ABSTRACT

Recently, forest operations are facing unfavorable climatic conditions more frequently. In Central Europe, machine trafficability and induced soil disturbances are negatively affected by periods of high precipitation and less intensive frost during ground-based harvesting operations. Winch-assist technology is assumed to reduce soil disturbance by forest machines in steep terrain. Still, the potential positive effects of winches to assist traction of forest machines in flat terrain have rarely been surveyed. In this study, a field trial was conducted in flat terrain (slope < 5%). There, a forwarder with an integrated traction-assist was monitored during six consecutive machine passes on a permanent machine operating trail. The first section of the machine operating trail was passed without traction-assist, the remaining section with traction-assist, resulting in two treatment groups. To assess soil impacts, three test plots were positioned per treatment group. Within these plots, pre- and post-operational soil bulk density, soil displacement and rutting were determined. Additionally, wheel slippage and cable tensile force were examined, using incremental rotary encoders and a flexible tensile force measurement kit, respectively. It was observed, that wheel slippage responded inversely with tensile force. Traction-assist technology reduced wheel slippage from 5.3 ± 11.9% to 0.37 ± 10.19% along the section of the machine operating trail, as compared to results from the unassisted section. Although wheel slippage was significantly reduced, no mitigating effect by the usage of traction-assist technology on soil disturbance could be observed, probably due to the low volumetric water content of 27%.

摘要

近期，林业经营面临不利气候条件的情况更加频繁。在中欧，在地面收割作业期间，机器通行性和诱发的土壤扰动受到高降水和较少霜冻期的负面影响。绞盘辅助技术被认为可以减少陡峭地形中林业机械对土壤的干扰。尽管如此，很少有人调查绞盘在平坦地形中辅助牵引林业机械的潜在积极影响。在本研究中，在平坦地形（坡度 < 5%）进行了现场试验。在那里，在永久性机器操作路径上连续六次机器通过期间，对带有集成牵引辅助系统的货运代理进行监控。机器操作路线的第一段在没有牵引辅助的情况下通过，其余部分采用牵引辅助，产生两个治疗组。为了评估土壤影响，每个处理组放置了三个测试地块。在这些地块内，确定了操作前和操作后的土壤容重、土壤位移和车辙。此外，还分别使用增量旋转编码器和灵活的拉力测量套件检查了车轮滑动和电缆拉力。据观察，车轮打滑与拉力成反比。与无辅助部分的结果相比，牵引辅助技术沿机器操作路径部分的车轮滑移率从 5.3 ± 11.9% 减少到 0.37 ± 10.19%。虽然车轮打滑明显减少，但没有观察到牵引辅助技术对土壤扰动的缓解效果，