Tire position determination system

Patent metadata

Field	Value
Publication number	US-9849736-B2
Application number	US-201415035028-A
Country	US
Kind code	B2
Filing date	Nov 12, 2014
Priority date	Nov 15, 2013
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

A tire position determination system is provided with: a plurality of tire air pressure transmitters each capable of transmitting a first radio signal including air pressure data and a tire ID; a plurality of axle rotation detection units each generating axle rotation information; and a receiver mounted to a vehicle body and capable of receiving the first radio signal. Each of the plurality of tire air pressure transmitters includes a specific position detection unit capable of detecting the arrival of the tire air pressure transmitter at a specific position on a trajectory of rotation of the tire, and a transmission control unit that, based on a result of detection, generates a second radio signal including data indicating the arrival of the tire air pressure transmitter at the specific position on the trajectory of rotation of the tire and the ID. The receiver includes a position determination unit that determines a tire position of the plurality of tires based on the second radio signal.

First claim

The invention claimed is:

1. A tire position determination system comprising:
transmitters respectively coupled to tires, wherein each of the transmitters is capable of transmitting a first radio wave signal that includes pressure data and a tire ID;
rotation detectors respectively arranged on axles, wherein each of the rotation detectors detects rotation of a corresponding one of the axles and generates axle rotation information; and
a receiver arranged on a vehicle body, wherein the receiver is capable of receiving the first radio wave signal transmitted from each of the transmitters, wherein
each of the transmitters includes:
a controller that detects that the transmitter has reached a specific position on a rotation path of the tire, and
the controller generates a second radio wave signal, which includes an ID and data indicating that the transmitter has reached the specific position on the rotation path of the tire, based on a detection result detected by the controller and transmits the second radio wave signal from the transmitter, and

the receiver includes:
a processor that acquires the axle rotation information from each of the rotation detectors whenever the receiver receives the second radio wave signal, and
the processor calculates a distribution of the axle rotation information for each of the IDs by collecting statistics of the axle rotation information for each of the IDs and determines tire positions of the tires by specifying an ID of a tire that rotates in synchronism with the axle rotation information of each of the axles based on the distribution,

wherein
in an operation of the transmitter, a relatively short first time period, during which transmission of a radio wave signal is allowed, and a second time period, during which transmission of a radio wave signal is temporarily stopped, are alternately repeated, and
the controller transmits the second radio wave signal a number of times in the first time period.

2. A tire position determination system comprising:
transmitters respectively coupled to tires, wherein each of the transmitters is capable of transmitting a first radio wave signal that includes pressure data and a tire ID;
rotation detectors respectively arranged on axles, wherein each of the rotation detectors detects rotation of a corresponding one of the axles and generates axle rotation information; and
a receiver arranged on a vehicle body, wherein the receiver is capable of receiving the first radio wave signal transmitted from each of the transmitters, wherein
each of the transmitters includes:
a controller that detects that the transmitter has reached a specific position on a rotation path of the tire, and
the controller generates a second radio wave signal, which includes an ID and data indicating that the transmitter has reached the specific position on the rotation path of the tire, based on a detection result detected by the controller and transmits the second radio wave signal from the transmitter, and

the receiver includes:
a processor that acquires the axle rotation information from each of the rotation detectors whenever the receiver receives the second radio wave signal, and
the processor calculates a distribution of the axle rotation information for each of the IDs by collecting statistics of the axle rotation information for each of the IDs and determines tire positions of the tires by specifying an ID of a tire that rotates in synchronism with the axle rotation information of each of the axles based on the distribution,

wherein the processor performs absolute evaluation, which determines validity of the distribution using the axle rotation information of each of the axles, and relative evaluation, which determines validity of the distribution using the axle rotation information of the axles, to determine a tire position based on a result of the absolute evaluation and a result of the relative evaluation.

3. The tire position determination system according to claim 1 , wherein the processor performs relative evaluation that determines validity of the distribution using variance of the axle rotation information of the axles to determine a tire position based on a result of the relative evaluation.

4. The tire position determination system according to claim 1 , wherein
the processor of the receiver further determines a traveling state, and weights the second radio wave signal received by the receiver based on the traveling state determined by the processor; and
the processor calculates a distribution of the axle rotation information for each of the IDs by collecting statistics on the axle rotation information that reflects the weighting for each of the IDs and determines tire positions of the tires based on the distribution.

5. The tire position determination system according to claim 4 , wherein
the processor is capable of determining a speed of a vehicle, and weights the second radio wave signal based on speed dependency.

6. The tire position determination system according to claim 4 , wherein
the processor is capable of determining acceleration and deceleration of a vehicle, and weights the second radio wave signal based on acceleration/deceleration dependency.

7. A tire position determination system comprising:
transmitters respectively coupled to tires, wherein each of the transmitters is capable of transmitting a first radio wave signal that includes pressure data and a tire ID;
rotation detectors respectively arranged on axles, wherein each of the rotation detectors detects rotation of a corresponding one of the axles and generates axle rotation information; and
a receiver arranged on a vehicle body, wherein the receiver is capable of receiving the first radio wave signal transmitted from each of the transmitters, wherein
each of the transmitters includes:
a controller that detects that the transmitter has reached a specific position on a rotation path of the tire, and
the controller generates a second radio wave signal, which includes an ID and data indicating that the transmitter has reached the specific position on the rotation path of the tire, based on a detection result detected by the controller and transmits the second radio wave signal from the transmitter, and

the receiver includes:
a processor that acquires the axle rotation information from each of the axle rotation detectors whenever the receiver receives the second radio wave signal, and
the processor calculates a distribution of the axle rotation information for each of the IDs by collecting statistics of the axle rotation information for each of the IDs and determines tire positions of the tires by specifying an ID of a tire that rotates in synchronism with the axle rotation information of each of the axles based on the distribution,

wherein, when a tire position of a tire of a specific ID is not specified, and a plurality of candidate tires remain, and when a tire position of a tire of another ID is specified, the processor deletes the specified tire from the plurality of candidate tires and narrows down or specifies a correct tire.

8. The tire position determination system according to claim 2 , wherein the processor statistically determines variance of the axle rotation information of the axles as the relative evaluation to determine tire positions of the tires.

9. The tire position determination system according to claim 2 , wherein the processor relatively evaluates variance of the axle rotation information of the axles and ranks the axles to determine tire positions of the tires.

10. The tire position determination system according to claim 1 , wherein
the receiver includes an information storage that holds one or more pieces of specific positi

Assignees

• Tokai Rika Co Ltd

Inventors

• Watanabe Naoki
• Tsuchikawa Yuta
• Kumagai Katsuhide
• Matsushita Masahiro

Classifications

• B60C23/02

  Signalling devices actuated by tyre pressure {(hand-held tyre pressure gauges G01L17/00)} · CPC title

• B60C23/0415

  Automatically identifying wheel mounted units, e.g. after replacement or exchange of wheels · CPC title

• G08C17/00

  Arrangements for transmitting signals characterised by the use of a wireless electrical link · CPC title

• G01L17/00

  Devices or apparatus for measuring tyre pressure or the pressure in other inflated bodies · CPC title

• B60C23/0489 Primary

  for detecting the actual angular position of the monitoring device while the wheel is turning · CPC title