Automatic initialization method applied to device for detecting pneumatic abnormalities on the basis of variations in angular velocity of tire

• US 5,724,266 A
• Filed: 04/30/1996
• Issued: 03/03/1998
• Est. Priority Date: 12/21/1992
• Status: Expired due to Term

• Current Assignee: Sumitomo Rubber Industries Limited
• Original Assignee: Sumitomo Rubber Industries Limited
• Inventors: Yanase, Minao, Kishimoto, Yoshikazu
• Primary Examiner(s): Trammell, James P.
• Assistant Examiner(s): Stamber, Eric W.
• Application Number:
  US08/641,265
• Time in Patent Office: 672 Days
• Field of Search: 364/565, 364/566, 364/424.053, 364/424.046, 364/424.058, 364/426.016, 364/426.021, 364/426.023, 364/426.037, 364/426.038, 73/146.2, 73/146.5, 307/10.1, 340/442, 340/444
• US Class Current: 702/141
• CPC Class Codes: B60C 23/061 by monitoring wheel speed measuring distance traversed on the ground by vehicles G01C22/00

Abstract

An automatic initialization method including the steps of: measuring and monitoring acceleration of a vehicle in a lateral direction, defining correction values for each tire of the vehicle, and obtaining baseline values under normal pneumatic pressure conditions by using only data of angular velocity of rotation of each tire when the acceleration of the vehicle in the lateral direction ranges from -0.03 g to +0.03 g, when the steering angle of the vehicle ranges from -15° to +15°, or when both the lateral acceleration and the steering angle are in the specified ranges. In the method of the present invention, only the data of angular velocities of tires is automatically picked up in the optimum driving status and initialization can be performed with high precision.

Claims

1. An automatic initialization method in a device for detecting pneumatic abnormality of a tire on the basis of variations in angular velocity of the tire wherein angular velocities of tires are relatively compared with one another and if a predetermined difference exists an alarm for tire deflation is issued, comprising the steps of:

measuring and monitoring acceleration of a vehicle in a lateral direction,

obtaining for each tire 1, 2, 3 and 4, under normal tire pressure, an angular velocity of rotation A, B, C and D, respectively and only using the data of angular velocity of rotation of each corresponding tire when the acceleration of the vehicle in the lateral direction ranges from -0.03 g to +0.03 g, and

obtaining a correction value for each tire Ac, Bc, Cc and Dc from the angular velocity of rotation A, B, C and D of corresponding tire 1, 2, 3 and 4, respectively, on the basis of the following formulas;

space="preserve" listing-type="equation">Ac=A/A

space="preserve" listing-type="equation">Bc=A/B

space="preserve" listing-type="equation">Cc=A/C

space="preserve" listing-type="equation">Dc=A/D

wherein the device is so designed to relatively compare Ac×

A'"'"';

Bc×

B'"'"';

Cc×

C'"'"' and Dc×

D'"'"', A'"'"', B'"'"', C'"'"' and D'"'"' being defined as angular velocities of rotation detected for each corresponding tire, respectively, when the vehicle is running.

2. An automatic initialization method in a device for detecting pneumatic abnormality of a tire on the basis of variations in angular velocity of the tire wherein angular velocities of tires are relatively compared with one another and if a predetermined difference exists an alarm for tire deflation is issued, comprising the steps of:

measuring and monitoring a steering angle of a vehicle,

obtaining for each tire 1, 2, 3 and 4, under normal tire pressure, an angular velocity of rotation A, B, C and D, respectively, and only using the data of angular velocity of rotation of each corresponding tire when the steering angle of the vehicle ranges from -15°

to +15°

, and

obtaining a correction value for each tire Ac, Bc, Cc and Dc from the angular velocity of rotation A, B, C and D of corresponding tire 1, 2, 3 and 4, respectively, on the basis of the following formulas;

space="preserve" listing-type="equation">Ac=A/A

space="preserve" listing-type="equation">Bc=A/B

space="preserve" listing-type="equation">Cc=A/C

space="preserve" listing-type="equation">Dc=A/D

wherein the device is so designed to relatively compare Ac×

A'"'"';

Bc×

B'"'"';

Cc×

C'"'"' and Dc×

D'"'"', A'"'"', B'"'"', C'"'"' and D'"'"' being defined as angular velocities of rotation detected for each corresponding tire, respectively, when the vehicle is running.

3. An automatic initialization method in a device for detecting pneumatic abnormality of a tire on the basis of variations of angular velocity of the tire wherein angular velocities of tires are relatively compared with one another and if a predetermined difference exists an alarm for tire deflation is issued, comprising the steps of:

measuring and monitoring acceleration of a vehicle in the lateral direction,

measuring and monitoring a steering addle of the vehicle,

obtaining for each tire 1, 2, 3 and 4, under normal tire pressure, an angular velocity of rotation A, B, C and D, respectively, and only using the data of angular velocity of rotation of each corresponding tire when the acceleration in the lateral direction ranges from -0.03 g to +0.03 g and the steering angle of the vehicle ranges from -15°

to +15°

, and

obtaining a correction value for each tire Ac, Bc, Cc and Dc from the angular velocity of rotation A, B, C and D of corresponding tire 1, 2, 3 and 4, respectively, on the basis of the following formulas;

space="preserve" listing-type="equation">Ac=A/A

space="preserve" listing-type="equation">Bc=A/B

space="preserve" listing-type="equation">Cc=A/C

space="preserve" listing-type="equation">Dc=A/D

wherein the device is so designed to relatively compare Ac ×

A'"'"';

Bc×

B'"'"';

Cc×

C'"'"' and Dc×

D'"'"', A'"'"', B'"'"', C'"'"' and D'"'"' being defined as angular velocities of rotation detected for each corresponding tire, respectively, when the vehicle is running.