METHOD AND SYSTEM FOR GENERATING ELECTRICAL ENERGY WITHIN A VEHICLE TYRE

• US 20100186493A1
• Filed: 07/18/2007
• Published: 07/29/2010
• Est. Priority Date: 07/18/2007
• Status: Active Grant

• Current Assignee: Pirelli Tyre SPA (Pirelli & C SPA)
• Original Assignee: Pirelli Tyre SPA (Pirelli & C SPA)
• Inventors: Mancosu, Federico, Brusarosco, Massimo
• Granted Patent: US 8,387,452 B2
• Time in Patent Office: Days
• US Class Current: 73/146.300
• CPC Class Codes: B60C 23/0411 Piezoelectric generators
• CPC Class Codes: H10N 30/302 Sensors

Abstract

A tyre includes a flexible piezoelectric element associated with an energy storage device (e.g. a capacitor). The flexible piezoelectric element is mounted in cantilever-beam fashion within a housing so that a first end thereof is fixed to the housing. A loading mass is associated with the second end of the flexible piezoelectric element. A small gap is formed between the inner walls of the housing and the outer surface of the loading mass in order to allow limited flexure of the piezoelectric element. The housing, including the piezoelectric element, is mounted in a crown portion of the tyre, preferably on the inner surface of the tyre. The piezoelectric element flexes under the action of the longitudinal acceleration when the tyre rotates. Sufficient electrical power for powering an electronic device included within the tyre is obtained, together with a long durability of the piezoelectric element.

Claims

1-31. -31. (canceled)

32. A method for generating electrical energy within a tyre, comprising:

providing an oscillating structure comprising a housing and a piezoelectric element coupled to said housing and capable of oscillating in an oscillation direction;

coupling said oscillating structure to a crown portion of said tyre;

rotating said tyre on a rolling surface so as to cause oscillation of said piezoelectric element, thereby leading to a deformation of said piezoelectric element during the tyre rotation; and

storing electrical energy generated from said deformation of said piezoelectric element,

wherein said coupling of said oscillating structure to a crown portion of said tyre is performed so as to substantially match said oscillation direction with a longitudinal direction of the tyre.

33. The method according to claim 32, wherein said piezoelectric element is coupled to said housing so as to have a first end substantially fixed to the housing and a second end fixed to a loading mass.

34. The method according to claim 33, wherein a gap is formed between at least one inner wall of said housing and an outer surface of said loading mass.

35. The method according to claim 32, wherein said crown portion of said tyre is a portion of an inner surface of the tyre.

36. The method according to claim 32, wherein said coupling of said oscillating structure to said crown portion of the tyre is performed so as to dispose a longer side of said piezoelectric element substantially according to an axial direction of the tyre.

37. A system for generating electrical energy comprising:

a tyre;

an oscillating structure coupled to a crown portion of said tyre, comprising a housing and a piezoelectric element coupled to said housing and capable of oscillating in an oscillation direction so as to generate electrical energy upon oscillation; and

a storing circuit capable of being adapted for storing said electrical energy, coupled to said oscillating structure,

wherein said oscillating structure is coupled to said crown portion of said tyre so as to substantially match said oscillation direction with a longitudinal direction of the tyre.

38. The system of claim 37, wherein said piezoelectric element is disposed within said housing so as to have a first end substantially fixed to the housing and a second end fixed to a loading mass.

39. The system according to claim 38, wherein said loading mass is less than 4 grams.

40. The system according to claim 38, wherein said loading mass is U-shaped.

41. The system according to claim 38, wherein a gap is formed between of least one inner wall of said housing and an outer surface of said loading mass.

42. The system according to claim 41, wherein said gap has an overall maximum extent of 400 :

m.

43. The system according to claim 37, wherein said crown portion of said tyre is a portion of an inner surface of the tyre.

44. The system according to claim 37, wherein said oscillating structure is coupled to said crown portion of the tyre so as to dispose a longer side of said piezoelectric element substantially according to an axial direction of the tyre.

45. The system according to claim 37, wherein a resonance peak frequency of said oscillating structure is greater than 150 Hz.

46. The system according to claim 45, wherein said resonance peak frequency is greater than 200 Hz.

47. The system according to claim 46, wherein said resonance peak frequency is greater than 300 Hz.

48. The system according to claim 37, wherein said piezoelectric element is a bimorph element.

49. The system according to claim 37, wherein said piezoelectric element is a planar element.

50. The system according to claim 37, wherein said storing circuit comprises a capacitor.

51. A system for monitoring at least one operating parameter of a tyre fitted on a vehicle, comprising:

a system for generating electrical energy according to claim 37; and

a processing device capable of being adapted to process electrical signals generated by the piezoelectric element so as to determine said at least one operating parameter of the tyre.

52. The system according to claim 51, wherein said processing device is capable of being adapted to process said electrical signals so as to extract information related to characteristic peaks of said electrical signals, said characteristic peaks being related to an entering of the crown portion coupled to the oscillating structure in a contact region between the tyre and a rolling surface, and to an exiting of the crown portion coupled to the oscillating structure from said contact region.

53. The system according to claim 52, wherein said information related to said characteristic peaks comprises a distance between predetermined points of said characteristic peaks.

54. The system according to claim 52, wherein said information related to said characteristic peaks comprises a sequence of signs of said characteristic peaks.

55. The system according to claim 54, wherein said at least one operating parameter of the tyre comprises a fitting position of the tyre on the vehicle, and wherein said processing device is capable of being adapted to determine said fitting position of the tyre based on said sequence of signs.

56. The system according to claim 52, wherein said at least one operating parameter of the tyre comprises a number of tyre revolutions performed by said tyre during rolling in a given time period, and wherein said processing device is capable of being adapted to determine said number of tyre revolutions by counting an occurrence of one of said characteristic peaks during said given time period.

57. The system according to claim 51, further comprising a measurement device of at least a further operating parameter of the tyre, the measurement device being coupled to said system for generating electrical energy and to said processing device.

58. The system according to claim 57, wherein said measurement device comprises a pressure sensor.

59. The system according to claim 53, wherein said at least one operating parameter of the tyre comprises a load to which the tyre is subjected, and wherein said processing device is capable of being adapted to determine said load based on said distance between said predetermined points of said characteristic peaks and a pressure measured by a pressure sensor.

60. The system according to claim 57, wherein said measurement device comprises a temperature sensor.

61. The system according to claim 57, wherein said measurement device comprises an acceleration sensor.

62. The system according to claim 51, further comprising a transmitter device coupled to said system for generating electrical energy and to said processing device, the transmitter device capable of being adapted to transmit said at least one operating parameter or said at least one further operating parameter to a receiving device disposed on said vehicle.