System and method for calibrating variable actuation system

A method of calibrating a variable valve actuation system, comprising:

• moving an engine valve from a first position where the engine valve blocks a flow of fluid to a second position where the engine valve passes a flow of fluid;
• trapping fluid in a valve actuator to prevent the engine valve from returning to the first position;
• transmitting a signal to cause release the trapped fluid from the valve actuator to allow the engine valve to return to the first position, wherein the transmitted signal is a reduction in a magnitude of a current waveform;
• monitoring the current transmitted to a directional control valve;
• determining when the engine valve returns to the first position;
• and
• determining a time parameter indicative of an elapsed time between the transmission of the signal and movement of the engine valve to the first position.

A method of calibrating a variable valve actuation system, comprising:

• moving an engine valve from a first position where the engine valve blocks a flow of fluid to a second position where the engine valve passes a flow of fluid;
• trapping fluid in a valve actuator to prevent the engine valve from returning to the first position;
• transmitting a signal to release the trapped fluid from the valve actuator to allow the engine valve to return to the first position;
• determining when the engine valve returns to the first position;
• determining a time parameter indicative of an elapsed time between the transmission of the signal and movement of the engine valve to the first position;
• and
• adjusting a second signal transmitted to the valve actuator based on the time parameter.

An engine valve actuation system, comprising:

• an engine valve moveable between a first position where the engine valve blocks a flow of fluid and a second position where the engine valve passes a flow of fluid;
• a spring engaged with the engine valve and biasing the engine valve towards the first position;
• a valve actuator having a piston adapted to operatively engage the engine valve and an actuator chamber, the valve actuator adapted to trap fluid in the actuator chamber to thereby prevent the engine valve from returning to the first position;
• a sensor configured to measure the displacement of the valve actuator and to provide an indication when the engine valve is at the first position;
• and
• a controller configured to deliver a control signal to the valve actuator to release fluid trapped in the actuator chamber to thereby return the engine valve to the first position and to receive said indication from the sensor, the controller determining an elapsed time between the delivery of the control signal and movement of the engine valve to the first position.

An engine valve actuation system, comprising:

• an engine valve moveable between a first position where the engine valve blocks a flow of fluid and a second position where the engine valve passes a flow of fluid;
• a spring engaged with the engine valve and biasing the engine valve towards the first position;
• a valve actuator having a piston adapted to operatively engage the engine valve and an actuator chamber, the valve actuator adapted to trap fluid in the actuator chamber to thereby prevent the engine valve from returning to the first position,
• a sensor configured to provide an indication when the engine valve is at the first position, wherein the sensor measures at least one of a fluid pressure in the actuator chamber and a fluid flow rate from the actuator chamber;
• and
• a controller configured to deliver a control signal to the valve actuator to release fluid trapped in the actuator chamber to thereby return the engine valve to the first position and to receive said indication from the sensor, the controller determining an elapsed time between the delivery of the control signal and movement of the engine valve to the first position.

An engine, comprising:

• an engine block defining a cylinder;
• a piston slidably disposed within the cylinder;
• an engine valve associated with the cylinder and moveable between a first position where the engine valve blocks a flow of fluid and a second position where the engine valve passes a flow of fluid;
• a cam assembly configured to move the at least one engine valve between the first and second positions;
• a spring engaged with the engine valve and biasing the engine valve towards the first position;
• a valve actuator having a piston adapted to operatively engage the engine valve and an actuator chamber, the valve actuator adapted to trap fluid in the actuator chamber to thereby prevent the engine valve from returning to the first position,
• a sensor configured to deliver a positional signal in response to the engine valve being at the first position;
• and
• a controller connected to the sensor and configured to deliver a signal to cause the valve actuator to release fluid trapped in the actuator chamber to thereby return the engine valve to the first position, the controller determining a time parameter indicative of an elapsed time between the delivery of the signal and the return of the engine valve to the first position.