A fuel supply system includes an electronic control unit that outputs a target fuel pressure for controlling a low-pressure pump and an engine status, and a fuel pump controller (FPC) that generates a drive signal for driving the low-pressure pump based on the target fuel pressure. The FPC is configured to obtain an actual fuel pressure, to set a duty ratio and to perform a feedback control for the actual fuel pressure to follow the target fuel pressure, and to set a lower limit guard value based on the engine status. The lower limit guard setter sets a duty ratio of 0% as the lower limit guard value when the engine status indicates a stop of the engine.

Systems and methods are provided for operating a port fuel and direct injection fuel system of a rolling variable displacement engine (rVDE). In one example, a method may include selecting between controlling a lift pump of the fuel system to output fuel at a mechanically limited pressure and controlling the lift pump to output fuel at a pressure lower than the mechanically limited pressure based on whether port fuel injection is used. In this way, the lift pump may be controlled without feedback from a pressure sensor, reducing system costs, while electrical power consumption increases due to operating the lift pump to output fuel at the mechanically limited pressure are minimized due to the rVDE technology, which reduces port fuel injection usage.

Systems and methods are provided for diagnosing cylinders in an engine. In one example, the method may include while receiving first feedback from a vibration sensor coupled to a first cylinder of the engine, perturbing the first cylinder during engine operation. Responsive to the first feedback indicating a first vibration level difference greater than or equal to a first threshold difference, a first indication of a first degradation condition of the first cylinder may be set, and thereafter the engine may be operated based on whether or not the first indication was set.

A method and system for operating a hybrid vehicle that includes an integrated starter/generator and a driveline disconnect clutch is described. In one example, the method determines whether or not to rotate an engine via an electric machine while propelling a vehicle via the electric machine according to vehicle efficiency.

A piston engine is provided; the piston engine has a cylinder, a main piston and an auxiliary piston; a combustion chamber is formed between the main piston and the auxiliary piston within the cylinder; the main piston has an crankpin offset L0, the auxiliary piston and the main piston move in different frequencies, an extended constant V≈Vc of the combustion chamber is formed from θ to >10° CA; when at a=θ=arc sin[L0/(L+R)] the main piston is at its top dead center; at a=arc sin(L0/R) the side force on the main piston is 0; when peak pressure of combustion is located at PPmax by choosing ignition timing, the most effective torque can be obtained; the torque is controlled by the amount of fuel injected; engine knocking can be prevented by retarded ignition at a>θ.

A system comprising engine driven pumps, control units, a rate control algorithm, and a trained algorithmic model. The control units store operation variables for the engine driven pumps. The rate control algorithm includes an instruction set to read the operation variables for the engine driven pumps. The instruction set comprises a trained algorithmic model with a parameter space based on historical operation variables. The trained algorithmic model determines an optimal distribution rate based on an objective. The instruction set generates rate control variables based on the determined optimal distribution rate. Each rate control variable comprises a selected control unit identifier and a rate value. The instruction set distributes each rate control variable based on the selected control unit identifier. The trained algorithmic model determine the optimal distribution rate using an objective that defines a desired mixture between a first fuel and a second fuel.

The present subject matter relates to a control unit for controlling an internal combustion engine, wherein the internal combustion engine includes at least one cylinder 100, at least one combustion chamber 90 within which a fuel is burned, at least one fuel injector 40, 50, at least one ignition device 60, and an oxygen determination unit 20 configured to determine the content of oxygen in the fuel, wherein the control unit 10 is configured to control the internal combustion engine based on the content of oxygen in the fuel detected by the oxygen determination unit 20.

Methods and systems are provided for an engine for adjusting cylinder parameter settings to optimize engine output during a transient mode. In one example, a method may include adjusting cylinder parameter settings, including a cam timing setting, a spark timing setting, and a fuel injection timing setting based on a chamber temperature in response to a rate of fuel injection acceleration being greater than a positive threshold, thus indicating the engine is in the transient mode.

In a combustion cycle in which fuel for forming a homogenized air-fuel mixture in the combustion chamber is injected from the first fuel injector, ignition-use fuel for forming an ignition-use air-fuel mixture in the vicinity of the electrode part is injected from the second fuel injector, and lean combustion is performed by an excess air rate of 2.0 or more, the ignition-use fuel is injected by at least an injection rate of 1.0 mm.sup.3/ms or more for a duration of 250 μs or more in an interval from a crank angle advanced by exactly 20 degrees from an ignition timing of the spark plug to the ignition timing, and the quantity of the ignition-use fuel is 2.0 mm.sup.3/st or less.

A system is provided for controlling engine fueling and includes an internal combustion engine, a fuel source, means for delivering fuel from the fuel source to the engine, and a controller configured to control the fuel delivering means according to a first operational mode so that, upon attaining a predetermined operational state of the engine, an amount of fuel delivered to the engine per unit time is kept constant. The system will typically but not necessarily be provided in a vehicle such as a truck or a passenger automobile. A method for controlling engine fueling is also provided.