TIRE POSITION DETERMINATION SYSTEM

• US 20140354421A1
• Filed: 05/27/2014
• Published: 12/04/2014
• Est. Priority Date: 06/03/2013
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho
• Original Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho
• Inventors: KOSUGI, Masanori, KUMAGAI, Katsuhide, WATANABE, Naoki
• Granted Patent: US 9,180,742 B2
• Time in Patent Office: Days
• US Class Current: 340/447
• CPC Class Codes: B60C 23/0415 Automatically identifying wheel mounted units, e.g. after replacement or exchange of wheels
• CPC Class Codes: B60C 23/0416 allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
• CPC Class Codes: B60C 23/0488 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

Abstract

A tire position determination system including tire pressure detectors respectively attached to tires, axle rotation detectors respectively corresponding to axles, and a receiver located on a vehicle body. Each tire pressure detector detects when reaching a specific position on a rotation trajectory of the corresponding tire and transmits a radio wave including the tire ID. An ID temporary registration unit temporarily registers tire IDs to the memory that are received from the tire pressure detectors existing in a signal receivable area of the receiver. An ID registration acquires axle rotation information from each axle rotation detector whenever receiving the radio wave from each tire pressure detector, and specifies a tire ID of a tire that rotates in synchronism with rotation of each axle to determine the tire position of the tire.

Claims

1. A tire position determination system comprising:

a plurality of tire pressure detectors, each attached to one of a plurality of tires and each capable of transmitting a first radio wave, wherein the first radio wave includes a tire ID and pressure data associated with the tire ID;

a plurality of axle rotation detectors, each corresponding to one of a plurality of axles, wherein each of the axle rotation detectors detects rotation of the corresponding one of the axles and outputs axle rotation information;

a receiver located on a vehicle body of a vehicle, wherein the receiver is capable of receiving the first radio wave from each of the tire pressure detectors; and

a controller that monitors the pressure of each of the tires based on the first radio wave received by the receiver, wherein

each of the tire pressure detectors is configured to detect when reaching a specific position on a rotation trajectory of the corresponding one of the tires and transmit a second radio wave including the tire ID, and

the controller includes

an ID temporary registration unit that temporarily registers, to a memory, tire IDs received from all tire pressure detectors existing in a signal receivable area of the receiver, and

an ID registration unit that receives the second radio wave from each of the tire pressure detectors, acquires the axle rotation information from each of the axle rotation detectors whenever receiving the second radio wave, and specifies a tire ID of a tire that rotates in synchronism with the axle rotation information of each of the axles, from the tire IDs temporarily registered in the memory, to determine a tire position of each of the tires.

2. The tire position determination system according to claim 1, wherein the controller further includes an ID candidate selector that checks whether or not the temporarily registered tire IDs are continuously received when the vehicle is traveling to select a tire ID of which the tire position is to be determined from the temporarily registered tire IDs.

3. The tire position determination system according to claim 1, wherein the ID temporary registration unit is configured to temporarily register all tire IDs received during a certain time.

4. The tire position determination system according to claim 1, wherein the ID temporary registration unit is configured to temporarily register all tire IDs received in a time period during which the ID registration unit is not operating.

5. The tire position determination system according to claim 2, wherein the ID registration unit is configured so that when receiving in regular or irregular intervals, as the vehicle is traveling, a non-selected tire ID that was not selected by the ID candidate selector as a tire ID of which the tire position is to be determined, the ID registration unit determines that the non-selected tire ID is a tire ID of a spare tire.

6. The tire position determination system according to claim 1, wherein the ID registration unit is configured to repetitively perform a tire position determination process for a number of times and formally register tire positions of the tires to the memory when determining that the tire positions of the tires are continuously the same.

7. The tire position determination system according to claim 1, wherein

each of the tire pressure detectors includes

a gravitational force detector that detects the position of the corresponding tire pressure detector,

a specific position detector that detects when the corresponding tire pressure detector reaches the specific position based on a detection signal of the gravitational force detector, and

a specific position notification unit that transmits the second radio wave to indicate that the corresponding tire pressure detector has reached the specific portion;

and

the ID registration unit includes a formal registration unit in the receiver, wherein the formal registration unit is configured to

calculate a first relative rotation angle of each of the tire pressure detectors during a first determination period from a first determination timing to when each tire completes a single rotation,

calculate a second relative rotation angle of each of the tire pressure detectors during a second determination period from a second determination timing, which is subsequent to the first determination period, to when each tire completes a single rotation,

calculate, from the first relative rotation angle and the second relative rotation angle, a detector rotation angle representing a relative rotation angle of each of the tire pressure detectors that changes from the first determination period to the second determination period, and

determine the tire position by comparing the detector rotation angle of each of the tire pressure detectors with a rotation angle of each of the axles that changes from the first determination period to the second determination period.

8. The tire position determination system according to claim 1, further comprising:

a plurality of gravitational force detectors, each arranged in one of the tire pressure detectors;

a characteristic value acquisition unit capable of acquiring a characteristic value corresponding to the position of the tire pressure detector based on a detection signal of the corresponding gravitational force detector, wherein the characteristic value acquisition unit is configured to acquire

a first characteristic value corresponding to the position of the tire pressure detector when an ignition switch of the vehicle is deactivated, and

a second characteristic value corresponding to the position of the tire pressure detector when the ignition switch is activated;

a characteristic value comparator that compares the first characteristic value and the second characteristic value; and

an operation control unit that determines whether or not the tire position has changed based on the comparison of the characteristic value comparator.

9. The tire position determination system according to claim 1, wherein:

each of the tire pressure detectors includes

a gravitational force detector that detects the position of the corresponding tire pressure detector,

a specific position detector that detects when the corresponding tire pressure detector reaches the specific position based on a detection signal of the gravitational force detector, and

a specific position notification unit that transmits the second radio wave from the corresponding tire pressure detector at a certain timing; and

the ID registration unit includes

a formal registration unit configured to

calculate a distribution of the axle rotation information of each axle for each of the tire IDs based on a statistic value of the axle rotation information of each axle, and

determine the tire position by specifying, based on the distribution, a tire ID of a tire that rotates in synchronism with the axle rotation information of each axle.

10. A tire position determination system comprising:

a plurality of tire pressure detectors, each attached to one of a plurality of tires and each capable of transmitting a first radio wave, wherein the first radio wave includes a tire ID and pressure data associated with the tire ID;

a plurality of axle rotation detectors, each corresponding to one of a plurality of axles, wherein each of the axle rotation detectors detects rotation of the corresponding one of the axles and outputs axle rotation information;

a receiver located on a vehicle body of a vehicle, wherein the receiver is capable of receiving the first radio wave from each of the tire pressure detectors; and

a controller that monitors the pressure of each of the tires based on the first radio wave received by the receiver, wherein

each of the tire pressure detectors is capable of transmitting position data corresponding to a position on a rotation trajectory of the corresponding one of the tires, and

the controller includes

an ID temporary registration unit that temporarily registers, to a memory, tire IDs received from all tire pressure detectors existing in a signal receivable area of the receiver, and

an ID registration unit that receives the position data from each of the tire pressure detectors, acquires the axle rotation information from each of the axle rotation detectors whenever receiving the position data, and specifies a tire ID of a tire that rotates in synchronism with the axle rotation information of each of the axles, from the tire IDs temporarily registered in the memory, to determine a tire position of each of the tires.