Our younger generation works with the photographic concept of time – lapse primarily for the purpose of entertainment. According to a study of the environment of the Faculty of Forestry and Wood Sciences, CULS, it can also be used in the field of timber harvesting, specifically in measuring the load of forwarders.
There is no doubt that in the world production of wood, the maximum use of technical means, such as forwarders, is key. In the Czech Republic they are daily, either when harvesting in the so-called harvester knot (29-38% of the total volume of harvested wood – data from 2019), or to export wood after harvesting with a chainsaw.
The measurement of the wood itself – the load of the forwarder in our case – is undergoing very noticeable changes. From the manual measurement of games at the transport point, we switched to the use of a smartphone with an application with which it is enough to aim at a pile from a certain distance at a pile of wood or a forwarder, and it is measured. The customer can also use the function of measuring the weight of the load on the forwarder, but this is difficult because of estimation of the density of wood and subsequent conversion to volume in cubic meters. For this study, our researchers chose a relatively little-studied method, the so-called photogrammetric method, which has its advantages in relative accuracy and, above all, in price and technical affordability.
The John Deere 1110D forwarder from the School Forest Enterprise in Kostelec nad Černými lesy, CULS in Prague was used in the research, and mainly Norway spruce (Picea abies) or Scots pine (Pinus sylvestris) as a load. wo cameras (LAMAX X10.1) with a time-lapse photograph of three seconds were used for the measurements. The cameras were placed in the cab and aimed at the fronts of the assortment cut-outs on the forwarder. For comparison, a manual measurement of the load was performed.
During the research, the researchers also encountered minor problems, such as the low battery life of the cameras, which they solved using an external power bank. Despite this, they found a relatively large difference in measurements with this method, compared to the manual one. During manual measurement, the height was overestimated by 5 cm.
Thanks to researchers from our faculty, we know that it is definitely worth exploring these progressive methods. However, it is already possible to reduce measurement inaccuracy and make forestry work easier. Good luck to the forest and modern technology!
doc. Ing. Jiří Dvořák, Ph.D.
Associate Professor Dvořák graduated from the Forestry School in Žlutice then Forest Engineering at the current CULS in Prague. He now works at the Department of Forestry Technologies and Constructions. He has operational experiences and deals with topics related to logging.
Prepared by Václav Kinský