Importance

Loading Importance Indicators...

Abstract

A process for determining a safety margin with respect to adhesion between tires and roadway of a travelling motor vehicle comprises, detecting longitudinal and transverse acceleration values (ax, ay), a rotational wheel acceleration value (Phi), and a dynamic steering angle value, and producing signals indicative thereof. A longitudinal adhesion value (Six) is determined as a function of the longitudinal acceleration (ax) and the rotational wheel acceleration (Phi), while a transverse adhesion value (Siy) is determined as a function of the transverse acceleration (ay) and the dynamic steering angle. Maximum attainable longitudinal and transverse acceleration values (axLIM, ayLIM) are next determined by multiplying the longitudinal and transverse acceleration values (Six, Siy) by vehicle specific coefficients (Kx, Ky) and a limit curve (aLIM), e.g., an ellipse, is established. Next a current vehicle movement state vector (AF) is formed by a vectorial combination of the longitudinal and transverse acceleration values (ax, ay). A safety margin value (SAFLIM) is obtained by comparing the lengths of the vehicle movement state vector (AF) with a collinear limit vector (AMAX) which reaches the limit curve (aLIM), and the safety margin value (SAFLIM) is displayed to the driver. Desirably, if the safety margin value (SAFLIM) exceeds predetermined threshold values, perceptible warning signals, e.g., a yellow light and then a red light, are triggered.

Loading the Abstract Image...

First Claim