ABSTRACT

In the steep terrain of the European Alps, cable yarding still plays an important role. To maintain low costs of timber harvesting and improve the productivity of cable yarding operations, system integration by mounting of a tower yarder, crane, and processing unit onto a single carrier is the major pathway of innovation. In particular, under mountainous conditions, with small landings at the forest road and high production rates, cable yarding systems require well-coordinated transport to available storage space at the landing. Otherwise, the operation will run out of storage space and be shut down until serviced by a log truck. To investigate the system behavior and determine the overall performance effects, an agent-based simulation model was developed. The impact of the storage capacities, number of trucks employed, weather conditions, and timing of truck orders were evaluated. Cable yarders, trucks, and individual yarding lines form a population of agents placed in the spatial model environment, acting as the top-level agent. To harvest and transport an assumed volume of 52,500 m³ of timber from 65 different harvesting sites with 150 yarding lines, 301 days are required, in the best case. For the worst case, 484 days are required to complete all operations. Early information flow of the storage level at the landing saves a majority of the waiting cost if the storage capacity at the road is low and the number of trucks high, with 2.5 € m⁻³. The results also show that adopting measures to increase the storage capacity at the landing will lead to less sensitive reactions in the supply chain.

摘要

在欧洲阿尔卑斯山的陡峭地形中，电缆堆放仍起着重要作用。为了保持较低的木材采伐成本并提高电缆堆放作业的生产率，将塔式堆放机，起重机和处理单元安装到单个托架上的系统集成是创新的主要途径。尤其是在山区条件下，林道上的着陆点少且生产率高，电缆堆放系统需要协调良好的运输到着陆点的可用存储空间。否则，该操作将耗尽存储空间并被关闭，直到由原木卡车进行维修为止。为了调查系统行为并确定总体性能影响，开发了基于代理的仿真模型。储存量，使用卡车的数量，天气状况，和卡车订单的时间进行了评估。电缆架势器，卡车和单独的架势线形成了放置在空间模型环境中的代理程序群体，这些代理程序充当顶级代理程序。假设运输和收集的体积为52,500 m在最好的情况下，需要65天不同采伐场的³种木材和150条调料线，需要301天。在最坏的情况下，需要484天才能完成所有操作。如果道路上的存储容量低而卡车数量高，则在着陆点的存储级别的早期信息流节省了大部分的等待成本，为2.5€m ^-3。结果还表明，采取措施增加登陆处的存储容量将导致供应链中的敏感反应减少。