Determining a maximum frictional-connection coefficient

Patent metadata

Field	Value
Publication number	US-11260870-B2
Application number	US-201816488719-A
Country	US
Kind code	B2
Filing date	Jan 31, 2018
Priority date	Feb 27, 2017
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

A tire (100) rolls on a surface (105). A method (600) for providing maximum traction coefficient between the tire (100) and the surface (105) include steps for detecting a momentary slip of the tire (100) on the surface (105); detecting a momentary traction coefficient; forming a tuple (410, 510) from the slip and the current traction coefficient; choosing a characteristic curve (205, 305) from a number of predetermined characteristic curves (205, 305) on the basis of the tuple (410, 510), whereby each characteristic curve (205, 305) describes a traction behavior of the tire (100) or a corresponding characteristic pitch; determining the maximum traction coefficient on the basis of the selected characteristic curves (205, 305); and thus providing the maximum traction coefficient.

First claim

The invention claimed is:

1. A method for providing a maximum traction coefficient between a tire and a surface on which the tire runs by an on-board processing device on a vehicle in real-time, the method comprising:
providing a plurality of predetermined traction characteristic curves in a memory of the on-board processing device, whereby each characteristic curve describes a different traction behavior of the tire;
detecting current slip of the tire on the surface;
detecting current traction coefficient;
forming a first tuple from the detected slip and the detected traction coefficient;
providing a plurality of predetermined pitch characteristic curves in the memory of the on-board processing device, whereby each pitch characteristic curve describes a different pitch curve of the tire;
detecting a pitch based on the detected slip;
forming a second tuple from the detected slip and the detected pitch;
operating the processing device to choose a traction characteristic curve from the plurality of predetermined traction characteristic curves that best matches to the first tuple;
operating the processing device to choose a pitch characteristic curve from the plurality of predetermined pitch characteristic curves based on the second tuple; and
providing the maximum traction coefficient from the processing device of the chosen pitch characteristic curve.

2. The method according to claim 1 , wherein each of the predetermined traction characteristic curves indicates a correlation between a slip and a traction coefficient; and wherein choosing a characteristic curve further comprises choosing the characteristic curve that includes a point to which the tuple comes as close as possible.

3. The method according to claim 1 , wherein each of the predetermined pitch characteristic curves indicates a pitch of traction characteristics; and wherein choosing a pitch characteristic curve that comes as near as possible to the second tuple based on slip and pitch m.

4. The method according to claim 2 , wherein the provided maximum traction coefficient is determined based on a combination of maximum traction coefficients detected with regard to different types of characteristics.

5. The method according to claim 1 , wherein the provided maximum traction coefficient from the chosen characteristic curve and the provided maximum traction coefficient from the chosen pitch characteristic curve are compared and a selected maximum traction coefficient is provided only if a difference between the provided maximum traction coefficient from the chosen characteristic curve and the provided maximum traction coefficient from the chosen pitch characteristic curve does not exceed a predetermined value.

6. The method according to claim 2 , whereby a momentary traction coefficient is provided if it is greater than the determined maximum traction coefficient.

7. The method according to claim 2 , wherein the maximum traction coefficient is provided only if the pitch exceeds a predetermined threshold.

8. The method according to claim 2 , whereby a histogram is formed based on a number of determined maximum traction coefficients; and wherein a quality of a given maximum traction coefficient based on the histogram.

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Zdych Robert
• Gilsdorf Heinz-Joachim
• Wagner Volker
• Mair Ulrich
• Turner Lara Ruth
• King Julian

Classifications

• B60W2520/16

  Pitch · CPC title

• B60T2210/12

  Friction · CPC title

• B60W2555/20

  Ambient conditions, e.g. wind or rain · CPC title

• B60W50/14

  Means for informing the driver, warning the driver or prompting a driver intervention · CPC title

• B60W2520/26

  Wheel slip · CPC title