Apparatus for identifying tires and method thereof

• US 6,339,957 B1
• Filed: 07/08/1999
• Issued: 01/22/2002
• Est. Priority Date: 07/09/1998
• Status: Expired due to Term

• 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: Yanase, Minao, Oshiro, Yuji
• Primary Examiner(s): Fuller, Benjamin R.
• Assistant Examiner(s): AW MUSSE, ABDULLAHI H
• Application Number:
  US09/349,237
• Time in Patent Office: 929 Days
• Field of Search: 731/46.OR, 731/465, 731/462, 731/463, 731/468, 73/8, 73/9, 340/442, 340/445, 340/444, 340/443
• 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

An apparatus for identifying between summer tires and winter tires based on rotational information obtained from tires attached to a four-wheeled vehicle equipped with a limited slip differential device. The apparatus comprises a rotational information detecting means for detecting rotational information of each of the tires, a memory means for storing rotational information of each of the tires, an arithmetic processing means for respectively calculating reciprocals of turning radiuses based on rotational information of tires attached to a driving shaft as well as judged value based on rotational information of each of the tires, and an identification means for identifying whether the tires attached to the driving shaft are summer tires or winter tires from a relationship between reciprocals of turning radiuses and the judged value. It is possible to accurately perform detection of decrease in tire air-pressure since alarm is generated upon identification of the tires.

Claims

1. An apparatus for identifying between summer tires and winter tires based on rotational information that is obtained from tires attached to a driving shaft of a four-wheeled vehicle equipped with a limited slip differential device, wherein the apparatus comprises:

a rotational information detecting means for detecting rotational information of each of the tires attached to said driving shaft;

a memory means for storing the rotational information of each of the tires;

an arithmetic processing means for calculating a reciprocal of a turning radius based on the rotational information and for calculating judged values based on the rotational information of each of the tires; and

an identification means for identifying whether the tires attached to the driving shaft are summer tires or winter tires from a relationship between the reciprocal of the turning radius and the judged values.

3. The apparatus according to claim 1, wherein the reciprocal of the turning radius (1/Ro) is calculated from the following equation:

$\frac{1}{\mathrm{Ro}}=\frac{1}{T_W}\times <br><br>\frac{V_{\left(3\right)}-V_{\left(4\right)}}{V_{\mathrm{AVE}}}$

wherein T_W is the tread width, V₍₃₎ and V₍₄₎ are the velocity of the left and right tires attached to a driving shaft, respectively and V_AVE is an average velocity between right and left tires.

4. The apparatus according to claim 1, wherein the judged value (DEL) is calculated from the following equation:

$\mathrm{DEL}=\frac{\frac{V_{\left(1\right)}+V_{\left(4\right)}}{2}-\frac{V_{\left(2\right)}+V_{\left(3\right)}}{2}}{\frac{V_{\left(1\right)}+V_{\left(2\right)}+V_{\left(3\right)}+V_{\left(4\right)}}{4}}\times <br><br>100$

wherein V₍₁₎, V₍₂₎, V₍₃₎ and V₍₄₎ are the velocity of the front left tire, front right tire, rear left tire and rear right tire, respectively.

5. The apparatus according to claim 3, wherein the judged value (DEL) is calculated from the following equation:

$\mathrm{DEL}=\frac{\frac{V_{\left(1\right)}+V_{\left(4\right)}}{2}-\frac{V_{\left(2\right)}+V_{\left(3\right)}}{2}}{\frac{V_{\left(1\right)}+V_{\left(2\right)}+V_{\left(3\right)}+V_{\left(4\right)}}{4}}\times <br><br>100$

wherein V₍₁₎, V₍₂₎, V₍₃₎ and V₍₄₎ are the velocity of the front left tire, front right tire, rear left tire and rear right tire, respectively.

2. A method for identifying between summer tires and winter tires based on rotational information obtained from tires attached to a four-wheeled vehicle equipped with a limited slip differential device, said method comprising the steps of:

calculating a reciprocal of a turning radius based on rotational information of each of the tires and calculating judged values based on the rotational information; and

identifying whether the tires are summer tires or winter tires from a relationship between the reciprocals of the turning radius and the judged values.

6. The method according to claim 2, further comprising the step of calculating said reciprocal of the turning radius (1/Ro) from the following equation:

$\frac{1}{\mathrm{Ro}}=\frac{1}{T_W}\times <br><br>\frac{V_{\left(3\right)}-V_{\left(4\right)}}{V_{\mathrm{AVE}}}$

wherein T_W is the tread width, V₍₃₎ and V₍₄₎ are the velocity of the left and right tires attached to a driving shaft, respectively and V_AVE is an average velocity between right and left tires.

7. The method according to claim 2, further comprising the step of calculating the judged value (DEL) from the following equation:

$\mathrm{DEL}=\frac{\frac{V_{\left(1\right)}+V_{\left(4\right)}}{2}-\frac{V_{\left(2\right)}+V_{\left(3\right)}}{2}}{\frac{V_{\left(1\right)}+V_{\left(2\right)}+V_{\left(3\right)}+V_{\left(4\right)}}{4}}\times <br><br>100$

wherein V₍₁₎, V₍₂₎, V₍₃₎ and V₍₄₎ are the velocity of the front left tire, front right tire, rear left tire and rear right tire, respectively.

8. The method according to claim 6, further comprising the step of calculating the judged value (DEL) from the following equation:

$\mathrm{DEL}=\frac{\frac{V_{\left(1\right)}+V_{\left(4\right)}}{2}-\frac{V_{\left(2\right)}+V_{\left(3\right)}}{2}}{\frac{V_{\left(1\right)}+V_{\left(2\right)}+V_{\left(3\right)}+V_{\left(4\right)}}{4}}\times <br><br>100$

wherein V₍₁₎, V₍₂₎, V₍₃₎ and V₍₄₎ are the velocity of the front left tire, front right tire, rear left tire and rear right tire, respectively.