A variety of engine controllers and methods are described for controlling engines operating in a cylinder output level modulation mode. In one aspect transitions between different effective firing fractions are managed by gradually ramping an effective firing density. In another, when an engine transitions to a multi-level skip fire firing density that has more than one possible high/low/skip sequence, the phase of the high/low pattern is set relative to the phase of the firing pattern to ensure that a preferred high/low/skip sequence is generated. In another aspect, rapid large torque changes can be implemented in part by immediately changing the operational high/low fraction in response to a command to increase or reduce the desired engine torque.

A hybrid vehicle has an engine (E) that is capable of changing a combustion mode between a stoichiometric combustion mode and a lean combustion mode and a motor/generator (MG) that is capable of performing torque assist by a power running operation and torque absorption by a regenerative operation. As a boundary between a stoichiometric combustion operating region and a lean combustion operating region, a second boundary (L2) at a torque decrease has a hysteresis at a low torque side with respect to a first boundary (L1) at a torque increase. Upon shift from the stoichiometric combustion operating region to the lean combustion operating region, for delay in increase of an intake-air quantity, decrease in fuel and the torque assist by the motor/generator (MG) are carried out, and an exhaust air-fuel ratio is changed stepwise.

An engine-equipped vehicle capable of preventing gear noise and gear wear when the engine is started is provided. A multicylinder engine, a gear transmission that shifts power from the multicylinder engine by a shift operation, a centrifugal clutch arranged in a power transmission path from the multicylinder engine to the gear transmission, and an electronic control device that controls an operation of the multicylinder engine are included and the engine is configured to be started with a partial cylinder operation start where under control of the electronic control device, only some cylinders are operated and an operation of other cylinders is stopped.

A rotation adjusting device is controlled such that an engine speed rising rate at the time of acceleration request is made smaller when a turbocharging pressure is lower than the turbocharging pressure is higher. Therefore, an engine speed can be increased at such a low speed that a rising delay in the turbocharging pressure hardly occurs, in a low turbocharging pressure region. Further, when the rotation adjusting device is controlled such that the engine speed rising rate at the time of the acceleration request is set to a value corresponding to the turbocharging pressure, an MG2 torque is controlled to compensate for an insufficient drive torque of an actual engine torque for a request engine torque. Therefore, even when the engine torque is increased slowly by increasing the engine speed at a slow speed, the insufficient drive torque is compensated for by the MG2 torque.

A variety of methods and arrangements are described for managing transitions between operational states of an internal combustion engine during skip fire operation of the engine.

When it is determined that there is a likelihood of occurrence of an abnormality in a supercharger, a maximum engine rotation speed and a maximum MG2 rotation speed are changed to a low rotation speed side and operating points of an engine and a rotary machine are controlled such that an engine rotation speed and an MG2 rotation speed are respectively within ranges which do not exceed the changed maximum rotation speeds. Accordingly, even when the supercharger does not operate normally and an abnormal increase in a supercharging pressure occurs, it is possible to curb a high-rotation state of the engine rotation speed and the MG2 rotation speed. As a result, even when an abnormal increase in the supercharging pressure occurs, it is possible to curb a decrease in durability of components.

Aspects of the present invention relate to a control system (104) for controlling operation of an internal combustion engine (102), an internal combustion engine (102), a vehicle (100), a method (600) and a non-transitory computer readable medium (202). The control system (104), comprises at least one controller. The control system (104) and being configured to: receive a first request signal indicative of first torque demand; determine a schedule defining an opening timing of the intake valve (402) and a closing timing of the intake valve (402) of a cylinder (103) of the internal combustion engine (102) in dependence on the first torque demand; and cause the intake valve (402) to open in accordance with the schedule. The control system (104) is also configured to, during a period in which the intake valve (402) is open: receive a second torque request signal indicative of a second torque demand different to the first torque demand; determine an updated schedule defining an updated closing timing of the intake valve (402) in dependence on the second torque demand; and cause the intake valve (402) to close in accordance with the updated schedule.

A system and method for transitioning a firing fraction of a variable displacement internal combustion engine when generating a desired torque output. During and following the transition to the second firing fraction, a combustion recipe is ascertained and used operating the cylinders of the variable displacement internal combustion engine to generate the desired torque output. The recipe is preferably optimized for the engine operating at the second firing fraction, at least relative to the previous charge of the previous combustion recipe used with the first firing fraction.

Provided is a novel internal-combustion engine control device that can accurately determine a combustion state of an air-fuel mixture in a combustion chamber even in a case where operation is switched between a steady operation state and a transient operation state. For this purpose, the internal-combustion engine control device includes a physical quantity detection unit that detects a physical quantity that fluctuates output of the internal-combustion engine, an output fluctuation value calculation unit that calculates an output fluctuation value for each cylinder based on a detection result of the physical quantity detection unit, and a state determination unit that determines a transient operation state or a steady operation state based on a difference or a ratio between a first output fluctuation value of a predetermined first cylinder and a second output fluctuation value of a predetermined second cylinder calculated by the output fluctuation value calculation unit. Since combustion failure determination is performed in a section determined as the steady state, it is possible to accurately determine a combustion failure state of an air-fuel mixture of a cylinder even in a case where operation is switched between the steady operation state and the transient operation state.

Engine controllers and control schemes are provided for managing engine state transitions requiring increased compressor pressure ratios in turbocharged engines. In some circumstances, turbo lag can be mitigated by initially transitioning the engine to an intermediate engine state that directly or indirectly increases airflow through the engine and turbocharger relative to what would be possible if the engine were immediately commanded to operate at the target engine state. After reaching a point where the desired torque is actually generated at the intermediate engine state, the operational settings are gradually reduced to the target effective firing density while increasing the operational compressor pressure ratio to the target compressor ratio.