Okaspuupalkide kontrollmõõtmiste tulemused Stora Enso Eesti Imavere Saeveski näitel
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Kuupäev
2024
Kättesaadavus
10.09.2024
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Kontrollmõõtmine on Stora Enso Eesti Imavere Saeveski jaoks tootmise tähtis osa. Käsitsi mõõdetud ja mõõtejaama poolt saadud andmete võrdlemisel saab ülevaate mõõtejaama korrasolekust. Töö eesmärgiks oli uurida mõõteandmete võrdluse tulemusi ja nende põhjal leida kinnitust, kas teatud aastaaegadel on võrdluste tulemused suurema erinevusega. Magistritöö käigus viidi läbi lisakatsed, mille abil analüüsiti tulemusi täiendavalt. Töös kasutati palkide mõõtmisandmeid ajavahemikust 2021 oktoober kuni 2023 detsember. Käsitsi mõõdetud palkide arv oli 1263 tk ja mõõtmised teostati Stora Enso Imavere Saeveski kontrollmõõtmiste meeskonna poolt. Mõõdetud palkide hulgas oli 698 kuusepalki ja 565 männipalki.
Töös selgus, et külmadel kuudel oli diameetrite keskmine erinevus 1 mm. Talvisel ajal on ka rohkem määramatuseid, mis mõõtmist mõjutavad, nagu näiteks jäätunud palgid. Juhuslike andmetega tehtud simulatsioon näitas mahu muutumist juba 1 mm lisamisel palgi diameetrile. Saeveski töötlusprogrammis samas 1 mm diameetri vahet ei pruugi mahu muutumist näidata, kuna mõõtejaama pole vaja reguleerida väiksema kui 2% mahu muutuse puhul. T-testid näitasid p-väärtuste abil, et tõestatud erinevused diameetrite erinevusel on olemas. Kümne palgi peenemas otsas 30 cm ulatuses läbimõõdu asukohavaliku mõõtmistest näitas, et seost mõõtmiskoha valikul ja läbimõõdu tulemusel ei ole. Töö tulemuste põhjal on võimalik palkide mõõtmise metoodikat täpsemaks teha.
Control measurements are important for Stora Enso Eesti Imavere Sawmill. In the sawmill logs are measured automatically by a 3D measurement station. By comparing the data of manual validation measurements and 3D – station measurement results it is possible to get overview of 3D – measurement device precision and acuraccy in time. The aim of the work was to analyze the log measurement data and find evidence whether the measurement results are statistically different during certain seasons and to explore the influencing factors. Data used in this work is from measurement period that covers dates from 2021 October to 2023 December. During that time 1263 logs were manually measured by Stora Enso Imavere Sawmill validation team. The sample of 1263 logs contained 698 spruce logs and 565 pine logs. The work revealed that the average difference in diameters was 1 mm during cold months. During winter there are more uncertainties that affect measurement, for example frozen logs. A simulation was made with random data to show volume change in log when only 1 mm is added to diameter. In sawmill calculation program, a difference of 1 mm in diameter might not show a change in volume since there is no need to adjust the measurement station when volume difference is less than 2%. T-tests showed with p-values that there were proven differences in diameters. Measurement results from test measurement of ten logs from thinner end of log (5 – 30 cm from smaller end) showed that there is no connection between the selection of measurement location and the result of diameter. With the results of this work, it is possible to make the log measurement methodology more accurate.
Control measurements are important for Stora Enso Eesti Imavere Sawmill. In the sawmill logs are measured automatically by a 3D measurement station. By comparing the data of manual validation measurements and 3D – station measurement results it is possible to get overview of 3D – measurement device precision and acuraccy in time. The aim of the work was to analyze the log measurement data and find evidence whether the measurement results are statistically different during certain seasons and to explore the influencing factors. Data used in this work is from measurement period that covers dates from 2021 October to 2023 December. During that time 1263 logs were manually measured by Stora Enso Imavere Sawmill validation team. The sample of 1263 logs contained 698 spruce logs and 565 pine logs. The work revealed that the average difference in diameters was 1 mm during cold months. During winter there are more uncertainties that affect measurement, for example frozen logs. A simulation was made with random data to show volume change in log when only 1 mm is added to diameter. In sawmill calculation program, a difference of 1 mm in diameter might not show a change in volume since there is no need to adjust the measurement station when volume difference is less than 2%. T-tests showed with p-values that there were proven differences in diameters. Measurement results from test measurement of ten logs from thinner end of log (5 – 30 cm from smaller end) showed that there is no connection between the selection of measurement location and the result of diameter. With the results of this work, it is possible to make the log measurement methodology more accurate.
Kirjeldus
Magistritöö
Metsatööstuse õppekaval
Märksõnad
magistritööd, kontrollmõõtmine, diameetrite keskmine erinevus, jäätunud palgid