Device for estimating air pressure of tire from vibration components of vehicle wheel speed
First Claim
1. A device for estimating air pressure of a tire of a driven vehicle wheel of a vehicle having a drive system which operates to drive said driven vehicle wheel, said driven vehicle wheel being one of a pair of left and right vehicle wheels, comprising:
- means for detecting vehicle wheel speed of said driven vehicle wheel to provide a vehicle wheel speed signal;
means for extracting vibration components from said vehicle wheel speed signal;
means for canceling from said extracted vibration components those vibration components which are originated in the operation of said drive system and which are in the same phase between the left vehicle wheel and the right vehicle wheel, resulting in a modified vibration signal; and
means for estimating an air pressure of said tire of a driven vehicle wheel based upon a spring constant of said tire which is calculated from said modified vibration signal.
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Accused Products
Abstract
In a tire air pressure estimation based upon vibration components extractedrom a vehicle wheel speed signal, when the vehicle is a driven vehicle wheel, the precision of estimation is improved by canceling the components of vibration due to the resonance of the drive system from the vibration components based upon which the estimation calculation is made. The vibration components due to the resonance of the drive system can be canceled by canceling those vibration components extracted from the vehicle wheel speed signal which are the same in the phase between left and right driven vehicle wheels. When the tire air pressure of one of a pair of left and right driven vehicle wheels is lower than that of the other, the lower tire air pressure is more correctly estimated. Therefore, the higher tire air pressure may be estimated according to the lower tire air pressure against the drive system resonance.
58 Citations
10 Claims
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1. A device for estimating air pressure of a tire of a driven vehicle wheel of a vehicle having a drive system which operates to drive said driven vehicle wheel, said driven vehicle wheel being one of a pair of left and right vehicle wheels, comprising:
- means for detecting vehicle wheel speed of said driven vehicle wheel to provide a vehicle wheel speed signal;
means for extracting vibration components from said vehicle wheel speed signal;
means for canceling from said extracted vibration components those vibration components which are originated in the operation of said drive system and which are in the same phase between the left vehicle wheel and the right vehicle wheel, resulting in a modified vibration signal; and
means for estimating an air pressure of said tire of a driven vehicle wheel based upon a spring constant of said tire which is calculated from said modified vibration signal. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- means for detecting vehicle wheel speed of said driven vehicle wheel to provide a vehicle wheel speed signal;
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8. A device for estimating air pressure of a tire of a non-driven vehicle wheel, comprising:
- means for detecting vehicle wheel speed of a non-driven vehicle wheel to provide a non-driven vehicle wheel speed signal;
means for extracting vibration components of vehicle wheel speed due to vibration of a tire thereof from said non-driven vehicle wheel speed signal;
means for estimating air pressure of the tire of the non-driven vehicle wheel based upon said vibration components;
means for detecting loaded radius of each of the non-driven vehicle wheel and a driven vehicle wheel; and
means for estimating air pressure of a tire of the driven vehicle wheel based upon the tire air pressure of the non-driven vehicle wheel and the loaded radii detected by said loaded radius detection means. - View Dependent Claims (9, 10)
- means for detecting vehicle wheel speed of a non-driven vehicle wheel to provide a non-driven vehicle wheel speed signal;
Specification