Articles by Hagos Lundström
Category : Research note
Crane work accounts for the majority of a harvester’s productive working time. Boom-tip control assists operators by coordinating end-effector movements, offering the potential to improve productivity. With boom-tip control, the operator steers the boom-tip directly rather than controlling individual crane joints. Despite being commercially available for several years, research on boom-tip control’s impact on harvester work – particularly compared to forwarder work – is limited. Therefore, this study analysed the effect of boom-tip control on harvester time consumption (s m-3) in final-felling stands, involving two experienced operators (A and B) driving a John Deere 1470G harvester. John Deere’s boom-tip control system, Intelligent Boom Control (IBC), was compared to a conventional boom-control system. Data were analysed separately for each operator. While operator A saved time using IBC, no statistically significant difference between IBC and the conventional boom-control system was observed for operator B. For operator A, IBC reduced total time consumption (s m-3) by approximately 10%. The results indicate a need for further research, involving multiple machine manufacturers, operators, and work environments such as thinning and final-felling stands. Moreover, future studies should preferably utilise automated data recording to generate large follow-up datasets on harvester work.
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Manner,
Skogforsk, Uppsala Science Park, 751 83 Uppsala, Sweden
https://orcid.org/0000-0002-4982-3855
E-mail:
jussi.manner@skogforsk.se
- Lundström, Skogforsk, Uppsala Science Park, 751 83 Uppsala, Sweden E-mail: hagos.lundstrom@skogforsk.se
The consensus on the factors affecting harvester productivity is generally widely acknowledged in the discipline. However, research results regarding the effect of forking on productivity are diverse. Some studies show that harvester productivity is halved when harvesting double stems compared to single-stem trees, while other studies indicate that forking does not necessarily decrease harvester productivity. These differences in study results can depend on what is considered forking. In our study, the forking occurred above the breast-height level. We defined codominant stems as forked trees too large to be multi-tree handled. In contrast, we defined double crowns as forked trees that could be multi-tree handled. The objective of our study was to analyse how the presence of codominant stems and/or double crowns affects harvester time consumption. The study was conducted in Sweden in 2022, involving two operators and two large harvesters. The 45-year-old Pinus contorta Douglas ex Loudon-dominated stand was clearcut during the study. We found that the presence of codominant stems doubles harvester time consumption per tree, while double crowns had only a minor impact on harvester time consumption. Additionally, total time consumption increased linearly with increasing diameter at breast height. Based on these findings, we recommend that forked trees be removed already during thinning when they can still be time-efficiently multi-tree handled. Dealing with forked trees later during the rotation cycle, when they are too large for multi-tree handling, is excessively time-consuming.
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Manner,
Skogforsk, Uppsala Science Park, 751 83 Uppsala, Sweden
https://orcid.org/0000-0002-4982-3855
E-mail:
jussi.manner@skogforsk.se
- Lundström, Skogforsk, Uppsala Science Park, 751 83 Uppsala, Sweden E-mail: hagos.lundstrom@skogforsk.se
