Methods of data filtration and their effects on the resulting image of a log at the electronic sensing its dimentisons

• Main Authors: Veronika Hunková, Karel Janák
• Format: Article
• Language: English
• Published: Mendel University Press 2010-01-01
• Series: Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis
• Subjects: data filtration; electronic measurement; log dimensions; running average; median; log diameter
• Online Access: https://acta.mendelu.cz/58/1/0077/

The data taken at the electronic reception of logs are tasked with mistaken values and do not correspond to the real shape of a stem. The aim of the data filtration is to remove the incorrect data and replace them by the ones, closer to the real values.The goal of presented work was to analyse the effect of different filtration methods on original data and to recommend the methods, which results correspond to the real shape of the logs with their defects on a surface as close as possible.Methods of filtration are based on simple mathematical and statistical procedures, which are subsequently variously combined, because the simplest comparative methods did not fulfil the expectations.More than 50 methods were combined and analyzed. Approximately 15 of them were selected and tested. The methods were applied to data scanned on ca 150 logs randomly selected from thousands of files in the sawmill log yard. The filtration effects of different methods were visually assessed. The most applicable three methods were selected and they will be tested practically at sawmill in the next step of research. These three methods are described in following paper.Results refer, that all proposed methods correspond to necessities for log dimensions determination. It is not possible to define the best method generally. Different properties of these methods make them suitable for calculation of log dimensions if different type of use is requested. It means for mid diameter determination necessary for volume calculation by using Huber method; for section dia­me­ter determination for volume calculation by using section method; for top diameter determination necessary for sorting; for filtration of drive dogs of the conveyor passing through the measuring equipment.