Tire air pressure monitoring system
First Claim
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1. A tire air pressure monitoring system for monitoring a tire air pressure of each tire comprising:
- a tire air pressure detection mechanism installed on each wheel that detects the tire air pressure;
an acceleration detection mechanism installed on each wheel that detects a centrifugal acceleration while the wheel rotates;
a position determination mechanism that detects a position of a gravitational acceleration component, in a sampling time period, of the centrifugal acceleration subject to a varying periodical change along with a rotation of the wheel, wherein the position determination mechanism detects the position of the gravitational acceleration component using two or more samples of the gravitational acceleration component taken, during the sampling time period, immediately before a transmission by a transmitter;
the transmitter installed on each wheel that transmits, in the transmission, the detected tire air pressure, the position of the gravitational acceleration component, and identification information unique to each transmitter as a wireless signal, wherein the transmitter transmits at fixed time intervals unrelated to the wheel rotation, and wherein each fixed time interval corresponds to a respective sampling time period;
a receiver installed on a vehicle body to receive the wireless signal;
a rotational position detection mechanism installed on the vehicle body in correspondence with each wheel to detect the rotational position of the wheel; and
a wheel position determination mechanism having a learning mode and a monitoring mode, and during the learning mode, the wheel position determination mechanism corrects, to provide a corrected rotational position, the rotational position of each wheel at the time of transmission of the wireless signal including specific identification information by a correction value set in accordance with the position of the gravitational acceleration component superposed on the wireless signal containing the identification information to determine the wheel position of the wheel on which the transmitter is installed based on the corrected rotational position of each wheel,and during the monitoring mode, the wheel position determination mechanism detects the gravitational acceleration component at the time of the transmission of a wireless signal using the corrected rotational position of each wheel from the learning mode.
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Abstract
Provided is a tire air pressure transmission device configured to determine the rotational position of the tire air pressure transmission device based on a gravitational acceleration component of a centrifugal acceleration at the time of transmission of the tire air pressure information and to transmit in a wireless signal and at a prescribed cycle, tire air pressure information and tire air pressure transmission device rotational position information.
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Citations
5 Claims
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1. A tire air pressure monitoring system for monitoring a tire air pressure of each tire comprising:
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a tire air pressure detection mechanism installed on each wheel that detects the tire air pressure; an acceleration detection mechanism installed on each wheel that detects a centrifugal acceleration while the wheel rotates; a position determination mechanism that detects a position of a gravitational acceleration component, in a sampling time period, of the centrifugal acceleration subject to a varying periodical change along with a rotation of the wheel, wherein the position determination mechanism detects the position of the gravitational acceleration component using two or more samples of the gravitational acceleration component taken, during the sampling time period, immediately before a transmission by a transmitter; the transmitter installed on each wheel that transmits, in the transmission, the detected tire air pressure, the position of the gravitational acceleration component, and identification information unique to each transmitter as a wireless signal, wherein the transmitter transmits at fixed time intervals unrelated to the wheel rotation, and wherein each fixed time interval corresponds to a respective sampling time period; a receiver installed on a vehicle body to receive the wireless signal; a rotational position detection mechanism installed on the vehicle body in correspondence with each wheel to detect the rotational position of the wheel; and a wheel position determination mechanism having a learning mode and a monitoring mode, and during the learning mode, the wheel position determination mechanism corrects, to provide a corrected rotational position, the rotational position of each wheel at the time of transmission of the wireless signal including specific identification information by a correction value set in accordance with the position of the gravitational acceleration component superposed on the wireless signal containing the identification information to determine the wheel position of the wheel on which the transmitter is installed based on the corrected rotational position of each wheel, and during the monitoring mode, the wheel position determination mechanism detects the gravitational acceleration component at the time of the transmission of a wireless signal using the corrected rotational position of each wheel from the learning mode. - View Dependent Claims (2, 3, 4, 5)
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Specification