TIRE AIR PRESSURE TRANSMISSION DEVICE AND TIRE AIR PRESSURE MONITORING SYSTEM

• US 20140150543A1
• Filed: 02/20/2012
• Published: 06/05/2014
• Est. Priority Date: 05/13/2011
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Shima, Takashi, Sakaguchi, Kazuo, Terada, Syoji
• Granted Patent: US 9,823,167 B2
• Time in Patent Office: Days
• US Class Current: 73/146
• CPC Class Codes: B60C 23/04 mounted on the wheel or tyre
• CPC Class Codes: B60C 23/0416 allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
• CPC Class Codes: B60C 23/0459 self triggered by motion sensor
• CPC Class Codes: B60C 23/0488 Movement sensor, e.g. for sensing angular speed, acceleration or centripetal force
• CPC Class Codes: B60C 23/0489 for detecting the actual angular position of the monitoring device while the wheel is turning
• CPC Class Codes: G01M 17/02 Tyres

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.

Claims

1. A tire air pressure monitoring system for monitoring an 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 in a single period of a gravitational acceleration component of the centrifugal acceleration subject to a periodical change along with a rotation of the wheel;

a transmitter installed on each wheel that transmits the detected tire air pressure, the position of the gravitational acceleration component at the time of the transmission of a wireless signal, and identification information unique to each transmitter as the wireless signal;

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 that corrects 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 positional information 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.

2. The tire air pressure monitoring system as claimed in claim 1, wherein the position determination mechanism is configured to perform sampling of the gravitational acceleration component of the centrifugal acceleration at each prescribed sampling period before the transmission of the wireless signal and to detect the position in the single period of the gravitational acceleration component based on a magnitude and a direction of change of the gravitational acceleration component.

5. The tire air pressure monitoring system as claimed in claim 1, wherein the position determination mechanism is configured to determine, when the single period of the gravitational acceleration component is divided into a plurality of zones, to which zone the detected gravitational acceleration component of the centrifugal acceleration is positioned,

and wherein the transmitter transmits the wireless signal superimposed with the zone in which the gravitational acceleration component is positioned as the positional information of the gravitational acceleration component at the time of transmission of the wireless signal.

3. (canceled)

4. (canceled)