Assume that a boundary on the air-fuel ration operation is changed from a boundary (i) to a boundary (ii). Then, after the boundary is changed, a high EGR operation region where a target EGR rate is set to a high value overlaps partially with a rich operation region. Therefore, when it is determined that the current operating point exists in the overlapped region, the target EGR rate is forcibly lowered. In addition, the boundary on a drive cam for an intake valve is changed from a boundary (I) to a boundary (II) thereby a region where a small cam is selected is enlarged.

A vehicle powertrain control technique includes obtaining, by a controller, a set of parameters each indicative of a gear shift operation for an automatic transmission. Cased on the set of parameters, the controller detects whether a gear shift operation of the automatic transmission is imminent. In response to detecting that the gear shift operation of the automatic transmission is imminent, the controller (i) determines a desired reduction in powertrain output torque for performing the gear shift operation and (ii) controls the powertrain to temporarily reduce its torque output via a technique other than spark retardation. After reducing the powertrain output torque, the controller commands the automatic transmission to perform the gear shift operation. The temporary powertrain output torque reduction is achieved by controlling a variable valve control (VVC) system of an engine, such as commanding a lower valve lift profile, or decreasing power supplied to an electric motor.

A control system and method for a vehicle having a powertrain comprising a torque generating system and an automatic transmission each utilize a pedal position sensor configured to measure a position of an accelerator pedal of the vehicle and a controller configured to, based on the accelerator pedal position, detect a pedal tip-in or tip-out event and, in response to detecting the pedal tip-in or tip-out event: (i) determine a desired output torque for the torque generating system corresponding to the pedal tip-in or tip-out event and (ii) command the torque generating system to gradually transition, over a period, from its current output torque to the desired output torque to mitigate clunk caused by abrupt contact between gear teeth of the torque generating system shaft and the automatic transmission shaft.

When it is determined that the igniting environment is out of the desired range, the variable valve mechanism is controlled so that the swirl ratio is increased. When the swirl ratio becomes high, the discharge spark and the initial flame move largely in the flow direction of the swirl flow SW and approach the closest fuel spray. Therefore, the discharge spark and the initial flame are attracted to the closest fuel spray and the initial flame enlarges by involving the closest fuel spray (middle stage of FIG. 7). Further, the initial flame enlarges further by involving surrounded fuel spray (lower stage of FIG. 7).

Advanced combustion modes, such as PCCI, operate near the system stability limits. In PCCI, the combustion event begins without a direct combustion trigger in contrast to traditional spark-ignited gasoline engines and direct-injected diesel engines. The lack of a direct combustion trigger encourages the usage of model-based controls to provide robust control of the combustion phasing. The nonlinear relationships between the control inputs and the combustion system response often limit the effectiveness of traditional, non-model-based controllers. Accurate knowledge of the system states and inputs is helpful for implementation of an effective nonlinear controller. A nonlinear controller is developed and implemented to control the engine combustion timing during diesel PCCI operation by targeting desired values of the in-cylinder oxygen concentration, pressure, and temperature during early fuel injection.

A method for starting or stopping an internal combustion engine which reduces starter loading and engine vibrations is provided. The method includes varying a valve stroke of at least one cylinder of the engine such that during the starting or stopping procedure the at least one cylinder undergoes decompression.

An abnormality diagnosis system of an internal combustion engine that is installed on a vehicle and includes an actuator includes an electronic control unit. The electronic control unit receives vehicle outside information concerning a period of time for which the vehicle speed is less than a predetermined value, and determines whether the period for which the vehicle speed is less than the predetermined value is expected to be equal to or longer than a length of time required for an abnormality diagnosis of an abnormality diagnosis target device. The electronic control unit activates the actuator and starts the abnormality diagnosis as the vehicle speed becomes lower than the predetermined value, when it determines that the period for which the vehicle speed is lower than the predetermined value is expected to be equal to or longer than the time required for the abnormality diagnosis of the target device.

Methods and systems are provided for indicating degradation of a VCR mechanism that mechanically alters a cylinder compression ratio. Degradation is detected based on an elevated knock incidence and increased spark retard usage. If the VCR mechanism is stuck, knock and pre-ignition that could be induced by continued operation in a higher than intended compression ratio is mitigated by limiting the engine load.

To provide an internal combustion engine control device provided with a generator driven by an exhaust gas of an internal combustion engine and capable of increasing the power generation opportunity of the generator.

The internal combustion engine control device according to the present invention is provided with the generator driven by the exhaust gas of the internal combustion engine, and includes an exhaust amount control unit which increases the amount of the exhaust gas supplied to the generator in a coasting state.

An internal combustion engine includes a first intake valve, a second intake valve, an accelerator open degree sensor that detects a load state, and an ECU 26 that controls the valve opening timing of the first and second intake valves and an amount of intake gas introduced to a combustion chamber from the first and second intake valves. When a load of a vehicle increases, the ECU reduces the ratio of the amount of intake gas from, among the two or more intake valves, the second intake valve having a later valve opening timing, whereas when the load decreases, the ECU increases the ratio.