Tire air pressure monitor device

摘要

Provided is a tire air pressure monitoring device capable of accurately determining the wheel position of a transmitter. The tire air pressure monitoring device comprises: a transmitter installed on each wheel for transmitting detected air pressure information via a wireless signal; a rotational position detection mechanism disposed on the vehicle body side which detects the rotational position of each wheel and also outputs rotational position information to a communications line at prescribed time intervals; and a vehicle body side rotation position estimation mechanism that estimates the rotational position (i.e., number of teeth) at the time of transmission by the transmitters, on the basis of the reception information for the wireless signal from the transmitters and the rotation position information for the wheels input via the communications line.

主权项

1. A tire pressure monitoring device for a vehicle with a plurality of wheels comprising:
a tire pressure detection mechanism installed on the tire of each wheel for detecting the air pressure of the tire; a transmitter installed on each wheel for transmitting the air pressure in a wireless signal with identification information unique to each transmitter included in the wireless signal; a receiver mounted on the side of a vehicle body for receiving the wireless signal; a rotational position detection mechanism installed on the vehicle body in correspondence with each wheel for detecting a rotational position of each wheel and outputting the rotational position at a predetermined time interval to a communication line; a vehicle body side rotational position estimate mechanism installed on the vehicle body, the vehicle body side rotational position estimate mechanism configured, for each wheel, to:
receive a transmitted wireless signal,determine a receiving start time and a receiving completion time of the received transmitted wireless signal, and a time of a transmission command or a time of actual transmission of the received transmitted wireless signal,determine a rotational position of the wheel immediately before the receiving start time and a rotational position of the wheel immediately after the receiving completion time based on the rotational position at the predetermined time interval, the receiving start time and the receiving completion time, andestimate the wheel's rotational position at the time of the transmission command, the time of actual transmission or at the time of receipt completion of the wireless signal based on:
the rotational position of the wheel immediately before the receiving start time,the rotational position of the wheel immediately after the receiving completion time, andthe respective times of input of the rotational position of the wheel immediately before the receiving start time and immediately after the receiving completion time; anda wheel position determination mechanism for identifying a position of the wheel on which the transmitter is installed based on the estimated rotational position and the identification information included in the wireless signal.