METHOD FOR DETERMINING ROLLING FRICTION COEFFICIENT AND ROLLING RESISTANCE COEFFICIENT Russian patent published in 2012 - IPC G01N19/02 

FIELD: test equipment.

SUBSTANCE: invention refers to equipment and method of determining friction parameters, and namely to methods for determining rolling friction coefficients. The effect is achieved by the fact that in the method involving the operation of arrangement of the tested wheel on horizontal hard coating, as well as fixing operation of deformation of pneumatic part of the wheel, that operation is performed by means of video camera recording of the picture of deformation of contact zone of wheel pneumatic part and hard coating, which occurs at the wheel back and forth movements; after that, the recorded process is split on the computer into frames with resolution of 0.04 sec or less; the concerned frames are displayed; the picture is enlarged to the necessary sizes, and by means of the coordinate grid on the display there determined is value and direction of horizontal offset of the centre of contact platform of wheel pneumatic part with hard coating in the place parallel to its movement, relative to point of intersection of the perpendicular drawn through the wheel suspension axis to hard coating, i.e. preliminary offset value Δx; besides, considering the scale of the picture, which has been found by comparing the size of the known element of transport vehicle as it is x_N and the size of that element on the computer display x, which is equal to ratio x_N/x, there determined is preliminary full-size offset by the formula: which is rolling friction coefficient; after that, rolling resistance coefficient K_Rt is determined by the formula: where R - wheel radius, and those operations are repeated for all the frames of camera shooting, thus providing the determination of coefficients of Δ_N and K_Rt at all stages of wheel movement and resistance.

EFFECT: effect consists in use of video cameras for displaying and recording the contact line being an intersection of the investigated wheel of transport vehicle with road pavement in analogue or digital form to determine rolling friction coefficient and rolling resistance coefficient.

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