle period. The expansion/exhaust stroke injection is not performed in the other period. By effectively utilizing oxygen absorbed on the catalyst, while suppressing slip HC, the activation time of the catalyst can be shortened.

Abstract: A control apparatus capable of ensuring high control accuracy even if a controlled object is in a transient state, when a control input is calculated based on a value obtained by correcting a value calculated by a feedforward control method using a value calculated by a feedback control method. The control apparatus calculates a fuel correction coefficient such that an output from an oxygen concentration sensor converges to a target output, and multiplies a basic injection amount by the coefficient to calculate a fuel injection amount. The basic injection amount is selected from three values according to the cause of a mapping error. Two of them are calculated by searching respective maps according to corrected throttle valve opening values and engine speed. The other is calculated by multiplying a value obtained by searching a map according to the opening and the speed by a correction coefficient.

Abstract: A control apparatus which can improve the accuracy of control of a controlled variable by a control input exhibiting a periodic fluctuating behavior. The control apparatus calculates an air-fuel ratio correction value DKCMD such that the output from an oxygen concentration sensor converges to a target output, and calculate a modulated value DKCMD_DSM by modulating DKCMD with an algorithm to which is applied a ? ? modulation algorithm. Further, the control apparatus calculates a reference air-fuel ratio KCMDBS according to an exhaust gas volume, calculates a model modification coefficient KTRQFF using a modification coefficient calculated such that DKCMD become equal to 0, calculates an adaptive reference air-fuel ratio KCMDADP by the equation of KCMDADP=KCMDBS×KTRQFF, and calculates a target air-fuel ratio KCMD by the equation of KCMD=KCMADP+DKCMD_DSM.

Abstract: A control apparatus which is capable of compensating for a control error properly and quickly even under a condition where the control error is temporarily increased e.g. by degradation of reliability of the detection results of reference parameters other than controlled variables, thereby making it possible to ensure a high accuracy of control. An air-fuel ratio controller of the control apparatus calculates modified errors by multiplying e.g.

Abstract: A control apparatus which is capable of compensating for a control error properly and quickly even under a condition where the control error is temporarily increased e.g. by degradation of reliability of the detection results of reference parameters other than controlled variables, thereby making it possible to ensure a high accuracy of control. An air-fuel ratio controller of the control apparatus calculates an air-fuel ratio error estimated value and an error weight, calculates an modified error, calculates a basic lift correction value such that the modified error becomes equal to 0, calculates a lift correction value, calculates corrected valve lift by adding the lift correction value to valve lift, calculates a first estimated intake air amount for feedforward control of an air-fuel ratio according to the corrected valve lift, calculates an air-fuel ratio correction coefficient for feedback control of the air-fuel ratio, and calculates a fuel injection amount according to these.

Abstract: A control apparatus and method, and an engine control unit for an internal combustion engine are provided for restraining a torque step and sudden fluctuations in rotation when an air/fuel mixture combustion mode is switched among a plurality of combustion modes, and for improving the fuel economy. A control apparatus of an internal combustion engine operated with a combustion mode switched between a stratified combustion mode and a uniform combustion mode comprises an ECU. The ECU calculates an ignition manipulated variable to cancel out a change in the engine rotational speed associated with the switching of the combustion mode when a first-time injection ratio changes during idle rotational speed control, and calculates an intake manipulated variable to cancel a change in the engine rotational speed caused by the ignition manipulated variable when the first-time injection ratio changes.

Abstract: An exhaust emission control device for an internal combustion engine, capable of supplying a just enough amount of reducing agent to a selective reduction catalyst even when a NOx purification ratio of the catalyst is changed by various causes, thereby enabling a high NOx purification ratio and very low exhaust emissions to be maintained. An ECU calculates a filtered value based on a signal from an exhaust gas concentration sensor, calculates a moving average value of a product of the filtered value and a reference input, calculates a control input such that the moving average value becomes equal to 0, and adds a reference input to the control input to calculate an FB injection amount. The ECU calculates an FF injection amount with a predetermined feedforward control algorithm, and adds the FF injection amount to the FB injection amount, to thereby calculate a urea injection amount.

Abstract: An ignition timing control system for an internal combustion engine, which is capable of reducing the capacity of a memory that stores data used in controlling ignition timing, thereby reducing manufacturing costs. An ignition timing control system that controls ignition timing of an internal combustion engine calculates a maximum torque parameter indicative of a maximum torque that the engine can output when the engine is at the detected rotational speed, according to the detected rotational speed, calculates an output torque parameter indicative of an output torque being output from the engine, calculates a torque ratio as a ratio between the output torque parameter and the maximum torque parameter, and determines the ignition timing according to the engine speed and the torque ratio.

Abstract: Nonlinear functions (table and map) of a temperature estimation model are corrected based on outputs from a temperature sensor. An electronic control system calculates, for a plant model constructed to calculate an estimated temperature value of the plant, an estimated temperature value using a correlation model between a first parameter regarding the plant and a second parameter regarding the plant model. This control system controls the temperature of the plant based on the calculated estimated temperature value of the plant. The control system also defines a plurality of functions (Wi) in a range of a plurality of the first parameters for the correlation model, calculates correction coefficients (Kli, Kci) that adjust the height of the plurality of functions based on the output of the temperature sensor and the calculated estimated temperature value of the plant, and corrects the correlation model by the plurality of functions (Wi) and correction coefficients (Kli, Kci).

Abstract: A control apparatus which is capable of compensating for a control error properly and quickly even under a condition where the control error is temporarily increased e.g. by degradation of reliability of the detection results of reference parameters other than controlled variables, thereby making it possible to ensure a high accuracy of control. An air-fuel ratio controller of the control apparatus calculates modified errors by multiplying e.g.

Abstract: A control apparatus which is capable of compensating for a control error properly and quickly even under a condition where the control error is temporarily increased e.g. by degradation of reliability of the detection results of reference parameters other than controlled variables, thereby making it possible to ensure a high accuracy of control. An air-fuel ratio controller of the control apparatus calculates an air-fuel ratio error estimated value and an error weight, calculates an modified error, calculates a basic lift correction value such that the modified error becomes equal to 0, calculates a lift correction value, calculates corrected valve lift by adding the lift correction value to valve lift, calculates a first estimated intake air amount for feedforward control of an air-fuel ratio according to the corrected valve lift, calculates an air-fuel ratio correction coefficient for feedback control of the air-fuel ratio, and calculates a fuel injection amount according to these.

Abstract: A control apparatus and method, and an engine control unit for an internal combustion engine are provided for restraining a torque step and sudden fluctuations in rotation when an air/fuel mixture combustion mode is switched among a plurality of combustion modes, and for improving the fuel economy. A control apparatus of an internal combustion engine operated with a combustion mode switched between a stratified combustion mode and a uniform combustion mode comprises an ECU. The ECU calculates an ignition manipulated variable to cancel out a change in the engine rotational speed associated with the switching of the combustion mode when a first-time injection ratio changes during idle rotational speed control, and calculates an intake manipulated variable to cancel a change in the engine rotational speed caused by the ignition manipulated variable when the first-time injection ratio changes.