Fuel injection control of an internal combustion engine requires an optimized fuel amount that can be burned completely with oxygen in intake air to be supplied, but the oxygen concentration in the atmospheric air is affected by humidity.

By separately calculating a dry air flow rate that directly affects the oxygen amount and a humidity flow rate that is a change factor of the oxygen concentration in the intake air of the internal combustion engine, the fuel can be supplied to the cylinder of the internal combustion engine at an optimized air-fuel ratio. In addition, highly precise control involving EGR for flowback of a part of the exhaust gas flowing in the exhaust pipe to the intake pipe can also be achieved.

In a control device for an internal combustion engine, when a target pre/post compressor pressure ratio calculated by a target pre/post compressor pressure ratio calculation part is more than a turbine-limit-time pre/post compressor pressure ratio calculated by a turbine-limit-time pre/post compressor pressure ratio calculation part, an upper limit of the target pre/post compressor pressure ratio is limited by the turbine-limit-time pre/post compressor pressure ratio, and a change rate of the target pre/post compressor pressure ratio is limited by a change rate limit value during a change rate limitation period after upper limit limitation processing starts, thereby preventing the target pre/post compressor pressure ratio from being suddenly fluctuated by a sudden fluctuation in a compressor passage flow rate, and suppressing the occurrence of the over rotation of the turbine and the control hunting.

Methods and systems are provided for indicating a presence or absence of a source of degradation stemming from one of an intake manifold, exhaust system, or engine of an engine system. In one example, a method comprises rotating the engine unfueled and indicating the source of degradation based on both an intake air flow and an exhaust flow, as compared to baseline intake air flow and baseline exhaust flow. In this way, a source of degradation may be pinpointed, which may increase a lifetime of a vehicle engine system, reduce undesired emissions, and which may increase customer satisfaction resulting from shorter time spent on diagnosing such a source of degradation.

A method for analyzing a fuel injection system includes generating injection commands, including attenuating a predetermined fuel request schedule for a different one of the plurality of injectors in a plurality of test cycles. Fuel is injected according to the injection commands to complete the plurality of test cycles. The processor generates pump commands for the pump to maintain a substantially constant pressure of the common rail during the test cycles. First command data are stored for the plurality of test cycles corresponding to the injection commands sent during the test cycles. Second command data are stored for the test cycles corresponding to the pump commands sent during the test cycles. The processor processes the first command data and the second command data to determine flow characteristics of the plurality of fuel injectors.

A control system comprising a variable valve timing mechanism (B) able to set a closing timing of an intake valve (7), a fuel injector (13) for feeding fuel to a combustion chamber (5), an intake air amount detector (17) for detecting an amount of intake air fed to an intake passage from the outside air, and a pressure sensor (16) for detecting the pressure in the intake passage downstream of a throttle valve (16). When air in the combustion chamber (5) is blown back to the intake passage when injection of fuel is restarted after the fuel injection is stopped at the time of deceleration operation, the basis for calculation of the fuel injection amount in the initial cycle when fuel injection is restarted is switched from the amount of intake air detected by the intake air amount detector (17) to the pressure in the intake passage detected by the pressure sensor (18).

A torque request module is configured to, while a vehicle speed is greater than a predetermined speed, decrease a torque request in response to a first signal from a start/stop switch being in a first state continuously for greater than a first predetermined period and less than a second predetermined period. A control module is configured to, as the torque request decreases, decrease torque output of at least one of an engine and an electric motor. A light control module is configured to: selectively turn exterior hazard lights on and off in response to a second signal from a hazard light switch being in a first state; and selectively turn the exterior hazard lights on and off in response to the first signal from the start/stop switch being in the first state continuously for greater than the first predetermined period.

A method for analyzing a fuel injection system includes generating injection commands, including attenuating a predetermined fuel request schedule for a different one of the plurality of injectors in a plurality of test cycles. Fuel is injected according to the injection commands to complete the plurality of test cycles. The processor generates pump commands for the pump to maintain a substantially constant pressure of the common rail during the test cycles. First command data are stored for the plurality of test cycles corresponding to the injection commands sent during the test cycles. Second command data are stored for the test cycles corresponding to the pump commands sent during the test cycles. The processor processes the first command data and the second command data to determine flow characteristics of the plurality of fuel injectors.

Control of airflow in a uniflow-scavenged, two-stroke cycle, opposed-piston engine during transient operation includes monitoring at least one operating parameter of the engine to recognize a transition to a transient state of engine operation. If a transient state of operation is detected, fuel injection and airflow into to the cylinders of the engine are controlled to optimize combustion and limit emissions. Airflow into cylinders of the engine may be controlled by increasing a scavenging ratio of the engine or by increasing a trapping efficiency of the engine.

Disclosed is a method for establishing an engine maintenance diagnosis. The engine includes a throttle which regulates air access into an air intake system of the engine, a position sensor which measures the position of the throttle, a manifold in fluidic communication with the throttle, a pressure sensor which measures the pressure in the manifold, at least one intake valve, a richness probe which measures an oxygen level and a richness controller for modifying the proportions of air and fuel in the air-fuel mixture. The method uses two air flow measurements in order to identify a problem in the throttle or the play at the valves.

A method for measuring the flow rate MAF of cool air entering an intake manifold of a two-stroke engine, the intake manifold being located between a throttle body and an intake system. The method uses a specific prediction model depending on whether the two-stroke engine is subject, on the one hand, to a light load and, on the other hand, to a medium or heavy load. The model suitable for the load is selected using a predetermined threshold and two absolute pressure measurements taken at the intake manifold at crankshaft angles of rotation around top dead center and bottom dead center. Next, a pressure quotient is formed for each model which will be used to deduce the flow rate of cool air entering the intake manifold.