System and method of adjusting actuation timing of valves in a piston engine

1. A system that provides adjustable actuation timing of at least one valve ( 16 ) in a piston engine, the system comprising:

a position sensor ( 12 ) taking position readings of a valve ( 16 ) as the valve ( 16 ) actuates in the piston engine; and

a variable valve actuation assembly ( 10 ) equipped at the valve ( 16 ) of the piston engine to control actuation timing of the valve ( 16 );

wherein actuation timing of the valve ( 16 ) is adjustable based at least in part upon at least one position reading of the valve ( 16 ) taken by the position sensor ( 12 );

wherein the position sensor ( 12 ) takes position readings of the valve ( 16 ) of a first cylinder of the piston engine;

a second position sensor ( 12 ) taking position readings of a second valve ( 16 ) of a second cylinder of the piston engine as the second valve ( 16 ) actuates at the second cylinder; and

a second variable valve actuation assembly ( 10 ) equipped at the second valve ( 16 ) of the second cylinder to control actuation timing of the second valve ( 16 );

wherein the second position sensor ( 12 ) takes a position reading of the second valve ( 16 ) before slowdown occurs adjacent a closed position, the position reading is referenced to a predefined position of the second valve ( 16 ), and actuation timing of the second valve ( 16 ) is adjustable based at least in part upon the position reading being referenced to the predefined position.

2. The system of claim 1 , wherein the position sensor ( 12 ) takes a first position reading of the valve ( 16 ) when the valve ( 16 ) is at a closed position, the position sensor ( 12 ) takes a second position reading of the valve ( 16 ) when the valve ( 16 ) is at a fully open position, and wherein the first and second position readings are used for calibration to relate subsequent position sensor readings to valve position.

3. The system of claim 2 , wherein the position sensor ( 12 ) takes a third position reading of the valve ( 16 ) before slowdown occurs adjacent the closed position, the third position reading is referenced to a predefined position of the valve ( 16 ), and actuation timing of the valve ( 16 ) is adjustable based at least in part upon the third position reading being referenced to the predefined position.

4. The system of claim 3 , wherein, after adjustments to actuation timing have been made to the valve ( 16 ) based upon the third position reading being referenced to the predefined position, the position sensor ( 12 ) takes a fourth position reading of the valve ( 16 ) before slowdown occurs adjacent the closed position, the fourth position reading is referenced to the predefined position of the valve ( 16 ), and actuation timing of the valve ( 16 ) is adjustable based at least in part upon the fourth position reading being referenced to the predefined position.

5. The system of claim 1 , wherein position readings of the valve ( 16 ) taken by the position sensor ( 12 ) are referenced to predefined positions of the valve ( 16 ) in order to monitor the functionality of the variable valve actuation assembly ( 10 ).

6. The system of claim 1 , wherein the position sensor ( 12 ) is a variable inductance position sensor ( 12 ).

7. The system of claim 1 , wherein the variable valve actuation assembly ( 10 ) is a lost motion assembly ( 10 ) that comprises a master piston ( 18 ), a slave piston ( 26 ), a solenoid valve ( 20 ), an accumulator ( 22 ), and a fluid-flow circuit ( 28 ), the fluid-flow circuit ( 28 ) fluidly communicating the master piston ( 18 ), slave piston ( 26 ), solenoid valve ( 20 ), and accumulator ( 22 ).

8. The system of claim 7 , wherein actuation timing of the valve ( 16 ) is adjustable via activations and deactivations of the solenoid valve ( 20 ).

9. The system of claim 1 , further comprising an electronic control unit ( 14 ) receiving input from the position sensor ( 12 ), and wherein actuation timing of the valve ( 16 ) is adjustable based at least in part upon the received input.

10. A method of adjusting actuation timing of at least one valve ( 16 ) in a piston engine via at least one variable valve actuation assembly ( 10 ), the method comprising:

taking a first position reading of a valve ( 16 ) in the piston engine when the valve ( 16 ) is at a closed position;

taking a second position reading of the valve ( 16 ) in the piston engine when the valve ( 16 ) is at a fully open position;

using the first and second position readings to calibrate subsequent position readings of the valve ( 16 );

taking a third position reading of the valve ( 16 ) before slowdown occurs adjacent the closed position;

referencing the third position reading to a predefined position of the valve ( 16 ); and

making adjustments to actuation timing of the valve ( 16 ), if called for, based at least in part upon the third position reading being referenced to the predefined position.

11. The method of claim 10 , further comprising:

after adjustments to the actuation timing are made based upon the third position reading being referenced to the predefined position, taking a fourth position reading of the valve ( 16 ) before slowdown occurs adjacent the closed position;

referencing the fourth position reading to the predefined position of the valve ( 16 ); and

making adjustments to the actuation timing of the valve ( 16 ), if called for, based at least in part upon the fourth position reading being referenced to the predefined position.

12. The method of claim 10 , wherein the method of adjusting actuation timing of valves ( 16 ) in the piston engine via variable valve actuation assemblies ( 10 ) is performed on a plurality of valves ( 16 ) in the piston engine and at a plurality of cylinders in the piston engine, the plurality of valves ( 16 ) having variable valve actuation assemblies ( 10 ) equipped thereat.

13. A system that provides adjustable actuation timing of valves ( 16 ) in a piston engine, the system comprising:

a first position sensor ( 12 ) located near a first valve ( 16 ) of a first cylinder of the piston engine;

a first lost motion assembly ( 10 ) actuating the first valve ( 16 ), the first lost motion assembly ( 10 ) including a first master piston ( 18 ), a first slave piston ( 26 ), and a first solenoid valve ( 20 );

a second position sensor ( 12 ) located near a second valve ( 16 ) of a second cylinder of the piston engine;

a second lost motion assembly ( 10 ) actuating the second valve ( 16 ), the second lost motion assembly ( 10 ) including a second master piston ( 18 ), a second slave piston ( 26 ), and a second solenoid valve ( 20 ); and

an electronic control unit ( 14 ) receiving a first position reading from the first position sensor ( 12 ) of the first valve ( 16 ) before slowdown occurs adjacent a closed position, the first position reading referenced to a first predefined position, and actuation timing of the first valve ( 16 ) is adjustable via activation and deactivation of the first solenoid valve ( 20 ) based at least in part upon the first position reading being referenced to the first predefined position, and the electronic control unit ( 14 ) receiving a second position reading from the second position sensor ( 12 ) of the second valve ( 16 ) before slowdown occurs adjacent a closed position, the second position reading referenced to a second predefined position, and actuation timing of the second valve ( 16 ) is adjustable via activation and deactivation of the second solenoid valve ( 20 ) based at least in part upon the second position reading being referenced to the second predefined position.

14. The system of claim 13 , wherein the first position sensor ( 12 ) takes a first calibration position reading of the first valve ( 16 ) when a base ( 38 ) of a first cam ( 34 ) engages the first master piston ( 18 ), the first position sensor ( 12 ) takes a second calibration position reading of the first valve ( 16 ) when a lobe ( 40 ) of the first cam ( 34 ) engages the first master piston ( 18 ) at a peak of the lobe ( 40 ), the first and second calibration position readings of the first valve ( 16 ) used to relate subsequent position readings to positions of the first valve ( 16 ), and the second position sensor ( 12 ) takes a first calibration position reading of the second valve ( 16 ) when a base ( 38 ) of a second cam ( 34 ) engages the second master piston ( 18 ), the second position sensor ( 12 ) takes a second calibration position reading of the second valve ( 16 ) when a lobe ( 40 ) of the second cam ( 34 ) engages the second master piston ( 18 ) at a peak of the lobe ( 40 ), the first and second calibration position readings of the second valve ( 16 ) used to relate subsequent position readings to positions of the second valve ( 16 ).