Abstract: A fuel injection control apparatus includes a first injection controller, a second injection controller, and a selector. The first injection controller is configured to perform a first injection operation in an intake stroke and is configured to perform a second injection operation in a compression stroke. The second injection controller is configured to perform both the first injection operation and the second injection operation in the intake stroke. The selector is configured to select fuel injection performed by the first injection controller when an internal combustion engine is in a warm-up operating state and is configured to select fuel injection performed by the second injection controller when the internal combustion engine is not in the warm-up operating state.

Abstract: A fuel injection control apparatus includes a first injection timing setting device, a target second injection timing setting device, a reference injection timing calculator, and a second injection timing setting device. The reference injection timing calculator is configured to calculate, as a reference injection timing, a timing at which a second-injection boosting operation is to be completed. The second-injection boosting operation is to re-boost a reduced voltage which has been reduced because of an execution of a first injection operation by using a booster circuit. The second injection timing setting device is configured to set, as a second injection timing at which a second injection operation is to be started, a later one of a target second injection timing set by the target second injection timing setting device and the reference injection timing calculated by the reference injection timing calculator.

Abstract: A fuel injection control apparatus includes a first injection timing setting device, a target second injection timing setting device, a reference injection timing calculator, and a second injection timing setting device. The reference injection timing calculator is configured to calculate, as a reference injection timing, a timing at which a second-injection boosting operation is to be completed. The second-injection boosting operation is to re-boost a reduced voltage which has been reduced because of an execution of a first injection operation by using a booster circuit. The second injection timing setting device is configured to set, as a second injection timing at which a second injection operation is to be started, a later one of a target second injection timing set by the target second injection timing setting device and the reference injection timing calculated by the reference injection timing calculator.

Abstract: A fuel injection control apparatus includes a first injection controller, a second injection controller, and a selector. The first injection controller is configured to perform a first injection operation in an intake stroke and is configured to perform a second injection operation in a compression stroke. The second injection controller is configured to perform both the first injection operation and the second injection operation in the intake stroke. The selector is configured to select fuel injection performed by the first injection controller when an internal combustion engine is in a warm-up operating state and is configured to select fuel injection performed by the second injection controller when the internal combustion engine is not in the warm-up operating state.

Abstract: An air fuel ratio controller for an internal combustion engine includes an exhaust gas sensor, an identifier and a control unit. The exhaust gas sensor detects oxygen concentration of exhaust gas. The identifier calculates model parameters for a model of a controlled object based on the output of the exhaust gas sensor. The controlled object includes an exhaust system of the engine. The control unit is configured to use the model parameters to control the air-fuel ratio so that the output of the exhaust gas sensor converges to a desired value, and to stop the identifier from calculating the model parameters during and immediately after the engine operation with a lean air-fuel ratio. The calculation of the model parameters may be also stopped during and immediately after fuel-cut operation that stops fuel supply to the engine.

Abstract: A fuel supply control system for an internal combustion engine wherein an operating condition of the engine is detected and an amount of fuel supplied to the engine is controlled according to the detected operating condition of the engine. A cooling degree of at least one exhaust valve of the engine is estimated, and the fuel amount is corrected in an increasing direction based on the estimated cooling degree of the at least one exhaust valve. The corrected fuel amount is then supplied to the engine.

Abstract: A fuel supply control system for an internal combustion engine wherein an operating condition of the engine is detected and an amount of fuel supplied to the engine is controlled according to the detected operating condition of the engine. A cooling degree of at least one exhaust valve of the engine is estimated, and the fuel amount is corrected in an increasing direction based on the estimated cooling degree of the at least one exhaust valve. The corrected fuel amount is then supplied to the engine.

Abstract: A control system capable of controlling a heater that heats an oxygen concentration detector in a fine-grained, efficient, and optimal manner. The control system controls an O2 heater for heating an O2 sensor provided in an exhaust pipe of an internal combustion engine, when the engine is started. An ECU sets a duty ratio of a control signal supplied to the O2 heater to a first predetermined value until a first predetermined time period has elapsed after the start of the engine was detected, and sets the same to a second predetermined value smaller than the first predetermined value until a second predetermined time period has elapsed after the lapse of the first predetermined value. Further, the ECU sets the duty ratio of the control signal to a third predetermined value smaller than the second predetermined value after the lapse of the second predetermined time period.

Abstract: A control system capable of controlling a heater that heats an oxygen concentration detector in a fine-grained, efficient, and optimal manner. The control system controls an O2 heater for heating an O2 sensor provided in an exhaust pipe of an internal combustion engine, when the engine is started. An ECU sets a duty ratio of a control signal supplied to the O2 heater to a first predetermined value until a first predetermined time period has elapsed after the start of the engine was detected, and sets the same to a second predetermined value smaller than the first predetermined value until a second predetermined time period has elapsed after the lapse of the first predetermined value. Further, the ECU sets the duty ratio of the control signal to a third predetermined value smaller than the second predetermined value after the lapse of the second predetermined time period.

Abstract: An air fuel ratio controller for an internal combustion engine comprises an exhaust gas sensor, an identifier and a control unit. The exhaust gas sensor detects oxygen concentration of exhaust gas. The identifier calculates model parameters for a model of a controlled object based on the output of the exhaust gas sensor. The controlled object includes an exhaust system of the engine. The control unit is configured to use the model parameters to control the air-fuel ratio so that the output of the exhaust gas sensor converges to a desired value, and to stop the identifier from calculating the model parameters during and immediately after the engine operation with a lean air-fuel ratio. The calculation of the model parameters may be also stopped during and immediately after fuel-cut operation that stops fuel supply to the engine.