Method and apparatus for alarming decrease in tire air-pressure

• US 6,696,934 B2
• Filed: 12/11/2001
• Issued: 02/24/2004
• Est. Priority Date: 12/14/2000
• 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: Sugisawa, Toshifumi
• Primary Examiner(s): Pope, Daryl
• Application Number:
  US10/011,288
• Publication Number:
  US 20020105419A1
• Time in Patent Office: 805 Days
• Field of Search: 340/442, 340/443, 340/444, 340/445, 702/138, 702/140, 702/148, 701/70, 731/462, 731/463, 731/464, 731/465
• US Class Current: 340/442
• CPC Class Codes: B60C 23/061 by monitoring wheel speed measuring distance traversed on the ground by vehicles G01C22/00

Abstract

A method for alarming decrease in tire air-pressure in which a decrease in internal pressure of a tire is detected on the basis of rotational information obtainable from wheels mounted to a vehicle and a driver is accordingly alarmed. A plurality of thresholds for judging bad road are set. Decrease in air-pressure of a tire can be judged and alarm is issued upon decrease in air-pressure also when running on a bad road so that it is possible to secure safe driving for the driver.

Claims

1. A method for alarming a decrease in tire air-pressure in which a decrease in internal pressure of a tire is detected on the basis of rotational information obtainable from wheels mounted to a vehicle and a driver is accordingly alarmed, comprising the steps of:

detecting rotational signals of respective tires;

storing rotational information upon calculation of the rotational signals of the respective tires;

setting a plurality of thresholds for judging air-pressure when the vehicle is traveling on a bad road;

judging, on the basis of rotational information of the respective tires, that the vehicle is traveling on a bad road; and

judging a decrease in air-pressure of a tire on the basis of a judged value which is calculated from the rotational information of the respective tires, when it has been judged that the vehicle is traveling on a bad road.

2. The method according to claim 1, further comprising the step of setting a plurality of thresholds for judging whether the vehicle is traveling on a bad road on the basis of the rotational information of the respective tires.

3. A method for alarming a decrease in tire air-pressure in which a decrease in internal pressure of a tire is detected on the basis of rotational information obtainable from wheels mounted to a vehicle and a driver is accordingly alarmed, comprising the step of:

setting a plurality of thresholds for judging air-pressure when the vehicle is traveling on a bad road.

4. The method according to claim 3, further comprising the step of setting a plurality of thresholds for judging whether the vehicle is traveling on a bad road on the basis of the rotational information of the respective tires.

5. The method according to claim 4, further comprising the steps of:

judging on the basis of rotational information of the respective tires, that the vehicle is running on a bad road; and

judging a decrease in air-pressure of a tire on the basis of a judged valve which is calculated from the rotational information of the respective tires, when it has been judged that the vehicle is traveling on a bad road.

6. An apparatus for alarming a decrease in tire air-pressure in which a decrease in internal pressure of a tire is detected on the basis of rotational information obtainable from wheels mounted to a vehicle and a driver is accordingly alarmed, the apparatus comprising:

a threshold setting means for setting a plurality of thresholds for judging air-pressure when the vehicle is traveling on a bad road.

7. The apparatus according to claim 6, further comprising means for setting a plurality of thresholds for judging whether the vehicle is traveling on a bad road on the basis of the rotational information of the respective tires.

8. The apparatus according to claim 7 further comprising:

a bad road judging means for judging on the basis of rotational information of the respective tires, that the vehicle is running on a bad road; and

a decompression judging means for judging a decrease in air-pressure of a tire on the basis of a judged valve which is calculated from the rotational information of the respective tires, when it has been judged that the vehicle is traveling on a bad road.

9. An apparatus for alarming a decrease in tire air-pressure in which a decrease in internal pressure of a tire is detected on the basis of rotational information obtainable from wheels mounted to a vehicle and a driver is accordingly alarmed, comprising:

a speed detecting means for detecting rotational signals of respective tires;

an information storing means for storing rotational information upon calculation of the rotational signals of the respective tires;

a threshold setting means for setting a plurality of thresholds for judging air-pressure when the vehicle is traveling on a bad road;

a bad road judging means for judging, on the basis of rotational information of the respective tires, that the vehicle is traveling on a bad road; and

a decompression judging means for judging a decrease in air-pressure of a tire on the basis of a judged value which is calculated from the rotational information of the respective tires when it has been judged that the vehicle is traveling on a bad road.

10. The apparatus according to claim 9, further comprising means for setting a plurality of thresholds for judging whether the vehicle is traveling on a bad road on the basis of the rotational information of the respective tires.