No 5 (2020)

Articles

Synthesis of the law of optimal control of the system of active dynamic stabilization of the movement of a self-propelled machine with a mounted working body

Sirotin P.V.

Abstract

The paper is devoted to the development of systems and technical devices for reduction of dynamic loads acting on operators and the supporting system of self-propelled vehicles. The goal of the paper is to develop an algorithm and a law of optimal control of the stabilization system. The set of tasks to be solved for this is determined, the requirements for the information field are highlighted, the element base of the stabilization system is substantiated. The problem of optimal control of the stabilization system is formulated. The development of a law of control of the stabilization system of the movement of self-propelled wheeled vehicles based on the principle of active inertial vibration damping is presented. The law of optimal control of the stabilization system with the possibility of correcting the requirements for attenuation and the type of transient process was developed. On the basis of quadratic integral criteria, the indicators for assessing the quality of system control are distinguished. It is substantiated that for the system of stabilization of the harvester body it is necessary to regulate the output variables, such as the angular velocity of the body and the angle of the longitudinal inclination of the harvester body. A linearized model of the longitudinal-angular motion of the combine is considered, the equations that connect the laws of the disturbed motion of the body and the law of optimal control are presented. With the help of simulation modeling, the effectiveness of the proposed stabilization method and the law of control of the stabilization system in terms of reducing the longitudinal angles of inclination of the body when driving on an asphalt-concrete highway and a dirt road are shown. The effectiveness of the proposed law of control for suppressing the pitch of the combine body during emergency braking is shown. The calculated values of the power spent on control of the stabilization system for the considered driving modes are given. On the basis of calculations, it is shown that in the total energy balance of the combine, the power consumption for control is insignificant, which confirms the efficiency of the proposed stabilization method and the law of control. Conclusions are drawn, stages and directions of further research are determined.
Tractors and Agricultural Machinery. 2020;(5):5-12
pages 5-12 views

Efficiency of a cogeneration plant based on a diesel engine under uneven electrical load conditions

Antipov Y.U., Val'yekho M.P., Oshchepkov P.P., Shatalov I.K., Shatalova I.I.

Abstract

A feature of electrical energy is that it must be produced at a given moment as much as the consumer needs. However, the graphs of energy consumption are very uneven over the time of day. In order to cover peak loads, the highly mobile equipment, which is often less economical, is used. This equipment is operated at partial power modes, where its efficiency is markedly reduced. One of the real ways to get out of this situation can be the use of heat pumps (HP) in circuits with cogeneration units (CU) based on heat engines. In this case, it becomes possible to use the heat engine in an economical mode throughout the day, and direct excess electricity at night to the heat pump drive. The paper considers two options for the operation of a cogeneration plant based on a diesel engine in power supply schemes for an individual consumer under conditions of an uneven electrical load schedule. Wartsila 12V32 is taken as an example of a CU. Such plants are operated in different regions of the Russian Federation. The main data of the CU in the design mode are given. Diesel generator: electric power - 6000 kW, hourly fuel consumption - 1080 kg/h, thermal power - 5240 kW, exhaust gas temperature - 485 °C, effective efficiency - 0,46, fuel heat utilization factor 0,89. In the first version, the CU operates in a standard mode. This ensures the generation of electrical power in accordance with the schedule. In the second version, the CU is used in conjunction with the HP to obtain additional thermal power. Calculations have shown that by including a heat pump in a cogeneration unit operating in an uneven electrical load schedule mode, it is possible to ensure that the diesel engine operates at maximum efficiency during the whole day and to increase the fuel heat utilization rate by 17-20 %.
Tractors and Agricultural Machinery. 2020;(5):13-17
pages 13-17 views

The methodology for assessing the level of localization of agricultural tractors production

Godzhayev Z.A., Lavrov A.V., Shevtsov V.G., Zubina V.A.

Abstract

The existing list of requirements for agricultural tractors to classify them as products manufactured in Russia is considered. An assessment of the impact of the requirements of the Government of the Russian Federation decree on the fulfillment of tasks for the development of the Russian economy was made. It is proposed to stimulate the creation of jobs by setting a threshold value for the level of localization in terms of cost indicator. An assessment of the technological need for agricultural tractors for the primary stimulation of the production of the most scarce equipment was carried out. An approach to motivate the technological development of production and improve the technical level of products of enterprises is proposed. It is indicated that it is necessary to take into account in the methodology the directions of the manufacturer's activity that are important for the agricultural consumer. An improved methodology for assessing the level of localization of production of agricultural mobile energy products is presented. The basic methodology was significantly adjusted with the transition from an arbitrary list of obsolete technological operations to the cost assessment of modern technologies, quantitative accounting of the scarcity of manufactured equipment, the volume of service, the development of R&D works, the operational provision of spare parts, etc. The level of localization, which is sufficient to recognize a specific model as produced in Russia, is calculated as the sum of the shares of the cost of the tractor using a number of reducing factors that take into account the progressive influence of localized production: the scarcity ratio of the manufactured model; the service network coefficient; R&D funding ratio; spare parts warehouse availability factor. The implementation of this methodology contributes to the solution of tasks for the development of the Russian economy: job creation; organization of production of scarce equipment (import substitution); promotion of innovative technologies; maintenance of service; development of research and development work; prompt provision of spare parts.
Tractors and Agricultural Machinery. 2020;(5):18-24
pages 18-24 views

Calculation and identification of the coordinate of oil jet ejection from the gap of a rotating connecting rod bearing

Putintsev S.V., Strelnikova S.S., Anikin S.A.

Abstract

The development of a modern high-speed, energy-efficient and reliable diesel engine requires high-quality lubrication of all friction parts in general and parts of the cylinder-piston group (CPG) in particular. The relevance of this research is due to the insufficient study of the process of oil jet supply of CPG parts, implemented in combined lubrication systems of modern high-speed four-stroke engines and significantly affecting the processes of friction, wear and scuffing of parts of this group. The analysis of previously performed works in this area has shown the feasibility of not only setting up an experiment, but also using computational modeling in order to increase the informativity of the results obtained. The aim of the study was to determine the coordinates of the point of ejection of the oil jet from the gap of the rotating connecting rod bearing. According to the accepted working hypothesis, the point of ejection of the oil jet was the geometric place of the maximum gap in the connecting rod bearing. To calculate the angular coordinate of this point, we used the method of composing and solving equations of plane motion of a solid body. As a result of the research, an analytical expression of the desired coordinate was obtained and its value was calculated during the working cycle for the conditions of the nominal operating mode of the research object - a high-speed universal air-cooled diesel engine 1CH 8.5/8.0 (TMZ-450D). Ensuring the reliability and increasing the accuracy of the results of the study is confirmed by comparison with the calculated data obtained by the method of classical dynamics of piston engines. The array of calculated values of the coordinate of the oil jet ejection point from the gap of the rotating connecting rod bearing of the diesel engine, defined in this paper, will be used for debugging the developed tool for calculating modeling of the oil jet feed process and subsequent optimization of the conditions of lubrication, friction and wear of CPG parts on this basis.
Tractors and Agricultural Machinery. 2020;(5):25-32
pages 25-32 views

Modernization of technical means for separation of grain-grain graff

Harayev G.I., Shukhanov S.N.

Abstract

The successful functioning of agricultural production at the present stage of development presupposes the creation of agro-engineering systems operating on innovative principles. In this set of tasks, the technical support of cereal production has a key place. Post-harvest treatment of grain is of paramount importance, including its pre-purification, namely, separation of grain straw heap. Therefore, the solution of the technical task of modernizing the technical means for separation of grain straw heap is a pressing problem. A wide overview of literary sources devoted to this topic, a comprehensive and thoughtful analysis of inventions made it possible to modernize device at the level of patentability. Proposed modernization of apparatus is achieved due to uniform feed, which provides thin-layer stratification with required orientation of particles moved by conical spreader into formed annular air flow. A distinctive feature of the proposed device is a new form of execution of known structural components, namely, the representation of the feeder in the form of a funnel-shaped hopper with an outlet slot, as well as a ring-shaped dispenser, the design of a conical spreader equipped with straight blades, including receiving chambers made in the form of a design of circular funnel-shaped working chambers. In addition, a characteristic feature of the proposed apparatus is the presence of a device for directing the air flow in the form of a cone. The hopper of a funnel-shaped design with an outlet slot allows to stabilize the movement of the components of the processed material before they arrive at the ring dispenser. Availability of design features of the proposed apparatus ensures realization of technical result at the level of patentability, which provides an increase of productivity, as well as efficiency of extraction of output components from processed material.
Tractors and Agricultural Machinery. 2020;(5):33-36
pages 33-36 views

Research on the price of harvesters in the secondary market as an aspect of changing their technical condition

Piskunov M.A.

Abstract

In the timber industry complex of Russia, medium-sized and small enterprises with a volume of timber harvesting up to 100 thousand cubic meters per year occupy a share of 48 % in the total volume. Most of these enterprises do not have the capacity to purchase new harvesters. An alternative to the new harvesters are the harvesters from the secondary market. Thus the study of changes in the technical condition of harvesters during their operation is an actual study for Russia. The data on the models, age, number of hours worked and the cost of harvesters that are offered on the secondary market was collected. 202 commercial offers were collected. In total there are 31 harvesters under 5 years of operation; 99 harvesters from 5 to 10 years of operation; 56 - from 10 to 15 years of operation; and 16 - older than 15 years of operation. There are 73 John Deere harvesters (including the outdated Timberjack models), with 8 tracked vehicles, 29 Ponsse harvesters; 49 Komatsu harvesters (including the outdated Valmet models) with 4 harvesters based on a tracked excavator; 37 harvesters of different models made on the basis of tracked excavators and 18 harvesters of other models. Hypothetically assuming that there is a connection between the price of the harvester and its condition, correlations were analyzed between the price and the age of the harvester and between the price and the number of worked hours of the harvester. The relationship between the price and the age is described by power and exponential curves, with coefficients of determination of 0,56 and 0.54, respectively. Filtering data by power range (160-205 kW) and by model (three models were considered: John Deere 1270; Ponsse Ergo; Komatsu 931) did not lead to clear certainty about the form of regression, although it slightly increased the coefficient of determination. There are groups of factors that can influence the type of regression: the seller's factor, the repair factor, the operation factor, and the technical characteristics factor, but determining the degree of influence of these groups requires additional research. The dependence between the price and the number of worked hours is characterized by a very weak relation due to a large spread of data owing to incorrect values of the hours marked by sellers. General regression trends for harvesters are consistent with data for other types of tractors. But to determine unambiguity in regressions requires the accumulation of empirical data on the reliability of machinery and changes in their price over a number of years.
Tractors and Agricultural Machinery. 2020;(5):37-44
pages 37-44 views

This website uses cookies

You consent to our cookies if you continue to use our website.

About Cookies