摘要 |
The purpose of the present invention is to provide a tire air pressure monitor device capable of accurately determining the wheel position of a transmitter. In order to achieve same, the tire air pressure monitor device comprises: transmitters (2d) disposed in each wheel (1) and which transmit detected air pressure information using wireless signals; rotation position detection means (wheel speed sensor (8), ABSCU (6)) disposed on the frame side corresponding to each wheel (1), and which detect the rotation position (wheel speed pulse) of each wheel (1) and also output rotation position information (wheel speed pulse count values) to a communications line (CAN communications line (7)) at prescribed time intervals (?T0) (cycle 20 msec); and a frame-side rotation position estimation means (rotation position calculation unit (4a)) that estimates the rotation position (number of gear teeth (zt2)) at the time of transmission (transmission command time (t2)) by the transmitters (2d), on the basis of the reception information (reception completion time (t4)) for the wireless signal from the transmitters (2d) and the rotation position information (input times (t1, t5), number of gear teeth (zt1, zt5)) for the wheels (1) input via the communications line (CAN communications line (7)). |