Method and device for monitoring the instantaneous behavior of a tire during the running of a motor vehicle

• US 6,561,018 B2
• Filed: 05/10/2002
• Issued: 05/13/2003
• Est. Priority Date: 11/18/1999
• Status: Expired due to Term

• Current Assignee: Pirelli Pneumatici S.P.A. (Pirelli & C SPA)
• Original Assignee: Pirelli Pneumatici S.P.A. (Pirelli & C SPA)
• Inventors: Misani, Piero, Mancosu, Federico, Matrascia, Giuseppe, Gelosa, Elda
• Primary Examiner(s): OEN, WILLIAM L
• Application Number:
  US10/142,243
• Publication Number:
  US 20020166373A1
• Time in Patent Office: 368 Days
• Field of Search: 731/46, 731/462, 731/465, 340/442, 340/443, 340/444
• US Class Current: 73/146
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60T 8/1725 Using tyre sensors, e.g. Sidewall Torsion sensors [SWT] for tyre pressure and temperature detection B60C23/00

Abstract

A method for monitoring the instantaneous behavior of a tire includes the steps of acquiring and storing at least one basic reference curve representing variation of a displacement of at least one specified point of the tire in at least one of three spatial directions as a function of a spatial position of the at least one specified point during at least one portion of a revolution of the tire, continuously acquiring first signals representing the spatial position of the at least one specified point, deriving from the spatial position signals of the at least one specified point at least one cyclic curve of current operating displacement in at least one spatial direction, continuously comparing the at least one cyclic curve of current operating displacement with the at least one basic reference curve, and emitting a second signal depending on results of the comparison. A related device is also disclosed.

Claims

1. A method for monitoring instantaneous behaviour of a tyre during running of a motor vehicle, comprising the steps of:

associating three spatial directions with the tyre;

acquiring and storing, at least temporarily, at least one basic reference curve representing variation of a displacement of at least one specified point of the tyre in at least one of the three spatial directions as a function of a spatial position of the at least one specified point during at least one portion of a revolution of the tyre;

continuously acquiring first signals representing the spatial position of the at least one specified point during the at least one portion of the revolution of the tyre;

deriving from the spatial position signals of the at least one specified point at least one cyclic curve of current operating displacement in the at least one of the three spatial directions as a function of the spatial position of the at least one specified point during the at least one portion of the revolution of the tyre;

continuously comparing the at least one cyclic curve of current operating displacement with the at least one basic reference curve; and

emitting a second signal depending on results of the comparison;

wherein the tyre comprises at least one tread and one casing,

wherein the three spatial directions are longitudinal, transverse, and vertical, and wherein the second signal indicates an instantaneous behaviour of the tyre.

2. The method of claim 1, wherein the at least one basic reference curve is acquired during the running of the motor vehicle during an earlier revolution of the tyre,

wherein the at least one basic reference curve is temporarily stored for a specified period, and

wherein the at least one cyclic curve of current operating displacement is derived from spatial position signals acquired during a later revolution of the tyre.

3. The method of claim 2, wherein the earlier revolution immediately precedes the later revolution.

4. The method of claim 1, wherein the at least one basic reference curve is acquired before the running of the motor vehicle, and

wherein the at least one basic reference curve is permanently stored.

5. The method of claim 1, wherein a state of deformation of the casing in a vicinity of a point in an area of contact between the tyre and a surface contacted by the tyre is measured using the at least one basic reference curve and the at least one cyclic curve of current operating displacement,

wherein the state of deformation is used to evaluate adhesion present between the tyre and the surface contacted by the tyre, and

wherein the state of deformation is used to evaluate a capacity of the tyre to develop forces tangential to the tyre in the area of contact.

6. The method of claim 5, wherein first signals representing the spatial position of at least two specified points are continuously acquired during the at least one portion of the revolution of the tyre,

wherein at least one cyclic curve of current operating displacement is derived from the spatial position signals of each of the at least two specified points,

wherein the cyclic curves of current operating displacement of the at least two specified points are continuously compared with each other to reveal at least one of acquisition errors, rapid changes in the state of deformation, or acquisition errors and rapid changes in the state of deformation.

7. The method of claim 1, further comprising the steps of:

obtaining at least one basic reference curve of velocity of the at least one specified point by calculating a derivative with respect to time of the at least one basic reference curve representing the variation of the displacement of the at least one specified point;

storing, at least temporarily, the at least one basic reference curve of velocity;

obtaining at least one cyclic curve of operating velocity of the at least one specified point by calculating a derivative with respect to time of the at least one cyclic curve of current operating displacement of the at least one specified point; and

continuously comparing the at least one cyclic curve of operating velocity with the at least one basic reference curve of velocity.

8. The method of claim 7, wherein a state of deformation of the casing in a vicinity of a point in an area of contact between the tyre and a surface contacted by the tyre is measured using the at least one basic reference curve and the at least one cyclic curve of current operating displacement,

wherein the state of deformation is used to evaluate adhesion present between the tyre and the surface contacted by the tyre, and

wherein the state of deformation is used to evaluate a capacity of the tyre to develop forces tangential to the tyre in the area of contact.

9. The method of claim 8, wherein first signals representing the spatial position of at least two specified points are continuously acquired during the at least one portion of the revolution of the tyre,

wherein at least one cyclic curve of current operating displacement is derived from the spatial position signals of each of the at least two specified points, and

wherein the cyclic curves of current operating displacement of the at least two specified points are continuously compared with each other to reveal at least one of acquisition errors, rapid changes in the state of deformation, or acquisition errors and rapid changes in the state of deformation.

10. The method of claim 7, wherein a state of deformation of the casing in a vicinity of a point in an area of contact between the tyre and a surface contacted by the tyre is measured using the at least one basic reference curve of velocity and the at least one cyclic curve of operating velocity,

wherein the state of deformation is used to evaluate adhesion present between the tyre and the surface contacted by the tyre, and

wherein the state of deformation is used to evaluate a capacity of the tyre to develop forces tangential to the tyre in the area of contact.

11. The method of claim 10, wherein first signals representing the spatial position of at least two specified points are continuously acquired during the at least one portion of the revolution of the tyre,

wherein at least one cyclic curve of current operating displacement is derived from the spatial position signals of each of the at least two specified points,

wherein at least one cyclic curve of operating velocity is obtained by calculating a derivative with respect to time of the at least one cyclic curve of current operating displacement of each of the at least two specified points, and

wherein the cyclic curves of operating velocity of the at least two specified points are continuously compared with each other to reveal at least one of acquisition errors, rapid changes in the state of deformation, or acquisition errors and rapid changes in the state of deformation.

12. The method of claim 7, wherein a state of deformation of the casing in a vicinity of a point in an area of contact between the tyre and a surface contacted by the tyre is measured using the at least one basic reference curve, the at least one cyclic curve of current operating displacement, the at least one basic reference curve of velocity, and the at least one cyclic curve of operating velocity,

wherein the state of deformation is used to evaluate adhesion present between the tyre and the surface contacted by the tyre, and

wherein the state of deformation is used to evaluate a capacity of the tyre to develop forces tangential to the tyre in the area of contact.

13. The method of claim 12, wherein first signals representing the spatial position of at least two specified points are continuously acquired during the at least one portion of the revolution of the tyre,

wherein at least one cyclic curve of current operating displacement is derived from the spatial position signals of each of the at least two specified points,

wherein at least one cyclic curve of operating velocity is obtained by calculating a derivative with respect to time of the at least one cyclic curve of current operating displacement of each of the at least two specified points,

wherein the cyclic curves of current operating displacement of the at least two specified points are continuously compared with each other to reveal at least one of acquisition errors, rapid changes in the state of deformation, or acquisition errors and rapid changes in the state of deformation, and

wherein the cyclic curves of operating velocity of the at least two specified points are continuously compared with each other to reveal at least one of acquisition errors, rapid changes in the state of deformation, or acquisition errors and rapid changes in the state of deformation.

14. A method for monitoring instantaneous behaviour of a tyre during running of a motor vehicle, comprising the steps of:

associating three spatial directions with the tyre;

acquiring at least one basic reference curve representing variation of a displacement of at least one specified point of the tyre in at least one of the three spatial directions as a function of a spatial position of the at least one specified point during at least one portion of a revolution of the tyre;

obtaining at least one basic reference curve of velocity of the at least one specified point by calculating a derivative with respect to time of the at least one basic reference curve representing the variation of the displacement of the at least one specified point;

storing, at least temporarily, the at least one basic reference curve of velocity;

continuously acquiring first signals representing the spatial position of the at least one specified point during the at least one portion of the revolution of the tyre;

deriving from the spatial position signals of the at least one specified point at least one cyclic curve of current operating displacement in the at least one of the three spatial directions as a function of the spatial position of the at least one specified point during the at least one portion of the revolution of the tyre;

obtaining at least one cyclic curve of operating velocity of the at least one specified point by calculating a derivative with respect to time of the at least one cyclic curve of current operating displacement of the at least one specified point;

continuously comparing the at least one cyclic curve of operating velocity with the at least one basic reference curve of velocity; and

emitting a second signal depending on results of the comparison;

wherein the tyre comprises at least one tread and one casing,

wherein the three spatial directions are longitudinal, transverse, and vertical, and

wherein the second signal indicates an instantaneous behaviour of the tyre.

15. The method of claim 14, wherein a state of deformation of the casing in a vicinity of a point in an area of contact between the tyre and a surface contacted by the tyre is measured using the at least one basic reference curve of velocity and the at least one cyclic curve of operating velocity,

wherein the state of deformation is used to evaluate adhesion present between the tyre and the surface contacted by the tyre, and

wherein the state of deformation is used to evaluate a capacity of the tyre to develop forces tangential to the tyre in the area of contact.

16. The method of claim 15, wherein first signals representing the spatial position of at least two specified points are continuously acquired during the at least one portion of the revolution of the tyre,

wherein at least one cyclic curve of current operating displacement is derived from the spatial position signals of each of the at least two specified points,

wherein at least one cyclic curve of operating velocity is obtained by calculating a derivative with respect to time of the at least one cyclic curve of current operating displacement of each of the at least two specified points, and

wherein the cyclic curves of operating velocity of the at least two specified points are continuously compared with each other to reveal at least one of acquisition errors, rapid changes in the state of deformation, or acquisition errors and rapid changes in the state of deformation.

17. A device for monitoring instantaneous behaviour of a tyre during running of a motor vehicle, comprising:

means for acquiring and storing, at least temporarily, at least one basic reference curve representing variation of a displacement of at least one specified point of the tyre in at least one of three spatial directions as a function of a spatial position of the at least one specified point during at least one portion of a revolution of the tyre;

at least one sensor means, associated with the at least one specified point, emitting first signals representing the spatial position of the at least one specified point;

pick-up means continuously acquiring the spatial position signals during at least one portion of the revolution of the tyre; and

processor means deriving from the spatial position signals of the at least one sensor means at least one cyclic curve of current operating displacement in the at least one of three spatial directions as a function of the spatial position of the at least one specified point during the at least one portion of the revolution of the tyre;

wherein the processor means continuously compares the at least one cyclic curve of current operating displacement with the at least one basic reference curve,

wherein the processor means emits a second signal depending on results of the comparison,

wherein the tyre comprises at least one tread and one casing,

wherein the three spatial directions are longitudinal, transverse, and vertical, and

wherein the second signal indicates an instantaneous behaviour of the tyre.

18. The device of claim 17, wherein the at least one basic reference curve is acquired during the running of the motor vehicle during a first revolution of the tyre, and

wherein the at least one cyclic curve of current operating displacement is derived from spatial position signals acquired during a second revolution of the tyre.

19. The device of claim 18, wherein the first revolution immediately precedes the second revolution.

20. The device of claim 17, wherein the at least one basic reference curve is acquired before the running of the motor vehicle, and

wherein the at least one basic reference curve is permanently stored.

21. The device of claim 17, wherein the processor means measures a state of deformation of the casing in a vicinity of a point in an area of contact between the tyre and a surface contacted by the tyre using the at least one basic reference curve and the at least one cyclic curve of current operating displacement,

wherein the state of deformation is used to evaluate adhesion present between the tyre and the surface contacted by the tyre, and

wherein the state of deformation is used to evaluate a capacity of the tyre to develop forces tangential to the tyre in the area of contact.

22. The device of claim 21, wherein at least two sensor means are each associated with at least one specified point,

wherein each sensor means emits first signals representing the spatial position of the associated at least one specified point,

wherein the processor means derives at least one cyclic curve of current operating displacement from the spatial position signals of each sensor means, and

wherein the processor means continuously compares the cyclic curves of current operating displacement of the sensor means with each other to reveal at least one of acquisition errors, rapid changes in the state of deformation, or acquisition errors and rapid changes in the state of deformation.

23. The device of claim 17, wherein the processor means obtains at least one basic reference curve of velocity of the at least one specified point by calculating a derivative with respect to time of the at least one basic reference curve representing the variation of the displacement of the at least one specified point,

wherein the processor means obtains at least one cyclic curve of operating velocity of the at least one specified point by calculating a derivative with respect to time of the at least one cyclic curve of current operating displacement of the at least one specified point, and

wherein the processor means continuously compares the at least one cyclic curve of operating velocity with the at least one basic reference curve of velocity.

24. The device of claim 23, wherein the processor means measures a state of deformation of the casing in a vicinity of a point in an area of contact between the tyre and a surface contacted by the tyre using the at least one basic reference curve and the at least one cyclic curve of current operating displacement,

wherein the state of deformation is used to evaluate adhesion present between the tyre and the surface contacted by the tyre, and

wherein the state of deformation is used to evaluate a capacity of the tyre to develop forces tangential to the tyre in the area of contact.

25. The device of claim 24, wherein at least two sensor means are each associated with at least one specified point,

wherein each sensor means emits signals representing the spatial position of the associated at least one specified point,

wherein the processor means derives at least one cyclic curve of current operating displacement from the spatial position signals of each sensor means, and

wherein the processor means continuously compares the cyclic curves of current operating displacement of the sensor means with each other to reveal at least one of acquisition errors, rapid changes in the state of deformation, or acquisition errors and rapid changes in the state of deformation.

26. The device of claim 23, wherein the processor means measures a state of deformation of the casing in a vicinity of a point in an area of contact between the tyre and a surface contacted by the tyre using the at least one basic reference curve of velocity and the at least one cyclic curve of operating velocity,

wherein the state of deformation is used to evaluate adhesion present between the tyre and the surface contacted by the tyre, and

wherein the state of deformation is used to evaluate a capacity of the tyre to develop forces tangential to the tyre in the area of contact.

27. The device of claim 26, wherein at least two sensor means are each associated with at least one specified point,

wherein each sensor means emits first signals representing the spatial position of the associated at least one specified point,

wherein the processor means derives at least one cyclic curve of current operating displacement from the spatial position signals of each sensor means,

wherein the processor means obtains at least two cyclic curves of operating velocity by calculating derivatives with respect to time of each cyclic curve of current operating displacement, and

wherein the processor means continuously compares the cyclic curves of operating velocity with each other to reveal at least one of acquisition errors, rapid changes in the state of deformation, or acquisition errors and rapid changes in the state of deformation.

28. The device of claim 23, wherein the processor means measures a state of deformation of the casing in a vicinity of a point in an area of contact between the tyre and a surface contacted by the tyre using the at least one basic reference curve, the at least one cyclic curve of current operating displacement, the at least one basic reference curve of velocity, and the at least one cyclic curve of operating velocity,

wherein the state of deformation is used to evaluate adhesion present between the tyre and the surface contacted by the tyre, and

wherein the state of deformation is used to evaluate a capacity of the tyre to develop forces tangential to the tyre in the area of contact.

29. The device of claim 24, wherein at least two sensor means are each associated with at least one specified point,

wherein each sensor means emits first signals representing the spatial position of the associated at least one specified point,

wherein the processor means derives at least one cyclic curve of current operating displacement from the spatial position signals of each sensor means,

wherein the processor means obtains at least two cyclic curves of operating velocity by calculating derivatives with respect to time of each cyclic curve of current operating displacement,

wherein the processor means continuously compares the cyclic curves of current operating displacement of the sensor means with each other to reveal at least one of acquisition errors, rapid changes in the state of deformation, or acquisition errors and rapid changes in the state of deformation, and

wherein the processor means continuously compares the cyclic curves of operating velocity with each other to reveal at least one of acquisition errors, rapid changes in the state of deformation, or acquisition errors and rapid changes in the state of deformation.

30. A device for monitoring instantaneous behaviour of a tyre during running of a motor vehicle, comprising:

means for acquiring at least one basic reference curve representing variation of a displacement of at least one specified point of the tyre in at least one of three spatial directions as a function of a spatial position of the at least one specified point during at least one portion of a revolution of the tyre;

means for obtaining at least one basic reference curve of velocity of the at least one specified point by calculating a derivative with respect to time of the at least one basic reference curve representing the variation of the displacement of the at least one specified point;

means for storing, at least temporarily, the at least one basic reference curve of velocity;

at least one sensor means, associated with the at least one specified point, emitting signals representing the spatial position of the at least one specified point;

pick-up means continuously acquiring the spatial position signals during at least one portion of the revolution of the tyre; and

processor means deriving from the spatial position signals of the at least one sensor means at least one cyclic curve of current operating displacement in the at least one of three spatial directions as a function of the spatial position of the at least one specified point during the at least one portion of the revolution of the tyre and obtaining at least one cyclic curve of operating velocity of the at least one specified point by calculating a derivative with respect to time of the at least one cyclic curve of current operating displacement;

wherein the processor means continuously compares the at least one cyclic curve of operating velocity with the at least one basic reference curve of velocity,

wherein the processor means emits a second signal depending on results of the comparison,

wherein the tyre comprises at least one tread and one casing,

wherein the three spatial directions are longitudinal, transverse, and vertical, and

wherein the second signal indicates an instantaneous behaviour of the tyre.

31. The device of claim 30, wherein the processor means measures a state of deformation of the casing in a vicinity of a point in an area of contact between the tyre and a surface contacted by the tyre using the at least one basic reference curve of velocity and the at least one cyclic curve of operating velocity,

wherein the state of deformation is used to evaluate adhesion present between the tyre and the surface contacted by the tyre, and

wherein the state of deformation is used to evaluate a capacity of the tyre to develop forces tangential to the tyre in the area of contact.

32. The device of claim 31, wherein at least two sensor means are each associated with at least one specified point,

wherein each sensor means emits first signals representing the spatial position of the associated at least one specified point,

wherein the processor means derives at least one cyclic curve of current operating displacement from the spatial position signals of each sensor means,

wherein the processor means obtains at least two cyclic curves of operating velocity by calculating derivatives with respect to time of each cyclic curve of current operating displacement, and

wherein the processor means continuously compares the cyclic curves of operating velocity with each other to reveal at least one of acquisition errors, rapid changes in the state of deformation, or acquisition errors and rapid changes in the state of deformation.