An intake air temperature estimation system includes: an adiabatically compressed intake air temperature computing unit that computes an adiabatically compressed intake air temperature based on an intake air temperature before compression, an intake air pressure before compression and an intake air pressure after compression; and an estimated intake air temperature computing unit that computes an estimated intake air temperature. The estimated intake air temperature computing unit variably sets a coefficient of the function in response to an amount of change per unit time in the intake air pressure after compression such that a followability of the estimated intake air temperature to the adiabatically compressed intake air temperature at the time when the amount of change is large is higher than a followability of the estimated intake air temperature to the adiabatically compressed intake air temperature at the time when the amount of change is small.

An intake air temperature estimation system includes: an adiabatically compressed intake air temperature computing unit that computes an adiabatically compressed intake air temperature based on an intake air temperature before compression, an intake air pressure before compression and an intake air pressure after compression; and an estimated intake air temperature computing unit that computes an estimated intake air temperature. The estimated intake air temperature computing unit variably sets a coefficient of the function in response to an amount of change per unit time in the intake air pressure after compression such that a followability of the estimated intake air temperature to the adiabatically compressed intake air temperature at the time when the amount of change is large is higher than a followability of the estimated intake air temperature to the adiabatically compressed intake air temperature at the time when the amount of change is small.

The engine controller includes an acceleration input detector that detects an accelerator pedal motion, a fuel injection amount calculator that calculates a target fuel injection amount, a fuel injection controller that controls the fuel injector, an EGR valve opening calculator that calculates a target EGR valve opening, and an EGR controller that controls the EGR valve. The EGR controller controls, after the accelerator pedal motion has been given, the EGR valve in a direction to decrease an opening of the EGR valve to a target EGR valve opening corresponding to a running condition to be reached after the accelerator pedal motion has been given. The control of the EGR valve opening is started before the fuel injection controller controls the fuel injector based on the target fuel injection amount calculated by the fuel injection amount calculator based on the accelerator pedal motion.

The engine controller includes an acceleration input detector that detects an accelerator pedal motion, a fuel injection amount calculator that calculates a target fuel injection amount, a fuel injection controller that controls the fuel injector, an EGR valve opening calculator that calculates a target EGR valve opening, and an EGR controller that controls the EGR valve. The EGR controller controls, after the accelerator pedal motion has been given, the EGR valve in a direction to decrease an opening of the EGR valve to a target EGR valve opening corresponding to a running condition to be reached after the accelerator pedal motion has been given. The control of the EGR valve opening is started before the fuel injection controller controls the fuel injector based on the target fuel injection amount calculated by the fuel injection amount calculator based on the accelerator pedal motion.

The method for controlling valve timing of an engine includes: classifying control regions; applying a maximum duration to an intake valve and a long duration to an exhaust valve in a first control region; advancing Intake Valve Closing timing, applying the long duration to the exhaust valve, and maintaining a maximum valve overlap in a second control region; applying the long duration to the exhaust valve and advancing the IVC timing and Exhaust Valve Closing timing in a third control region; applying a short duration to the exhaust valve and controlling the EVC timing in a fourth control region; controlling a throttle valve, applying the short duration to the exhaust valve, and retarding Exhaust Valve Opening timing in a fifth control region; and controlling the throttle valve and the EVC timing, applying the long duration to the exhaust valve, advancing the EVO timing in a sixth control region.

The method for controlling valve timing of an engine includes: classifying control regions; applying a maximum duration to an intake valve and a long duration to an exhaust valve in a first control region; advancing Intake Valve Closing timing, applying the long duration to the exhaust valve, and maintaining a maximum valve overlap in a second control region; applying the long duration to the exhaust valve and advancing the IVC timing and Exhaust Valve Closing timing in a third control region; applying a short duration to the exhaust valve and controlling the EVC timing in a fourth control region; controlling a throttle valve, applying the short duration to the exhaust valve, and retarding Exhaust Valve Opening timing in a fifth control region; and controlling the throttle valve and the EVC timing, applying the long duration to the exhaust valve, advancing the EVO timing in a sixth control region.

A method for a vehicle engine is presented, wherein during a first condition, a vehicle controller is placed in a sleep mode following a vehicle-off event and then awoken following a duration, at which time contents of an air intake system hydrocarbon trap are purged to a fuel vapor canister by operating an electric motor to rotate the vehicle engine in a reverse direction. Rotating the vehicle engine in a reverse direction causes atmospheric air to enter an intake of the engine via an exhaust of the engine, desorbing hydrocarbons bound to the air intake system hydrocarbon trap. By porting the desorbed hydrocarbons to the fuel vapor canister, bleed emissions from the air intake system hydrocarbon trap may be reduced.

A system is disclosed including but not limited to a processor; a hybrid power source for servicing a system load, the hybrid power source comprising a natural gas engine, a diesel engine and a battery; a linear computer program comprising, instructions determining a current system load serviced by power provided from the hybrid power source; instructions to determine a current operating state for the natural gas engine, the diesel engine and the battery; instructions to use linear programming to determine a new operating state for the natural gas engine, the diesel engine and the battery to reduce for power consumption servicing the current system load the natural gas engine, the diesel engine and the battery; and instructions to replace the current operating state for the natural gas engine, the diesel engine and the battery to the new operating state for the natural gas engine, the diesel engine and the battery.

A system is disclosed including but not limited to a processor; a hybrid power source for servicing a system load, the hybrid power source comprising a natural gas engine, a diesel engine and a battery; a linear computer program comprising, instructions determining a current system load serviced by power provided from the hybrid power source; instructions to determine a current operating state for the natural gas engine, the diesel engine and the battery; instructions to use linear programming to determine a new operating state for the natural gas engine, the diesel engine and the battery to reduce for power consumption servicing the current system load the natural gas engine, the diesel engine and the battery; and instructions to replace the current operating state for the natural gas engine, the diesel engine and the battery to the new operating state for the natural gas engine, the diesel engine and the battery.

A system includes an engine and a controller. The engine is capable of multiple operating modes, and each mode has a relatively different fuel ratio such that as the engine is changed from a first operating mode having a first ratio of a first fuel to a second fuel to a second operating mode having a second ratio of the first fuel to the second fuel. The controller is operable to change the engine from one operating mode to another operating mode.