A control method for an internal combustion engine including a variable compression ratio mechanism which includes: implementing a compression ratio fixing control in which a mechanical compression ratio is fixed to a predetermined low compression ratio, and controlling combustion form in a cylinder to stratified combustion, under engine idling during catalyst warming-up; controlling the combustion form in the cylinder to homogeneous combustion, under an operation state other than the engine idling during the catalyst warming-up; and implementing the compression ratio fixing control and controlling the combustion form in the cylinder to the homogeneous combustion, in response to pressing-down of an accelerator under the engine idling during the catalyst warming-up, and as long as the engine idling during the catalyst warming-up has a possibility to resume in response to release of the accelerator after the pressing-down.

In accordance with an exemplary embodiment, a method is provided for controlling operation of an engine of a vehicle during an idle mode of operation for the engine, the engine having a plurality of different types of fuel injectors and a combustion chamber, including: obtaining, via one or more first sensors of the vehicle, first sensor data as to a speed of the vehicle; obtaining, via one or more second sensors of the vehicle, second sensor data as to a measure of roughness of the engine; and adjusting, via instructions provided by a processor of the vehicle, a fuel injection ratio of respective amounts of fuel provided by the plurality of different types of fuel injectors to the combustion chamber, based on both the speed of the vehicle and the measure of roughness of the engine.

In accordance with an exemplary embodiment, a method is provided for controlling operation of an engine of a vehicle during an idle mode of operation for the engine, the engine having a plurality of different types of fuel injectors and a combustion chamber, including: obtaining, via one or more first sensors of the vehicle, first sensor data as to a speed of the vehicle; obtaining, via one or more second sensors of the vehicle, second sensor data as to a measure of roughness of the engine; and adjusting, via instructions provided by a processor of the vehicle, a fuel injection ratio of respective amounts of fuel provided by the plurality of different types of fuel injectors to the combustion chamber, based on both the speed of the vehicle and the measure of roughness of the engine.

Methods and systems are provided for reducing release of undesired evaporative emissions to atmosphere for a hybrid vehicle. In one example, a method comprises locking a transmission of the vehicle in park until a request to override the locking is received at a controller of the vehicle, and conducting one or more routines related to reducing release of undesired evaporative emissions to atmosphere, where the one or more diagnostic routines rely on a vacuum derived from an engine of the vehicle combusting air and fuel while the transmission is locked in park. In this way, completion rates for conducting the one or more routines may be improved, and issues related to the release of undesired evaporative emissions to atmosphere may be reduced or avoided.

Methods and systems are provided for reducing release of undesired evaporative emissions to atmosphere for a hybrid vehicle. In one example, a method comprises locking a transmission of the vehicle in park until a request to override the locking is received at a controller of the vehicle, and conducting one or more routines related to reducing release of undesired evaporative emissions to atmosphere, where the one or more diagnostic routines rely on a vacuum derived from an engine of the vehicle combusting air and fuel while the transmission is locked in park. In this way, completion rates for conducting the one or more routines may be improved, and issues related to the release of undesired evaporative emissions to atmosphere may be reduced or avoided.

The inhibition device includes a micro-controller configured with a triggering condition including a number of intervals and, for each interval, a corresponding duration and a corresponding threshold. Each interval is a range specifying how much the vehicle's acceleration pedal has changed its position in terms of percentages of a pedal stroke. Each duration specifies the fastest time duration allowable for the acceleration pedal to attain a corresponding interval of pedal position change. The micro-controller converts progress signals of the acceleration pedal to corresponding percentages, obtains a difference DEF between the successive percentages, records a time duration RES between successive progress signals, and calculates DEF/RES=X. When X is greater than or equal to a threshold of a corresponding interval, the micro-controller sends an idle signal to the vehicle's engine control unit or intercepts the progress signals to prevent them from reaching the engine control unit.

The inhibition device includes a micro-controller configured with a triggering condition including a number of intervals and, for each interval, a corresponding duration and a corresponding threshold. Each interval is a range specifying how much the vehicle's acceleration pedal has changed its position in terms of percentages of a pedal stroke. Each duration specifies the fastest time duration allowable for the acceleration pedal to attain a corresponding interval of pedal position change. The micro-controller converts progress signals of the acceleration pedal to corresponding percentages, obtains a difference DEF between the successive percentages, records a time duration RES between successive progress signals, and calculates DEF/RES=X. When X is greater than or equal to a threshold of a corresponding interval, the micro-controller sends an idle signal to the vehicle's engine control unit or intercepts the progress signals to prevent them from reaching the engine control unit.

A work vehicle may include an internal combustion engine, aftertreatment system, and at least one controller. The controller is configured to use a temperature of the aftertreatment system to determine a hydrocarbon level of the aftertreatment system, and set an idle speed of the engine to high idle if the hydrocarbon level is above a hydrocarbon ceiling, to ultra-low idle if the hydrocarbon level is below a hydrocarbon floor, and to low idle if the hydrocarbon level is between the hydrocarbon floor and the hydrocarbon ceiling.

A control method for an internal combustion engine including a variable compression ratio mechanism which includes: implementing a compression ratio fixing control in which a mechanical compression ratio is fixed to a predetermined low compression ratio, and controlling combustion form in a cylinder to stratified combustion, under engine idling during catalyst warming-up; controlling the combustion form in the cylinder to homogeneous combustion, under an operation state other than the engine idling during the catalyst warming-up; and implementing the compression ratio fixing control and controlling the combustion form in the cylinder to the homogeneous combustion, in response to pressing-down of an accelerator under the engine idling during the catalyst warming-up, and as long as the engine idling during the catalyst warming-up has a possibility to resume in response to release of the accelerator after the pressing-down.

A control method for an internal combustion engine including a variable compression ratio mechanism which includes: implementing a compression ratio fixing control in which a mechanical compression ratio is fixed to a predetermined low compression ratio, and controlling combustion form in a cylinder to stratified combustion, under engine idling during catalyst warming-up; controlling the combustion form in the cylinder to homogeneous combustion, under an operation state other than the engine idling during the catalyst warming-up; and implementing the compression ratio fixing control and controlling the combustion form in the cylinder to the homogeneous combustion, in response to pressing-down of an accelerator under the engine idling during the catalyst warming-up, and as long as the engine idling during the catalyst warming-up has a possibility to resume in response to release of the accelerator after the pressing-down.