Method and apparatus for alarming decrease in tire air-pressure

摘要

A method for alarming a decrease in tire air-pressure, in which rotational numbers of four tires are detected for judging whether any of the tire air-pressures is decreased or not, and issuing an alarm if the internal pressure of a tire is decreased. In an equation for calculating a judged value for detecting deflation of a tire, correction factor function values including a first factor related to lateral acceleration of the vehicle and a second factor related to lateral acceleration and front and rear wheel ratios are subtracted from actually measured values when performing actual running of the vehicle with the tires being set to specific air-pressures. The first and second factors are calculated such that a result of subtraction is approximately close to zero and is stored. It is possible to improve accuracy of detection of deflations of tires by automatically obtaining factors for turning correction after mounting the tires to the vehicle.