DEVICE FOR DETERMINING TIRE AIR PRESSURE DROP

摘要

PROBLEM TO BE SOLVED: To correctly determine that the tire air pressure is dropped to the warning value based on the degree of dispersion between rotational angular velocities of respective wheels irrespective of the characteristic of tires actually fitted to a vehicle. SOLUTION: A device for determining the tire air pressure drop calculates a parameter value D for determining the air pressure drop which is changed according to the degree of dispersion between rotational angular velocitiesω** of respective wheels by a formula D=ωfr/ωfl-ωrr/ωrl. The value of D (Dfref) which is obtained when the tire air pressure is dropped to the warning air pressure Pwarn from the D value (Dstd) obtained in a condition in which the tire air pressure of all wheels is set to a standard value (Pfstd for right and left front wheels) and the D value (Dfup) obtained in a condition in which only the tire air pressure of any one wheel (left front wheel FL) is increased byΔP from this condition is estimated for each wheel, and it is determined whether or not the tire air pressure is dropped to Pwarn based on the result of comparison of the D value obtained while the vehicle is traveling with Dfref. COPYRIGHT: (C)2005,JPO&NCIPI