Vol 90, No 4 (2023)

Based on the results of re-registration and based on the results of 2022, the Higher Attestation Commission of the Ministry of Education and Science of Russia included the journal Tractors and Agricultural Machinery in the list of peer-reviewed scientific publications in which the main scientific results of dissertations for the scientific degree of Candidate of Sciences, for the scientific degree of Doctor of Science should be published (information message ref. No. 02-1198 dated 12/06/2022).

And according to the coefficient of scientific significance, our journal is classified in category K1 (that is, in the top 25% of the total list of 2587 peer-reviewed scientific publications).

Tractors and Agricultural Machinery simultaneously expanded the list of scientific specialties in the branches of science in which academic degrees are awarded: six new specialties were added to the previous four.

BACKGROUND: The paper shows that the problem of determining objective indicators of fuel consumption in operation based on calculation methods remains relevant. One of these methods is simulation modeling. Current state of computer technology significantly simplifies building of system simulation models, for example, using the Simulink software by Mathworks. In the process of model development, it is necessary to keep the balance of generalization and detailing, since excessive detailing leads to an unreasonably deep consideration of individual elements of the system and to a significant increase in simulation time.

AIMS: Search for a reasonable structure of model of the “driver — car — environment” system, which makes it possible to simulate the car in driving cycles or other driving scenarios.

METHODS: The MATLAB/Simulink simulation environment was used in the study. Based on the analysis of the car design and the capabilities of individual Simulink tools, a block diagram to study fuel consumption using the example of a passenger vehicle was synthesized. The obtained model was debugged for the stable motion simulation of the vehicle in various driving cycles using graphical analysis.

RESULTS: The obtained results show that the developed system simulation model is well behaved. Control systems ensure the vehicle motion according to the mixed driving cycle modes in compliance with the required tolerances. It is possible to register fuel consumption and other simulation results of interest.

CONCLUSIONS: The model showed the relative simplicity of setting up and the ability of quick update for other vehicles. A minimal amount of vehicle data is required to bring the model to an operable condition. Particular unknown parameters are supposed to be refined using identification methods.

BACKGROUND: The necessity in intensification of agriculture with growing crop products needs demands constant improvement of soil-cultivating working bodies. Increase of field yield rate requires measures of their recultivation and melioration. Moreover, the demand in restoring crop acreage retired from crop rotation due to human economic activities.

AIMS: Justification of energy consumption of soil cultivating process with a tiller with V-shaped knives.

METHODS: Accomplishment of the given research tasks and calculation of the power demanded for operation of the proposed rotational mechanism with V-shaped knives, are done with resolution into components: power for overcoming of constant resistance, power for tillage process (deformation of soil shavings) and power of soil throwing-away. Processing of the theoretical data was performed with the Microsoft Office software package.

RESULTS: With the analysis of theoretical curves of influence of notion velocity and number of knives in plane of the proposed working body, it is apparent that having three knives in plane of the working body the resistance per knife almost doubles that leads to overall increase of soil resistance to the whole working body. Meanwhile, increase of motion velocity has a positive effect on lowering the reaction of soil on the working body.

CONCLUSIONS: With the analysis of the given data, it is observed that values of soil resistance change the tendency to the positive one with velocity increasing.

BACKGROUND: Analysis of trends in the development of industrial technologies in the field of agriculture showed that manufacturers of technological equipment used on farms turn to robotics to exclude human labor when performing labor-intensive cyclical operations that are accompanied by a high degree of tension. To perform operations for the preparation and distribution of feed on a farm, maintenance of the feed table, as well as for manure harvesting, it is necessary to use a wheeled robotic platform with an automatic positioning system.

AIMS: Development and testing of the software and hardware system of the Feed Pusher robot for the autonomous execution of operations for the maintenance of the feed table at livestock facilities.

METHODS: Wheeled robot motion simulation, as well as a mathematical description of the kinematic and dynamic properties of the wheeled robot motion was carried out using the MATLAB software and the Simscape library and the Simulink application. The Figma graphic design software was used to develop layouts of mobile software interfaces for the wheeled robot remote control.

RESULTS: During the wheeled robot motion simulation, direct and inverse kinematics problems were solved, consisting in finding the ${\omega }_1, {\omega }_2,$ vectors with the input parameters $x_0, y_0, {\phi }_0, x, y, \phi$, as well as the final angle of the path (relative to the horizontal). Layouts of the robot remote control software interfaces have been developed, as well as the frontend and backend development of the program adapted to the use at a smartphone has been carried out. The testing of the wheeled robot was carried out at a livestock facility, during the maintenance of the feed table and the simultaneous execution of operations to push the feed to the fence and dosing of feed additives.

CONCLUSIONS: The practical value of the research lies in the possibility of using the results of the wheeled robot motion simulation to adjust the operation of the automatic positioning system. At the same time, the farmer using the proposed Feed Pusher robot will ensure an increase in the technological efficiency of cattle keeping, in particular dairy cattle, with an increase in milk yields up to 1 liter per day per head, which was determined during the tests on the farm.

BACKGROUND: The efficiency and energy capacity of translatory moving soil tillage tools are largely determined by the parameters of their blades. If the parameters do not match the specified operating conditions, clogging the working tools with plant residues becomes possible, and a less energy-consuming type of soil cutting — sliding — may be replaced with a more energy-consuming type — chopping cutting. In this regard, it is very important for scientists engaged in improving the designs of translatory moving soil tillage tools to have a method for assessing the shape of the blades.

AIMS: Development of a method for comparative assessment of various blade shapes of translatory moving soil tillage tools.

METHODS: For this study, the fundamentals of agricultural mechanics, higher mathematics, and theoretical mechanics were used. The objects of the study were the blades of various soil tillage tools, providing with sliding cutting of soil. The study was conducted at the Gorsky State Agrarian University in the period from 2022 to 2023. The calculations results were compared with the materials of the corresponding standards.

RESULTS: The method that helps to determine the relative values and directions of the resultant force of soil cutting resistance with a translatory moving blade of a soil tillage tool having a diverse shape has been developed. An example of the application of the method for assessment the effectiveness of blades of a garden tool, the cutting part of which is described by the equation of a straight line, a circle, an Archimedes spiral, a logarithmic spiral, as well as an example of assessment of a curved blade for soil tillage tools of cultivators are given.

CONCLUSIONS: The proposed method for assessing the influence of the shape of a translatory moving flat blade of the soil tillage tools on the value of soil cutting resistance forces is easy to use and can be the basis for further development in order to analyze the effectiveness of the knives’ blade shape performing a plane-parallel movement.

BACKGROUND: Confirmation of the operability of agricultural tractor transmission units is obtained by machinery manufacturers on the basis of bench tests. The development of technical solutions for test rigs for transmissions and load control systems with an approximation to operational modes is a relevant technical task.

AIMS: Development of technical solutions of test rigs for testing transmissions of tracked tractors and load management systems based on the analysis of operational loading of transmissions.

METHODS: An analysis of the operational loading of the transmissions of the DT and VT series tracked agricultural tractors was performed, based on the results of which the technical solutions for loading devices of test rigs were developed that allow reproducing loading modes with parameters statistically equivalent to the operational loading modes on the tested transmissions.

RESULTS: A technical solution is proposed for a test rig with a hydro-closed power circuit, in which a hydraulic loader with a rotating spool, by lifting and relieving the pressure of the working fluid in the pressure lines, forms a load on the parts of the tested transmission in accordance with the operational loading mode obtained as a result of preliminary analysis. A technical solution for a test rig with eccentric loaders is also proposed, in which a constant level of load on the tested transmission is created by hydraulic loaders acting on the track chains, and variable loads are formed by eccentric mechanisms and disturbances from the track chains rewinding.

CONCLUSIONS: The practical value of the study lies in the possibility of using the proposed technical solutions of test rigs to conduct tests of tracked tractor transmissions with an increase in the degree of reliability of their results due to the approximation of the transmission loading conditions on the test rigs to the operational ones.

BACKGROUND: In modern harvesting technologies, the main technological operation is mechanized crops pulling. The flax-pulling machine with transverse band-disc channels is the most promising. However, the basic design parameters of pulling sections are not justified sufficiently, the peculiarities of their layout are not considered, the processes of moving plants through sections and pulling short-stemmed flax are not sufficiently studied, which reduces the effectiveness of its use.

AIMS: Theoretical and experimental justification of the parameters and operation modes of pulling sections of the device with transverse band-disc channels.

METHODS: Experimental studies to justify the parameters and operation modes of experimental pulling machines were carried out according to known and developed methods, and the assessment of flax products was carried out according to current GOST standards. The influence of the velocity of the unit and the width of the grip of pulling sections on the indicators of the agrotechnical and technological assessment of the operation of pulling device was determined.

RESULTS: Dependences for determining the design parameters of a pulling section and the minimum height of plant stand suitable for mechanized harvesting were obtained, the conditions for finishing and moving plants in the zone of fixed guides were established. The structures of the experimental pulling machines were used to assess the unit velocity, the effect of the width of a pulling section and the elimination of the separation of technological currents of plants during processing on improving agrotechnical performance and increasing the yield and number of long fiber. The frame elements of the TLN-1.9P unit, are placed above the pull pulleys, and the operating width of a section is 0.38 m. In the TLN-1.9M and the TLN-1.9K units, they are located behind the pull pulleys, with the operating width of a section of 0.35 and 0.31 m respectively. As a result, the flax straw had higher quality indicators: 1.5 numbers for the TLN-1.9M and the TLN-1.9K and 1.25 numbers for the TLN-1.9P; the average yield of long fiber of these units was 13.41, 13.1 and 12.59% respectively.

CONCLUSIONS: When assembling pulling machines with transverse band-disc channels, the elements of the frame structure should be positioned behind pulling drums, technical solutions should be used to ensure the kinematic operation mode equal to one, with the operating width of a section of 0.31 m for harvesting seed breeding and 0.35 m for harvesting commercial crops.

BACKGROUND: The digital transformation of various sectors of the national economy including agriculture is one of the main tasks of economic development. The implementation of digital technologies in production processes helps to improve the technical and economic indicators of production by ensuring the timely adoption of optimal management decisions, increasing labor productivity, and reducing the impact of the human factor on production. To ensure the digital transformation of agricultural production, first of all, it is necessary to assess the state of machinery and technology provision for agriculture, in particular, the tractor fleet, in terms of the level of equipment readiness for being equipped with digital systems and the availability of standard technical solutions for equipment adaptation to digital agriculture.

AIMS: Determination the expected values of indicators of the level of technical and technological state of agricultural production by developing a forecast for the development of the agricultural tractor fleet and the level of provision with these types of equipment for the period up to 2030 taking into account current trends.

METHODS: For the tractor fleet state assessment, the data taken from specialized databases on the tractor fleet and the area of arable land retired from active agricultural circulation, statistical materials of the Rosstat and Avtoselkhozmash-Holding organizations were used. Statistical extrapolation methods implemented in the Microsoft Excel environment were used to predict the development of the tractor fleet.

RESULTS: The forecast for the tractor fleet development was made according to two scenarios: pessimistic and optimistic, taking into account the use of digital technologies.

CONCLUSIONS: The development forecast made it possible to assess the state of the tractor fleet by 2030 according to various scenarios.