Method for diagnosing an internal combustion engine in a motor vehicle

• US 20080134789A1
• Filed: 11/20/2007
• Published: 06/12/2008
• Est. Priority Date: 11/22/2006
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Becker, Markus, Schneider, Marcus, Scheuerle, Thomas
• Granted Patent: US 7,971,475 B2
• Time in Patent Office: Days
• US Class Current: 73/587
• CPC Class Codes: F02D 2041/288 for performing a transformation into the frequency domain, e.g. Fourier transformation
• CPC Class Codes: F02D 2200/025 Engine noise, e.g. determined by using an acoustic sensor
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method for diagnosing an internal combustion engine in a motor vehicle having at least one sensor unit, including at least one sound receiver, the sound receiver converting sound waves into an electrical signal. Sound waves of the internal combustion engine are recorded using the sound receiver of the sensor unit and converted into an electrical signal, and the electrical signal is used for the diagnosis of the operating state of the internal combustion engine.

Claims

1. A method for diagnosing an internal combustion engine in a motor vehicle having at least one sensor unit which includes at least one sound receiver, the method comprising:

recording sound waves of the internal combustion engine using the sound receiver;

converting the sound waves into an electrical signal using the sound receiver; and

using the electrical signal for a diagnosis of an operating state of the internal combustion engine.

2. The method according to claim 1, wherein the sound waves include at least one of airborne noise and structure-borne noise.

3. The method according to claim 1, wherein the sensor unit includes a sound transmitter and a sound receiver.

4. The method according to claim 3, wherein the sound transmitter and the sound receiver are for transmitting and receiving ultrasound, respectively.

5. The method according to claim 1, wherein the use of the electrical signal for the diagnosis of the operating state of the internal combustion engine includes a determination of signal components at predefined frequency spectra.

6. The method according to claim 5, further comprising comparing the frequency spectrum with a reference spectrum associated with an error of the internal combustion engine.

7. The method according to claim 5, further comprising, when a maximum amplitude of a spectrum is exceeded, outputting an error associated with the spectrum.

8. The method according to claim 6, further comprising, when a maximum value of a cross-correlation between the frequency spectrum and the reference spectrum is exceeded, outputting an error associated with the reference spectrum.

9. The method according to claim 1, wherein the sound waves of the internal combustion engine are recorded above a minimum velocity of the vehicle using the sound receiver of the sensor unit.

10. The method according to claim 1, wherein a sensor unit of an ultrasound distance sensor in a motor vehicle is used to carry out the method.

11. A control unit for diagnosing an internal combustion engine in a motor vehicle having at least one sensor unit which includes at least one sound receiver, the control unit comprising:

means for recording sound waves of the internal combustion engine using the sound receiver;

means for converting the sound waves into an electrical signal using the sound receiver; and

means for using the electrical signal for a diagnosis of an operating state of the internal combustion engine.

12. A computer program embodied on a computer-readable medium which when executed by a processor performs the following method for diagnosing an internal combustion engine in a motor vehicle having at least one sensor unit which includes at least one sound receiver:

recording sound waves of the internal combustion engine using the sound receiver;

converting the sound waves into an electrical signal using the sound receiver; and

using the electrical signal for a diagnosis of an operating state of the internal combustion engine.