Method of detecting a deflated tire on a vehicle
First Claim
1. A method of detecting a partially deflated pneumatic tire on a vehicle having four tires each mounted on a wheel comprising the steps of:
- (a) sensing the angular velocity of each wheel and producing four signals proportional thereto;
(b) processing the four signals in a processing unit which subtracts a first sum of the signals from one pair of diagonally opposite wheels from a second sum of the signals from the other pair of diagonally opposite wheels;
(c) sensing when the magnitude of the result of the processing at said step (b) is between 0.05% and 0.6% of the mean of said first and second sums to produce a signal factor; and
(d) operating a warning device, when said signal factor is present, to indicate a tire is partially or completely deflated, wherein the angular velocity of each wheel is measured simultaneously by a pulse generator providing a digital signal of more than twenty pulses per revolution of the wheel, the angular velocities derived from the single pulse signals being interpolated to provide the angular velocity of each wheel at the same instant, and a second signal of a single pulse per revolution of the wheel and the two angular velocity signals are both used.
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Accused Products
Abstract
A method of detecting a partially deflated pneumatic tire on a vehicle having four tires each mounted on a wheel including the steps of sensing the angular velocity of each wheel and producing a signal proportional thereto, processing the four signals in a processing unit which subtracts the sum of the signals from one pair of diagonally opposite wheels from the sum of the signals from the other pair of diagonally opposite wheels, sensing when the magnitude of the result is between 0.05% and 0.6% of the mean of the two sums to produce a signal factor and when said signal factor is present operating a warning device to indicate a tire is partially or completely deflated wherein the angular velocity of each wheel is measured simultaneously by a pulse generator providing a digital signal of more than twenty pulses per revolution of the wheel and a second signal of a single pulse per revolution of the wheel and the two angular velocity signals are both used. The method may also compare the signal for each wheel with the average of all four wheels and if the difference is greater than 0.1%, a deflation is indicated for allowing the detection of which wheel is deflated. Multi-pulse and single pulse detection may be selected according to speed and both may be used simultaneously.
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Citations
14 Claims
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1. A method of detecting a partially deflated pneumatic tire on a vehicle having four tires each mounted on a wheel comprising the steps of:
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(a) sensing the angular velocity of each wheel and producing four signals proportional thereto; (b) processing the four signals in a processing unit which subtracts a first sum of the signals from one pair of diagonally opposite wheels from a second sum of the signals from the other pair of diagonally opposite wheels; (c) sensing when the magnitude of the result of the processing at said step (b) is between 0.05% and 0.6% of the mean of said first and second sums to produce a signal factor; and (d) operating a warning device, when said signal factor is present, to indicate a tire is partially or completely deflated, wherein the angular velocity of each wheel is measured simultaneously by a pulse generator providing a digital signal of more than twenty pulses per revolution of the wheel, the angular velocities derived from the single pulse signals being interpolated to provide the angular velocity of each wheel at the same instant, and a second signal of a single pulse per revolution of the wheel and the two angular velocity signals are both used. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A system for detecting a partially deflated pneumatic tire on a vehicle having four tires each mounted on a wheel, comprising:
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signal generating means for sensing the angular velocity of each wheel and producing four signals proportional thereto; a processing unit for processing said four signals by subtracting a first sum of the signals from one pair of diagonally opposite wheels from a second sum of the signals from the other pair of diagonally opposite wheels; sensing means for sensing when the magnitude of the result from said processing unit is between 0.05% and 0.6% of the mean of said first and second sums to produce a signal factor; a pulse generator for simultaneously measuring the angular velocity of each wheel to provide a digital signal of more than twenty pulses per revolution of the wheel, the angular velocities derived from the single pulse signals being interpolated to provide the angular velocity of each wheel at the same instant, and a second signal of a single pulse per revolution of the wheel and the two angular velocity signals are both used; and a warning device for operating to indicate a tire is partially or completely deflated when said signal factor is present. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification