Tire position determination system

摘要

A travelling state determination unit of a tire pressure detector determines a travelling state of a vehicle based on a gravitational component force detected by an acceleration sensor. An operation mode switching unit of the tire pressure detector switches the operation mode of the tire pressure detector from a pressure determination mode to an automatic locating mode when the vehicle speed become lower than a threshold value. An interval of period transmission of radio waves in the automatic locating mode is set to be shorter than an interval of the periodic radio wave transmission in the pressure determination mode.

主权项

1. A tire position determination system that determines positions of tires, the tire position determination system comprising:
a tire pressure detector attached to each of the tires, wherein the tire pressure detector transmits a tire pressure signal; a receiver arranged on a vehicle body, wherein the receiver receives the tire pressure signal from each tire pressure detector; an axle rotation amount detector that detects a rotation amount of an axle corresponding to each of the tires; and an automatic locating function unit that calculates an axle rotational angle from an axle rotation amount detected by the axle rotation amount detector during a first vehicle stopping operation and an axle rotation amount detected by the axle rotation amount detector in a second vehicle stopping operation, calculates a detector rotational angle from a gravitational component force generated in the tire pressure detector during the first vehicle stopping operation and a gravitational component force generated in the tire pressure detector during the second vehicle stopping operation, and determines the position of each of the tires based on the axle rotational angle and the detector rotational angle, wherein each tire pressure detector is selectively operated in a pressure determination mode and an automatic locating mode, and each tire pressure detector includes
a gravitational component force detection unit that detects the gravitational component force and generates a detection signal,a travelling state determination unit that determines a travelling state of the vehicle using the detection signal from the gravitational component force detection unit, andan operation mode switching unit that switches an operation mode of the tire pressure detector from the pressure determination mode to the automatic locating mode based on the determination of the travelling state determination unit.