Tobias Semberg, Anders Nilsson, Rolf Björheden, Linnea Hansson. (2024). Real-time target point identification and automated log grasping by a forwarder, using a single stereo camera for both object detection and boom-tip control. Silva Fennica vol. 58 no. 1 article id 23062. https://doi.org/10.14214/sf.23062

Keywords: vector analysis; forwarder; forest operations; loading; boom automation; object detection; stereo camera

Highlights: Simple target-point detection in real time using only a stereo camera; Sturdiness ensured through the simple feedback system based on the same camera; Automated boom-tip control and log grasping successfully tested on full-sized forwarder; A step toward semi-automation (operator support) or autonomous forwarding.

Abstract | Full text in HTML | Full text in PDF | Author Info

The forest industry is constantly striving to increase productivity and cut costs, and many research and innovation projects are currently focusing on semi-automated or autonomous systems. A key element, with several possible solutions, is automated log grasping, where researchers and manufacturers are looking for efficient and sturdy ways to solve the task in real-time forwarding operations. This study presents a simple method for automated log grasping using only a single stereo camera for object detection (log and grapple) and a simple controller moving the boom, with feedback from the camera as boom-tip control. The accuracy, precision, and repeatability of the method was tested on a full-scale forwarder. Boom movements were examined from two different start positions in relation to the target position, with the log placed at three different angles. The overall log-grasping success was also evaluated. The tests were performed in a full-scale, real-time operation, without hand-eye calibration or other sensor data from the machine. The method was precise, with high repeatability, but the grasping point showed a minor systematic offset, depending on log angle. However, the deviation in accuracy was too small to affect the success rate. In practice, the most difficult log angles can be avoided by moving the machine slightly. The log grasping method may become part of an autonomous forwarding system or could provide operator support in semi-automated systems.

Semberg, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden E-mail: tobias.semberg@skogforsk.se
Nilsson, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden E-mail: anders.nilsson@skogforsk.se
Björheden, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden https://orcid.org/0000-0002-4158-102X E-mail: rolf.bjorheden@skogforsk.se
Hansson, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden https://orcid.org/0000-0002-9788-1734 E-mail: linnea.hansson@skogforsk.se

Category : Discussion article

article id 23053, category Discussion article

Back Tomas Ersson, Linnea Hansson, Jussi Manner, Per Sandström, Johan Sonesson. (2023). Forest management in northern Fennoscandia: the need for solutions that mitigate conflicts during forest regeneration and increase the use of continuous cover forestry. Silva Fennica vol. 57 no. 3 article id 23053. https://doi.org/10.14214/sf.23053

Keywords: mechanical site preparation; reforestation; reindeer husbandry; indigenous rights; natural resources conflict; Sámi; Sápmi

Highlights: In Sápmi, increased use of continuous cover forestry (CCF) can reduce the frequent conflicts between forest industry and reindeer herding communities; Nordic forestry needs to develop new technical solutions for gentle and lichen-adapted mechanical site preparation during CCF in Sápmi; Such site preparation technology will promote pioneer tree species’ germination and growth, and increase the forest industry’s acceptance of CCF.

Abstract | Full text in HTML | Full text in PDF | Author Info

Today, conflicts often occur in northern Fennoscandia (also known as Sápmi) between forestry and reindeer husbandry. Continuous cover forestry (CCF) is requested by both reindeer herding communities and the general public and is becoming more common, but the forest industry criticizes CCF for lower wood production. Mechanical site preparation (MSP) increases regeneration success and, thus, increases wood production in CCF. To reduce the conflict between forestry and reindeer husbandry, MSP in Sápmi should destroy as little ground lichen as possible. Today, there are no solutions for gentle and lichen-adapted MSP in CCF. Thus, there is a strong need to develop and test new technical solutions that increase regeneration success in a lichen-adapted way during CCF in Sápmi. We suggest that MSP solutions be developed which are gentle, work selectively and function in shelterwoods, gap cuts, and selection cutting stands. We envision that these solutions could fill the gap between the desired adaptivity on the part of the reindeer herding communities and the desired efficiency on the part of the forest industry. Such MSP technology would contribute to increased acceptance of CCF in the forest industry, higher biodiversity, and considerably reduce the conflict between forestry and reindeer herding communities.

Ersson, Swedish University of Agricultural Sciences (SLU), School of Forest Management, SE-739 21 Skinnskatteberg, Sweden https://orcid.org/0000-0003-2442-7482 E-mail: back.tomas.ersson@slu.se
Hansson, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden https://orcid.org/0000-0002-9788-1734 E-mail: linnea.hansson@skogforsk.se
Manner, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden https://orcid.org/0000-0002-4982-3855 E-mail: jussi.manner@skogforsk.se
Sandström, Swedish University of Agricultural Sciences (SLU), Department of Forest Resource Management, SE-901 83 Umeå, Sweden https://orcid.org/0000-0003-0977-0071 E-mail: per.sandstrom@slu.se
Sonesson, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden https://orcid.org/0000-0002-2018-7496 E-mail: johan.sonesson@skogforsk.se

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