Title: Method for detecting decrease in inner pressure of tire using GPS speed information
Application Number: 200610111150 Application Date: 2006.08.08
Publication Number: 1912566 Publication Date: 2007.02.14
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: G01M17/02;G01L17/00;B60C23/00
Applicant(s) Name: Sumitomo Rubber Ind Address:
Inventor(s) Name: Nakao Yukio
Attorney & Agent: xu shenmin
Abstract:
    Provided is a method for detecting decrease in an inner pressure of a tire with excellent accuracy by calculating accurate dynamic load radii by comparing the GPS speed information with tire rotational speed information collecting data only when a stable measurement of the dynamic load radii is possible, as well as by utilizing GPS positioning information for a running state of a vehicle, and an apparatus and a program thereof. The present invention is characterized in judging decrease in an inner pressure of a tire from change in size of dynamic load radii by comparing an effective dynamic load radius with an initial value preliminarily stored as a dynamic load radius at a normal inner pressure, wherein the effective dynamic load radius is obtained by calculating an apparent dynamic load radius of a tire at running by successively comparing a calculated speed of a vehicle by a GPS device, in which the speed of the vehicle at running is calculated from information obtained by the GPS device, with a rotational speed of the tire obtained by a tire rotational speed detection apparatus installed on tire rotational portions of four wheels of the vehicle, and judging the apparent dynamic load radius to be effective only when a running state is judged to be straight on a flat road at a constant speed from GPS positioning information.
Time: 7
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