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Hydroplaning is a unique phenomenon in which the water on a wet runway or highway is not displaced from the nominal tire-ground contact area by a rolling tire or by a moving but nonrotating (full-skidding) tire at a rate fast enough to allow the tire to make contact with the ground surface over its complete nominal footprint area, as would the case of operation on a dry surface. When hydroplani...

Loss of braking power and rubber skidding on a wet road is still an open physics problem, as neither the hydrodynamic effects nor the loss of surface adhesion that are sometimes blamed really manage to explain the 20-30% observed loss of low-speed tyre-road friction. Here we report a novel mechanism based on sealing of water-filled substrate pools by the rubber. The sealed-in water effectively ...

Differentially driven skid-steering vehicles are often considered for navigation in outdoor terrains. However, the control of such vehicles is challenging because the wheels must skid laterally to follow a curved path, and motion stability can be lost as a result of excess skidding due to the position of the instantaneous center of rotation (ICR). To accommodate for the potential loss of stabil...

Abstract: Autonomous guidance of the mining vehicle is based on the path tracking algorithm that use pre-calculated desired paths. These paths are often calculated without taking into account the nonholonomic nature of the vehicle motion. As a result the calculated path might be not feasible and the path tracking controller will be required to correct the situation, deteriorating at the same ti...

Nacrtak After a decade of regression in forest engineering a distinct increase in skidding trail construction and intentional revival of road constructions in state forests have occurred since the year 2000. In this paper novelties and trends in forest traffic way construction in Slovenia are described. Improved procedures for operational road planning and integration of forest traffic ways int...

A continuous-speed felling and bunching prototype machine was evaluated in harvesting a three-year-old, short-rotation sycamore plantation. A small tractor, grapple skidder, and large chipper were evaluated along with the prototype machine as complete harvesting systems. Prediction equations, production rates, and costs were developed for each component of the systems. Production of the feller ...

Demand information is an input for a great deal of operations research models. Assumed as given in many problem instances addressed in the literature, demand data are di cult to generate. In this tutorial, we provide an introduction to disaggregate demand models that are designed to capture in detail the underlying behavioral mechanisms at the foundation of the demand.