| 摘要 |
PROBLEM TO BE SOLVED: To provide a wheel position decision unit capable of deciding on a wheel position even when a vehicle is stopped, and a tire air pressure monitoring system.SOLUTION: A control unit 11 first decides on the positions (rotational positions) on wheels opposed to wheel-side units 30a to 30d on the basis of first data signals sent from acceleration sensors 34 included in the respective wheel-side units 30a to 30d. In addition, the control unit 11 compares the results (positive or negative) of outputs of the wheel-side units 30a to 30d concerning the south-north azimuths of the wheel-side units with the result of output of a body-side unit 10 (vehicle body 4) concerning the south-north azimuth of the body-side unit on the basis of a second data signal sent from a magnetic earth sensor 33 and a third data signal sent from a direction sensor 13 incorporated in a vehicle, and decides whether a wheel that has originated a signal is a wheel on the right side of the vehicle body 4 or a wheel on the left side thereof. |
