Vol 91, No 5 (2024)

BACKGROUND: 2024 marks one hundred years since the start of serial production of the Fordson-Putilovets tractor at the Krasny Putilovets plant in Leningrad. This is the milestone of the formation of the tractor industry in the domestic mechanical engineering industry. Reflection of historical facts of the appearance of new serial models of tractors are important events in the history of science and technology.

AIM: Review and analysis of the historical development of the tractor design at the St. Petersburg Tractor Plant from the date of production of the first serial tractor in the USSR in 1924 to the present day.

METHODS: The research was carried out in accordance with the principles of historicism, scientific objectivity and credibility. The statistical data were processed and presented in the form of graphs and diagrams using the Microsoft Excel software.

RESULTS: On October 1, 1924, in the workshops of the Krasny Putilovets plant (until 1922 — the Putilov plant), the serial production of the Fordson-Putilovets wheeled tractors began. In 1934, serial production of the Universal row-crop tractors was established. In the late 1930s, the K-8, K-9, K-10 tracked row-crop tractors were created. In 1945, the Kirov plant, located in Chelyabinsk on the premises of the ChTZ during the war, created and mastered the serial production of the first industrial tracked tractor in our country, the Stalinets-80. In 1947, the Kirov plant began to produce the KT-12 skidding tractors, which had no analogues in the world tractor industry. In 1964, the plant began production of the Kirovets tractor with all drive wheels, an articulated frame, and the power of 200 HP. Over the past sixty years (1964–2024), 52 models of Kirovets agricultural tractors have been developed and put into production. Analysis of the power-to-weight ratio of these tractors shows a 1.5-factor increase from 12.3 to 18.6 W/kg. Starting from 2000, the Kirovets tractors have been developed within the framework of the “traction-energy” concept, where ballast weights, double wheels, wide-profile tires, rubber-cord tracks, etc. are used to realize their potential traction capabilities. From 1964 to 2024, specific fuel consumption decreased by 1.2 times (from 258 to 214 g/kWh), which indicates the improvement of diesel engines. The new Kirovets K 525T (250 HP) and K-530T (300 HP) produced in 2024 absorbed all the achievements of the domestic tractor industry. The K-525T is equipped with a new gearbox that provides speeds of up to 50 km/h. The modern tractor of the Kirovets brand manufactured by the PTZ is a reflection of modern scientific and technological progress, effectively performs technological operations in agricultural production and provides the tractor driver with comfortable working conditions.

CONCLUSION: A review of the output of tractor products for a hundred years at the St. Petersburg Tractor Plant (PTZ JSC) revealed its lineup and made it possible to find some regularities in the historical development of individual parameters of the machinery. The studies carried out show that the improvement of the design of the Kirovets tractors corresponds to scientific and technological progress, their functionality improves, power-to-weight ratio increases, specific fuel consumption decreases, and speeds gradually increase. The number of models of tractor products is also increasing and is striving to meet the needs of consumers as much as possible.

BACKGROUND: The rapid development of unmanned aerial vehicle (UAV) today is largely driven by the needs of the defense industry. The new scientific and technological phase of research substantiates the necessity for a systematic analysis and review of existing regulations concerning the use of agrochemicals in agriculture with the application of unmanned aerial vehicles.

AIM: Conducting an analysis of the current state of the application of UAV in agriculture for the use of agrochemicals and identifying problematic issues that limit the development of this field as a whole.

METHODS: The material used in this study includes publications of scientific articles and reviews that cover the researched topic and are available in scientific libraries: elibrary.ru; dissercat.com; medline.ru; scholar.google.com.ru; cyberleninka.ru. Additionally, legislative acts published on the websites of the Ministry of Agriculture of the Russian Federation; the Federal Air Transport Agency; the Ministry of Natural Resources and Environment of the Russian Federation; the Ministry of Transport of the Russian Federation; Rospotrebnadzor of the Russian Federation; and the Government of the Russian Federation were utilized. The study was conducted using generally accepted methods of scientific information processing: citation, grouping, editing, aggregation, and transformation into a new form.

RESULTS: The study analyzes the results of existing research works, the technical capabilities of UAV fleet models, and the requirements of legislative acts regulating the operation of agricultural drones when applying agrochemicals.

CONCLUSION: The imperfections of the existing legal framework, new technical capabilities of unmanned aerial vehicles, and modern advancements in agricultural chemicalization necessitate the review of current approaches and the development and justification of new strategies for the use of unmanned aerial vehicles in agriculture, particularly when applying agrochemicals.

BACKGROUND: Single-bucket hydraulic excavators are used in mining industry, construction industry, public utilities and other sectors of the economy. The productivity of these machines depends on a number of factors, among which the main one is the bucket volume.

Due to the impossibility of overcoming the digging resistance forces, it is impossible to install a larger bucket on an excavator of a certain category.

AIM: Development of the excavator bucket design, the shape and mechanics of which reduce digging resistance to make it possible to install larger buckets.

METHODS: The bucket model was built in the Kompas-3D software, and the APM FEM Kompas-3D application was used for strength calculations.

RESULTS: Sketches of the proposed buckets with a volume of 0.25 m³ are considered. The search for optimal parameters of the bucket parts to make it possible to install it on a production excavator and to perform the digging process was carried out. Justification of the parameters of the bucket parts is given. In order to check the operability, a strength calculation of the designed bucket structure was carried out. This will help to increase the productivity of the excavator and to expand its functionality.

CONCLUSION: As a result of the study, changes in the design of the production bucket, which make it possible to install buckets of increased volume on an excavator without losing the strength and reliability of the structure, were proposed. The strength calculation showed a safety factor of 3.3, which proves the operability of the designed structure of the proposed bucket.

BACKGROUND: The trapezoidal lever mechanism used in the steering linkage for turning steerable wheels to change the motion direction of a wheeled vehicle does not fully meet the conditions for ensuring pure wheels rolling and corresponding to the correct turn kinematics, which is especially evident when adjusting the track.

AIM: Assessment of the degree of discrepancy between the actual turn kinematics and the correct turn kinematics when changing the track of the tractor.

METHODS: Analytical methods were used in the study, which made it possible to obtain some computational dependencies, to perform a numerical analysis of the curvilinear motion of a tractor with a variable track for different parameters of the steering linkage, and on this basis to establish patterns between the geometric characteristics of the steering linkage and the kinematic parameters.

RESULTS: Reasonable geometric characteristics of the steering linkage, which ensure the turn kinematic parameters closest to the required ones, are set for the most commonly used value of the width of the kingpin track. For the Belarus-80.1 tractor, it corresponds to 1.02 m. At the same time, for example, at a steer angle of the inner steerable wheel of 25°, the minimum turning radius ensured by the steering linkage differs by 0.6521 m (10.44%) and at the steer angle of 40° by 0.2829 m (9.27%) from their values obtained from the pure rolling condition. When changing the track width of the machine, there is a violation of the initial geometric characteristics of the linkage and the corresponding mismatch of the turn kinematic parameters ensured with the steering linkage and the correct turn kinematics increases. A comparison of the minimum turning radii at an angle of 25° and a kingpin track of 1.42 m showed an increase by 3.2340 m (35.83%), and at 40° — by 0.8956 m (20.21%).

CONCLUSION: To ensure the correct turn, it is necessary to conduct a thorough theoretical analysis of the steering linkage and to improve its design on this basis.

BACKGROUND: An important feature of fiber flax is a significant difference in the timing of fiber formation and seed maturation. Therefore, in order to obtain the greatest effect from both types of products, a time gap between the cultivation of plants and the separation of seeds from them is necessary. The use of the two-phase flax harvesting technology, in which the second phase is most dependent on weather conditions and is responsible for the selection of dried plants and the separation of seeds from them, will make it possible to satisfy this requirement. In Russian conditions, this operation is most effectively performed by combing pickers with combing machines that reliably work with flax of any ripeness and moisture. However, the quality of operation of such devices is noticeably reduced with accidental deviations of the picker towards butt or vertex parts of the plant ribbon. To eliminate errors of the harvested strip copying before feeding it to the combing unit, it is advisable to use an orienting device made as an inclined table with conveyors, which ensures the displacement of plants in the direction of the tilt of the table under the uncontrolled and short-term influence of gravity. Therefore, this process needs further investigation.

AIM: Justification of the parameters of the orienting device for correcting errors in horizontal copying of the flax strip by the picking machine of the flax harvester.

METHODS: Studies of the process of plants displacement in the orienting device were carried out in stationary conditions using the experimental laboratory unit. At the same time, the amount of displacement of the flax strip under the action of gravity of the stems along the inclined table of the orienting device was determined depending on the table inclination angle, the speed of its conveyors and the moisture content of the plant mass.

RESULTS: The results of the conducted studies adequately state the ability of the orienting device to effectively correct the consequences of accidental deviations of the picker from the plant strip before feeding it to the combing device. The indicated effect will be ensured with a length of an inclined table of 1 m, a conveyor speed of 2 m/s and a tilt of the table of 60°. A slight influence of plant moisture on the operation of the orienting device in combination with a combing device in the design of the comb picker will reduce the dependence of the two-phase flax harvesting on weather conditions.

CONCLUSION: The results obtained clearly show the expediency of using the orienting device to correct errors in horizontal copying of a flax strip by a flax harvesting machine. The study results were used to create the prototypes of the POL-1.5K flax strip combing picker, which was tested in production conditions in the fields of flax farms.

BACKGROUND: Nowadays, cabins of agricultural and construction machinery with integrated roll-over protecting structures are widely used. Using aluminum alloys is one of the ways for significant weight reduction of these load-bearing structures; however, there are issues with mechanical properties of aluminum in the welded joint zone. The recently appeared additive technologies for aluminum alloys help to obtain structures with complex shape that demonstrate high ductility and impact toughness. However, their application in development of roll-over protecting structures requires additional research to determine compliance with passive safety requirements according to the GOST ISO 3471-2015.

AIM: To study the stress-strain state of aluminum alloy specimens and their welded joint for compliance with passive safety requirements according to the GOST ISO 3471-2015.

METHODS: The experiment-simulation approach is used in this study. A universal tensile machine and an impact testing machine are used in the experiment.

RESULTS: The mechanical properties of the samples made of 3D-printed aluminum alloys and their welded joints were obtained. Their degree of compliance with passive safety requirements according to the GOST ISO 3471-2015 was established.

CONCLUSION: According to the conducted study, the potential for use of 3d-printed aluminum alloys and their welded joints in rollover protection structures of cabins in agricultural and construction machinery is confirmed.

BACKGROUND: The creation of competitive machine parts capable of withstanding standard and increased operational loads is a relevant task in mechanical engineering. Developing additive synthesis technologies together with strengthening technologies make it possible to create products with high load-bearing capacity. However, to improve the efficiency of these technologies, it is necessary to create theoretical models of the considered processes. The paper presents the results of the first stage of creating complex theoretical models of the combined 3DMP process and wave strain hardening (WSH) required for designing the technological processes for manufacturing engine parts and brake systems of automotive equipment.

AIM: Creation and adequacy assessment of the models of materials used in finite element modeling of additive synthesis processes with subsequent hardening.

METHODS: Theoretical models of the material were created in the ANSYS software package, which is capable of performing multidisciplinary calculations. The experimental data required for preparing the models were obtained by testing tensile samples manufactured using standardized methods. The hardness of materials was studied using the KB 30S automatic hardness tester. The adequacy of additive synthesis modeling was assessed based on the distribution of temperature fields. The adequacy of models of the material for the WSH process was assessed based on the sizes of individual plastic indentations and the distribution diagrams of the depth and degree of hardening in the surface layer.

RESULTS: Theoretical models of the following materials were created: steel 45, stainless steel 12Cr18Ni10Ti, bronze alloy CuAl8Fe3, titanium alloy VT 1-0, aluminum alloy V95. The theoretical data obtained from the modeling results have a high level of significance. The studies were conducted for various thermal (in the range from +20ºС to +800ºС) and deformation modes. Graphical results of theoretical and experimental studies make it possible to obtain a qualitative assessment of the studied processes with the required accuracy.

CONCLUSION: As a result of the adequacy assessment of the created models, it was found that the discrepancy between the empirical and theoretical data does not exceed 7.4%. The obtained models of materials are statistically significant and can be correctly applied in further studies.

BACKGROUND: Driving safety of transport-technological machines, especially in off-road conditions, largely depends on the stiffness and damping of suspension. These properties directly affect the ride smoothness and static transverse stability of the machine on a slope, ensure the ability of long-term motion on rough roads in the range of operating velocities without exceeding the established limits of vibration accelerations, causing unpleasant sensations and rapid fatigue of a driver, constant contact of wheels with the ground, as well as avoiding excessive wheel bump. Therefore, it is necessary to provide the suspension with the required elastic and damping characteristics by using a pneumohydraulic shock absorber in the design and to evaluate its effect on the safety of driving in off-road conditions.

AIM: Development of a method for assessing the impact of ride smoothness of transport and technological machines on the main indicators of driving safety in off-road conditions in the development of new technical solutions aimed at improving the ride smoothness.

METHODS: Modeling of oscillatory processes of the machine masses connected with each other by stiffness-damping links at unsteady and steady oscillations, modeling of the influence of the stiffness of the elastic suspension element on the static transverse stability of the machine on a slope are performed in the Mathcad software environment.

RESULTS: As a result of mathematical modeling of oscillatory processes of masses of the machine it was established that the application of the proposed shock absorber allows in case of driving over a single bump of 0.08 m height at a speed of 30 km/h to reduce body displacement from 0,070 m to 0,056 m and its acceleration from 3,50 m/s² to 1,35 m/s², there by achieving complete damping of the oscillatory process of the masses already in the fourth period, and in the case of driving over a sinusoidal bump, the oscillatory process is largely stabilized, the wheel copies the profile of the bump, as a result of which the movement of the body decreases from 0,045 m to 0,030 m, and the acceleration of the body after the transition process decreases from 2,2 m/s² to 0,8 m/s². The analysis of evaluation of influence of smooth running on static transverse stability of the machine has shown that as a result of taking into account the elasto-hydraulic characteristics of the shock absorber and the pneumatic tires themselves it is possible to increase the angle of static stability on lateral overturning from 38° to 43° with maximum permissible angle of body roll of 8.4°.

CONCLUSION: The knowledge of methods of estimation of influence of ride smoothness of transport-technological machines on the main indicators of driving safety in off-road conditions makes it possible to analyze the efficiency of application of the proposed technical solutions aimed at increasing the ride smoothness of the machine in off-road conditions.

BACKGROUND: The most important condition for obtaining livestock products is a high-quality feed base. A complete balance of diets in terms of nutrition elements — protein and others, which guarantees high animal productivity and low production costs of over 75%, and it is economically advantageous for the agricultural enterprise to meet the need for animal feed. For their preparation, farms use feed mills such as the R1-BKZ-5 (Melinvest) and reliable, easy-to-operate and inexpensive units that are capable of producing concentrated mixtures from local raw materials are needed. Thus, the development of a feed mill, which is capable of obtaining a high-quality finished product with low unit costs and metal consumption, is a relevant task.

AIM: The economic assessment of the use of a technological line for the preparation of concentrated feed, for example, sunflower seed cake.

METHODS: The economic efficiency of the developed lines for the preparation of seed cake according to patents of the Russian Federation №№ 2646092, 2690882, 2685123, 2694673, 2693741, 2693437, 2694573, 2694722 are evaluated in comparison with the R1-BKZ-5 feed mill unit. The method for calculating them is given in the recommendations.

RESULTS: To calculate the proposed technological lines for the preparation of seed cake, a program was compiled in the Excel environment. The initial data and calculation results are presented.

CONCLUSION: The proposed technological lines for the preparation of sunflower seed cake are profitable and economically advantageous compared to the serial R1-BKZ-5 unit with and without a multimedia device due to a reduction in direct operating costs by 24%, whereas annual savings in total costs amounted to 91% and the payback period for additional capital investments varies from 4.59 to 5.27 years. The developed lines contain modern technical means and equipment that help to evaluate and to improve its quality in real time, as well as to simplify the design, to reduce the energy intensity of the process.

BACKGROUND: Intensification of the agricultural industry requires increasing the efficiency of all processes occurring in this area. In conditions of intensification, the interconnection and interdependence of all factors of agricultural production increases, among which the human factor is of particular importance. The article discusses the use of a process approach, an expert system, as well as a neuro-fuzzy model to solve the problem of reducing the influence of the human factor to increase the efficiency of operation of agricultural machines.

AIM: Reducing the influence of the human factor to improve the operating efficiency of agricultural machines.

METHODS: The work used a process approach within the framework of the methodology of total quality management, an expert system based on artificial intelligence, including methods of engineering psychology and fuzzy logic.

RESULTS: As a result of research, it has been established that more than 50% of all emergency situations are directly or indirectly due to the human factor, while more than 60% of emergency situations occur with drivers who have a high level of aggressive and risky behavior, while the share of such drivers is about 30% of the total number. A comprehensive process model, software tools for assessing the components of risk associated with the human factor, as well as an expert system for assessing risks at a qualitative level have been developed. The developed expert system model makes it possible to assess risks with an error not exceeding 15% (relative to the assessment carried out by a group of experts).

CONCLUSION: The novelty of the results obtained is due to the comprehensive consideration of the technical and human aspects of ensuring the efficient operation of agricultural machines, as well as the use of modern apparatus based on artificial intelligence, which allows the model to be rebuilt to suit specific needs.