US 5,864,056 A · Method and apparatus for monitoring the coefficient of friction between a tire and rolling surface, particularly to provide the vehicle operator with coefficient of friction, tire tread wear out and skid warning indications

Abstract

A method for providing skid warning, a qualitative assessment of the coefficient of friction in the footprint of each tire, and a tire tread wear out indication to a vehicle operator or other automatic systems, is described. The method uses tread force sensors, which can be installed in a tire with minimal changes to tire materials and manufacturing methods, or after tire manufacture. Tread forces within the footprint of a tire are sensed by means of embedded sensors anchored at one end to the tire structure, and at the other end to the tire tread, such that slipping of small discrete tread elements in contact with the roadway can be detected; thereby enabling the determination of the coefficient of friction before the entire footprint slips. Furthermore, coupling of the sensors between the tire structure and the tread within a small area, enables the system to use tire deformation-induced tread gripping forces to determine the coefficient of friction without the presence of maneuvering loads. Tread wear is also determined by monitoring tread slip behavior and tread forces. A suitable system for conveying the tread force information from each tire and converting it into a measure of the coefficient of friction within each footprint, and then generating a skid warning indication, qualitative coefficient of friction and tread wear out displays is provided.

Claims20

Dependent claims

A method for generating a skid warning for a motor vehicle on a road surface comprising,

a) monitoring the tread slip behavior of at least one discrete tread element within the footprint of at least one tire;
b) using said tread slip behavior of said discrete tread element to determine a footprint coefficient of friction value between said tire and said road surface, by measuring the forces on said discrete tread element;
c) comparing said footprint coefficient of friction value with at least one predetermined reference coefficient of friction value;
d) generating said skid warning when said footprint coefficient of friction value approaches said predetermined reference coefficient of friction value;
e) whereby said footprint coefficient of friction value can be determined using said tread slip behavior from the single tire in contact with said road surface, and said skid warning is achieved by sensing the slip of said discrete tread element before all the discrete tread elements within said footprint slip.

2 more elements

An apparatus for determining forces acting on a discrete tire tread element within the footprint of a motor vehicle tire comprising,

a) a sensing means that is at least partially embedded within said discrete tire tread element for sensing said forces acting on said discrete tire tread element;
b) an anchoring means for said sensing means, wherein one end of said sensing means is anchored to the tire structure and the other end of said sensing means is anchored to said discrete tire tread element;
c) a feed through means to enable the electrical connections of said sensing means to pass without damage from the region of the tire containing said sensing means, through the tire structure, to the tire hub;
d) whereby said sensing means is anchored to said discrete tread element on one end and to the tire structure on the other end, and said forces acting on said discrete tire tread element and resisted by said tire structure are sensed, and said electrical connections are protected as they pass between said sensing means and said tire hub, and further whereby the forces on an individual discrete tread element are determined.

1 more element

Dependencies are inferred from the claim text.

Method and apparatus for monitoring the coefficient of friction between a tire and rolling surface, particularly to provide the vehicle operator with coefficient of friction, tire tread wear out and skid warning indications

Life of this patent

Method and apparatus for monitoring the coefficient of friction between a tire and rolling surface, particularly to provide the vehicle operator with coefficient of friction, tire tread wear out and skid warning indications

Life of this patent

Abstract

Claims20