APPARATUS AND METHOD OF JUDGING ROAD SURFACE CONDITIONS FOR VEHICLE
First Claim
1. A tire type judging apparatus of a vehicle for judging a type of tires, comprising:
- means for detecting wheel speeds of respective wheels of said vehicle;
means for calculating a vehicle speed of said vehicle based on said wheel speeds of said respective wheels;
means for calculating a deceleration of said vehicle based on said vehicle speed;
slip ratio difference calculating means for calculating a difference of slip ratios between front and rear wheels based on said wheel speeds of said respective wheels and said vehicle speed;
slip ratio difference representative value calculating means for calculating a representative value of said difference of slip ratios between front and rear wheels; and
tire type judging means for judging a type of tires of said wheels when a preestablished condition is satisfied by comparing said representative value with a tire judgment value on which said type of tires is judged.
3 Assignments
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Accused Products
Abstract
A road surface condition judging apparatus of a vehicle includes means for detecting wheel speeds of respective wheels, means for calculating a vehicle speed of the vehicle based on the wheel speeds, means for calculating a deceleration of the vehicle, slip ratio difference calculating means for calculating a difference of slip ratios between front wheels and rear wheels based on the wheel speeds of the respective wheels and the vehicle speed, tire judgment value establishing means for variably establishing a tire judgment value, tire type judging means for judging a tire type of the wheels based on the tire judgment value, grip threshold value establishing means for variably establishing a grip threshold value in accordance with the tire type and road surface judging means for judging a road surface condition based on a comparison of the difference of slip ratios with the grip threshold value.
24 Citations
38 Claims
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1. A tire type judging apparatus of a vehicle for judging a type of tires, comprising:
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means for detecting wheel speeds of respective wheels of said vehicle;
means for calculating a vehicle speed of said vehicle based on said wheel speeds of said respective wheels;
means for calculating a deceleration of said vehicle based on said vehicle speed;
slip ratio difference calculating means for calculating a difference of slip ratios between front and rear wheels based on said wheel speeds of said respective wheels and said vehicle speed;
slip ratio difference representative value calculating means for calculating a representative value of said difference of slip ratios between front and rear wheels; and
tire type judging means for judging a type of tires of said wheels when a preestablished condition is satisfied by comparing said representative value with a tire judgment value on which said type of tires is judged. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A road surface condition judging apparatus of a vehicle for judging a grip condition between a road surface and wheels, comprising:
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means for detecting wheel speeds of said respective wheels;
means for calculating a vehicle speed of said vehicle based on said wheel speeds;
means for calculating a deceleration of said vehicle based on said vehicle speed;
slip ratio difference calculating means for calculating a difference of slip ratios between front wheels and rear wheels based on said wheel speeds of said respective wheels and said vehicle speed;
slip ratio difference representative value calculating means for calculating a representative value of said difference of slip ratios;
tire judgment value establishing means for variably establishing a tire judgment value on which a type of tires is judged to a first reference value when it is judged that there is no difference of dynamic radiuses between front and rear wheels and said tire judgment value is established to a second reference value when it is judged that there is a difference of dynamic radiuses between front and rear wheels;
tire type judging means for judging a type of tires of said wheels to be a summer tire or a studless tire when a preestablished condition is satisfied by comparing said representative value with said tire judgment value;
grip threshold value establishing means for variably establishing a grip threshold value according to said tire type and a difference of dynamic radiuses between front and rear wheels; and
road surface judging means for judging a road surface condition between said road surface and said wheels by comparing said difference of slip ratios with said grip threshold value. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A method of judging a type of tires of a vehicle, comprising the steps of:
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detecting wheel speeds of respective wheels of said vehicle;
calculating a vehicle speed of said vehicle based on said wheel speeds of said respective wheels;
calculating a deceleration of said vehicle based on said vehicle speed;
calculating a difference of slip ratios between front and rear wheels based on said wheel speeds of said respective wheels and said vehicle speed;
calculating a representative value of said difference of slip ratios between front and rear wheels; and
judging a type of tires of said wheels when a preestablished condition is satisfied by comparing said representative value with a tire judgment value on which said type of tires is judged. - View Dependent Claims (26, 27, 28, 29)
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30. A method of judging a grip condition between a road surface and wheels for a vehicle, comprising the steps of:
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detecting wheel speeds of said respective wheels;
calculating a vehicle speed of said vehicle based on said wheel speeds;
calculating a deceleration of said vehicle based on said vehicle speed;
calculating a difference of slip ratios between front wheels and rear wheels based on said wheel speeds of said respective wheels and said vehicle speed;
calculating a representative value of said difference of slip ratios;
variably establishing a tire judgment value on which a type of tires is judged to a first reference value when it is judged that there is no difference of dynamic radiuses between front and rear wheels and said tire judgment value is established to a second reference value when it is judged that there is a difference of dynamic radiuses between front and rear wheels;
judging a type of tires of said wheels to be a summer tire or a studless tire when a preestablished condition is satisfied by comparing said representative value with said tire judgment value;
variably establishing a grip threshold value according to said tire type and a difference of dynamic radiuses between front and rear wheels; and
judging a road surface condition between said road surface and said wheels by comparing said difference of slip ratios with said grip threshold value. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38)
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Specification