Claims
- 1. A method for controlling fuel injection, comprising:
measuring a parameter corresponding to a ramp time between a voltage application time and an actual injection start time, wherein the voltage application time corresponds to a time when an applied voltage is applied to an injector coil and wherein the actual injection start time corresponds to a time when a load current through the injector coil reaches a desired level; detecting a difference between the actual injection start time and a desired injection start time; and adjusting the voltage application time to shift the actual injection start time to the desired injection start time.
- 2. The method of claim 1, wherein the measuring step comprises:
measuring the applied voltage as the parameter; and comparing the applied voltage with a nominal voltage.
- 3. The method of claim 2, wherein the measuring, comparing and adjusting steps are conducted every injection cycle.
- 4. The method of claim 2, wherein the adjusting step comprises:
retarding the voltage application time if the applied voltage is greater than the nominal voltage; advancing the voltage application time if the applied voltage is less than the nominal voltage; and maintaining the voltage application start time if the parameter indicates the actual injection start time is the same as the desired injection start time.
- 5. The method of claim 1, wherein the measuring step comprises measuring the ramp time for a first injection cycle as the parameter, and wherein the adjusting step comprises shifting the voltage application time for a second injection cycle based on the measured ramp time.
- 6. The method of claim 5, wherein the adjusting step comprises:
retarding the voltage application time if the measured ramp time causes the actual injection start time to be before the desired injection start time; advancing the voltage application start time if the measured ramp time causes the actual injection start time to be after the desired injection start time; and maintaining the voltage application start time if the parameter indicates the actual injection start time is the same as the desired injection start time;.
- 7. The method of claim 5, further comprising repeating the measuring and adjusting steps for every cycle during fuel injection operation.
- 8. The method of claim 5, wherein the first injection cycle and the second injection cycle are consecutive cycles.
- 9. A method for controlling fuel injection for a cylinder in an engine, the fuel injection being conducted over a plurality of injection cycles, the method comprising:
measuring a parameter corresponding to a ramp time between a voltage application time and an actual injection start time for the cylinder, wherein the voltage application time corresponds to a time when an applied voltage is applied to an injector coil associated with the cylinder and wherein the actual injection start time corresponds to a time when a load current through the injector coil reaches a desired level; retarding the voltage application start time if the parameter indicates that the actual injection start time is before the desired injection start time; advancing the voltage application start time if parameter indicates that the actual injection start time is after the desired injection start time; maintaining the voltage application start time if the parameter indicates the actual injection start time is the same as the desired injection start time; and repeating the measuring step and applying the retarding step, the advancing step, or the maintaining step over consecutive injection cycles.
- 10. The method of claim 9, wherein the parameter is the applied voltage, and wherein the method further comprises comparing the applied voltage with a nominal voltage to determine whether to conduct the retarding step, the advancing step, or the maintaining step.
- 11. The method of claim 9, wherein the measuring step comprises measuring the ramp time for a first injection cycle, and wherein the retarding step, the advancing step, or the maintaining step are applied in a second injection cycle directly after the first injection cycle based on the measured ramp time.
- 12. A fuel injection system for an engine, comprising:
an applied voltage source; a fuel injector coil; and a processor coupled to the applied voltage source, the processor having an algorithm comprising
measuring a parameter corresponding to a ramp time between a voltage application time and an actual injection start time for the cylinder, wherein the voltage application time corresponds to a time when an applied voltage is applied to an injector coil associated with the cylinder and wherein the actual injection start time corresponds to a time when a load current through the injector coil reaches a desired level; retarding the voltage application time if the parameter indicates that the actual injection start time is before the desired injection start time; advancing the voltage application start time if parameter indicates that the actual injection start time is after the desired injection start time; maintaining the voltage application start time if the parameter indicates the actual injection start time is the same as the desired injection start time; and repeating the measuring step and applying the retarding step, the advancing step, or the maintaining step over consecutive injection cycles.
- 13. The fuel injection system of claim 12, wherein the measured parameter is the applied voltage on the injector coil, and wherein the algorithm compares the applied voltage with a nominal voltage to determine whether to conduct the retarding step, the advancing step, or the maintaining step.
- 14. The fuel injection system of claim 12, wherein the algorithm measures the applied voltage on the injector coil and compares the applied voltage with a nominal voltage.
- 15. The fuel injection system of claim 12, wherein the algorithm measures the ramp time for a first injection cycle and applies the retarding step, the advancing step, or the maintaining step in a second injection cycle directly after the first injection cycle based on the measured ramp time.
- 16. A current regulator that controls a load current through a load, comprising:
a high voltage source; a low voltage source; a first switch that selectively connects the high voltage source and the low voltage source to the load; a second switch that controls a regulation mode of the low voltage source based on feedback dependent on a load current through the load; and a drive circuit that receives a command signal and controls the first switch and the second switch based on the command signal, wherein the first switch selects the first voltage source to change the load current and selects the low voltage source to maintain the load current, and wherein the second switch causes the low voltage source to be regulated by an output voltage across the load when the low voltage source is not connected to the load and causes the low voltage source to be regulated by the load current when the low voltage source is connected to the load.
- 17. The current regulator of claim 16, further comprising:
a voltage comparator; and a current comparator, wherein the second switch connects the voltage comparator to the low voltage source when the low voltage source is not connected to the load, and wherein the second switch connects the current comparator to the low voltage source when the low voltage source is connected to the load.
- 18. The current regulator of claim 17, wherein the voltage comparator inhibits operation of the current regulator when an output voltage across the load exceeds a reference voltage and wherein the current comparator inhibits operation of the current regulator when the load current exceeds a reference current.
- 19. An adaptive voltage source for a current regulator for a load, comprising:
a voltage comparator; a current comparator; and a switch that controls a regulation mode of the voltage source based on feedback dependent on a load current through the load, wherein the switch connects the voltage comparator to the low voltage source when the low voltage source is not connected to the load and connects the current comparator to the low voltage source when the low voltage source is connected to the load.
RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional Patent Application Serial Nos. 60/368,277, 60/380,108, and 60/380,705, filed Mar. 28, 2002, May 6, 2002, and May 15, 2002, respectively.
Provisional Applications (3)
|
Number |
Date |
Country |
|
60368277 |
Mar 2002 |
US |
|
60380108 |
May 2002 |
US |
|
60380705 |
May 2002 |
US |