Biografi

Det meste av arbeidet mitt ved NIBIO har dreid seg om å håndtere og analysere store datamengder. Dette arbeidet kan deles inn i tre hovedområder: analyse av StandForD-filer fra skogsmaskiner, simuleringer av skogsmaskiner, og studier av CANBUS-data fra tømmerbiler. I tillegg til dette arbeidet har jeg deltatt i mer tradisjonell skogdriftsforskning, som tidsstudier og målinger av arbeidskvalitet.

Tidligere erfarenhet
Min akademiske reise begynte ved Sveriges lantbruksuniversitet (SLU), der jeg tok en mastergrad i skogbruk (Jägmästare). Studiene mine fokuserte på råvareforsyning og produksjonsplanlegging. Jeg fortsatte sedan ved SLU med doktorgradsstudier i skogsteknologi, med prosjektet "Technology and Systems for Stump Harvesting with Low Ground Disturbance ". Etter doktorgraden tilbrakte jeg et år som postdoktor ved Universitetet i Tokyo. Der jobbet jeg med små lastbærere i bratt terreng. Deretter returnerte jeg til SLU for å jobbe med logistikk rundt terminaler og overføring av GIS-kunnskap.

Mitt doktorgradsprosjekt, i mer detalj, inkluderte måling av markforstyrrelser, simulering av produktiviteten til forskjellige stubbrytningssystemer, kostnadsanalyser, utvikling av en eksperimentell rigg for stubbvridning, og tidsstudier. Doktorgradsprosjektet var en del av forskerskolen FIRST, som førte til at jeg tilbrakte et år på andre forskningsstudier. Disse studiene omfattet måling av temperatur og gassutslipp under lagring av torv og sagflis, utførelse av produktivitetsstudier, og undersøkelse av variasjonen i fuktighetsprosent i skogsbrensel flis for å estimere det nødvendige antall prøver for forskjellige målepresisjoner. Som postdoktor inkluderte arbeidet mitt produktivitetsstudier og kostnadsanalyser av japanske lastbærere og separate lastere i bratt terreng. Jeg medvirkede også i en studie om hogging av skogsbrensel. Under min andre periode ved SLU, jobbet jeg med potensielle fordeler ved åpne terminaler og utførte en økonomisk vurdering av forskjellige terminallokasjoner, med tanke på høgst, transport og kapitalkostnader.

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Sammendrag

Butt rot is a main defect in Norway spruce (Picea abies (L.) Karst.) trees and causes large economic losses for forest owners. However, little empirical research has been done on the effects of butt rot on harvested roundwood and the magnitude of the resulting economic losses. The main objective of this study was to characterize the direct economic losses caused by butt rot in Norway spruce trees for Norwegian forest owners. We used data obtained from seven cut-to-length harvesters, comprising ∼400,000 trees (∼140,000 m3) with corresponding stem profiles and wood grade information. We quantified the economic losses due to butt rot using bucking simulations, for which in a first case, defects caused by butt rot were included, and in a second case, all trees were assumed to be free of butt rot. 16% of trees were affected by butt rot, whereby butt rot tended to occur in larger trees. When butt rot was present in a tree, the saw log volume was reduced by 48%. Proportions of roundwood volume affected by butt rot varied considerably across harvested stands. Our results suggest that butt rot causes economic losses upwards of 7% of wood revenues, corresponding to € 18.5 million annually in Norway.

Sammendrag

Normal log lengths in Norway are 3–6 m (NL), but occasionally there is a demand for short timber with a 2.5 m log length (ST). There are concerns that ST could reduce the forwarders' productivity. Six type stands were created based on harvester data. Different assortment distributions, conditions, and forwarders were simulated in each type stand. It was found that an additional ST assortment almost always decreased productivity (from –15.5 to +4%). Increased forwarding distance (m), more difficult driving conditions, and increased log concentration [m3·(100 m strip road)–1] decreased the productivity difference between sites with ST and NL and sites with only NL. Increased forwarder size increased the productivity difference between sites with ST and NL and sites with only NL. It is possible to load two stacks of ST on some forwarders. Such loading was more productive than loading one stack on longer forwarding distances, while the opposite was the case on short distances. However, loading two stacks of ST can lead to overloading.

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Sammendrag

Because of generally small log piles, loading forwarders during thinning is time consuming. The Assortment Grapple, an innovative grapple with an extra pair of claws which facilitates the handling of two assortments during one loading crane cycle, has been designed to decrease forwarders’ loading time consumption. A standardized experiment was performed in a virtual thinning stand using a machine simulator with the objectives to form guidelines for working with the Assortment Grapple and to analyse its development potential. Four experienced operators participated in the study. According to the results, the Assortment Grapple’s accumulating function is beneficial only when there are no remaining trees between piles loaded during the same crane cycle. In such cases, none of participating operators lost time, and 3 of 4 operators saved time notably. The problem with the remaining trees is the extra time required to steer the crane tip around them. Therefore, a harvester should place those log piles that are later to be forwarded together in the same space with no remaining trees between the piles. Furthermore, we recommend that the Assortment Grapple’s usability will be improved by adding an own rocker switch on the forwarder’s controls to command the extra claws.