An Engineering Model of a Knife Roller for Thinning Forest Crops

To carry out the thinning of forest crops, it is necessary to use mechanized means, such as knife rollers. The review of scientific literature has shown that the lack of domestic knife rollers is a significant problem in artificial reforestation. The aim of this study has been to substantiate the technological parameters of knife rollers, considering their position relative to the soil surface, as well as the level of rigidity of the safety springs. To develop the parameters of new types of tools, it is necessary to use modern software that allows taking into account all the factors affecting the design. Using computer-aided design systems, a 3-dimensional solid model of a knife roller has been created, which has become the object of study. A review of modeling methods has shown that the most widely used approaches today are those based on numerical calculations. To perform the calculations, the Universal Mechanism 9.1 complex has been used, designed for modeling dynamic and kinematic processes in mechanical systems. Using the named software package, a virtual model of a knife roller has been created, taking into account the interaction of the machine links and the friction force of the roller upon contact with the ground. A computational experiment has been conducted to establish the kinematic and dynamic characteristics of the roller at different levels of rigidity of the safety springs and a change in the height of the hitch installation relative to the soil surface. Parameters such as the trajectory of the hitch movement, the tractor traction force, and the forces arising during the interaction of the roller with the soil have been determined. Based on the developed parameters, a prototype of a knife roller has been manufactured, which has passed laboratory tests in a soil channel. In the course of experiments using strain gauge equipment, the traction forces required for the operation of the tool have been measured. The data obtained have confirmed the accuracy of the proposed simulation model and its efficiency for further design and practical application

EXPERIMENTAL STUDIES OF TRACTOR LOAD DURING THE CARE OF FOREST PLANTATIONS USING DIFFERENT AGGREGATION METHODS

This work evaluates the tests of a 2 class tractor (integrated packaging LTZ -155) with front, rear, and combined aggregation, with the possibility of combining operations in the cultivation of row crops and forest plantations by using combined aggregates with forestry and agricultural vehicles with front and rear hinges. An assessment of the performance and efficiency of using such units with their vibration loading has been shown. During experimental studies of the tractor with different mounting methods (rear, front, both front and rear) of a cultivator weighing 2200 kg, horizontal and vertical components of traction resistance, as well as torques on the driving wheels of the tractor, were obtained by tensometric measurements. The work of the tractor took place at a specially prepared landfill for reforestation, to a depth of 4 and 8 cm, respectively, for the rear and front cultivators. The developed tensometric framework was used to analyze the resulting traction resistance. Field tests showed that the dynamics of the processes of power parameters for a unit with front and rear cultivators was significantly lower than with only front or rear cultivators. The absolute value exceeded 2 tons, i.e. traction class of the tractor. The applied spectral correlation analysis showed that these processes had low-frequency spectra (up to 1 Hz). They were “white” noise relative to each other. This, in mathematical modeling, simplifies the formation of the structures of the "impact" and "machine" subsystems</jats:p

SCAN DETACHED TREES USING 3D SENSE AND THEIR RECONSTRUCTION IN CAD

Harvesters are state-of-the-art high-performance forestry machines that carry out a series of continuous operations, such as felling, pruning, and so on. During the alignment process of the harvester head to capture the trunk, the operator requires a large number of observations, judgments and multiple operations, which leads to loss of time and fuel. In order to increase operational efficiency and reduce operating costs, before cutting a tree, it is advisable to obtain a scan in the form of a point cloud. We suggest using a 3D Sense laser scanner for this, which is a non-contact measuring system. &#x0D; The distance between the scanner and the tree is determined by the travel time of the laser light pulse: a pulsed laser beam is emitted and reflected if it encounters an object. Based on these measurements, it is possible to optimize tree felling and increase the automation of harvesters, which will lead to increased efficiency in the use of various resources However, the natural environment poses problems for any computer read task. This article presents the results of scanning single-standing trees surrounded by foliage and branches.</jats:p

SIMULATION MODEL OF THE BRUSH CUTTER ROTOR WITH SIX BLADES

Brush cutters are used in forestry for the care of forest plantations in operations for cutting unwanted tree and shrub vegetation (TSV). Rotors can be used as working bodies. The rotor we are considering is a flywheel, on the outer sides of which the blades are hinged. When cutting DKR with blades, a cutting moment arises, which is transmitted through the knife to the axis of its rotation and then to the shaft driving the flywheel. When designing a brush cutter structure, the impact from the cutting forces of the DKR is decisive for the choice of drive power and rotor parameters. We designed the brush cutter rotor in CAD Solidworks to study the cutting process of the DKR. Its geometric and mass parameters were set; the kinematic links of the links were established. The input motion characteristics were set in the Motion Solidworks module and the cutting moment was applied to the knives. Virtual sensors were installed on the model to record movement characteristics. As a result of a computer experiment for three options, which differ in cutting force and the presence of a damper, the trajectories of the knives and the power consumption of the drive were established</jats:p

Design and Research Sowing Devices for Aerial Sowing of Forest Seeds with UAVs

Modern unmanned aerial vehicles (UAV) can be effectively used for aerial sowing of forests. A feature of aerial sowing is the possibility of rapid reforestation at low costs, which is extremely important in the current environmental situation. The purpose of this study is to develop a set of sowing devices intended for use with UAVs. For this, the metering devices and seed distribution devices were analyzed, used on the UAV or having prospects for such use. The existing studies of metering devices, implemented by numerical methods, are analyzed. Further, the synthesis of eight different designs of sowing devices in the 3D CAD was carried out and their comparative assessment was completed in terms of mass and a set of technological parameters. Based on its results, a sowing device was selected that is most suitable for a specific given technology. Discrete Element Method (DEM) was used to simulate the workflow: imitation of loading of the sowing device, study of work in various modes, study of the process of impact interaction of seeds with the soil environment. The complex of developed sowing devices can provide sowing of almost any type of forest seeds within the framework of various technologies and soil climatic conditions

IMPROVEMENT OF TECHNOLOGIES OF WORK OF CHAINSAWS ON UNSAFE FELLING OF THE FOREST

The article presents a new comprehensive three-level concept for evaluating design decisions for performing processing operations on incomplete logging, which is distinguished by the ability to simultaneously predict energy costs, technical and economic results, and forestry and environmental consequences for the forest environment. To implement this concept, a structure of a three-level automated system for increasing the efficiency of working with chainsaws on incomplete cutting was proposed by substantiating the optimal technology and organization of work, a set of gasoline-powered tools, a method and parameters for developing apiaries. At the first level, to substantiate the optimal set of gasoline-powered tools, a mathematical model of the process of performing butt cuts for the determination of specific energy costs is proposed. At the second level, to substantiate the optimal technology and labor organization, simulation models of the process of performing processing operations to determine the specific reduced energy costs are proposed. At the third level, in order to justify the optimal method and parameters for apiary development, a generalized criterion is used to assess the efficiency of processing operations taking into account direct production costs, forestry damage, as well as damage to the undergrowth. For each indicated level of tasks to be solved, a mathematical apparatus, information and software recommended for use at logging enterprises was developed. Currently, it has been successfully implemented in the Moscow and Tambov regions. According to the results of the implementation, there is a decrease in the performance of processing operations: specific and specific reduced energy costs (from 4 to 9%); total direct costs (from 3 to 7%); as well as forestry and environmental damage (from 5 to 11%).</jats:p

Design and Research Sowing Devices for Aerial Sowing of Forest Seeds with UAVs

Modern unmanned aerial vehicles (UAV) can be effectively used for aerial sowing of forests. A feature of aerial sowing is the possibility of rapid reforestation at low costs, which is extremely important in the current environmental situation. The purpose of this study is to develop a set of sowing devices intended for use with UAVs. For this, the metering devices and seed distribution devices were analyzed, used on the UAV or having prospects for such use. The existing studies of metering devices, implemented by numerical methods, are analyzed. Further, the synthesis of eight different designs of sowing devices in the 3D CAD was carried out and their comparative assessment was completed in terms of mass and a set of technological parameters. Based on its results, a sowing device was selected that is most suitable for a specific given technology. Discrete Element Method (DEM) was used to simulate the workflow: imitation of loading of the sowing device, study of work in various modes, study of the process of impact interaction of seeds with the soil environment. The complex of developed sowing devices can provide sowing of almost any type of forest seeds within the framework of various technologies and soil climatic conditions.</jats:p

RESULTS OF THE STUDIES OF BRANCH CUTTING PROCESS USING A ROTOR WITH ARTICULATED AND RIGIDLY INSTALLED BLADES

An important technological operation in the care of forest crops is mechanized cutting of branches of unwanted vegetation. The working bodies used for cutting differ in design and energy costs for the cutting process. It is necessary to develop a methodology and conduct experimental studies of the process of cutting branches to select the working bodies to the greatest extent corresponding to the object of cutting. At present, systems based on strain gauges are widely used for the experimental study of machine parameters. However, along with them, digital interface is increasingly being introduced into measuring instruments such as oscilloscopes and multimeters. When studying the process of cutting branches with a rotor driven by an electric motor, the cutting resistance forces will create a torque on the shaft, which will lead to a change in the consumed current. The change in current strength can be measured with a multimeter, which enables to set the power indicators of the cutting process for the investigated rotors. In the work, a 3D model of rotors with rigidly mounted and hinged blades was developed using reverse engineering with the help of Solidworks CAD. The main geometric and mass characteristics of the rotors have been determined. The principle of connecting the measuring equipment (UNI-T 61E multimeter and shunt 75SHIP1-5-0.5) for measuring the cutting power of branches has been developed. Experimental studies have been carried out and differences in the power indicators of cutting for two types of working bodies have been established</jats:p

RELATIONSHIP OF THE TYPE OF WORKING BODY OF THE BRUSH CUTTER WITH THE POSSIBILITY OF CUTTING WOOD-SHRUB VEGETATION

To remove unwanted tree and shrub vegetation, it is necessary to use mechanized implements aggregated with traction means - tractors. The power consumption of the drive of these tools depends on their mass and the principles of the cutting process. Currently, mulchers, which are designed to grind felling residues with a diameter of tens of centimeters, remove shrubs with a diameter of up to several centimeters, which leads to unreasonably high costs for this type of work. The article studies the designs of frames and working bodies of brush cutters, which are a rotor rotating in a horizontal plane with a knife fixed on a flexible connection or hinge. On the basis of the structures, hypotheses have been put forward about the advisability of using the considered types of working bodies when cutting tree and shrub vegetation, taking into account its diameter. Using the presented connections between the types of working bodies and their ability to cut tree and shrub vegetation, it was revealed the possibility of developing narrowly focused mathematical models, which will reduce the energy consumption of hedge trimmers and increase their efficiency. The presented designs of rotors themselves are also insufficiently studied from the point of view of kinematics and dynamics of movement of their links, which is of certain scientific interest.</jats:p