Tractors and Agricultural Machinery

Numerous long-term domestic and foreign studies have noted a significant reduction in agricultural yields due to soil compaction caused by chassis of tractors and mobile agricultural machinery. Soil compaction also leads to cultivation costs increase. One of the solutions for reduction of the negative impact of chassis on the soil is to develop highly elastic track systems. Two types of pneumatic tracks are being considered: track treads with pneumatic tracks, longitudinally positioned relative to the track axis and tracks with transversely positioned tracks on a metal traction chain. Comparative tests of propulsions with pneumatic and metal track treads revealed that replacing metal track treads with pneumatic track treads results in a more uniform distribution of specific pressures along the length of the supporting surface. Moreover, the pressure nonuniformity coefficient for a propulsion with pneumatic track treads is 1.6–1.9 times lower. The redistribution of vertical loads on the ground by the rubber-cord casing is due to the high inverse stiffness of the pneumatic track tread. The results of studies on the distribution of vertical stresses in the soil column along the tracks of pneumatic and metal track treads and changes in soil density to a depth of 500 mm are presented. Design schemes and commercially available pneumatic track treads with transversely arranged pneumatic tracks are examined. Examples of the use of such track treads at excavators, logging equipment, floating snow and swamp-going vehicles, and the VT-150 agricultural tractor are given. A description of the design of the VT-150 tractor’s pneumatic track tread is provided. Comparative soil impact tests of the VT-150 tractor with metal and pneumatic track treads under spring and summer conditions at the North Caucasus Machine Testing Station are presented. Based on 30 years of experience in operating pneumatic tracked propulsion units, conclusions have been drawn about their applicability in agricultural machinery.

BACKGROUND: One of the features of improving the performance of diesel engines is the analytical evaluation method, as well as the analysis of operation in field conditions when using various types of fuel. The studied agricultural machinery operates at various speed load modes of their engines. Mathematical modeling of working processes that link output variables with input effects allows determining the emissions of harmful substances from automotive and tractor engines under operating conditions.

AIM: Compilation of a mathematical model of emissions of harmful substances from automotive and tractor engines under operating conditions.

METHODS: Experimental studies were carried out in accordance with the requirements of GOST 14846-2020 (Automotive engines. Bench test methods) and GOST 18509-88 (Tractor and combine diesel engines. Bench test methods). The main operational factors influencing the power, environmental and economic performance of engines running on water-fuel emulsion were analyzed at the Irkutsk State Agrarian University named after A.A. Ezhevsky and the Buryat State University named after D. Banzarov. During the experiments in the field, the following factors were found: a decrease in torque, a decrease in diesel power due to fluctuations in the resistance moment on the engine by an average of about 10% for each of the above indicators. This indicates a violation of the cyclic fuel supply, mixing and combustion processes, which negatively affects technical, economic and environmental indicators.

RESULTS: Experimental data were obtained for various indicator powers corresponding to fluctuations in the cyclic fuel supply for operating conditions. Under operating conditions, soot emissions ranged from 0.11 to 0.32 times; NO_x emissions ranged from 2.94 to 5.62 times, and when adding a 30% methanol additive, soot emissions ranged from 0.02 to 0.32 times; NO_x emissions ranged from 2.5 to 2.2 times. The calculated indicators show a satisfactory correlation to the theoretical studies, ranging within up to 5%. Therefore, according to the proposed method, it is possible to determine the emissions of harmful substances of diesel engines under operating conditions. An analysis of the dynamic properties of fuel supply under operating conditions is carried out and equations for the relationships of output coordinates with input ones are presented. Under field experiment conditions, a decrease in torque and diesel power with significant fluctuations in crankshaft velocity were found. Emissions of harmful substances of diesel engines were determined by calculation.

CONCLUSION: An integrated approach to the study of the influence of alternative fuels and operating conditions on emissions of harmful substances in diesel engines is crucial for development of effective solutions to reduce their negative impact on the environment.

BACKGROUND: Related to the active development of unmanned vehicles, the task of development of effective sensors capable of creating three-dimensional models of the road scene becomes relevant. One of the types of such sensors is millimeter-wave radars with linear frequency modulation of the signal. Currently, they are mainly used to create two-dimensional models of the road scene in azimuth/range coordinates. However, the ability to scan in an elevation plane can significantly improve the recognition of low objects against the ground, which is especially important at agricultural machinery operation, especially in fields during harvesting. The transition to three-dimensional modeling of the road situation requires the ability to scan not only in azimuth, but also in elevation, which leads to a significant complication of the radar design. To reduce the complexity and cost of the radar, it is proposed to use the MIMO architecture (Multiple Input Multiple Output), but this method has a number of disadvantages, such as increased losses in signal energy and difficulties in synchronization in time or frequency domain of transmitters’ signals.

AIM: The aim of the work is to conduct an experimental study and mathematical modeling of the radiation pattern characteristics of a combined microstrip two-dimensional antenna system with frequency scanning. To do this, we will use signal processing algorithms such as fast Fourier transform, correlation processing, and minimization of the L₁ norm using a redundant basis (dictionary) and a combination of them are used.

METHODS: This paper discusses signal processing methods for automotive radar designed to create a three-dimensional road scene. The radar uses an antenna array with a frequency-swinging beam pattern to scan in the vertical plane

RESULTS: This paper presents the results of modeling and experimental studies conducted using algorithms based on the fast Fourier transform (FFT), the use of weight processing functions, and the modified MFNN (Minimum Fuel Neural Network) algorithm.

CONCLUSION: This study demonstrates the effectiveness of constructing a three-dimensional road scene using frequency scanning of the beam pattern.

BACKGROUND: The modern market of seeding machines offers a large number of long-developed and well-proven models. Among them are various modifications of the SZS-2.1 grain stubble seeders, combining the qualities of a combined tool for continuous pre-sowing cultivation, sowing, application of granulated mineral fertilizers to the soil and soil compaction. Despite the undeniable advantages, the SZS seeders also have disadvantages, including the labor intensity of reconfiguration to the required seeding rate. To eliminate this drawback of the SZS type seeders, some modern manufacturers use continuously variable transmissions of various designs instead of a set of replaceable sprockets in the drive of seeding units. However, such a design solution leads not only to an increase in the cost of the seeder, but also to a decrease in its reliability.

AIM: Study of the ways of reducing the labor intensity of reconfiguring the SZS type seeder to required seeding rates without using replaceable sprockets and a continuously variable transmission in the drive of the seeding unit.

METHODS: The experimental data were obtained by mathematical processing of the results of laboratory studies conducted in the Mechanization and Economic Research Department of the Omsk Agrarian Scientific Center in 2025.

RESULTS: With the conducted research, it has been found that a reasonable design solution for upgrading the seeding system of the SZS type seeders is the use of grooved rollers of standard cross-section, but increased to 75 mm in length instead of standard rollers, which are 39 mm long. Rollers with increased length to 75 mm provide seeding of all main crops at any existing seeding rates at minimum rotation velocity and constant drive gear ratio i=0.292 (which corresponds to using a 36-teeth-sprocket from a set of replaceable sprockets). Rollers of this length can also be used to sow barley and oats, but at a higher rotation velocity of the seeding unit shaft (i=0.667 at z=14). In this case, damage to the seeds of these crops will be minimal due to their film-like nature. At the same time, the length of the roller, equal to 75 mm, ensures the necessary increase in the seeding rate, taking into account the decrease in seed germination in field conditions (up to 70%).

CONCLUSION: The practical significance of the conducted research lies in justification of the possibility of increasing the efficiency of using stubble grain seeders of the SZS type, reducing their cost in relation to seeders with continuously variable transmissions while simultaneously increasing reliability, as well as expanding the possibilities of their use in the implementation of differentiated seeding in the precision farming system.

BACKGROUND: During conventional machine harvesting of cabbage, heads of cabbage are significantly damaged during unloading into the body of a vehicle. Therefore, domestic and foreign cabbage harvesting machines are equipped with special unloading devices that protect heads of cabbage from damage. As the analysis shows, the unloading devices have drawbacks.

AIM: Scientific justification of the design and stiffness of the suspension of a new unloading device for a cabbage harvester, protecting heads of cabbage from damage.

METHODS: The authors propose a new unloading device comprising a rod elevator with scrapers, a rigid pallet installed under the horizontal part of the elevator, a П-shaped rigid frame hingedly attached by a shelf to the rear edge of the pallet, suspended on tension springs, a sack chute and a flexible apron pressed under its own weight to the sack chute. The sack chute, made of conveyor belt fabric, shaped as an isosceles trapezoid in the upper part and a rectangle in the lower part, is fixed in the upper part along the sides and in front to the П-shaped rigid frame so that a trough-shaped section is formed with a bottom slope α to the horizon and sags with its free end. In addition, a damping stop is installed tightly in the unloading device above the horizontal position of one of the longitudinals of the rigid П-shaped frame, fixed with a bracket on the pallet. The process of interaction between a head of cabbage and an unloading device is examined analytically in the paper.

RESULTS: The design of a new unloading device that allows damping the speed of cabbage heads when falling by means of shock absorption is justified. It has been found analytically that the damage to cabbage heads decreases during unloading by reducing the stiffness of the suspension springs of the unloading device. At the same time, the suspension springs must have a total stiffness c, sufficient to ensure its return to its original state before the next head of cabbage comes for unloading, depending on the operating velocity of the harvester, the planting step in rows, the moment of inertia of the unloading tray and the shoulder of the spring forces relative to the fastening hinge.

CONCLUSION: In the unloading device, to ensure a gentle mode of heads unloading, it is necessary to select suspension springs with minimum stiffness. However, for effective cyclic operation of the device, their total stiffness should not be lower than the ratio of parameters determined by expression (19).

BACKGROUND: The reliability of a fuel supply system determines the performance of a diesel engine. The weakest part of it is injectors. The most common cause of failure of the injector nozzle is the disruption of the needle mobility due to obliteration of the spraying holes.

AIM: Improving the fuel efficiency of a diesel engine by upgrading the injector nozzles.

METHODS: To diminish the obliteration process, upgrade of the injectors by cutting a helical groove on the guide part of the needle was proposed. Commercial and upgraded injectors were used for the experiment. During the pouring process, the helical groove was filled with fuel, which served as a lubricant and increased the fuel supply. Fuel efficiency was assessed by the value of injection rate. The obliteration process was assessed by the gap resistance coefficient, defined as the ratio of fuel consumption at the end of the fuel pouring to fuel consumption at the beginning of the fuel pouring.

RESULTS: As a result, the dependence of the gap resistance coefficient on the volume of the helical groove was obtained. When the total gap increases by 2 times (due to the screw channel), the fluid flow decreases by no more than 20%, and the gap filling coefficient is 0.8 ... 0.9. The dependences of the injection rate and unevenness of fuel injection on the fuel pump shaft rotation velocity were obtained. At the fuel pump shaft rotation velocity of 850...1100 rpm, the unevenness of fuel supply did not exceed 1...2%. When the rotation velocity decreases to 400...800 rpm, the unevenness increases to 2.7...16.1%.

CONCLUSION: To diminish the process of obliteration of the spray gap, the reasonable volume of the helical groove should be 0.5...0.9 of the volume of the gap between the body and the nozzle needle.

BACKGROUND: This paper covers the issues of evaluating the unit coupling ability of mobile power units — the drawbar category 3 tractors, in a multi-criteria formulation. 9 main functional and operational characteristics of tractors being coupled as part of a machine tractor unit were adopted as evaluation criteria. The following criteria limitations were considered in the optimization calculations of unit coupling: “Coupling capacity”, “Tractor base”, “Tractor load capacity”, “Maximum power of the power take-off shaft”, “Limitations on handling of the tractor as part of the machine tractor unit”, “Hourly capacity”, “Traction force on the drawbar”, “Technical tractor readiness”, “mobile power unit coupling ability coefficient”. The use of multi–criteria optimization algorithms and software tools makes possible having a wide range of applications: at all stages of the full life cycle of mobile power unit — development, production, operation, disposal.

AIM: Conducting the optimization analysis for evaluating the unit coupling ability of the drawbar category 3 wheeled tractors, taking into account numerous quality criteria and functional limitations, which make it possible to expand the range of machine used as part of the machine tractor unit.

METHODS: For conducting the optimization analysis in the studied parameter space, variation ranges of variable parameters were formed according to the problem statement and the preferences of the decision maker, criterial and functional constraints were made for further determination of the admissible and Pareto set of solutions.

RESULTS: As a result of the analytical and optimization calculations, 3 Pareto-optimal variants of mobile power unit coupling ability and 12 acceptable variants satisfying the criteria and functional constraints were obtained. According to the decision maker, the points with the following values of the machine tractor unit coupling ability criteria were chosen as the most preferable among the Pareto points obtained for the drawbar category 3 wheeled mobile power units: coupling capacity — 2.5 tons; base length — 2.45 m; load capacity — 3.5 tons; maximum power of the power take-off shaft — 56 hp.; handling of the machine tractor unit — not less than 0.78 tons; hourly capacity of the machine tractor unit — 2.5 ha / hour; traction force on the drawbar — 35 kN; the coefficient of technical readiness — 0.86; the coefficient of unit coupling ability of the tractor — 0.9.

CONCLUSION: The conducted analysis of the unit coupling ability of wheeled tractors made it possible to identify the most preferable options based on the given constraints. The results suggest a high level of significance for the criteria under consideration.

BACKGROUND: The application of electroplating coatings based on iron alloys to increase the durability of road milling machines parts is relevant and of great practical interest. The most preferred is the use of iron-cobalt electrochemical alloys, which possess higher physico-mechanical properties compared to the “pure” iron. At the same time, data on the performance of precipitates under conditions of contact with soils and sand are insufficient to evaluate the effectiveness of their application for road milling machine teeth. There is a lack of data to determine the relationship between the mechanical properties of electrochemical alloys and the design parameters of strengthened parts, which limits the possibilities of choosing the electrolyte composition and modes of obtaining them, and objectively judging the in-service behavior of coated parts.

AIM: Verification of the prerequisites for obtaining wear-resistant electrolytic iron-cobalt alloys and development of a technological process on their basis to increase the durability of road milling machine teeth.

METHODS: Standard methods of determining the structure and properties of materials, verified instruments and equipment, methods of statistical processing of research results, comparison of theoretical results with experimental data, carrying out pilot tests of technology and operational tests of parts with coatings were used in the study.

RESULTS: As a result of theoretical research, the dependence between the parameters of teeth and mechanical properties of wear-resistant coating has been established, allowing to determine the optimal precipitation parameters depending on the working conditions of parts for the most effective use of the service life embedded in them.

CONCLUSION: The conditions for obtaining wear-resistant iron-cobalt coatings have been determined experimentally. It is shown that the application of iron-cobalt coatings on the working surface of the teeth makes it possible to increase their durability.