SYSTEM AND METHOD FOR DETERMINING TIRE FORCE

• US 20080011092A1
• Filed: 06/29/2007
• Published: 01/17/2008
• Est. Priority Date: 10/27/2003
• Status: Active Grant

• Current Assignee: Akihiro Miyoshi, Miwa Kunii, Tamio Tsurita
• Original Assignee: Akihiro Miyoshi, Miwa Kunii, Tamio Tsurita
• Inventors: Miyoshi, Akihiro, Tsurita, Tamio, Kunii, Miwa
• Granted Patent: US 7,506,539 B2
• Time in Patent Office: Days
• US Class Current: 73/779
• CPC Class Codes: G01L 5/164 using variations in inductance

Abstract

A system and method for determining the magnitude of a force acting on a tire are disclosed. Further, a sensor and a tire suitable for use in the system and method are also disclosed. The system comprises: a tire strain sensor mounted on the tire, for detecting a tire strain at the mounted position, and generating data representing tire strain; a sensor locator for locating the sensor on the tire; a memory in which data on the relationship between the tire strain and force acting on the tire at each of measuring points are stored; and a processor computing the magnitude of the force, using the data representing tire strain obtained from the tire strain sensor and the data on the relationship acquired from the memory based on the data on the sensor location obtained from the sensor locator. The method comprises: obtaining data on tire strain from a tire strain sensor mounted on the tire; locating the tire strain sensor, to obtain data on the position of the tire strain sensor; obtaining data on a relationship between the tire strain and the force at the located position of the tire strain sensor, from previously stored data on relationships between the tire strain and force at a plurality of sensor positions; and computing the force using the obtained data on the tire strain and the obtained data on the relationship between the tire strain and the force.

Claims

1. A pneumatic tire comprising

a tread portion,

a pair of sidewall portions,

a pair of bead portions, and

at least one strain sensor, wherein

said at least one strain sensor is disposed in one of the sidewall portions,

each said strain sensor is composed of a magnet and a magnetometric sensor element which are embedded in a resilient material so that the magnetometric sensor element is disposed in the magnetic flux of the magnet, and their geometrical arrangement is changed under a tire strain so as to generate data on the tire strain.

2. The pneumatic tire according to claim 1, wherein said at least one sensor is at least three sensors disposed circumferentially around the tire rotation axis.

3. The pneumatic tire according to claim 1 or 2, wherein the strain sensor is composed of a single magnet and a single magnetometric sensor element.

4. The pneumatic tire according to claim 1 or 2, wherein the strain sensor is composed of a single magnet and a plurality of magnetometric sensor elements.

5. The pneumatic tire according to claim 1 or 2, wherein the strain sensor is composed of a plurality of magnets and a single magnetometric sensor element.

6. The pneumatic tire according to claim 1, wherein the strain sensor has the most sensitive direction, and the most sensitive direction is inclined at an angle of from 10 to 80 degrees with respect to the tire radial direction.

9. The pneumatic tire according to claim 1, wherein said at least one strain sensor is disposed on the inner surface of the sidewall portion.

10. The pneumatic tire according to claim 1, wherein said at least one strain sensor is disposed on the outer surface of the sidewall portion.

11. The pneumatic tire according to claim 1, wherein said at least one strain sensor is embedded in the sidewall portion.

12. The pneumatic tire according to claim 1, wherein said resilient material is not harder than a tire sidewall rubber to which the sensor is attached.

13. The pneumatic tire according to claim 1, wherein said resilient material is a sidewall rubber of the tire, whereby said magnet and said magnetometric sensor element are embedded in the sidewall rubber, leaving a distance therebetween the magnetometric sensor element is a hall element.

7. A tire strain sensor comprising

at least one magnet, and

at least one magnetometric sensor element, which are embedded in a resilient material so that the magnetometric sensor element is disposed in the magnetic flux of the magnet, and their geometrical arrangement is changed under a strain so as to generate data on the strain.

8. A tire strain sensor according to claim 7, wherein the magnetometric sensor element is a hall element.