Том 19, № 1 (2022)
Articles
Methodology enhancement for program determination of roundwood batch volume to improve the accuracy of its application
Аннотация
The problem of improving the accuracy and automation of round timber accounting is still quite urgent. In domestic and foreign practice various manual piece-by-piece methods of volume measurement are used, both with and without taking bark into account. These include the method of end sections, the middle section method, and the truncated cone method. At the same time automated methods, mainly sectional methods, are finding wide application. . Group methods are also being developed. In addition to the manual stacking method, accounting practice uses weight methods, construction of 2-D and 3-D models on the basis of photographic and laser surveying. However, quite often there is no normative regulation of timber accounting issues: which method and when to use, what measurement errors are acceptable and how to deal with discrepancies. To date, application software packages based on machine vision have been developed to significantly reduce the labor intensity of operations to measure the volume of round timber in a dense stack or on a timber truck. The article shows that in software-based volume determination of coniferous and hardwood timber the direct estimates are overestimated as compared with the control ones. The distribution of relative deviations of estimates from the reference values does not adhere to the normal distribution law. As a result of analyzing a sample of hardwood timber batches, a regression model was obtained to adjust the software estimates of the batch volume with regard to the volume, average diameter, and number of logs. This model allows improving the accuracy of program estimation compared to the control one. The work was performed within the framework of the scientific school «Innovative developments in the field of logging industry and forestry» of the Arctic State Agrotechnological University.
Resources and Technology. 2022;19(1):1-47
1-47
New technical solutions for reducing the negative impact of forest industries on the forest environment
Аннотация
In addition to the most frequently considered negative factors of logging impact on the natural environment, new aspects that have arisen with the improvement of legislation are considered. Incomplete use of wood waste leads to the formation of warehouses and dumps of unused wood waste. Also in forest settlements household waste is generated, which is accumulated on landfills, emitting toxic filtrate, gases, waste decay products. Lack of control on forest sites leads to accidents and leaks of oil products during refueling and operation of forestry equipment. This results in a long-term polluting effect on the soil and water in places where equipment, fuel and lubricants are concentrated. According to environmental legislation, forest users are responsible for the negative impact on the environment and must eliminate the consequences of their activities or prevent potential environmental risks. Long-term use of the harvesting area leads to intensive exploitation of forest roads, contributing to the pollution of water bodies with oil products. The corresponding technological regulations to reduce the negative environmental impact factors in the process of logging have not been established. The author proposes to use all waste generated at the logging site to produce soil substrate by the process of composting. During the process an organic component such as organic waste, sewage sludge, nitrogen-containing agricultural waste should be added to compensate for the lack of nitrogen. According to reports, wood bark amounted to 92% of waste, wood chips comprised 4%, slab wood - 2% in the Republic of Karelia during last three years. In general, it was found that 32% of wood waste from forest enterprises is not used. With effective interdepartmental interaction, these types of waste can be processed into a useful product, reducing the volume of landfill waste at the regional level. The author suggests collecting oil products spillage by washing away the pollution substances. These substances will be processed on local treatment systems by using combined natural sorption materials formed from logging products as cleaning agents. The following features of the cleaning systems design on forest sites and roads have been identified: swampy and water-saturated forest areas as the most typical ones in the North-West of the Russian Federation, the lack of power supply, the inability to deepen structures due to a small difference in elevations between the roadbed and the adjacent terrain or water level. It is required to install a sand trap with a power reserve because of ground cover and sand removal necessity. The capacity of structures should be selected according to the amount of wastewater flow, designed for shorter drainage areas, providing wastewater intake with a flow rate of 0.3—3.0 l/s.
Resources and Technology. 2022;19(1):48-71
48-71
Мathematical model of operating processes of the chocker-free trip with energy-saving hydraulic drive
Аннотация
Chokerless hauling devices are often used in combination with wheeled agricultural tractors for thinning operations in the forest-steppe zone of Russia. Negative fluctuations often occur during the movement of the tractor with the above-mentioned unit along uneven terrain in clearings. They cause jumps in the working fluid in the hydraulic system and general high dynamic loads, which in turn reduce the reliability of both technological equipment and the traction unit. One of the options for reducing dynamic loads and energy consumption is the use of an energy-saving (recuperative) hydraulic drive with a hydraulic accumulator. The aim of the study was to develop a new chokerless hauling grip and a mathematical model that took into account external and internal forces acting on a skidded bundle of wood, as well as the parameters of an energy-saving hydraulic drive that allowed reducing the dynamic loading and energy intensity of work processes. The authors of the article proposed a new design and technological scheme for a chokerless hauling grip with an energy-saving hydraulic drive, protected by a patent of the Russian Federation for an invention. A mathematical model is presented that takes into account not only the external and internal forces acting on the skidding pack of wood, but also the parameters of an energy-saving hydraulic drive. The working processes of gripping together with a pack of wood during transient acceleration and deceleration modes are described by the equation of motion of the recuperation hydraulic cylinder piston and by the equation of the hydraulic fluid consumption of the recuperation hydraulic cylinder, taking into account leakages into the accumulator at a pressure higher than the pre-charge one. The Cauchy problem for a nonlinear system of differential equations of a hauling grip motion with an energy-saving hydraulic drive was considered. Theoretical time dependences of the working fluid pressure and the stroke of the recuperation hydraulic cylinder were obtained, their adequacy was confirmed by the results of experimental studies on an operating laboratory stand for a chokerless gripper with an energy-saving hydraulic drive with the following design parameters: hydraulic accumulator pre-charge pressure 5 MPa; hydraulic accumulator working volume 0.005 m3; hydraulic cylinder piston diameter 0.1 m; hydraulic cylinder rod diameter 0.04 m. It has been established that the energy recovery system of the hauling grip reduced bursts of the working fluid pressure during transient processes by 1.4…1.7 times and allowed reserving power in the range of 1.7 ... 2.1 kW.
Resources and Technology. 2022;19(1):72-86
72-86
Multifunctional forestry or timber harvesting?
Аннотация
To meet the rapidly growing demand for numerous forest ecosystem services (FES) and to preserve biodiversity, the traditional forestry practices in Russia, aimed primarily at timber harvesting should be transformed into a multifunctional approach that takes into account the criteria of not only economic, but also social and environmental sustainability. The purpose of this study is to assess the importance of forests for people, people’s responsibility for forest state and their understanding of the multifunctional forestry concept. The authors applied the method of quantitative research using a sociological survey of one hundred and fifty-three people. The results showed that most significant criteria for the respondents were regulating and supporting FES, cultural services occupied an intermediate position, and the least valuable criterion was the provisioning FES. The respondents expressed the belief that they had little impact on forests, but at the same time felt major responsibility for forest state. The combination of a high responsibility level and their confidence in insignificance of their individual impact on forest can serve as an indicator of people’s distancing from participation in solving environmental problems. There also seems to be a discrepancy between the understanding and the practical implementation of the multipurpose forest use concept, expressed in the forest legislation of Russia. The concept of multipurpose forest use was understood by most respondents as having the same meaning as multifunctional forestry, implying some benefits from provisioning, regulating, cultural and supporting FES. Timber harvesting has been identified as a service that conflicts with non-timber products, recreation, carbon sequestration, providing a habitat for living organisms. At the same time all those services were perceived as affecting timber harvesting negatively. Wood supply also turned out to be the most active (influencing other FES) and at the same time the most passive (not being influenced by other FES) service. The least active and at the same time the least passive FES was the provision of non-wood products. The overwhelming majority of respondents expressed their belief that the current Forest Code of the Russian Federation cannot ensure a balance between the FES.
Resources and Technology. 2022;19(1):87-113
87-113
Fuzzy modeling of disturbed lands natural revegetation
Аннотация
The problem of disturbed lands recultivation is considered. Since no methodological approach has been developed, the primary task to be solved is to determine the desired period of time for lands natural revegetation. Agrotechnical revegetation measures effectiveness could be compared with the one of natural revegetation only if this task has been solved. The object of this research was the fund of mined disturbed lands in the Sverdlovsk region. All parameters of this object were characterized by data uncertainty conditions, therefore the main idea of the work was to use fuzzy logic, first to describe the main parameters affecting the revegetation process, and then to obtain a functional dependence of the output parameter, i.e. the recovery time period from these initial parameters. Thus, the goal of the research was to develop a fuzzy model of the process of natural revegetation of disturbed lands. The authors studied experimentally the disturbed lands state in a particular region; developed the problem statement; justified fuzzy membership functions of the problem; developed a base of rules for fuzzy products; obtained fuzzy inference and the resulting function; and developed software implementation of the task. The research results were software-implemented in the Scilab environment functional dependence of disturbed lands revegetation period on the type of soil, its parameters and the type of vegetation. The results might be applied to design agrotechnical, regulatory and other measures for disturbed lands revegetation.
Resources and Technology. 2022;19(1):114-128
114-128
Assessment of the efficiency of the skidding portage on the slope of the thawing soil mass under cyclic static loads
Аннотация
In the Russian Federation, a significant part of the forest fund is located on permafrost. Such areas include: Republic of Sakha (Yakutia), Komi Republic, Magadan Oblast, Yamalo-Nenets Autonomous Okrug, Chukotka Autonomous Okrug, Murmansk Oblast, and significant areas of Siberia and the Far East. Many of these regions have large reserves of mature and overmature forests, and a significant portion of these reserves is located in places that are inaccessible due to road network and topography challenges. Currently, a vast majority of timber harvesting in Russia is performed by using modern machinery complexes mainly composed of wheeled forest machines of various configurations and purposes (harvesters, forwarders and skidders). These machines can successfully operate even on fairly steep slopes due to special technical solutions, such as winches integrated into the transmission, or self-propelled winches (T-winch, ROB). However, the problem of negative effect of wheeled forest machines and skidding systems based on them not only remains topical, but becomes even more acute, since the ecosystems of mountain forests and forests on the slopes of hills are among the most vulnerable ones, exposed to water and wind erosion. The article presents the developed mathematical model of dynamic interaction of a wheeled forest machine (a skidding system) with soil on slopes. The model allows adequate assessment of stability and working capacity of the skidding trail at the stage of design (preparatory) works given reliable data on hydrogeology of thawing soil massif. The work was performed within the framework of the scientific school «Innovative developments in the field of logging industry and forestry» of the Arctic State Agrotechnological University. The research was supported by the grant of the Russian Science Foundation № 22-26-00009, https://rscf.ru/project/22-26-00009/.
Resources and Technology. 2022;19(1):129-148
129-148