METHOD FOR EARLY DETECTION OF DAMAGE IN A MOTOR VEHICLE TRANSMISSION

• US 20120130607A1
• Filed: 07/14/2010
• Published: 05/24/2012
• Est. Priority Date: 08/10/2009
• Status: Abandoned Application

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Koenig, Hubert, Kurth, Joerg
• Application Number:
  US13/387,837
• Publication Number:
  US 20120130607A1
• Time in Patent Office: Days
• US Class Current: 701/51
• CPC Class Codes: G01H 1/003 of rotating machines G01H1/10 takes precedence
• CPC Class Codes: G01M 13/021 Gearings
• CPC Class Codes: G01M 13/028 Acoustic or vibration analysis

Abstract

A method of early recognition of damage in a motor vehicle transmission which comprises at least one acceleration sensor, with which mechanical vibrations in the motor vehicle transmission are detected and converted into an electrical signal. The electrical signal is then digitalized and thereafter carrying our a comparison with a comparison parameter. The mechanical vibrations are detected at defined operating points of the motor vehicle transmission and, from the digitalized electrical signal acceleration amplitudes, are determined over a time interval. A count is taken of conditions in which the acceleration amplitudes exceed the comparison parameter and, with reference to the number of such conditions, a calculated probability of damage in the motor vehicle transmission is determined. A motor vehicle transmission whose damage can be determined by the method, and a computer program product for carrying out the individual process steps are also proposed.

Claims

1-10. -10. (canceled)

11. A method for early recognition of damage in a motor vehicle transmission which comprises at least one acceleration sensor, the method comprising the steps of:

detecting (S1) mechanical vibrations at defined operating points of the motor vehicle transmission with the at least one acceleration sensor;

converting (S2) the mechanical vibrations into an electrical signal (a(t));

digitizing (S3) the electrical signal (a(t));

comparing (S4) the digitized electrical signal (a(t)) with a comparison parameter (aG);

determining acceleration amplitudes from the digitized electrical signal (a(t)) over a time interval (t);

taking a count of conditions (Z(t)) in which the acceleration amplitudes exceed the comparison parameter (aG); and

determining a calculated probability (P(t)) of damage in the motor vehicle transmission with reference to the count of conditions (Z(t)) in which the acceleration amplitudes exceed the comparison parameter (aG).

12. The method according to claim 11, further comprising the step of determining the conditions (Z(t)) in which the acceleration amplitudes exceed the comparison parameter (aG) by comparing acceleration gradients (Δ

a(t)) with a limit value (Δ

aG) and with reference to detection of elevated acceleration gradients in the electrical signal (a(t)) in addition to the comparison of the acceleration amplitudes with the comparison parameter (aG).

13. The method according to claim 12, further comprising the step of utilizing at least one steepness limiter in the comparison of the acceleration gradients (Δ

a(t)) with the limit value (Δ

aG) to filter out physically impossible gradients.

14. The method according to claim 11, further comprising the step of increasing the calculated probability (P(t)) by each count of conditions (Z(t)) in which the acceleration amplitudes exceed the comparison parameter (aG) and reducing the calculated probability (P(t)) in an absence of conditions (Z(t)) in which the acceleration amplitudes exceed the comparison parameter (aG) over a time interval.

15. The method according to claim 11, further comprising the step of the comparing (S6) the calculated probability (P(t)) with a threshold value (PS), and diagnosing damage in the motor vehicle transmission if the calculated probability (P(t)) exceeds a threshold value (PS).

16. The method according to claim 15, further comprising the step of at least one of recording a damage diagnosis and indicating damage diagnosis on a display (S7).

17. The method according to claim 11, further comprising the step of the forming defined operating points by characteristic operating ranges in which mild mechanical vibrations of the motor vehicle transmission usually predominate.

18. A motor vehicle transmission comprising at least one acceleration sensor located in an area of transmission components where the at least one acceleration sensor detects mechanical vibrations and converts the mechanical vibrations into an electrical signal (a(t)), and determining damage in the area of the transmission components, with reference to the electrical signal (a(t)), by a method comprising the steps of:

detecting (S1) the mechanical vibrations in an area of transmission components with the at least one acceleration sensor,

converting (S2) the mechanical vibrations into the electrical signal (a(t)),

digitizing (S3) the electrical signal (a(t)),

comparing (S4) the digitized electrical signal (a(t)) with a comparison parameter (aG),

determining acceleration amplitudes from the digitized electrical signal (a(t)) over a time interval (t),

taking a count of conditions (Z(t)) in which the acceleration amplitudes exceed the comparison parameter (aG), and

determining a calculated probability (P(t)) of damage in the area of transmission components with reference to the count of conditions (Z(t)) in which the acceleration amplitudes exceed the comparison parameter (aG).

19. A computer program product for a motor vehicle transmission having corresponding control commands stored in a software system which are implemented for carrying out a method comprising steps of:

detecting (S1) mechanical vibrations at defined operating points of the motor vehicle transmission with at least one acceleration sensor;

converting (S2) the mechanical vibrations into an electrical signal (a(t));

digitizing (S3) the electrical signal (a(t));

comparing (S4) the digitized electrical signal (a(t)) with a comparison parameter (aG);

determining acceleration amplitudes from the digitized electrical signal (a(t)) over a time interval (t);

taking a count of conditions (Z(t)) in which the acceleration amplitudes exceed the comparison parameter (aG); and

determining a calculated probability (P(t)) of damage in the motor vehicle transmission with reference to the count of conditions (Z(t)) in which the acceleration amplitudes exceed the comparison parameter (aG).

20. A data carrier with a computer program product for a motor vehicle transmission having corresponding control commands stored in a software system which are implemented for carrying out a method comprising steps of:

detecting (S1) mechanical vibrations at defined operating points of the motor vehicle transmission with at least one acceleration sensor;

converting (S2) the mechanical vibrations into an electrical signal (a(t));

digitizing (S3) the electrical signal (a(t));

comparing (S4) the digitized electrical signal (a(t)) with a comparison parameter (aG);

determining acceleration amplitudes from the digitized electrical signal (a(t)) over a time interval (t);

taking a count of conditions (Z(t)) in which the acceleration amplitudes exceed the comparison parameter (aG); and

determining a calculated probability (P(t)) of damage in the motor vehicle transmission with reference to the count of conditions (Z(t)) in which the acceleration amplitudes exceed the comparison parameter (aG).