Damage to residual stand is unavoidable and it is one of the main important issues in the forest harvesting. Trees damage may occur in felling and skidding work phase or during skid trail construction. In any case, damage can be very serious to residual stand. Detailed study is necessary to find out the amount and severity of damage to trees; therefore district 14 of Kilesara in Guilan Province...

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...

In order to deal with strong nonlinearity and external interference in the braking process, this paper proposes a robust self-learning PID algorithm based on particle swarm optimization, which does not depend precise mathematical model of controlled object. The function is used adapt diversity runway road surface friction, optimize rate self-learning, control modeling uncertainty disturbance sy...

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...

water erosion causes severe soil damage in northern forests of iran which is associated with different rut depths in skid trails. the aim of this study was to assess rutting and soil displacement on skid trails to mitigate water erosion. therefore the research was carried out in eight parcels of district no 3 of shafarood forest in the north of iran. in order to evaluate the amount of erosion i...

Water erosion causes severe soil damage in northern forests of Iran which is associated with different rut depths in skid trails. The aim of this study was to assess rutting and soil displacement on skid trails to mitigate water erosion. Therefore the research was carried out in eight parcels of district No 3 of Shafarood Forest in the North of Iran. In order to evaluate the amount of erosion i...

a nonlinear model consisting “yaw, roll, longitudinal, lateral and pitch” has been developed in which, tire and suspension characteristics have been considered. tire model is based on the elliptic concept and tire calspan data. according to this tire model, cornering force and aligning moment are computed as a function of slip and camber (inclination) angles, normal load, tire adhesion characte...