To manage the state of all tires based on tire information acquired from an electronic part installed in some tires of a vehicle mounted with a plurality of tires.
The tire information on the tire except for a measurement object tire is calculated from the tire information including at least internal pressure and the temperature of a tire 110 (the measurement object tire) measured by the electronic part 500, information on an installation position of the tire and the tire information on the measurement object tire, and a target value of the tire information stored in a data storage part 314 is compared with the tire information on the tire except for the measurement object tire. When a difference between the internal pressure and the target value of the measurement object tire differs, for example, by ±5% or more, it is determined as abnormal.
Iwa Saki Kokuni
Masakazu Ito
Shunichi Takahashi
Toshio Takamatsu