Tree species and litter play a key role in the functioning of forest ecosystems as influential factors affecting soil ecological processes distribution humus forms. This study investigates morphology under different trees on compacted skid trails at time intervals after skidding operations (6, 10, 20 years) Kheyrud forest, Nowshahr. Each trail was identified with three replications pure beech, ...

A model-based control for fast autonomous four-wheel mobile robots on soft soils is developed. This control strategy takes into account slip and skid effects to extend the mobility over planar granular soils. Each wheel is independently actuated by an electric motor. The overall objective is to follow a path roughly at relatively high speed. Some results obtained in dynamic simulation are prese...

The anti-skid resistance of six coatings (Alfa, Beta, Gamma, Lambda, Mu and Theta) designed for outdoor wood flooring were tested in chestnut (Castanea sativa Mill.) and pine (Pinus pinaster Ait.) using a Portable Skid Resistance Tester according to standard ENV 12633. Film thickness, coating retention level, and presence of mineral particles were determined for each coating. Furthermore, the l...

This study was executed to determine the plant species of herbaceous cover in a skid road subjected to soil compaction due to timber skidding in a beech (Fagus orientalis Lipsky.) stand. Our previous studies have shown that ground based timber skidding destroys the soils extremely, and degradations on ecosystem because of the timber skidding limit recovery and growth of plant cover on skid road...

Skid-steering mobile robots are widely used because of their simple mechanism and robustness. However, due to the complex wheel-ground interactions and the kinematic constraints, it is a challenge to understand the kinematics and dynamics of such a robotic platform. In this paper, we develop an analysis and experimental kinematic scheme for a skid-steering wheeled vehicle based-on a laser scann...

The objective of this work is to develop statistical models to predict Locked Wheel Skid Trailer (LWST) skid numbers from Dynamic Friction Tester (DFT) and Circular Texture Meter (CTM) measurements conducted on asphalt pavement surfaces. The analyses conducted are descriptive as well as analytical. They include all descriptive measures along with linear and nonlinear regressions. For both analy...