Method and apparatus for detecting decrease in tire air-pressure and program for judging decompression of tire

• US 20030130773A1
• Filed: 01/02/2003
• Published: 07/10/2003
• Est. Priority Date: 01/09/2002
• Status: Active Grant

• Current Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation), Sumitomo Rubber Industries Limited
• Original Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation), Sumitomo Rubber Industries Limited
• Inventors: Nakamura, Akihiko, Yanase, Minao, Oshiro, Yuji
• Granted Patent: US 6,836,709 B2
• Time in Patent Office: Days
• US Class Current: 701/29
• CPC Class Codes: B60C 23/061 by monitoring wheel speed measuring distance traversed on the ground by vehicles G01C22/00

Abstract

A method for detecting decrease in tire air-pressure on the basis of rotational information obtained from tires attached to a vehicle. The method includes the steps of: detecting rotational information of the respective tires; storing the rotational information of the respective tires; obtaining an acceleration/deceleration of the vehicle; obtaining a slip rate when the acceleration/deceleration of the vehicle is within a specified range proximate to zero; comparing the slip rate with a slip rate which has been preliminarily obtained when the tire is under normal air pressure; and judging simultaneous decompression of both front wheel tires or simultaneous decompression of both rear wheel tires on the basis of a relationship between a value obtained through comparison of the two slip rates and a specified threshold. It is possible to judge simultaneous decompression of both front wheel tires or both rear wheel tires when employing the present invention.

Claims

1. A method for detecting decrease in tire air-pressure in which decrease in internal pressure of a tire is detected on the basis of rotational information obtained from tires attached to a vehicle, comprising the steps of:

detecting rotational information of the respective tires;

storing the rotational information of the respective tires;

obtaining an acceleration/deceleration of the vehicle;

obtaining a slip rate when the acceleration/deceleration of the vehicle is within a specified range proximate to zero;

comparing the slip rate with a slip rate which has been preliminarily obtained when the tire is under normal air pressure; and

judging simultaneous decompression of both front wheel tires or simultaneous decompression of both rear wheel tires on the basis of a relationship between a value obtained through comparison of the two slip rates and a specified threshold.

2. An apparatus for detecting decrease in tire air-pressure in which decrease in internal pressure of a tire is detected on the basis of rotational information obtained from tires attached to a vehicle, comprising:

rotational information detecting means for detecting rotational information of the respective tires;

a rotational information storing means for storing the rotational information of the respective tires;

an acceleration/deceleration calculating means for obtaining an acceleration/deceleration of the vehicle;

a slip rate calculating means for obtaining a slip rate when the acceleration/deceleration of the vehicle is within a specified range proximate to zero;

a slip rate comparison means for comparing the slip rate with a slip rate which has been preliminarily obtained when the tire is under normal air pressure; and

a decompression judging means for judging simultaneous decompression of both front wheel tires or simultaneous decompression of both rear wheel tires on the basis of a relationship between a value obtained through comparison of the two slip rates and a specified threshold.

3. A program for judging decompression of a tire, in which for judging decrease in tire air-pressure, a computer is made to function as a rotational information storing means for storing the rotational information of the respective tires;

an acceleration/deceleration calculating means for obtaining an acceleration/deceleration of the vehicle;

a slip rate calculating means for obtaining a slip rate when the acceleration/deceleration of the vehicle is within a specified range proximate to zero;

a slip rate comparison means for comparing the slip rate with a slip rate which has been preliminarily obtained when the tire is under normal air pressure; and

a decompression judging means for judging simultaneous decompression of both front wheel tires or simultaneous decompression of both rear wheel tires on the basis of a relationship between a value obtained through comparison of the two slip rates and a specified threshold.