Method and device for detecting pneumatic abnormalities of tyre

Claim 1

A method for detecting pneumatic abnormalities of a tyre on a vehicle, the method characterised by the steps of: (a) detecting the angular velocity of each wheel, (b) producing signals proportional to the detected angular velocities, (c) measuring the acceleration of the vehicle in a forward or backward direction, (d) obtaining a speed in the forward or backward direction by integrating the measured accelerations, (e) producing a signal proportional to the speed in the forward/backward direction, and (f) arithmetically processing the signals produced in steps (b) and (e) wherein step (f) comprises obtaining, from a previously prepared table of wheel angular velocities under the normal tyre inflation condition a wheel angular velocity at the speed in the forward or backward direction which is obtained in step (d), comparing the wheel angular velocity at the speed in the forward and backward direction with the angular velocity of each wheel obtained in step (a), and operating a device which warns of pneumatic abnormalities of a tyre when the respective differences between the wheel angular velocity at the speed in the forward and backward direction and the angular velocity of each wheel detected in step (a) range from 0.05% to 0.60% of the wheel angular velocity in the table.

Claim 2

A method for detecting pneumatic abnormalities of a tyre on a vehicle, the method characterised by the steps of: (a) detecting the angular velocity of each wheel, (b) producing signals proportional to the detected angular velocities, (c) measuring the acceleration of the vehicle in a forward or backward direction, (d) obtaining a speed in the forward or backward direction by integrating the measured accelerations, (e) producing a signal proportional to the speed in the forward/backward direction, and (f) arithmetically processing the signals produced in steps (b) and (e) wherein step (f) comprises obtaining, from a previously prepared table of wheel angular velocities under the normal tyre inflation condition a wheel angular velocity at the speed in the forward or backward direction which is obtained in step (d), comparing the wheel angular velocity at the speed in the forward and backward direction with the angular velocity of each wheel obtained in step (a), and operating a device which warns of pneumatic abnormalities of a tyre when the respective differences between the wheel angular velocity at the speed in the forward and backward direction and the angular velocity of each wheel detected in step (a) range from 0.05% to 0.60% of the wheel angular velocity in the table.

Claim 6

The method of any of claims 1 to 4, characterised in that the method further includes the steps of: (I) measuring the throttle opening, differentiating the measured values and monitoring the differentiated value, and (m) invalidating the data of angular velocity of each wheel when the differentiated value exceeds 100%/sec.

Claim 7

A device for detecting pneumatic abnormalities of a tyre on a vehicle comprising angular velocity detecting means for detecting the angular velocity of each wheel, angular velocity signal producing means for producing signals proportional to the detected angular velocities, acceleration detecting means for detecting acceleration of the vehicle in a forward or backward direction, integrating means for integrating the acceleration and obtaining a speed in the forward or backward directions, speed signal producing means for producing a signal proportional to the obtained speed in the forward or backward direction, and arithmetically processing means for arithmetically processing the signals from the angular velocity signal producing means and the speed signal producing means wherein the arithmetically processing means obtains, from the previously prepared table of wheel angular velocities in the normal inflated tyre condition, a wheel angular velocity at the speed in the forward or backward direction which is obtained by the integrating means, compares the wheel angular velocity at the speed in the forward or backward direction with the angular velocity of each wheel obtained in the angular velocity detecting means, and operates a device which warns of the pneumatic abnormalities of the tyre when the respective differences between the wheel angular velocity at the speed in the forward and backward direction and the angular velocity of each wheel detected in the angular velocity detecting means range from 0.05% to 0.60% of wheel angular velocity in the table.

Claim 8

A device for detecting pneumatic abnormalities of a tyre on a vehicle comprising angular velocity detecting means for detecting the angular velocity of each wheel, angular velocity signal producing means for producing signals proportional to the detected angular velocities, acceleration detecting means for detecting acceleration of the vehicle in a forward or backward direction, integrating means for integrating the acceleration and obtaining a speed in the forward or backward directions, speed signal producing means for producing a signal proportional to the obtained speed in the forward or backward direction, and arithmetically processing means for arithmetically processing the signals from the angular velocity signal producing means and the speed signal producing means wherein the arithmetically processing means obtains, from the previously prepared table of wheel angular velocities in the normal inflated tyre condition, a wheel angular velocity at the speed in the forward or backward direction which is obtained by the integrating means, compares the wheel angular velocity at the speed in the forward or backward direction with the angular velocity of each wheel obtained in the angular velocity detecting means, and operates a device which warns of the pneumatic abnormalities of the tyre when the respective differences between the wheel angular velocity at the speed in the forward and backward direction and the angular velocity of each wheel detected in the angular velocity detecting means range from 0.05% to 0.60% of wheel angular velocity in the table.