Monitoring of the state of agricultural crops and forecasting the crops development begin with aerial photography using a unmanned aerial vehicles and a multispectral camera. Vegetation indexes are selected empirically and calculated as a result of operations with values of diff erent spectral wavelengths. When assessing the state of crops, especially in breeding, it is necessary to determine the limiting factors for the use of vegetation indexes.

(Research purpose) To analyze, evaluate and select vegetation indexes for conducting operational, high-quality and comprehensive monitoring of the state of crops and the formation of optimal management decisions.

(Materials and Methods) The authors studied the results of scientifi c research in the fi eld of remote sensing technology using unmanned aerial vehicles and multispectral cameras, as well as the experience of using vegetation indexes to assess the condition of crops in the precision farming system. The limiting factors for the vegetation indexes research were determined: a limited number of monochrome cameras in popular multispectral cameras; key indicators for monitoring crops required by agronomists. After processing aerial photographs from an unmanned aerial vehicle, a high-precision orthophotomap, a digital fi eld model, and maps of vegetation indexes were created.

(Results and discussion) More than 150 vegetation indexes were found. Not all of them were created through observation and experimentation. The authors considered broadband vegetation indexes to assess the status of crops in the fi elds. They analyzed the vegetation indexes of soybean and winter wheat crops in the main phases of vegetation.

(Conclusions) The authors found that each vegetative index had its own specifi c scope, limiting factors and was used both separately and in combination with other indexes. When calculating the vegetation indexes for practical use, it was recommended to be guided by the technical characteristics of multispectral cameras and took into account the index use eff ectiveness at various vegetation stages.

. For sowing small seeds of vegetables, in particular onions, special seeders are used. They are not produced in the Republic of Uzbekistan, while many diff erent pneumatic seeders are produced abroad. The authors note that foreign samples are complex in design, not adapted to local soil and climatic conditions, cannot provide even seed placement on ridges, and the cost of the seeders themselves and service are very high.

(Research purpose) To develop a vegetable seeder in relation to the soil and climatic conditions of Uzbekistan, to determine the seeding rate of onion seeds depending on the length of the active part of the seed reel, to evaluate the formation quality of sowing ridges and irrigation furrows.

(Materials and methods) The authors determined the sowing rate by turning the seeder drive wheel at a given length of the active part of the sowing reel and collecting the sown seeds in cups with further weighing. The quality of sowing ridges and irrigation furrows formation was evaluated by the method of profi ling the fi eld before and after the seeder’s pass.

(Results and discussion) The authors developed a vegetable seeder that performed three operations in one pass: cutting irrigation furrows, forming sowing ridges of a trapezoidal shape and sowing onion seeds and other small-seeded vegetable crops in a three-row tape method in each tape. They found that the dependence of the seeding rate on the length of the active part of the reel had a slightly fragile parabolic shape, and the required seeding rates – 24-48 pieces per linear meter (3.9-7.8 kilograms per hectare) – were provided with the length of the sowing reel 3.3- 6.2 millimeters. It was proved that the seeder provided a high-quality formation of sowing ridges and irrigation furrows: the row spacing was 68.8 centimeters (installation spacing – 70 centimeters), the top ridge width was 42.5 centimeters (the predetermined one was 40 centimeters), the depth of irrigation furrows was on average 9.6 centimeters.

(Conclusions) A vegetable seeder was developed for sowing small-seeded vegetable crops with the simultaneous formation of sowing ridges and cutting irrigation furrows, which ensured high-quality performance of all operations and observance of onion seeds.

The authors identifi ed the main factors that infl uenced signifi cantly the technological support of post-harvest processing processes over the past decades. They showed that in recent years, many farms faced the necessity to solve the problem of improving the seeds quality and reducing their losses in the process of post-harvest processing of grain in the shortest possible time.

(Research purpose) To conduct a historical analysis of machine technologies for post-harvest grain processing and seed preparation and determine promising directions for their development.

(Materials and methods) The authors used the historicalanalytical method applied to technical systems, in particular, to technologies of post-harvest grain processing and seed preparation. The research objects were the original works of domestic and foreign authors for more than a 100-year period and other regulatory and technical documentation.

(Results and discussion) The authors presented the results of the machine technologies for postharvest grain processing and seed preparation evolution in the Russian Federation over the past 100 years. They considered the scientifi c, technological, technical and organizational issues of the machine technologies for grain processing and seed preparation development. It was determined that the scientifi c foundations for creating domestic separating machines were developed in the 30s of the last century. They noted that in 1934 the fi rst domestic mobile grain cleaning machine with a capacity of 10 tons per hour for cleaning grain and 6-8 tons per hour for cleaning seeds was created and put into production. The following key stages were identifi ed: in the 60s, an in-line technology of post-harvest grain processing was developed; by the end of the 70s, with the completion of work on the creation of units and complexes, all processes of post-harvest grain processing for the fi rst time in the country were fully mechanized.

(Conclusions) The authors proved that labor productivity in the industry increased 7-10 times, the cost of grain processing decreased 2-3 times, its losses decreased, manual, unskilled labor was excluded. They identifi ed promising directions for the development of grain processing and seed preparation technologies.

The author researched the gravitational method of separating a grain heap, in which cleaning from large and small impurities was carried out without energy consumption, with the gravity material fl ow in vertical cleaning columns along fi xed zigzag separating combs.

(Research purpose) To study the gravity column operation for cleaning selection seeds and substantiate its design parameters.

(Materials and methods) A prototype gravity column was developed. The author experimentally determined: the combs teeth diameter; column throughput; the possibility of a more complete separation of the seed fraction from the basic material; completeness of large impurities separation. He compared the work of the gravity column and the fl at rocking sieve. He assessed the combs jamming by the cleaned culture seeds.

(Results and discussion) The author noted that on wheat cleaning at a productivity of 45.6 kilogram per hour, the yield of the "waste" fraction was 0.5 percent, a loss of 0.07 percent, and at a productivity of 227.8 kilogram per hour – 0.98 and 0.35 percent, which corresponded to the initial requirements for the main technological operations for post-harvest processing of selection seeds.

(Conclusions) It was found that a gravity column for separating selection wheat seeds small impurities separated particles with high effi ciency if they diff ered from each other in thickness of at least 0.3 millimeter with a gap between the comb bars of 2.0 millimeter and a bar cross-section diameter of 0.9 millimeter. It was determined that high productivity – up to 150 kilogram per hour – was possible with a column cross-section with sides of 60 and 70 millimeter. The author revealed practically the same quality of material separation when separating small impurities using both a sieve and a gravity column.

The author showed that it was possible to reduce the exhaust gases toxicity and increase tractors effi ciency using an electric power unit to implement traction. The effi ciency of modern electric motors was at its peak of 96 percent, compared to 45 for a diesel engine. He emphasized that this parameter for modern sources of electrical energy was 85-90 percent, which opened up opportunities for the implementation of an electric tractor.

(Research purpose) To present the general concept of an electric drive power unit for a tractor of a small traction class and to evaluate its parameters as a fi rst approximation.

(Materials and methods) For the tractor’s electric drive lithium-ion batteries were chosen as a source of electrical energy, showing the best characteristics of energy intensity – 432-864 kilojoule per kilogram with a unit cost of 4200-17400 rubles per kilogram. During the analyses of the power unit drive types, a D-120 diesel engine with a power of 20 kilowatt, a DC electric motor and an asynchronous motor with similar parameters were studied. The VTZ-2032 tractor with a nominal tractive eff ort of 600 Newtons when working on stubble was taken as the basis for the calculation.

(Results and discussion) The author determined the best indicators of the electric drive by the power characteristics fullness in the gears with a decrease in unit costs per kWh from 24 to 15-16 rubles.

(Conclusions) The most effi cient engine was determined – a brushless DC electric motor. The author calculated that the specifi c cost of its energy was 1.5-1.8 times less than that of a diesel engine, and amounted to 15-27 rubles per kilowatt-hour with a maximum effi ciency of 95 percent. It was found that lithium-ion batteries would be the optimal solution for powering the electric drive. They were distinguished by a high specifi c energy consumption – 432-864 kilojoule per kilogram – and a low price per energy unit, amounting to 5-45 rubles per kilojoule.

One of the conditions for achieving maximum land productivity is optimal soil density. In the Amur Region, ecological compaction thresholds for cereals are 1.0-1.24 grams per cubic centimeter, for soybeans – 1.09-1.25, which corresponds to a normal pressure of 80-120 kilopascals, depending on soil moisture. The authors showed that the tractors used in the Amur Region, acting on the soil, exceed the ecological compaction threshold. (Research purpose) To substantiate the ecological compatibility of mobile fi eld energy, primarily tractors engaged in fi eld work, in terms of the compacting eff ect from the normal load transmitted by their propulsion drive to the soil. (Materials and methods) The authors analyzed the experimental data on changes in density, hardness and resistance of soil to processing. An empirical dependence was obtained for calculating the increase in resistance to soil cultivation from the compaction load in a layer of 0-20 centimeters. (Results and discussion) The authors established an increase in plowing resistance of 12-25 percents at a normal load of 138-170 kilopascals, transmitted by the machine propulsion drive, which corresponded to a soil density of 1.25-1.30 grams per cubic centimeter; at a load of 180-250 kilopascals, the resistance increased by 43-50 percents which was equivalent to a soil density of 1.30-1.35 grams per cubic centimeter; at a pressure of 300-350 kilopascals, these indicators increased by 60-67 percents and up to 1.40-1.45 grams per cubic centimeter; and at 400 kilopascals, they showed an increase in resistance of 70-90 percents which is comparable to a density of 1.48 grams per cubic centimeter. (Conclusions) It was determined that the limit value of the normal pressure under the machine propulsion drive in fi eld work should be limited to 150-175 kilopascals. The ecological threshold of normal pressure was established – no more than 120-135 kilopascals with soil moisture of 20-23 percents which was comparable to the soil density of 1.2-1.25 grams per cubic centimeter. The limiting value of the normal pressure of the propulsion drive on the soil was calculated – 350 Pa, which corresponded to the critical soil compaction of 1.30 grams per cubic centimeter.

The authors showed that the main condition for assessing the harvesting transport complex is to reduce costs during harvesting and transportation of grain crops.

(Research purpose) To assess the technical and economic indicators and operational properties of foreign grain harvesters and their impact on the productivity of the entire harvesting transport complex. Based on the statistical data obtained during the information collection, to calculate the indicators that aff ect the harvesting transport complex management.

(Materials and methods) The authors used statistical materials on the combine harvesters operation, transport vehicles for transportation. They took studied combine harvesters and vehicles technical characteristics. They considered the elements of the theory of probability for the formation of the harvesting transport complex. The studies were carried out simultaneously in two structural divisions of an agricultural organization, located at a distance of 19-20 kilometers from each other. Economic and statistical, forecasting, economic and mathematical modeling, expert assessments and others methods were used.

(Results and discussion) The authors received 89 values for the indicator "Time to fi ll the combine harvester bunker", 45 – according to the criterion "Waiting time for vehicle loading". They calculated the mathematical expectation of the fi rst indicator: in the fi rst harvesting team for the Tucano 450 – 22.68 minutes; Mega 370 – 20.74 minutes; for a Tucano 450 from the second harvesting team – 19.24 minutes.

(Conclusions) The authors revealed the features of harvesting transport complexes formation, consisting of foreign combine harvesters and vehicles. They determined the productivity, quality indicators of the technological process of threshing grain crops and yield, at which the use of foreign combine harvesters became economically feasible.

The digital twin is a virtual model of the agricultural tool working element that allows you to calculate and predict its expected behavior during the entire period of operation.

(Research purpose) To develop an algorithm for consistent models that make up the digital twin of the agricultural tool working element.

(Materials and methods) The fi rst component of the digital twin algorithm was determined by the method of accelerated imitation loading of the wedgelock ripper working element, which was accepted as the research object. The second component was determined by testing various soils with the specifi cation of power equivalents. The physical and mechanical properties of soils and materials (hardening) for the manufacture of working elements were taken into account during the description of the following components.

(Results and discussion) The author showed that the algorithm for constructing a digital twin of the agricultural tool working element consisted from a chain of successive actions and was a system for digital description of the working element, which ensured the standard lifetime during operation. The results of a simulated immersion which registered the nature of the normal forces distribution over the friction surfaces were accepted as the fi rst component of the algorithm. The second component – the results of determining the force equivalent when loading the working element in a real soil environment. The possibility of constructing maps of the intensity of the friction surface abrasive wear, predictive calculations of structural elements was revealed. The third and fourth components were used to ensure the working element standard lifetime, based on the minimum production costs, correlated to the standard resource unit of development.

(Conclusions) The resulting algorithm for constructing a digital twin is a convenient tool for creating new designs of agricultural tools working elements.

A correctly selected positioning system for controlling the mobile robotic means movement ensures high positioning accuracy of the robotic platform in the garden, allows to automate precise operations in the garden and systematize route planning algorithms.

(Research purpose) To substantiate the rational choice of a positioning system for controlling the mobile robotic device movement.

(Materials and methods) The author formulated requirements for the positioning system to perform precise operations in the garden: mechanized collection of fruits and berries, diff erentiated application of fertilizers and chemical plant protection products. The main ones were: the positioning error was no more than 5 centimetres, the stability of information transfer to the server for building traffi c maps, the movement of a robotic device along a given trajectory, equipping beacons with a mobile power source with a capacity of at least 800 milliampere-hour, information exchange between the beacon and the built-in robotic means with a microprocessor controller according to the RS-485 standard, the signal coverage area was at least 100 square meter.

(Results and discussion) The six most relevant positioning systems of the following manufacturers were described: RealTrac, Rusoft CKT, Neomatic, ISBC, Avtosensor, Marvelmind. The author compared their technical and operational parameters: operating frequencies, range, data transfer interface, location accuracy and cost of ready-made kits. He showed that Marvelmind provided uninterrupted operation at frequencies of 433 and 915 megahertz with a positioning error of no more than 2 centimetres. The tests were carried out on a small robotic vehicle with the following characteristics: maximum transport speed – 30 kilometre per hour, operating weight – 500 kilograms, length 2 metres, width – 1.2 metres, height – 1.6 metres.

(Conclusions) The author substantiated the choice of the most suitable and aff ordable Marvelmind positioning system and experimentally confi rmed the positioning accuracy declared by the manufacturer. When driving in a loop-free and looped turn, the positioning accuracy did not exceed 1.5 centimetres, which met the agrotechnical requirements for mechanized collection of fruits and berries, for diff erentiated application of fertilizers and chemical plant protection products

Extrusion of feed ensures a high quality of the fi nished product.

(Research purpose) To increase structural elements durability of the press extruder by optimizing their strength characteristics.

(Materials and methods) The authors studied the technological principle of extrusion. The experiment planning method was applied. They examined the process of press extruder operation with a variable pitch screw during the lentils processing. The strength characteristics of the press-extruder elements were checked during design or strength calculations.

(Results and discussion) The authors showed the role of the main geometrical parameters of the extruder screw – the slope of the turn and the cutting step – in the preparation of high-quality grain feed. It was found that the turn pitch should be calculated depending on the friction coeffi cient of the starting material against the press-extruder body, the type and properties of the supplied material. The auger fatigue stresses were determined as a result of constant sign shear load and temperature eff ects. The drive power, the extruder productivity were calculated to clarify the screw characteristics, as well as the hydraulic resistance of the matrix output head, the distance of the technological zones. It was confi rmed that the prefabricated screw structure, consisting of sections with diff erent pitch, gave the press extruder versatility.

(Conclusions) The authors found that the key was one of the most loaded structural elements of the press-extruder screw. The maximum calculated voltage from a constant load was calculated – 26.98 megapascals. It was determined that the stress in the cross-section of the key under temperature action was 591 megapascals, which exceeded the yield stress for the selected material, equal to 360 megapascals for steel 45. In the course of experimental studies, a value of impact strength was obtained that corresponded to the standard value of the initially selected steel grade (38 kilojoules per cubic meter), but didn’t meet the requirements for this structural element (at least 50 kilojoules per cubic meter).

The author presented material on the evaluation of agricultural machines operating modes and operating conditions using the technical condition monitoring system developed by scientists of the Federal Scientifi c Agroengineering Center VIM. He showed an example of proximity sensors use on the Kioti CK22 tractor to assess the emergency mode of operation, which could subsequently lead to premature failure. The author considered the possibilities of the most rational application of the remote monitoring algorithm to diagnostics – to identify the causes of malfunctions.

(Research purpose) To improve the existing and develop new technologies for remote evaluation of the machines current technical condition throughout the entire operation.

(Materials and methods) It was confi rmed that the remote monitoring system algorithm developed by the VIM scientists made it possible to provide automated control of the units and machine assemblies technical condition parameters. The system was operated on the basis of documenting the facts of the machine's operation in emergency or pre-emergency modes. The parameters control within the acceptable limits was provided.

(Results and discussion) After analyzing the failure reasons, the author established the initial nomenclature of the studied processes. An algorithm for remote parameters monitoring was developed, which made it possible to assess the machine operating modes. He tested the algorithm functionality using the example of installing proximity sensors and an on-board computer on a Kioti CK22 tractor.

(Conclusions) Using the installed on-board system and 8 sensors,information was obtained that made it possible to assess the current technical condition of the Kioti CK22 tractor based on the dynamics of 8 monitored parameters characterizing a gradual change in the functionality of the machine/system and aff ecting technical and environmental safety