Method for ascertaining an error in a fuel metering unit of an injection system

• US 8,733,323 B2
• Filed: 06/18/2007
• Issued: 05/27/2014
• Est. Priority Date: 07/18/2006
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Mueller, Andreas, Sommerer, Andreas, Becker, Bernd
• Primary Examiner(s): Cronin, Stephen K
• Assistant Examiner(s): DALLO, JOSEPH J
• Application Number:
  US12/308,639
• Publication Number:
  US 20100294247A1
• Time in Patent Office: 2,535 Days
• Field of Search: 123/446, 123/447, 123/495, 123/497
• US Class Current: 123/446
• CPC Class Codes: F02D 2041/2051 using voltage control
• CPC Class Codes: F02D 2041/2058 using information of the actual current value
• CPC Class Codes: F02D 2041/2089 detecting open circuits
• CPC Class Codes: F02D 2041/224 Diagnosis of the fuel system
• CPC Class Codes: F02D 41/20 Output circuits, e.g. for controlling currents in command coils
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method for ascertaining an error in a fuel metering unit of an injection system for an internal combustion engine, wherein the gradients of a first signal representing a physical variable and of a second signal representing a physical variable are determined, and at a predefined magnitude and/or direction of the two gradients an error is recognized.

Claims

1. A method for ascertaining an error in a fuel metering unit of an injection system for an internal combustion engine, comprising:

determining a first gradient of a first signal representing a physical variable and a second gradient of a second signal representing a physical variable; and

recognizing an error at at least one of a predefined magnitude and a predefined direction of the first and second gradients.

2. The method according to claim 1, wherein the first signal represents a setpoint pumped quantity.

3. The method according to claim 1, wherein the first signal represents a trigger signal for the fuel metering unit, the trigger signal being a voltage applied to an actuator of the fuel metering unit.

4. The method according to claim 3, wherein the trigger signal includes a duty factor of the voltage applied to the actuator of the fuel metering unit.

5. The method according to claim 1, wherein the second signal represents a current flowing through an actuator of the fuel metering unit.

6. The method according to claim 1, wherein an error is recognized when the first and second gradients are opposite to each other within a time window.

7. The method according to claim 6, wherein an error is recognized when the first gradient within the time window is positive and the second gradient within the time window is negative.

8. The method according to claim 1, wherein the error is a circuit of an actuator of the fuel metering unit interrupted at least from time to time.

9. A device for ascertaining an error in a fuel metering unit of an injection system for an internal combustion engine, comprising:

a control unit for determining a first gradient of a first signal representing a physical variable and a second gradient of a second signal representing a physical variable, and for recognizing an error at at least one of a predefined magnitude and a predefined direction of the first and second gradients.

10. A computer-readable medium containing a computer program which, when executed by a processor, performs the following method for ascertaining an error in a fuel metering unit of an injection system for an internal combustion engine:

determining a first gradient of a first signal representing a physical variable and a second gradient of a second signal representing a physical variable; and

recognizing an error at at least one of a predefined magnitude and a predefined direction of the first and second gradients.