The frequent impulse collisions and wear between the ball cage pocket not only affect bearing stability but also significantly impact deterioration of service life. A comprehensive dynamic model for analyzing stability, skidding degree, ball–cage collision, distribution, rate four types is proposed. series tests whirling conducted on self-lubricating test bench using high-speed photographic tec...

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 ...

In this article, the problem of robust tracking control for wheeled mobile robot (WMR) with skidding, slipping, and parameter uncertainties is addressed. Through designing double sliding mode variables, a fixed time disturbance observer developed to estimate multiple disturbances within time, convergence regardless initial estimation error system. Based on fixed-time (FTDOB) novel power reachin...