Creating comfortable conditions for animals ensures their longevity and high productivity. Artificial ventilation, which includes supply and exhaust systems and a control system, minimizes the influence of the human factor on maintaining the indoor air parameters. The proposed system of indoor air-conditioning for the loose cattle housing layout was developed based on the analysis of ventilation systems of livestock premises and studies proving the effectiveness of dehumidification in winter using a regenerative heat exchanger. The system for providing indoor air parameters was developed using the computer-aided design program “Compass” (CAD) of the “Askon” company. The developed system for providing indoor air parameters for keeping cattle includes an electrofilter and a coarse filter, fans, a plate heat exchanger, a turbodefector; temperature, humidity, and air flow velocity sensors, dust collectors, a pump, a tank with a disinfectant, and a mechanism for shutting down supply air and recirculated air. The use of a recuperative dehumidification system at low outdoor temperatures helps maintain the relative indoor humidity within the regulatory limits (75…40%) and reduce the concentration of carbon dioxide by 20…45%. To ensure these indoor air parameters without dehumidification, 200 kW of thermal power is needed to heat the supply air. The proposed combined energy-saving all-season climate control system provides monitoring of indoor air parameters and energy saving through the use of a turbo deflector, disinfects the ventilation air, dehumidifies the air in the cowshed in winter and cools in summer, and also partially removes dust from the air with an electromagnetic filter.

Indoor climate parameters influence the productivity of animals and their physiological condition. Exceeding permissible concentrations of gases leads to animal diseases, loss of productivity, and the mortality of young cattle. Therefore, it is reasonable to predict the concentration of gas composition in the livestock houses. To determine and distribute harmful gases (ammonia, hydrogen sulphide, and carbon dioxide) in the livestock house, the authors performed the 3D modeling of a fragment of the farm in the SolidWorks 2020 software package. Parametric models of gas movement under different conditions were created and optimal measurement points of gas concentration in the livestock house were determined. The simulations made it possible to determine the direction of air flows and detect accumulations and clouds of gases. The maximum concentration of carbon dioxide was detected at 0.9m (an air speed of 0 m/sec) and at 1.3m (a speed of 0.75 m/sec). The highest concentration of hydrogen sulphide was found in the area bordering the ridge space (an air speed of 0 m/s) and at the level of 2.25 m (a speed of 2 m/s). The highest concentration of ammonia was observed under the roof and in the area under the ridge (an air speed of 2 m/s). It is recommended to install hydrogen sulphide and ammonia sensors under the ridge, while carbon dioxide, hydrogen sulphide and ammonia sensors – in the stall, carbon dioxide and hydrogen sulphide sensors – near the feed table. Concentrations should be measured at heights of 500, 1500, and 3000 mm. When the concentration of emitted gas increases and other conditions are equal, the concentration of gas in the cloud increases, but the structure of the cloud changes insignificantly. Parameter interrogation sensors should be installed in enclosed ventilated boxes in the same manner as in weather stations.

Automatic feeding systems are not common in Russia. To find the optimal solution for the development of an automatic feed wagon on the basis of FSAC VIM, the authors made a review of the scientific works of foreign scientists describing the industrial experience of operating automatic feeding systems and evaluating their effectiveness. Automatic feeding systems (AFS) have a number of advantages as compared with the traditional feeding system based on mobile TMR feeder-mixers. AFS can double reduce labor costs of the preparation and distribution of feed mixtures on cattle farms; increase the accuracy of feeding by dividing animals into a larger number of technological groups receiving different feeding rations depending on productivity, lactation stage, etc.; ensure the frequency of feeding cattle up to six to eight times a day (which favorably affects their health and milk productivity). Automatic feeding systems improve animal welfare and hygiene. The feed alley on farms equipped with AFS is almost two times narrower than on farms using mobile TMR mixers, which makes it possible to use the cowshed area more efficiently. The main disadvantage of AFS is their high cost – on average 1,230 €/head, with an average cost of using a system based on mobile TMR mixers of 400 €/head. In the existing AFS, storage containers account for most of the investment costs. To reduce the cost, the authors put forward the concept of an automatic feeding system based on an automatic feed wagon with a storage container for intermediate storage of ready-made feed mixtures. It can be loaded with a mobile TMR mixer.

Soil degradation due to water erosion accompanied by the loss of fertility results in reduced grain crop yields. To prevent water erosion on sloping fields during soil tillage and the sowing of grain crops, the authors offer an appropriate technology and a combined tool. The combine tool implements tillage and strip sowing by forming mini-terraces. Their width is determined by the installation of furrow formers at a distance from each other, which corresponds to the sowing width of six seed rows. Combined coulters sow cereals in two rows on the soil surface, in three rows – to a depth of 6 to 8 cm, in the last row – to a depth of 14 to 15 cm. Furrow shapers form anti-erosion furrows to a depth of 9 cm over the rows with seeds, sown to a depth of 14 to 15 cm and form ridges over the seeds sown on the surface. Ridges and furrows prevent water erosion on the slope crop fields. The ridge former is installed at an angle of 30 to 33° to the travel direction of the machine. The distance between ripper tines of the first and second rows shall be not less than 45 cm, and between cultivator teeth and the ridge former is not less than 90 cm. The proposed technology and the developed combined tool can reduce the direct energy consumption for tillage and the sowing of grain crops by 32%.

Using the grates of a combine feederhouse and directing the grain heap for cleaning, bypassing the threshing unit, we can reduce both the energy intensity of harvesting and the degree of grain crushing. The study purpose is to compare two variants of the combine feederhouse grates: with longitudinal holes of a finite length and transverse bars between them and with through holes without transverse bars. For a preliminary assessment, a theoretical model of the separation process is proposed, which includes the slipping of combed heap layers moved by a conveyor scraper into the hole at the angle of repose. Previously, it was assumed that upon contacting with a transverse bar, the corresponding heap layer completely stops slipping and the process resumes only after overcoming the edge of the next hole. As a result, the separation rate should significantly decrease. The upgraded version of the model takes into account the inertia effect on the sliding upper heap layer, which is activated by the friction force of its lower part acting along the bar surface. As a result of the total effect of the rolling force and the inertia force, the flow direction of the upper layer components changes to become nearly horizontal, as a result of which 50 to 60% of the layer slides into the next hole without stopping. According to the theoretical model, the separation of combed grain heap should be reduced by 4 to 5% if there are 120 mm long bars between the longitudinal holes and the total length of the separating part of the grates surface is 800 mm. As a result of a laboratory experiment on the Moskovskaya 56 wheat variety, the separation of a combed grain heap decreased by 4.6% due to transverse bars, which confirmed the adequacy of the theoretical hypothesis.

Grain molasses can compensate the deficiency of easily digestible carbohydrates in a cow’s ration. The best raw material to produce molasses is rye. Molasses can be produced on farms directly before feeding. Today it is highly promising to improve the technology and technical devices for the production of grain molasses. The research was conducted to determine optimum values of adjustment parameters of a passive shredder (the grate angle and the diameter of grate apertures) by estimating their influence on the optimization criterion – specific energy consumption. The author determined quality indicators: the number of whole grains and the residue amount on the sieve with a mesh side size of 3 mm. Whole grains (the “Grafinya” winter rye variety) were crushed with a passive shredder. According to its design, the grate angle is changed from 30 to 90° and the grates have different hole diameters (3, 6, and 9 mm). The author made a matrix of complete factor experiment 3² and obtained an adequate response function. They also evaluated the desirability profile and Pareto plot for the studied factors. At the first stage of the research, it was found that the reduction of specific energy consumption is greatly influenced by increasing the value of the grate aperture diameter. The response surface was plotted and the antigradient of the function was determined. At the second stage, a pitch towards increasing the hole diameter to 9 mm was selected and the planning matrix of the fractional factor experiment was made. An extremum point with the minimum value of the function was defined for the resulting response function. In the natural form, the specific energy cost is 55.56 Wh/kg with a grate angle of 60.6° and a grate hole diameter of 6.57 mm. The values of 60° and 6 mm with specific power inputs being in the area of minimum and amounting to 56.4 Wt-h/kg are recommended as adjustment parameters, which is 1.3 per cent higher than the calculated values.

Digital technologies introduced into agriculture are aimed at improving the efficiency of agricultural production. Agricultural robots carrying out technological operations, monitoring the field, crops, or crop yields may reduce their productivity, quality and safety of operation due to the geographical distance from the cloud storage, low bandwidth and network unreliability, significant delays and failures in data transmission. To increase the performance of units with unmanned robotic technical means for agricultural purposes, to ensure the high quality of their technological operations, as well as their safe operation, an intelligent control system using edge computing technologies based on Edge Computing is proposed. During the research, the authors used methods of complex structural-dynamic analysis and an expert-analytical method of information processing. As a result of the research, a structural and functional diagram of an intelligent control system for agricultural units with robotic technical means has been proposed to ensure centralized control of the technological process. Agricultural machines adjust the working tools and their operation process using built-in autonomous control systems that transmit data to the control system to generate commands. The operation of the working tools is adjusted in case of serious failures in the unit operation. The implementation of the Edge Computing concept in digital agriculture will reduce the amount of transmitted information and the load on the data transmission network, without reducing the technological process quality in case of failures in the operation of farm machines and embedded systems.

The rotary machines and implements used for the cultivation of agricultural crops do not fully meet the agrotechnical requirements. To determine the parameters of the working tools, the authors studied the absolute trajectory of their movement and classified rotary working tools of agricultural machines according to the special location of their rotation axis, dividing them into four groups and seven subgroups: A – the first group of rotors with a horizontal-transverse axis of rotation; B – the second group of rotors with a vertical axis of rotation; C – the third group of rotors with a longitudinal axis of rotation; D, D, E and F are the fourth group of rotors with the axis of rotation located in space relative to the coordinate system XYZ at angles α, β, and γ. The article presents kinematic analysis results for rotary working tools of classes G, D, E, W having a complex location of the axis of rotation in the space. The analysis of calculating the coordinates of the motion trajectory of rotary working tools showed that for the group of rotors of class G, D, E, the motion trajectory corresponds to a compressed cycloid, and for a rotor of class G, the trajectory represents a helicoid. The obtained motion trajectories of material points of rotary working tools can be used to evaluate the process of interaction of working tools with the soil and plant material, to determine the geometric parameters of working tools, the rotor speed, and the translational speed of an agricultural machine.

Possessing deep knowledge of mathematics and general mechanics, V.P. Goryachkin applied them to the design analysis of agricultural machines. Thereby at the beginning of the twentieth century, he established a new scientific discipline, which he called “Agricultural Mechanics”. Within the framework of this science, he also solved some theoretical problems of the tractor. He was engaged in the design of tractor equipment and recommendations for its development during numerous tests at the Machine Testing Station headed by him and within the framework of the government commission. The purpose of the research was to identify the theoretical and practical contribution of V.P. Goryachkin in the establishing of the tractor science and the domestic tractor construction. In accordance with the methods used in the history of science and technology, the author established that V.P. Goryachkin developed the theory of the driving and driven wheels of the tractor, justified proposals for improving the characteristics of the engine and the location of its longitudinal axis relative to the tractor’s travel direction, established the relationship between the tractor power and the operating speed, solved the constructive and power problems of coupling the tractor with a plow, formulated recommendations for improving mechanical propulsion and engines. Conducting numerous tests of tractors in the 1920s, and participating in the work of the government commission, V.P. Goryachkin contributed much to the development of the tractor industry. His recommendations greatly helped determine the pace and trends in the development of tractor construction in the USSR. Based on the conducted research, the author states that by his theoretical research and practical achievements, V.P. Goryachkin made a significant contribution to the history of domestic tractor construction, so his name should be mentioned along with other pioneers of the domestic tractor industry.

The import substitution of agricultural machinery implements is possible with the development of high quality steel and hardening technologies appropriate to the operating conditions of agricultural machinery. Along with high wear resistance in abrasive environment, steel must have high ductility and impact toughness. To investigate wear resistance of the developed low-alloy steels in the abrasive environment and estimate the possibility of their application for manufacturing high-resistance working tools of agricultural machinery the authors developed four batches of steel samples with additives. All samples were subject to heat treatment with heating to 900°C and quenching in water at 20°C. The second group of samples was additionally tempered at a temperature of 280°C for an hour, followed by air cooling. The wear resistance of samples was determined according to GOST 23.208‑79 with the test equipment. The least wear intensity of 0.0581 g/m was recorded for steel 0.43C‑1.60Si‑0.01Mn‑1.1Cr‑0.95Mo‑0.08V‑ 0.05Nb‑0.04Ti subjected to heat treatment with quenching. The high tensile strength of 2170 MPa was obtained through the formation of carbonitrides enriched with Nb. The wear resistance of this steel grade is 1.66 times higher than that of the 65G steel grade. The heat treatment of quenching with tempering yielded the relative wear resistance of the given steel by 10.7% lower, which can be explained by phase transformations reducing the ultimate strength to 2040 MPa, but increasing the plasticity of steel. Studies have shown a wide range of changes in wear resistance depending on the heat treatment mode. This makes it possible to modify the structure of steel in relatively small temperature intervals of quenching and tempering, thereby influencing the properties that provide the greatest wear resistance.

Technical diagnostics, and, particularly, automatic diagnostics of mechanical transmission units increases the reliability indicators of transport and processing machines. The technology of monitoring mechanical transmissions based on digital thermal diagnostics ensures the controllability of the diagnosed units. The unit’s adaptability to digital thermal diagnostics depends on its location, the presence of adjacent heat sources, the amount of power and kinematic loads. The controllability of the unit is ensured by determining the theoretical temperature value in the friction zone and the zone suitable for measuring the diagnostic temperature, and stating the relationship between the above temperatures. The control is carried out automatically, using specially developed software and hardware systems. To ensure the controllability of the bearing 50412 GOST 2893‑82 of the KAMAZ‑5320 gearbox, the authors determined the theoretical temperature value in the friction zone of 184.9°C during the gearbox operation in the first gear. The finite element analysis of the bearing assembly model under steady-state heat conduction determined a proportionality coefficient of 0.0812 relating the friction zone temperature to the diagnostic temperature on the bearing cap surface. As a result of theoretical and experimental studies involving thermal imaging, the temperature in the friction zone of 242.6°C was determined, indicating the pre-failure state of the diagnosed bearing. The approximate correspondence of theoretical and experimental temperatures showed the possibility of applying digital thermal diagnostics technology to the studied transmission unit. The comprehensive studies made it possible to justify the use of the digital thermal diagnostics technology and localize an area for installing a temperature sensor, namely, the bearing cover surface.

Fuel injector nozzle parts tend to wear out due to abrasive particles of quartz and aluminum oxide penetrating into the fuel. The hardness of quartz abrasive particles exceeds the hardness of work surfaces in 1.4 times, and that of aluminum oxide – in 2.7 times. Strengthening one part of the fuel injector nozzle does not increase the service life sufficiently, so it is necessary to harden both parts of the precision pair. The CVD method is the most promising technology of wear-resistant coating deposition on steel machine parts. It produces carbide-chrome coating with microhardness up to 19 GPa (in vacuum conditions of 100 to 0.001 Pa) at temperatures above 200°C. The analysis of available devices and the review of patents of known solutions on the coating deposition from a steam phase have shown the impossibility of using these devices for restoration of the nozzle body. In this respect, the author developed a new reactor design and a scheme of the CVD unit for the coating deposition on the inner hard-to-reach surfaces of the nozzle body. The developed CVD unit takes into account the factors affecting chromium carbide deposition: thermodynamic conditions, reagent feed, deposition duration, unit parameters, adhesion and coating properties. The CVD unit upgrade results in making chromium carbide coating on the inner surfaces of the nozzle sprayer body, achieving thermodynamic equilibrium of chemical reaction of chromium hexacarbonyl decomposition at temperatures below 200°C (below the low tempering level of 18Х2Н4ВА, 12Х2Н4А and 40ХН2МА steel), and ensuring a controlled supply of a reaction medium to hard-to-reach areas, where refractory metal coatings are formed.