METHOD AND SYSTEM FOR SIGNALING AN AQUAPLANING CONDITION OF A TYRE FITTED ON A VEHICLE (AS AMENDED)

• US 20110199201A1
• Filed: 10/22/2009
• Published: 08/18/2011
• Est. Priority Date: 10/24/2008
• 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 9,043,112 B2
• Time in Patent Office: Days
• US Class Current: 340/438
• CPC Class Codes: B60T 2210/13 Aquaplaning, hydroplaning
• CPC Class Codes: B60T 2240/04 Tire deformation
• 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 of signalling an aquaplaning condition of a tyre, the latter rolling on a rolling surface, a footprint area being defined between the tyre and the rolling surface, a layer of water being interposed between the tyre and the rolling surface, includes: detecting a first signal representative of a deformation of the tyre due to rolling of the tyre on the rolling surface, the first signal including at least one portion representative of the interaction between the tyre and the layer of water; processing the first signal so as to determine a parameter representative of an aquaplaning condition of the tyre as a function of the first signal; and generating a notification signal as a function of the at least one parameter. A system for signalling an aquaplaning condition of a tyre.

Claims

1-56. -56. (canceled)

57. A method of signalling an aquaplaning condition of a tyre rolling on a rolling surface, a footprint area being defined between said tyre and said rolling surface, a layer of water being interposed between said tyre and said rolling surface, comprising:

detecting a first signal representative of a deformation of said tyre due to rolling of said tyre on said rolling surface, said first signal comprising at least one portion representative of an interaction between the tyre and said layer of water;

processing said first signal so as to determine a parameter representative of an aquaplaning condition of said tyre; and

generating a notification signal as a function of said at least one parameter.

58. The method as claimed in claim 57, wherein said at least one parameter is representative of a deformation of an inner surface of said tyre.

59. The method as claimed in claim 57, further comprising filtering said first signal in a first frequency band between 700 Hz and 2000 Hz.

60. The method as claimed in claim 59, wherein said first band is between 1000 Hz and 1700 Hz.

61. The method as claimed in claim 57, wherein said first signal portion is representative of a deformation of said inner surface in a region that is external and substantially contiguous to said footprint area.

62. The method as claimed in claim 61, wherein said external region is a post-footprint region that is substantially contiguous to the footprint area and subsequent to the footprint layer in the rotation direction of the tyre.

63. The method as claimed in claim 62, wherein said post-footprint region has a first longitudinal end and a second longitudinal end, said first and second longitudinal ends defining a central angle of between 25°

and 65°

.

64. The method as claimed in claim 63, wherein the first and second longitudinal ends of said post-footprint region define a central angle of between 40°

and 50°

.

65. The method as claimed in claim 61, wherein said first signal portion is representative of an acceleration corresponding to a radial and/or lateral and/or longitudinal deformation of said inner surface of the tyre in the post-footprint region.

66. The method as claimed in claim 57, wherein said at least one parameter is a function of a mean value of amplitude of said first signal in said portion.

67. The method as claimed in claim 66, wherein said at least one parameter is a function of a root mean square value of the amplitude of said first signal in said portion.

68. The method as claimed in claim 57, wherein said notification signal is generated as a function of a comparison between said at least one parameter and a prestored threshold value.

69. The method as claimed in claim 68, wherein said threshold value is representative of a threshold between a total-aquaplaning condition and a grip condition to the rolling surface of said tyre.

70. The method as claimed in claim 58, further comprising filtering said first signal in a first frequency band between 700 Hz and 2000 Hz, wherein said first signal portion is representative of a deformation of said inner surface in a region that is external and substantially contiguous to said footprint area, wherein said at least one parameter is calculated according to the formula:

71. The method as claimed in claim 58, wherein said first signal portion is representative of a deformation of said inner surface in said footprint area.

72. The method as claimed in claim 58, wherein said first signal is representative of an acceleration or speed corresponding to radial deformation of said inner surface.

73. The method as claimed in claim 58, further comprising filtering said first signal in a second frequency band lower than 700 Hz.

74. The method as claimed in claim 73, wherein said second frequency band is lower than or equal to a first frequency corresponding to angular speed of said tyre multiplied by a factor of 30.

75. The method as claimed in claim 71, further comprising identifying at least one pair of significant points on a curve representing an evolution in time of said first signal.

76. The method as claimed in claim 75, wherein a first parameter is determined as a function of one or more mutual distances between co-ordinates of said significant points.

77. The method as claimed in claim 75, wherein said first signal is representative of a speed or an acceleration, and said significant points are selected from:

absolute-maximum point of acceleration, absolute-maximum point of speed, absolute-minimum point of the speed, first minimum point subsequent in time to said absolute acceleration maximum, first minimum point preceding in time said absolute maximum of the acceleration, and second minimum point preceding in time said absolute maximum of the acceleration, said second minimum point being prior in time relative to said first minimum point of the acceleration preceding the absolute-maximum point.

78. The method as claimed in claim 77, wherein said at least one parameter is calculated according to one or more of the following formulae:

79. The method as claimed in claim 72, wherein said first signal is representative of a speed corresponding to the radial deformation of said inner surface in the footprint area, said method comprising filtering said first signal between a first frequency and a second frequency, said first and second frequencies being lower than an angular speed of said tyre multiplied by a factor smaller than or equal to 30.

80. The method as claimed in claim 79, wherein said at least one parameter is calculated according to at least one of the following formulae:

81. The method as claimed in claim 72, wherein said first signal is representative of an acceleration corresponding to radial deformation of said inner surface in the footprint area, and comprising filtering said first signal between a first frequency and a second frequency, said first and second frequencies being lower than angular speed of said tyre multiplied by a factor smaller than or equal to 30.

82. The method as claimed in claim 81, wherein said first signal, after said filtering in the footprint area has a first peak, a second peak, and a third peak, identified by a pair of co-ordinates ((X_P1, Y_P1);

(X_P2, Y_P2);

(X_P3, Y_P3)) respectively, which are representative of an abscissa and an ordinate of a corresponding peak, respectively, and

wherein said at least one parameter is determined as a function of one or more distances between abscissae and/or ordinates of said peaks.

83. The method as claimed in claim 82, wherein said at least one parameter is calculated according to one or more of the following formulae:

84. A system capable of signalling an aquaplaning condition of a tyre, the tyre rolling on a rolling surface, a footprint area being defined between said tyre and said rolling surface, a layer of water being interposed between said tyre and said rolling surface, comprising:

a detection device for detecting a first signal representative of a deformation of said tyre due to rolling of said tyre on said rolling surface, said first signal comprising at least one portion representative of an interaction between the tyre and said layer of water; and

at least one processing unit operatively associated with said detection device and capable of being adapted to process said first signal so as to determine at least one parameter representative of an aquaplaning condition of said tyre,

said at least one processing unit capable of being further adapted to generate a notification signal as a function of said at least one parameter.

85. The system as claimed in claim 84, wherein said at least one parameter is representative of a deformation of an inner surface of said tyre.

86. The system as claimed in claim 84, wherein said processing unit comprises a sampling module for sampling said first signal to a predetermined sampling frequency.

88. The system as claimed in claim 86, wherein a first band is 1000 Hz to 1700 Hz.

89. The system as claimed in claim 84, wherein said first signal portion is representative of a deformation of an inner surface in a region that is external and substantially contiguous to said footprint area.

90. The system as claimed in claim 89, wherein said external region is a post-footprint region that is substantially contiguous to the footprint area and subsequent to the footprint area in a rotation direction of the tyre.

91. The system as claimed in claim 90, wherein said post-footprint region has a first longitudinal end and a second longitudinal end, said first and second longitudinal ends defining a central angle between 25°

and 65°

.

92. The system as claimed in claim 91, wherein the first and second longitudinal ends of said post-footprint region define a central angle between 40°

and 50°

.

93. The system as claimed in claim 90, wherein said first signal portion is representative of an acceleration corresponding to a radial and/or longitudinal and/or lateral deformation of said inner surface of the tyre in the post-footprint region.

94. The system as claimed in claim 84, wherein said processing unit comprises:

a first computing module for determining said at least one parameter as a function of a mean value of an amplitude of said first signal in said portion.

95. The system as claimed in claim 94, wherein said at least one parameter is a function of a root mean square value of the amplitude of said first signal in said portion.

96. The system as claimed in claim 94, further comprising a first filtering module for filtering said first signal in a first frequency band between 700 Hz and 2000 Hz, wherein said first signal portion is representative of a deformation of said inner surface in a region that is external and substantially contiguous to said footprint area, and wherein said first computing module determines said at least one parameter according to the formula:

97. The system as claimed in claim 85, wherein said first signal portion is representative of a deformation of said inner surface of said footprint area.

98. The system as claimed in claim 85, wherein said first signal is representative of an acceleration or speed corresponding to radial deformation of said inner surface.

99. The system as claimed in claim 85, wherein said processing unit comprises a second filtering module for filtering said first signal in a second frequency band lower than 700 Hz.

100. The system as claimed in claim 99, wherein said second frequency band is lower than or equal to a first frequency corresponding to an angular speed of said tyre multiplied by a factor of 30.

101. The system as claimed in claim 97, wherein said processing unit further comprises an analysis module for identifying at least one pair of significant points on a curve representative of an evolution in time of said first signal.

102. The system as claimed in claim 101, wherein said processing unit comprises a second computing module for determining said first parameter as a function of one or more mutual distances between said significant points.

103. The system as claimed in claim 102, wherein said first signal is representative of a speed or an acceleration, and said significant points are selected from:

absolute-maximum point of the acceleration, absolute-maximum point of speed, first minimum point subsequent in time to said absolute maximum of the acceleration, first minimum point preceding in time said absolute maximum of the acceleration, second minimum point preceding in time said absolute maximum of the acceleration, absolute-minimum point of the speed, said second minimum point being prior in time relative to said first minimum point of the acceleration preceding the absolute-maximum point.

104. The system as claimed in claim 103, wherein said second computing module determines said at least one parameter according to one or more of the following formulae:

105. The system as claimed in claim 98, wherein said first signal is representative of a speed corresponding to the radial deformation of said inner surface in the footprint area.

106. The system as claimed in claim 105, wherein said processing unit comprises a third filtering module for filtering said first signal in a third frequency band defined between a first frequency and a second frequency lower than an angular speed of said tyre multiplied by a factor smaller than or equal to 30.

107. The system as claimed in claim 96, wherein said processing unit further comprises a third computing module for determining said at least one parameter according to at least one of the following formulae:

108. The system as claimed in claim 98, wherein said first signal is representative of an acceleration corresponding to the radial deformation of said inner surface in the footprint area, said processing unit and further comprises a fourth filtering module for filtering said first signal between a first frequency and a second frequency, said first and second frequencies being lower than an angular speed of the tyre multiplied by a factor smaller than or equal to 30.

109. The system as claimed in claim 108, wherein said first signal, after being processed by said fourth filtering module in the footprint area, has a first peak, a second peak, and a third peak, each identified by a pair of co-ordinates ((X_P1, Y_P1);

(X_P2, Y_P2);

(X_P3, Y_P3)) which are representative of an abscissa and an ordinate of a corresponding peak, respectively,

said processing unit being provided with;

a second analysis module for identifying said peaks; and

a fourth computing module for determining said at least one parameter as a function of one or more distances between abscissae and/or ordinates of said peaks.

110. The system as claimed in claim 109, wherein said fourth computing module determines said at least one parameter according to one or more of the following formulae:

111. The system as claimed in claim 84, wherein said processing unit comprises:

a comparison module for comparing said at least one parameter with a preset threshold value,

said processing unit capable of being adapted to generate said notification signal as a function of said comparison.

112. The system as claimed in claim 111, wherein said preset threshold value is representative of a threshold between a total-aquaplaning condition and a grip condition to the rolling surface of said tyre.

87. The system as claimed in 84, further comprising a first filtering module for filtering said first signal in a first frequency band between 700 Hz and 2000 Hz.