The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 21, 2009
Filed:
Jul. 25, 2006
Yukio Nakao, Kobe, JP;
Yukio Nakao, Kobe, JP;
Sumitomo Rubber Industries, Ltd., Kobe-Shi, Hyogo-Ken, JP;
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.