METHOD AND DEVICE FOR RECOGNIZING ROTATIONAL SPEED / TORQUE FLUCTUATIONS IN A DRIVE DEVICE

• US 20140309851A1
• Filed: 10/09/2012
• Published: 10/16/2014
• Est. Priority Date: 10/13/2011
• Status: Active Grant

• Current Assignee: Audi AG (Volkswagen AG)
• Original Assignee: Audi AG (Volkswagen AG)
• Inventors: Felber, Mathias, Pfeiffer, Jrgen
• Granted Patent: US 9,250,157 B2
• Time in Patent Office: Days
• US Class Current: 701/33.9
• CPC Class Codes: F02D 2041/286 comprising means for signal processing
• CPC Class Codes: F02D 41/0097 using means for generating speed signals
• CPC Class Codes: F02D 41/1498 measuring engine roughness
• CPC Class Codes: F02N 11/106 for stopping or interrupting starter actuation
• CPC Class Codes: G01M 17/007 Wheeled or endless-tracked vehicles G01M17/08 takes precedence

Abstract

A method for detecting rotational speed/torque fluctuations, in particular patterns of such fluctuations, of a drive device, in particular in a motor vehicle, includes the following steps: detecting a critical rotational speed situation by comparing a measured actual rotational speed with specified characteristic rotational speeds; detecting a local rotational speed minimum and a local rotational speed maximum (local rotational speed variables); analyzing the local rotational speed variables by generating local rotational speed characteristic values, such as a local amplitude and a local frequency preferably; directly or indirectly determining the duration of a local vibration time period, wherein substantially constant local rotational speed characteristic values are present within the time period; and describing a local vibration pattern, the pattern exhibiting at least the local amplitude, local frequency, or the local vibration time period.

Claims

1-11. -11. (canceled)

12. A method for recognizing a succession of rotational speed/torque fluctuations, in particular of rotational fluctuation patterns of a drive device having at least one combustion engine and a torsional vibration influencing device, said method comprising:

recognizing an actual rotational speed, in particular a temporal course of the actual rotational speed, of the rotational speed/torque fluctuations of the torsional vibration influencing device for recognizing rotational speed/torque fluctuations of the torsional vibration influencing device;

detecting a local rotational speed minimum and a local rotational speed maximum of the torsional vibration influencing device as local rotational speed variables, in particular detecting minima and maxima and a temporal succession of the rotational speed fluctuations,

analyzing the local rotational speed variables, in particular establishing local rotational speed characteristic values, said local rotational speed characteristic values including a local amplitude and a local frequency.

determining directly or indirectly a duration of a local vibration time period, wherein within this time period one of the local rotational speed characteristic values, preferably all are essentially constant,

describing a local vibration pattern, said local vibration pattern exhibiting at least the local amplitude, the local frequency or the local vibration time period.

13. The method of claim 12, wherein the drive device is a drive device of a motor vehicle and the torsional vibration influencing device is a dual mass flywheel.

14. The method of claim 12, wherein the local vibration patterns are recognized when a critical rotational speed situation is present, wherein for recognizing this situation the determined actual rotational speed is compared with a predeterminable rotational speed threshold value.

15. The method of claim 14, wherein a critical rotational speed situation is present when the determined actual rotational speed falls below the predeterminable rotational threshold value.

16. The Method according to claim 13, wherein the rotational speed threshold value is dependent on one of the local rotational speed characteristic values.