TIRE AIR PRESSURE DETECTOR

摘要

PROBLEM TO BE SOLVED: To provide a new detection method that can precisely detect tire air pressure in a vehicle speed range higher than the vehicle speed range in which a detection method conventionally proposed as an indirect detection method can precisely detect tire air pressure. SOLUTION: A vibration level in a specific frequency range of wheel speed signals as time-series data on wheel speed detected by a wheel speed sensor for detecting an angular velocity of a wheel as a wheel speed is detected as an objective vibration level, according to which tire air pressure is estimated. Whether the estimation of tire air pressure is effective or not is determined according to a vibration-characteristic related value related to characteristics of vibration in the specific frequency range of the wheel speed signals.