US 2004/0111198 A1Published application

Underinflation detector

AssigneeHonda Motor Co., Ltd.

InventorsKeiyu Kin, Osamu Yano

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Abstract

A rotational speed V1 of a left front wheel T1, a rotational speed V2 of a right front wheel T2, a rotational speed V3 of a left rear wheel T3, and a rotational speed V4 of a right rear wheel T4 are detected by rotational speed sensors S1-S4, respectively. A front-wheel yaw rate γF arising due to a rotational speed difference between the front wheels T1, T2 and a rear-wheel yaw rate γR arising due to a rotational speed difference between the rear wheels T3, T4 are monitored. When a significant disparity between the both rotational speed differences is observed, it is determined that tire inflation pressure of any of the wheels T1-T4 has decreased. Upon detection, correction is made to an apparent yaw rate that would be observed in the properly inflated wheel as a result of steering for correction by a driver, thereby improving detection accuracy of underinflation of the tires.

Claims6

Dependent claims

An underinflation detector for a four-wheeled vehicle comprising:

a rotational speed sensor that detects rotational speeds of two front wheels and two rear wheels of the vehicle;
and
a controller that determines that inflation pressure of a tire of any of the wheels has decreased, if a parameter calculated from outputs of the rotational speed sensor exceeds a threshold, wherein a first value of the parameter is calculated using a disparity between a front-wheel rotational speed difference and a rear-wheel rotational speed difference;
and
wherein correction is made to the first value of the parameter to obtain a second value of the parameter to be compared with the threshold by canceling a deviation of one of the front-wheel rotational speed difference and the rear-wheel rotational speed difference caused by a steering operation which a driver performs so as to cancel the other of the front-wheel rotational speed difference and the rear-wheel rotational speed difference arising due to underinflation of the tire.

2 more elements

Dependencies are inferred from the claim text.