Road surface condition estimating method, vehicle control method, and road surface condition estimating apparatus
First Claim
1. A method for estimating a road surface condition,comprising the steps of:
- detecting vibrations of a tire having a block pattern by a vibration detecting unit;
performing a rotational order ratio analysis on the tire vibrations by a rotational order components extracting unit; and
estimating a current road surface condition from an amplitude of a rotational order component of the analyzed tire vibrations by a road surface condition estimating unit,wherein the tire has at least one row of blocks and lug grooves, each lug groove being disposed between adjacent blocks of the row of blocks, the total number N of the circumferentially disposed blocks and corresponding lug grooves being 10 or more,wherein a number n of lug grooves are provided with a joining section connecting circumferentially adjacent blocks, a relation between n and the total number N satisfying the range of (N/2)≦
n≦
(N−
5), andwherein the order of the rotational order component for estimation of the road surface condition is (N−
n).
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Accused Products
Abstract
The condition of a road surface on which a vehicle is traveling is estimated accurately, using a tire having a general variable-pitch tire pattern for detection of a road surface condition. The tire for detection of a road surface condition has rows of blocks, the total number N of the circumferentially disposed blocks being 10 or more and the number n of lug grooves, each provided with a joining section connecting circumferentially adjacent blocks, being in the range of (N/2)≦n≦(N−5). The vibrations of the tire are detected by an acceleration sensor and are subjected to a rotational order ratio analysis by a rotational order ratio analyzing unit. And the road surface condition is estimated by comparing the amplitude P of the rotational order component of the tire vibrations extracted by a rotational order component extracting unit with a predetermined threshold value K.
15 Citations
6 Claims
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1. A method for estimating a road surface condition,
comprising the steps of: -
detecting vibrations of a tire having a block pattern by a vibration detecting unit; performing a rotational order ratio analysis on the tire vibrations by a rotational order components extracting unit; and estimating a current road surface condition from an amplitude of a rotational order component of the analyzed tire vibrations by a road surface condition estimating unit, wherein the tire has at least one row of blocks and lug grooves, each lug groove being disposed between adjacent blocks of the row of blocks, the total number N of the circumferentially disposed blocks and corresponding lug grooves being 10 or more, wherein a number n of lug grooves are provided with a joining section connecting circumferentially adjacent blocks, a relation between n and the total number N satisfying the range of (N/2)≦
n≦
(N−
5), andwherein the order of the rotational order component for estimation of the road surface condition is (N−
n). - View Dependent Claims (2, 3, 4, 5)
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6. An apparatus for estimating a road surface condition, comprising:
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a tire for estimation of a road surface condition, the tire having at least one row of blocks and lug grooves, each lug groove being disposed between adjacent blocks of the row of blocks, the total number N of the circumferentially disposed blocks and corresponding lugs grooves being 10 or more, a number n of the lug grooves, are provided with a joining section connecting circumferentially adjacent blocks, a relation between n and the total number N satisfying the range of (N/2)≦
n≦
(N−
5);a vibrations detecting unit disposed in an unsprung portion of a vehicle for detecting vibrations of a tire tread propagated to the unsprung portion from the tire; a rotational order components extracting unit for performing a rotational order ratio analysis on the vibrations of the tire tread detected by the vibrations detecting unit and extracting the amplitude of a rotational order component whose order is (N−
n); anda road surface condition estimating unit for estimating a current road surface condition from the extracted amplitude of the rotational order component.
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Specification