Tire sensing system

Patent metadata

Field	Value
Publication number	US-9233693-B2
Application number	US-201414276208-A
Country	US
Kind code	B2
Filing date	May 13, 2014
Priority date	May 17, 2013
Publication date	Jan 12, 2016
Grant date	Jan 12, 2016

Abstract

Provided is a tire sensing system that reduces the power consumption, size, weight, and cost, while suppressing an increase in fuel consumption of moving means. The tire sensing system is adapted to monitor state of a tire or a road surface from vibration information to perform safety control of the moving means having the tire. The tire sensing system includes a sensor disposed in a position of an inner surface of the tire where the sensor can sense the vibration, a receiver for receiving the information sent from the sensor, and a control means for controlling the moving means on the basis of the information from the receiver. The state is estimated from first vibration applied to the sensor upon contact with the road surface via the tire, second vibration applied to the sensor upon departure from the road surface, and a contact time from the contact to the departure.

First claim

What is claimed is:

1. A tire sensing system for monitoring a state of a tire or a road surface from information on vibration around the tire to perform safety control of an object having the tire, the tire sensing system comprising:
a sensor to be disposed at a position of an inner surface of the tire where the sensor senses the vibration;
a receiver for receiving the information on the vibration sent from the sensor; and
a controller that
(a) extracts from the information on the vibration
(a1) a first vibration sensed by the sensor upon contact of the sensor with the road surface via the tire due to rotation of the tire,
(a2) a second vibration sensed by the sensor upon departure of the sensor from the road surface via the tire due to rotation of the tire, and
(a3) a contact time from the contact of the sensor, via the tire, with the road surface to the departure of the sensor, via the tire, from the road surface, and

(b) controls the object based on the first vibration, the second vibration, and the contact time.

2. The tire sensing system according to claim 1 , wherein the state of the tire or the road surface corresponds to an air pressure of the tire, or a friction force between the tire and the road surface.

3. The tire sensing system according to claim 1 , wherein the sensor senses the vibration along a tangential direction of the tire, and
when the first vibration and the second vibration become larger and the contact time becomes longer, an air pressure of the tire is determined to be decreased.

4. The tire sensing system according to claim 1 , wherein the sensor senses the vibration along a normal direction of the tire, and
when the contact time becomes longer, an air pressure of the tire is determined to be decreased.

5. The tire sensing system according to claim 1 , wherein the sensor senses the vibration along a tangential direction of the tire, and
when the first vibration and the second vibration become larger and the contact time becomes shorter, the tire is determined to be slippery.

6. The tire sensing system according to claim 1 , wherein the sensor senses the vibration along a tangential direction of the tire, and
when the first vibration and the second vibration become smaller and the contact time becomes shorter, a friction force between the tire and the road surface is determined to be decreased, and the tire is determined to be slippery.

7. The tire sensing system according to claim 1 , wherein the sensor senses the vibration along a normal direction of the tire, and
when the first vibration and the second vibration become larger and the contact time becomes shorter, the tire is determined to be slippery.

8. The tire sensing system according to claim 1 , further comprising a data table indicative of a list of vibration information and the state of the tire or the road surface corresponding thereto,
wherein referring to the data table, the information on the vibration from the sensor is verified against the vibration information included in the data table to determine the state of the tire or the road surface.

9. The tire sensing system according to claim 1 , wherein the information on the vibration is converted into a protocol to perform communications or information processing.

10. The tire sensing system according to claim 1 , wherein the sensor is a generation vibration sensor comprising a power generating element for converting the vibration into electric power and being adapted to output a power output waveform, and
wherein the tire sensing system further comprises a first power system, the first power system being connected to the power generating element and adapted to extract the information on the vibration from the power output waveform obtained by the power generating element.

11. The tire sensing system according to claim 10 , further comprising a second power system, the second power system being connected to the power generating element and adapted to supply the electric power for sending the information on the vibration extracted by the first power system to an outside.

12. The tire sensing system according to claim 11 , wherein the power generating element comprises:
a fixed substrate;
a movable substrate having one main surface opposed to one main surface of the fixed substrate, the movable substrate being capable of vibrating substantially in parallel to the fixed substrate;
a plurality of electrets disposed at one of the one main surface of the fixed substrate and the one main surface of the movable substrate in parallel with respect to a direction of vibration of the movable substrate; and
a first electrode and a second electrode alternately disposed over another of the one main surface of the fixed substrate and the one main surface of the movable substrate in parallel with respect to the direction of vibration, each of the first electrode and the second electrode being connected to a respective one of the first power system and the second power system.

13. The tire sensing system according to claim 11 , wherein the power generating element comprises:
an elastic structure adapted to vibrate;
a fixed substrate connected to one end of the elastic structure;
a movable substrate connected to another end of the elastic structure; and
a first laminated structure and a second laminated structure provided over the elastic structure, and each of the first laminated structure and the second laminated structure is connected to a respective one of the first power system and the second power system,
wherein the first laminated structure comprises a first lower electrode, a first piezoelectric element formed over the first lower electrode, and a first upper electrode formed over the first piezoelectric element, and
wherein the second laminated structure comprises a second lower electrode, a second piezoelectric element formed over the second lower electrode, and a second upper electrode formed over the second piezoelectric element.

Assignees

• Panasonic Corp
• Panasonic Ip Man Co Ltd

Inventors

• Naito Yasuyuki
• Onishi Keiji

Classifications

• B60C2019/004

  Tyre sensors other than for detecting tyre pressure · CPC title

• B60T8/1725

  Using tyre sensors, e.g. Sidewall Torsion sensors [SWT] (for tyre pressure and temperature detection B60C23/00) · CPC title

• B60T2240/04

  Tyre deformation · CPC title

• B60C23/064 Primary

  comprising tyre mounted deformation sensors, e.g. to determine road contact area · CPC title

• B60W40/10

  related to vehicle motion · CPC title