Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, engine volumetric efficiency actuators are adjusted in response to a request to activate engine cylinders so that engine intake manifold pressure is drawn down quickly toward its normal state at the engine's present speed and torque.

A method, control system, and variable valve timing system are provided for controlling an actuator that can be switched into an on state and an off state with pulse width modulation. The systems and method include controls configured to determine an actual system parameter on a first time schedule and a desired system parameter on a second time schedule. On a third time schedule, a position error difference between the actual system parameter and the desired system parameter is determined. The third time schedule is configured to begin and to determine the position error difference each time that the actual system parameter is determined and each time that the desired system parameter is determined. A desired duty cycle is determined, and a duty cycle command is sent to a pulse width modulation output unit.

A method of controlling intake and exhaust cam phase in an internal combustion engine includes sensing an engine speed and an engine load of the internal combustion engine, sensing or estimating a wall temperature of a cylinder of the internal combustion engine, utilizing the engine speed and the engine load in one or more lookup tables based on the cylinder wall temperature to determine intake phaser constraint values and exhaust phaser constraint values for cold operation of the internal combustion engine, and transitioning the intake phaser constraint values and the exhaust phaser constraint values for cold operation to intake phaser constraint values and exhaust phaser constraint values based on one or more lookup tables for normal hot operation of the internal combustion engine.

Various embodiments of the teachings herein include a method for controlling a cam using an ECU (electronic control unit) comprising: learning a holding region in which linearity is not ensured by increasing or decreasing a PWM signal while the cam maintains a holding state; based on the results of the learning, generating a final PWM signal; and transmitting the final PWM signal to an oil control valve. The final PWM signal comprises a sum of a minimum PWM signal for the cam to leave the holding region and a control PWM signal for the cam to reach a desired position.

An oil supply control device includes: a memory which stores first master data constituted by predetermined control value; a hydraulic controller which outputs the control value to an adjusting device to cause a hydraulic pressure to coincide with a target hydraulic pressure; and a determination portion which determines whether or not a first difference between an output control value and the control value of the first master data lies within a predetermined allowable range, wherein the hydraulic controller starts to control the adjusting device with use of the control value of the first master data, when the first difference lies within the allowable range, and starts to control the adjusting device with use of the control value of second master data, when the first difference does not lie within the allowable range, the control value of the second master data causing the first difference to lie within the allowable range.

Methods and systems are provided for controlling a variable camshaft timing system. In one example, a method may include actuating a camshaft phaser with a camshaft duty cycle determined based on a sampled camshaft position and an estimated camshaft position, the estimated camshaft position determined based on a previously determined camshaft duty cycle.

A method of operating a cam shaft phaser including a stator including a radially inwardly extending protrusion, a rotor including a radially outwardly extending protrusion and a slot in the radially outwardly extending protrusion, a cover non-rotatably connected to the stator, a chamber circumferentially bounded by the radially inwardly extending protrusion and the radially outwardly extending protrusion, a pin disposed in the slot, and a first channel connecting the chamber with the slot. The method comprises: blocking, with the locking pin, rotation of the rotor with respect to the stator; applying pulse width modulation voltage to a control valve as a non-rectangular wave form; flowing fluid from the control valve to the chamber; flowing the fluid through the first channel to the slot; axially displacing the locking pin with the fluid; disengaging the locking pin from the cover; and rotating the rotor with respect to the stator.

A method for operating an engine system is provided, the method may include varying a compression ratio of a cylinder by selectively releasing combustion charge from the cylinder through a cylinder bleed valve of a cylinder head, the cylinder bleed valve coupled to a bleed manifold with a turbine-generator, and varying combustion charge flow through a turbine-generator bypass conduit bypassing the turbine-generator based on engine operating conditions. In this way, the compression ratio may be varied by selectively bleeding combustion charge from the cylinder based on engine operating conditions to promote better engine performance. Additionally, the combustion charge bleed from the cylinder can routed around a turbine-generator to increase combustion efficiency during certain operating conditions, such as during start-up, to further improve engine performance.

A control unit for an internal combustion engine is configured for suppressing knocking phenomenon with reduction of overlap, while maintaining an opening timing of an exhaust valve at the time of low-rotation, high-load state. A valve opening/closing timing control apparatus includes a phase adjustment mechanism configured to vary a relative rotational phase between a driving side rotary body rotatable in synchronism with a crankshaft of the internal combustion engine and a driven side rotary body rotatable together with an exhaust cam shaft. After an opening timing of the exhaust valve, an advancing operation is effected for displacing the relative rotational phase in the advancing direction relative to the opening timing.

A method of phasing the opening and closing of internal combustion engine intake and exhaust valves relative to the rotation of the crankshaft is based upon changes in engine speed, engine load and ambient relative humidity. During certain conditions of higher humidity, in order to maintain good combustion stability and thus overall engine operation, it is necessary to reduce intake and exhaust valve overlap by adjusting the phase of the intake and exhaust camshafts. This is achieved by utilizing a set of cam position reference values and constraints based upon engine speed, engine load and humidity that are contained in lookup tables that adjust and limit cam position and valve overlap. Generally speaking, in order to maintain optimum engine performance, intake and exhaust valve overlap is reduced with higher ambient humidity and vice versa.