Feedback tailoring of fuel injector drive signal

• US 6,497,221 B1
• Filed: 11/06/2000
• Issued: 12/24/2002
• Est. Priority Date: 11/06/2000
• Status: Active Grant

• Current Assignee: Robert Bosch Corporation (Robert Bosch GmbH)
• Original Assignee: Robert Bosch Corporation (Robert Bosch GmbH)
• Inventors: Nowland, Maria Catherine, French, Richard Mark
• Primary Examiner(s): Wolfe, Willis R.
• Assistant Examiner(s): Hoang, Johnny H.
• Application Number:
  US09/707,174
• Time in Patent Office: 778 Days
• Field of Search: 123/478, 123/490, 123/494, 731/19.A, 361/152, 361/153, 361/154
• US Class Current: 123/478
• CPC Class Codes: F02M 51/0682 the body being hollow and its interior communicating with the fuel flow F02M51/0675 takes precedence
• CPC Class Codes: F02M 65/00 Testing fuel-injection apparatus, e.g. testing injection timing testing of ignition F02P17/00; measuring fuel consumption G01F9/00; Cleaning of fuel-injection apparatus
• CPC Class Codes: F02M 65/005 Measuring or detecting injection-valve lift, e.g. to determine injection timing
• CPC Class Codes: H01F 2007/185 with armature position measurement

Abstract

A method and system of adjusting a drive signal to a fuel injector or other electromagnetic device having an electromagnetic coil and an armature. The system includes an amplifier coupled to the electromagnetic coil by a link. A sensor is coupled to the link to measure the electric signal travelling through the link and produces an output signal based on the sensed electric signal. A controller coupled to the amplifier and to the sensor produces a drive signal for the electromagnetic coil. The controller determines the position of the armature based on the output signal of the sensor, and modifies the drive signal based on the position of the armature. The method includes sending a drive signal to a fuel injector, sensing whether the armature contacts the body of the fuel injector, running the injector with the drive signal if no contact is detected, and upon sensing contact between the armature and the body, modifying the drive signal. If the armature contacts the body of the fuel injector when driven by the modified drive signal, the controller modifies the modified drive signal until no contact between the armature and the body is detected. Then, the injector is run using the modified signal. The drive signal if preferably modified by notching the drive signal or stepping the drive signal.

Claims

1. A system for controlling an electromagnetic coil and an armature, the system comprising:

an amplifier coupled to the electromagnetic coil by a link;

a sensor coupled to the link to measure an electric signal travelling through the link and operable to produce an output signal; and

a controller coupled to the amplifier and to the sensor and operable to produce a drive signal for the electromagnetic coil, the controller further operable to determine a position of the armature based on the output signal of the sensor, wherein the drive signal is modified based on the position of the armature and the drive signal is notched such that it has an opening notch and a closing notch.

2. A system as claimed in claim 1, wherein the amplifier is a transistor.

3. A system as claimed in claim 1, wherein the sensor is a voltage sensor.

4. A system as claimed in claim 1, wherein the sensor is a current sensor.

5. A system as claimed in claim 4, wherein a location and duration of the opening and closing notches are controlled by the controller.

6. A system as claimed in claim 1, wherein the drive signal is modified to have an opening step and a closing step.

7. A system as claimed in claim 6, wherein a height and duration of the opening and closing steps are controlled by the controller.

8. A system as claimed in claim 1, wherein the controller is an engine control unit.

9. A method of modifying a drive signal to a fuel injector having an armature and a body, the method comprising:

sending the drive signal to a fuel injector;

sensing whether the armature contacts the body of the fuel injector;

running the fuel injector with the drive signal if no contact is detected;

upon sensing contact between the armature and the body, modifying the drive signal;

repeating the acts of sensing contact and modifying the drive signal until no contact between the armature and the body is detected; and

running the fuel injector with the modified drive signal.

10. A method as claimed in claim 9, wherein the act of modifying the drive signal includes notching the drive signal.

11. A method as claimed in claim 10, wherein notching the drive signal includes creating an opening notch and a closing notch.

12. A method as claimed in claim 11, wherein notching the drive signal includes controlling a location and duration of the opening and closing notches.

13. A method as claimed in claim 9, wherein the act of modifying the drive signal includes stepping the drive signal.

14. A method as claimed in claim 13, wherein stepping the drive signal includes creating an opening step and a closing step.

15. A method as claimed in claim 14, wherein stepping the drive signal includes controlling a height and duration of the opening and closing steps.

16. A method as claimed in claim 9, wherein the act of sensing whether the armature contacts the body of the fuel injector includes sensing a current of the drive signal.

17. A method as claimed in claim 9, wherein the act of sensing whether the armature contacts the body of the fuel injector includes sensing a voltage of the drive signal.

18. A method as claimed in claim 9, wherein the act of sending the drive signal to the fuel injector involves generating a square wave.

19. A system for controlling an electromagnetic coil and an armature, the system comprising:

an amplifier coupled to the electromagnetic coil by a link;

a sensor coupled to the link to measure a signal travelling through the link and operable to produce an output signal;

a controller coupled to the amplifier and to the sensor and operable to produce a drive signal for the electromagnetic coil, the controller further operable to determine a position of the armature based on the output signal of the sensor, wherein the drive signal is modified by being either notched or stepped based on the position of the armature and the drive signal is notched such that it has an opening notch and a closing notch.

20. A system as claimed in claim 19, wherein the amplifier is a transistor.

21. A system as claimed in claim 19, wherein the sensor is a voltage sensor.

22. A system as claimed in claim 19, wherein the sensor is a current sensor.

23. A system as claimed in claim 19, wherein a location and duration of the opening and closing notches are controlled by the controller.

24. A system as claimed in claim 19, wherein the drive signal is modified to have an opening step and a closing step.

25. A system as claimed in claim 19, wherein a height and duration of the opening and closing steps are controlled by the controller.

26. A system as claimed in claim 19, wherein the controller is an engine control unit.

27. A system for controlling an electromagnetic coil and an armature, the system comprising:

an amplifier operable to be coupled to the electromagnetic coil by a link;

a sensor operable to be coupled to the link to sense an electric signal travelling through the link and operable to produce an output signal; and

a controller operable to be coupled to the amplifier and to the sensor and operable to produce a drive signal for the electromagnetic coil, the controller further operable to determine a position of the armature based on the output signal of the sensor, wherein the drive signal is modified based on the position of the armature and the drive signal is notched such that it has an opening notch and a closing notch.