Patent ID: 6756891
Filing Date: 2004-06-29
Classification: B60C

Abstract:
A method for detecting decrease in tire air-pressure based on rotational information obtained from tires on front and rear wheels attached to a vehicle, comprising the steps of:detecting the rotational information from the front and the rear tires and sending signals to a control unit; detecting a steering angle and communicating a signal to the control storing the rotational information and the steering angle in the control unit; judging, based on the steering angle, whether the vehicle is performing straight-ahead driving; calculating a turning radius based on the rotational information of each of the tires; determining, based on the turning radius, whether the vehicle is performing straight-ahead driving or not in case it has been determined on the basis of the steering -angle that the vehicle is performing the straight-ahead driving; selecting thresholds for judging the decrease in the air-pressure of each of the tires; and calculating a judged value of decompression of the air-pressure of each of the tires and comparing the calculated judged valve with the selected thresholds to determine the decrease in the tire air pressure, wherein the thresholds for judging the decrease in the air-pressure of the rear wheels is different from the thresholds for judging the decrease in the air-pressure of the front wheels.