Judging method of vehicle loading condition

• US 20060042367A1
• Filed: 07/20/2005
• Published: 03/02/2006
• Est. Priority Date: 08/11/2004
• Status: Active Grant

• Current Assignee: Sumitomo Rubber Industries Limited
• Original Assignee: Sumitomo Rubber Industries Limited
• Inventors: Matsuura, Shinichi
• Granted Patent: US 7,213,453 B2
• Time in Patent Office: Days
• US Class Current: 73/146
• CPC Class Codes: B60C 23/061 by monitoring wheel speed measuring distance traversed on the ground by vehicles G01C22/00

Abstract

To provide a judging method of loading condition of a vehicle and a tire deflation warning system capable of preventing alarming four-wheel diffusion for a vehicle with heavy load. The judging method of vehicle loading condition including the steps of detecting rotational speeds of wheels mounted on a vehicle, calculating a judging value of tire pressures based on the difference of the sum of rotational speeds of two pairs of wheels located at the opposing corners of the vehicle and detecting an acceleration to a lateral direction of the vehicle, wherein the loading state of the vehicle is judged by the change of a primary coefficient when relation between the acceleration to a lateral direction and the judging value of the tire pressures is primarily approximated. The tire deflation warning system including means for detecting the rotational speeds of wheels mounted on a vehicle, calculating the judging value of the tire pressures based on the difference of the sum of rotational speeds of two pairs of wheels located at the opposing corners of the vehicle, detecting the acceleration to a lateral direction of the vehicle and detecting the stop of the vehicle, wherein the system includes a means for detecting the stop of the vehicle and the air pressure of four wheels is judged not to be decreased when the loading condition of a vehicle is changed more than a fixed value before and after the stop of the vehicle.

Claims

1. A judging method of vehicle loading condition, comprising the steps of:

detecting rotational speeds of wheels mounted on a vehicle;

calculating a judging value of tire pressures based on the difference of the sum of rotational speeds of two pairs of wheels located at the opposing corners of the vehicle;

detecting an acceleration to a lateral direction of the vehicle; and

detecting the stop of the vehicle;

wherein the loading state of the vehicle is judged by the change of a primary coefficient when relation between the acceleration to a lateral direction and the judging value of the tire pressures is primarily approximated before and after the stop of the vehicle.

2. A judging method of vehicle loading condition according to claim 1, wherein the step of detecting the acceleration to a lateral direction is performed by calculating based on the difference of the left and right wheels of the rotational speeds of the wheels.

3. A judging method of vehicle loading condition according to claim 1, wherein the step of detecting the stop of the vehicle is performed by detecting that the rotational speeds of the wheels are continuously zero for a fixed time.

4. A judging method of vehicle loading condition according to claim 1, wherein the step of detecting the stop of the vehicle is performed by detecting that the ignition switch of the vehicle is switched off.

5. A judging device for vehicle loading condition, comprising:

means for detecting the rotational speeds of wheels mounted on a vehicle;

means for calculating the judging value of the tire pressures based on the difference of the sum of rotational speeds of two pairs of wheels located at the opposing corners of the vehicle;

means for detecting the acceleration to a lateral direction of the vehicle; and

means for detecting the stop of the vehicle;

wherein the loading state of the vehicle is judged by the change of a primary coefficient when relation between the acceleration to a lateral direction and the judging value of the tire pressures is primarily approximated before and after the stop of the vehicle.

6. A judging device for vehicle loading condition according to claim 5, wherein the means for detecting the acceleration to a lateral direction includes means for calculating based on the difference of the left and right wheels of the rotational speeds of the wheels.

7. A judging device for vehicle loading condition according to claim 5, wherein the means for detecting the stop of the vehicle includes means for detecting that the rotational speeds of the wheels are continuously zero for a fixed time.

8. A judging device for vehicle loading condition according to claim 5, wherein the means for detecting the stop of the vehicle includes means for detecting that the ignition switch of the vehicle is switched off.

9. A judging program of vehicle loading condition, comprising the steps of:

detecting the rotational speeds of wheels mounted on a vehicle;

calculating the judging value of the tire pressures based on the difference of the sum of rotational speeds of two pairs of wheels located at the opposing corners of the vehicle;

detecting the acceleration to a lateral direction of the vehicle; and

detecting the stop of the vehicle;

wherein the loading state of the vehicle is judged by the change of a primary coefficient when relation between the acceleration to a lateral direction and the judging value of the tire pressures is primarily approximated before and after the stop of the vehicle.

10. A judging program of vehicle loading condition according to claim 9, wherein the step of detecting the acceleration to a lateral direction includes the step of calculating based on the difference of the left and right wheels of the rotational speeds of the wheels.

11. A judging program of vehicle loading condition according to claim 9, wherein the step of detecting the stop of the vehicle includes the step of detecting that the rotational speeds of the wheels are continuously zero for a fixed time.

12. A judging program of vehicle loading condition according to claim 9, wherein the step of detecting the stop of the vehicle includes the step of detecting that the ignition switch of the vehicle is switched off.

13. A detection method of the decreased tire pressures, comprising the steps of:

detecting the rotational speeds of wheels mounted on a vehicle;

calculating the judging value of the tire pressures based on the difference of the sum of rotational speeds of two pairs of wheels located at the opposing corners of the vehicle; and

detecting the acceleration to a lateral direction of the vehicle;

wherein four-wheel diffusion is detected by a primary coefficient when relation between the acceleration to a lateral direction and the judging value of the tire pressures is primarily approximated;

wherein the pressures of four wheels of the vehicle is judged not to be decreased when the primary coefficient is changed at a fixed value or more before and after the stop of the vehicle.

14. A tire deflation warning system, comprising:

means for detecting the rotational speeds of wheels mounted on a vehicle;

means for calculating the judging value of the tire pressures based on the difference of the sum of rotational speeds of two pairs of wheels located at the opposing corners of the vehicle; and

means for detecting the acceleration to a lateral direction of the vehicle;

wherein four-wheel diffusion is detected by a primary coefficient when relation between the acceleration to a lateral direction and the judging value of the tire pressures is primarily approximated;

wherein the system comprises a means for detecting the stop of the vehicle and the air pressure of four wheels is judged not to be decreased when the primary coefficient is changed at a fixed value or more before and after the stop of the vehicle.

15. A detection program of the decreased tire pressures, comprising the steps of:

inputting the rotational speeds of wheels mounted on a vehicle;

calculating the judging value of the tire pressures based on the difference of the sum of rotational speeds of two pairs of wheels located at the opposing corners of the vehicle; and

detecting the acceleration to a lateral direction of the vehicle;

wherein four-wheel diffusion is judged by a primary coefficient when relation between the acceleration to a lateral direction and the judging value of the tire pressures is primarily approximated;

wherein the stop of the vehicle is detected and the air pressure of four wheels is judged not to be decreased when the primary coefficient is changed at a fixed value or more before and after the stop of the vehicle.