Fuel injector control including state selection based on a control signal characteristic

1. A fuel injector control system, comprising:

a driver that is configured to supply electrical power to a fuel injector;

and

a controller configured to

control the driver by implementing a predetermined sequence of a plurality of predefined states for an injection cycle, the plurality of predefined states each include parameters for supplying electrical power to a fuel injector, and

select one of the states to implement as a next one of the states in the sequence based on a characteristic of an activation signal and information indicative of the state corresponding to the characteristic of the activation signal.

2. The fuel injector control system of claim 1 , wherein

the characteristic comprises a signal interrupt;

the controller is configured to interrupt an active one of the states in response to the signal interrupt; and

the controller is configured to alter control of the driver from the predetermined sequence for a remainder of the injection cycle in response to the signal interrupt.

3. The fuel injector control system of claim 2 , wherein the controller is configured to cause the driver to reduce current supplied to a fuel injector during a remainder of the injection cycle compared an amount of current required by a portion of the predetermined sequence corresponding to the remainder of the predetermined injection cycle.

4. The fuel injector control system of claim 2 , wherein

the activation signal has a first value indicating that the sequence of states should be implemented to provide power to a fuel injector;

the characteristic comprises a second, different value of the activation signal; and

the characteristic comprises a duration of time when the activation signal has the second, different value.

5. The fuel injector control system of claim 4 , wherein

the first value corresponds to a logical high; and

the second value corresponds to a logical low.

6. The fuel injector control system of claim 2 , wherein the controller changes to a different sequence of the states from a remainder of the predetermined sequence in response to detecting the second value during the injection cycle.

7. The fuel injector control system of claim 1 , wherein the characteristic defines an index signal as an indicator of the one of the states to select as an initial state of the predetermined sequence at a beginning of the injection cycle.

8. The fuel injector control system of claim 7 , wherein

there are a plurality of index signals that each indicate a corresponding initial state; and

the characteristic of each index signal is different than the characteristic of the other index signals.

9. The fuel injector control system of claim 7 , wherein the characteristic comprises an index signal duration.

10. The fuel injector control system of claim 9 , wherein

the controller is configured to determine the initial one of the states based on the duration of a recognized index signal; and

the controller is configured to recognize an injection cycle start command based on a duration of the activation signal that exceeds a longest one of the index signal durations.

11. The fuel injector control system of claim 10 , wherein

the controller is configured to control the driver to initiate a fuel injection cycle after a delay from a beginning of the activation signal; and

the delay is longer than the longest one of the index signal durations.

12. A method of controlling a fuel injector based on a plurality of predefined states that each include parameters for supplying electrical power to a fuel injector, the method comprising:

controlling power supplied to a fuel injector according to a predetermined sequence of the states for an injection cycle, and

selecting one of the states to implement as a next one of the states in the sequence based on a characteristic of an activation signal and information indicative of the state corresponding to the characteristic of the activation signal.

13. The method of claim 12 , wherein the characteristic comprises a signal interrupt and the method comprises

interrupting an active one of the states in response to the signal interrupt; and

altering control of the driver from the predetermined sequence for a remainder of the injection cycle in response to the signal interrupt.

14. The method of claim 13 , wherein

the activation signal has a first value indicating that the sequence of states should be implemented to provide power to a fuel injector;

the characteristic comprises a second, different value of the activation signal; and

the characteristic comprises a duration of time when the activation signal has the second, different value.

15. The method of claim 14 , wherein

the first value corresponds to a logical high; and

the second value corresponds to a logical low.

16. The method of claim 13 , comprising changing to a different sequence of the states from a remainder of the predetermined sequence in response to detecting the second value during the injection cycle.

17. The method of claim 12 , wherein the characteristic defines an index signal as an indicator of the one of the states to select as an initial state of the predetermined sequence at a beginning of the injection cycle.

18. The method of claim 17 , wherein

there are a plurality of index signals that each indicate a corresponding initial state; and

the characteristic of each index signal is different than the characteristic of the other index signals.

19. The method of claim 17 , wherein the characteristic comprises an index signal duration and the method comprises

determining the initial one of the states based on the duration of a recognized index signal; and

recognizing an injection cycle start command based on a duration of the activation signal that exceeds a longest one of the index signal durations.

20. The method of claim 19 , comprising initiating a fuel injection cycle after a delay from a beginning of the activation signal, wherein the delay is longer than the longest one of the index signal durations.