For the construction of automobiles intended for off-road and
cross-country driving and the evaluation of their characteristics
from the viewpoint of cross-country capacity it is necessary to
know the relations between the parameters of the vehicle and its
abilities to overcome principal types of terrain obstacles. Till
now, the problem was investigated only under the conditions of very
slow driving of the vehicle, neglecting the effect of inertial
forces and kinetic energy and the published data are not in mutual
correspondence.
Stated in this paper are the results of complex analysis of the
step-obstacle performance of a two-axle vehicle and the used method
of analysis which can be applied also to other shapes of obstacles.
The derived relations for the "static" step-obstacle
performance, when neglecting the effect of inertial forces, show
that this step-obstacle performance depends on the adhesion and on
the dimensional parameters of the automobile, which are the radius
of its wheels, wheel base of axles and longitudinal and height
coordinate of the centre of gravity. For practical verification of
the validity of derived relations was selected the method of test
runs with reduced model of vehicles, having variable parameters. A
portion of tests was executed with actual vehicles. In the course
of these tests it is important to pay attention to the value of the
coefficient of adhesion and to process correctly the results of the
measurements.
Author(s):
František Obermann
Pages: 9
Event:
17th FISITA Congress (1978), Budapest, Hungary
Related Topics:
Center of gravity (CG)
Test procedures
Wheels
Axles
Terrain
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