Methods and apparatuses for calibration and control of various engine subsystems using a target value approach. Under the target value approach, the control of each engine subsystem is separated or decoupled to include a set of target values, or a reference value set. A subsystem has a corresponding target determiner, which provides a target value set, or reference value set, in response to a basis variable set and optionally an overall subsystem target. The basis variable set includes parameters selected to robustly characterize the variables that affect the operation of the particular subsystem. The target determiner is optionally calibrated to provide a reference value set within specifications of the subsystem. A physical subsystem controller operates in response to the reference value set.

The invention relates to a method for controlling gaseous fuel pressure in an accumulator (12) of a fuel system (10) for a combustion engine (102) of a vehicle (100), wherein the method comprises the steps of: determining a nominal amount of gaseous fuel to be introduced into the accumulator; introducing less gaseous fuel into the accumulator than the determined nominal amount by reducing or closing an inlet valve (24), which inlet valve is adapted to regulate input of gaseous fuel to the accumulator; and while the inlet valve is reduced or closed, performing at least one injection of gaseous fuel coming from the accumulator into at least one combustion chamber (104a-f) of the combustion engine by at least one injector (14a-f) of the fuel system, which at least one injection contributes to combustion in the combustion engine, thereby reducing pressure in the accumulator. The invention also relates to a corresponding fuel system (10).

A vehicle comprising: an internal combustion engine configured to generate an engine torque using high-gasoline content fuel; at least one fuel injector configured to deliver the high-gasoline content fuel to a cylinder of the engine; at least one heating element configured to heat the high-gasoline content fuel prior to it being delivered to the cylinder by the fuel injector; a fuel pump connected to the heating element to supply high-gasoline to the heating element, the fuel pump being configured to pressurise the high-gasoline content fuel; and an engine controller configured to control the engine torque generated by the engine and control the fuel pressure generated by the fuel pump, the engine controller using a heated-fuel behaviour model of the engine, when the fuel is being heated by the heating element(s), to: (i) control an amount of fuel delivered by the fuel injector, the heated-fuel behaviour model causing a reduced fuel injection amount for a given engine torque relative to unheated high-gasoline content fuel; and (ii) cause a higher fuel pressure to be generated by the fuel pump relative to unheated high-gasoline content fuel.

Methods and apparatuses for calibration and control of various engine subsystems using a target value approach. Under the target value approach, the control of each engine subsystem is separated or decoupled to include a set of target values, or a reference value set. A subsystem has a corresponding target determiner, which provides a target value set, or reference value set, in response to a basis variable set and optionally an overall subsystem target. The basis variable set includes parameters selected to robustly characterize the variables that affect the operation of the particular subsystem. The target determiner is optionally calibrated to provide a reference value set within specifications of the subsystem. A physical subsystem controller operates in response to the reference value set.

A fuel supply apparatus is operated so as to increase an upon-stopping fuel pressure in accordance with an increase in an upon-stopping vehicle speed, the upon-stopping fuel pressure being a fuel pressure in a state in which an internal combustion engine is intermittently stopped, the upon-stopping vehicle speed being a vehicle speed upon intermittently stopping the internal combustion engine.

A method of injecting fuel with a fuel injector includes applying a spill valve current to close a spill valve and applying a control valve current to move a control valve to an injection position. The method also includes discontinuing the application of the spill valve current to open the spill valve and preventing a return of the control valve to a non-injection position while detecting a timing when the spill valve opens.

A fuel pump includes a camshaft that rotates in accordance with operation of an engine and a tappet provided in contact the camshaft. An ECU includes an angle determination unit configured to determine whether a rotation angle from a start of rotation of the camshaft when starting the engine is under a predetermined angle required for forming an oil film on a sliding portion of the tappet, and a control unit configured to, when the rotation angle from the start of rotation of the camshaft is determined to be under the predetermined angle, execute a limit process including at least one of limiting a fuel discharge pressure of the fuel pump or limiting a rotation of the camshaft.

A system for control of an internal combustion system having subsystems, each with different response times. Subsystems may include a fuel system, an air handling system, and an aftertreatment system, each being operated in response to a set of reference values generated by a respective target determiner. Calibration of each subsystem may be performed independently. The fuel system is controlled at a first time constant. The air handling system is controlled on the order of a second time constant slower than the first time constant. The aftertreatment system is controlled on the order of a third time constant slower than the second time constant. A subsystem manager is optionally in operative communication with each target determiner to coordinate control. Generally, dynamic parameters from slower subsystems are treated as static parameters when determining reference values for controlling a faster subsystem.

In at least some implementations, a fuel pump assembly includes a fuel pump having an inlet through which fuel enters the fuel pump and a first outlet from which pressurized fuel is discharged for delivery to an engine, and a second outlet through which some of the fuel discharged from the fuel pump is routed wherein that fuel is not delivered to the engine, wherein the second outlet has a flow area that permits a flow of fuel through the second outlet that is sufficient to reduce the maximum pressure of fuel downstream of the first outlet for delivery to an engine to between 1/10th and 1/25th of the output pressure of the fuel pump without flow through O the second outlet.

In at least some implementations, a system includes a pump having an electric motor and a pump outlet, a controller coupled to the pump to vary the power provided to the motor to vary the flow rate of liquid discharged from the pump outlet, a pressure regulator having an inlet communicated with the pump outlet, a regulator outlet from which liquid is discharged from the regulator, a bypass outlet through which liquid is discharged from the regulator, and a pressure responsive valve that opens to permit liquid flow through the bypass outlet, and a flow sensor. The flow sensor is communicated with the bypass outlet to sense or determine a flow rate of liquid at or downstream of the bypass outlet, the flow sensor also communicated with the controller to provide an indication of the bypassed liquid flow rate to the controller.