Patent ID: 8387451
Filing Date: 2013-03-05
Classification: B60C

Abstract:
1. A method for detecting a decrease in tire air pressure based on wheel rotation speed information obtained from tires attached to a four-wheel vehicle, comprising: a wheel rotation speed information detection step for detecting wheel rotation speed information of the respective tires; a first storage step for storing the wheel rotation speed information detected in the rotation speed information detection step; a decreased pressure determination step for determining, based on the wheel rotation speed information, a decrease in tire air pressure; a second storage step for, assuming that a driving wheel torque required for a vehicle to run on a flat road at a fixed speed is a standard driving torque, storing a relation between the standard driving torque and a vehicle speed obtained in advance; a decreased pressure determination prohibition step for prohibiting the determination of a decrease in tire air pressure based on the wheel rotation speed information when a vehicle turning radius is lower than a predetermined threshold value determined by the relation between the driving wheel torque and the standard driving torque depending on the vehicle speed, and a decreased pressure determination start step for starting the determination of a decrease in tire air pressure based on the wheel rotation speed information when the turning radius is equal to or higher than the predetermined threshold value.