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Aspects of automation of selective cleaning

Vestlund, Karin (2005). Aspects of automation of selective cleaning. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2005:74
ISBN 91-576-6973-2
[Doctoral thesis]

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Cleaning (pre-commercial thinning) is a silvicultural operation, primarily used to improve growing conditions of remaining trees in young stands (ca. 3 - 5 m of height). Cleaning costs are considered high in Sweden and the work is laborious. Selective cleaning with autonomous artificial agents (robots) may rationalise the work, but requires new knowledge. This thesis aims to analyse key issues regarding automation of cleaning; suggesting general solutions and focusing on automatic selection of main-stems. The essential requests put on cleaning robots are to render acceptable results and to be cost competitive. They must be safe and be able to operate independently and unattended for several hours in a dynamic and non-deterministic environment. Machine vision, radar, and laser scanners are promising techniques for obstacle avoidance, tree identification, and tool control. Horizontal laser scannings were made, demonstrating the possibility to find stems and make estimations regarding their height and diameter. Knowledge regarding stem selections was retrieved through qualitative interviews with persons performing cleaning. They consider similar attributes of trees, and these findings and current cleaning manuals were used in combination with a field inventory in the development of a decision support system (DSS). The DSS selects stems by the attributes species, position, diameter, and damage. It was used to run computer-based simulations in a variety of young forests. A general follow-up showed that the DSS produced acceptable results. The DSS was further evaluated by comparing its selections with those made by experienced cleaners, and by a test in which laymen performed cleanings following the system. The DSS seems to be useful and flexible, since it can be adjusted in accordance with the cleaners’ results. The laymen’s results implied that the DSS is robust and that it could be used as a training tool. Using the DSS in automatic, or semi-automatic, cleaning operations should be possible if and when selected attributes can be automatically perceived. A suitable base-machine and thorough research, regarding e.g. safety, obstacle avoidance, and target identification, is needed to develop competitive robots. However, using the DSS as a training-tool for inexperienced cleaners could be an interesting option as of today.

Authors/Creators:Vestlund, Karin
Title:Aspects of automation of selective cleaning
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :2005
Number of Pages:54
ALLI. Vestlund, K. & Hellström, T. Requirements and system design for a robot performing selective cleaning in young forest stands. (Accepted for publication in Journal of Terramechanics). II. Vestlund, K. 2004. Assessing rules and ideas for stem selection in cleaning. Baltic Forestry, 10(2): 61-71. III. Vestlund, K., Nordfjell, T., Eliasson, L. & Karlsson, A. A decision support system for selective cleaning. (Submitted). IV. Vestlund, K., Nordfjell, T. & Eliasson, L. Comparison of human and computer-based selective cleaning. (Submitted). V. Erikson, M. & Vestlund, K. 2003. Finding tree-stems in laser range images of young mixed stands to perform selective cleaning. In: Hyyppä, J., Naesset, E., Olsson, H., Granqvist-Pahlén, T. & Reese, H. (Eds.) Proceedings of the Scandlaser scientific workshop on airborne laser scanning of forests. Working paper 112, Department of Forest Resource, Management and Geomatics, Swedish University of Agricultural Sciences, Umeå, Sweden. p. 244-250. ISSN: 1401-1204.
Place of Publication:Umeå
ISBN for printed version:91-576-6973-2
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:N Machinery and buildings > N20 Agricultural machinery and equipment
K Forestry > K10 Forestry production
Subjects:Not in use, please see Agris categories
Agrovoc terms:forest stands, thinning, thinners, robots, automation, sweden
Keywords:autonomous off-road vehicle, decision support system, interviews, robot, pre-commercial thinning, simulations, training-tool
Permanent URL:
ID Code:886
Department:(S) > Institutionen för skogsskötsel
Deposited By: Karin Vestlund
Deposited On:12 Aug 2005 00:00
Metadata Last Modified:02 Dec 2014 10:07

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