Active valve and methods of operation thereof

1. A method for operating a valve, the method comprising the steps of:

Holding a flow determining component in a position that closes a passageway between an inlet and an outlet of the valve;

providing a plurality of actuating signals to a movable element of a linear motor;

incrementally controlling, in a predetermined manner, movement of the movable element, the movement being incrementally controlled using the plurality of actuating signals;

contacting the flow determining component with an actuating element connected to the movable element;

and moving, as a result of the contact, the flow determining component away from the position that closes the passageway;

wherein the valve is operated by a change in the position of the flow determining component,

wherein incrementally controlling movement of the movable element comprises:

providing an arming signal to the movable element, said arming signal being capable of closing a gap in a thrust path between a motor shaft of the linear motor and the flow determining component while the flow determining component is held in the position that closes the passageway between the inlet and the outlet of the valve;

providing an actuating opening signal to the movable element, the actuating opening signal being capable of providing a force, transmitted by the actuating element in contact with the flow determining component, sufficient to place the flow determining component in a condition allowing flow; and

limiting a rate-of-rise of the actuating opening signal so as to achieve a controlled rate of opening.

2. The method of claim 1 further comprising the step of: retracting the movable element and the actuating element connected thereto away from the flow determining component.

3. The method of claim 2 wherein the step of incrementally controlling in the predetermined manner the movement of the movable element comprises the step of: moving, from a retracted position, in an incrementally controlled manner, the movable element until the actuating element connected thereto contacts the flow determining component.

4. The method of claim 1 wherein the condition allowing flow comprises a force balance such that the flow determining component moves to an open position in response to changes in fluid pressure.

5. The method of claim 1 wherein the condition allowing flow comprises a force balance such that the flow determining component is held at an open position.

6. The method of claim 1 wherein the step of incrementally controlling in the predetermined manner the movement of the movable element further comprises the step of providing at least one actuating overtravel signal to the movable element, the at least one actuating overtravel signal being capable of providing a force, transmitted by the actuating element in contact with the flow determining component, sufficient to move the flow determining component to a limit position.

7. The method of claim 1 wherein the step of incrementally controlling in the predetermined manner the movement of the movable element further comprises the step of providing at least one positioning closing signal to the movable element, the at least one positioning closing signal being capable of causing the movable element, and the actuating element connected thereto, to move to a position at which the flow determining component does not allow flow.

8. The method of claim 1 wherein the step of incrementally controlling in the predetermined manner the movement of the movable element comprises the steps of: (a) retracting the movable element and the actuating element connected thereto away from the flow determining component; and (b) moving, from a retracted position, in an incrementally controlled manner, the movable element until the flow determining component is in an open position.

9. The method of claim 8 wherein the incrementally controlled manner produces a force acting on the flow determining, component that is greater than a steady state force.

10. The method of claim 8 wherein the predetermined manner of incrementally controlling the movement of the movable element further comprises the step of repeating steps (a) and (h) a predetermined number of repetitions.

11. The method of claim 1 , wherein limiting the rate-of-rise of the actuating opening signal comprises limiting the rate-of-rise of the actuating opening signal such that the plurality of actuating signals have a signal profile that is not rectangular.

12. The method of claim 11 , wherein the signal profile is substantially trapezoidal.

13. The method of claim 1 , wherein the step of providing the actuating opening signal coincides with a depressurization of a pump cylinder.

14. The method of claim 1 , wherein limiting the rate-of-rise of the actuating opening signal comprises providing a sequence of commanded current values.

15. The method of claim 1 ,

wherein the step of incrementally controlling comprises the steps of:

providing the actuating opening signal, said actuating opening signal having a predetermined time duration and being capable of achieving opening of the valve;

providing an open state signal capable of maintaining the valve in a predetermined open state, said open state signal being of another predetermined time duration; and

providing an actuating closing signal capable of achieving closing of the valve.

16. The method of claim 15 , wherein the step of incrementally controlling comprises the step of:

limiting a rate-of-change of the actuating closing signal so as to achieve a controlled rate of closure.

17. The method of claim 15 , further comprising the step of providing a second arming signal, after achieving closing of the valve, said second arming signal being capable of closing a gap in the thrust path between the motor shall of the linear motor and the flow determining component while the flow determining component is held in the position that closes the passageway between inlet and outlet of the valve, thereby enabling the movable element to respond to an opening command with reduced time latency.