JUSTIFICATION OF PARAMETERS OF THE CONTROL SYSTEM OF ELECTROMECHANICAL DEBALANCE VIBRODRIVE OF VIBRATION MACHINES ON THE BASIS OF ARTIFICIAL NEURAL NETWORK

The article analyzes and proposes an approach to the construction of a control system for electromechanical debalance vibrodrive for vibration machines based on an artificial neural network. As a result of the analysis of various methods of managing dynamic objects it is concluded that the most appropriate and perfect for this type of machine is neurocontrol method of predictive model neurocontrol, which allows to expand the functionality of these vibrating machines and significantly save energy for vibratory drive of their oscillations. A direct neuro-emulator is used to predict the future behavior of the oscillating mechanical system of the vibration technological machines and to calculate errors. An important feature of the predictive neurocontrol model in the proposed method of controlling the operation of vibrating technological machines using an artificial neural system is that there is no neurocontroller that needs to be trained, its place is taken by the optimization algorithm. Applying the proposed method of controlling operation of adaptive vibration technology machines using artificial neural network will optimize the electromechanical control of debalanced vibration drive of vibrating machines and provide optimal resonant modes of its operation (which is energy efficient) in all technological modes of vibrating operation. The technical and economic characteristics of this control method are further improved due to the fact that the proposed control method uses the technology of predictive model neurocontrol and as a result is constantly calculated (forecasted) several cycles in advance and determines the best strategy to control the frequency of forced cyclic vibration. As a result, the mechanical system of vibration machines spends less time in non-resonant mode. This method of control also minimizes the duration of transients when changing the load mass of the working body vibration or changing the mode of vibration parameters and the parameters of their technological process.

EXPERIMENTAL RESEARCH INTENSITY OF OSCILLATIONS AGRICULTURAL MACHINE-TRACTOR UNITS

Smoothness of movement of agricultural units is one of the important operational indicators of their work which is estimated on influence of fluctuations (translational vertical, cross, angular longitudinal, etc.) The article presents the method and results of experimental assessment of the smoothness of the movement of the bridge agricultural unit, which moves in the footsteps of a constant technological track. Studies of the smoothness of the bridge unit showed that the graphs of normalized correlation functions of vertical oscillations of the bridge agricultural tool developed by us in its motion in the wake of a constant technological track is characterized by a function containing along with random components harmonic, which are expressed by attenuating periodic oscillations. The frequency spectrum of oscillations of the agricultural tool core is concentrated in the range from 0 to 20 s–1, which agrees with the frequency range 0…0.3 cm−1 in which the variances of oscillations of the irregularities of the profile of the traces of the technological track are concentrated. The length of the correlation connection is approximately 0.25 s, which is equal to 0.25 m at the speed of the agricultural tool within 1.0 m / s.The obtained result is explained by the fact that the main spectrum of oscillations of the profile irregularities has a periodicity that corresponds to the step of ground engagement of the tires of the wheels of the agricultural tool. The research confirmed the effectiveness of the method of estimating the intensity of vertical oscillations of an agricultural unit by a measuring and registration complex based on a tablet computer with Android operating system with built-in accelerometer sensors and Accelerometer Meter application.

DETERMINING THE THERMO PHYSICAL CHARACTERISTICS OF VIBRATION DRYING OBJECTS

Crop products require good moisture content for successful storage. The drying process is mainly used for this purpose. For its successful design and implementation it is necessary to have information about the physical and mechanical properties of the material, including thermo physical characteristics. It is for the successful implementation of the process of post-harvest processing of pumpkin seeds were planned and conducted experimental studies. Analysis of previous studies to determine the thermo physical characteristics of various materials, including plant products, showed that in most cases one series of experiments to determine three main indicators - heat capacity, thermal conductivity and thermal conductivity of products. Unfortunately, there is no universal method and installation for determining the required indicators, so in our research we used the original installation, the principle of which is based on the use of non-stationary heating patterns of two semi-bounded rods, where the source of heat is constant power. The theoretical basis of the implemented method is the solution and analysis of the thermal equation with the corresponding boundary conditions. Intermediate equations were obtained from which the values of thermal conductivity and thermal conductivity for each series of experiments were found by the graph-analytical method of solution. The value of heat capacity of the material was determined from the well-known formula of the ratio of these three indicators. As a result of research and processing of the obtained data, the dependences of the thermo physical properties of the material on its humidity were determined, which are presented in graphical and analytical form. The obtained dependences confirmed the results of researches of some authors on the presence of inflection in the graph of thermal conductivity which is explained by the transition of moisture from free to bound state.

CREATION OF ELECTRIC CONDUCTIVE COATINGS USING GAS-DYNAMIC SPRAYING

The article presents the results of research on the processes of creating conductive coatings based on copper and aluminum in order to determine the interaction of components on each other during cold gas-dynamic spraying (CGDS) and substantiate the method of introducing an additional component to obtain the desired composite coating. In particular, under conditions when the copper sputtering coefficient is almost zero (at a working air temperature of 300 °C), it is the search for the experimental dependence of the sputtering coefficient on the percentage of copper and aluminum powders in the sprayed mixture, determining their residual content in the coating and then calculating based on these data, the sputtering coefficients of copper and aluminum. The CGDS method obtained samples with composite coatings from mixtures of aluminum and copper powders at different initial mass concentrations of aluminum (from 0 to 100%, in increments of 10%) Other things being equal (air pressure 0,6 MPa, air heating temperature 300 ° C) . The spraying ratio of the mixture and the residual content of the components in the obtained composite coatings were measured. Data on the residual content of the components in the coating allows you to select the composition of the source powder required to obtain a given content of components in the coating. The dependences of the sputtering coefficients of copper and aluminum on the mass content of aluminum in the sprayed mixture are found. At an initial concentration of aluminum less than 66%. the coefficient of copper sputtering is higher than the coefficient of sputtering of aluminum. Both increase monotonically with increasing aluminum concentration until it reaches 61%. At high concentrations of aluminum (more than 66%) the spray coefficients of copper, aluminum and their mixtures coincide. The obtained data on the residual content of the components in the coating allows you to select the composition of the source powder required to obtain a given content of components in the coating. For example, the maximum residual copper content (~ 95%) can be obtained by adding to the source powder 30-40% aluminum. The obtained results confirm the interaction of the components on each other and justify the method of introducing an additional component to obtain a composite coating containing a component that is difficult to spray.

VIBRATION DIAGNOSTICS OF FATIFUE DAMAGE IN STRUCTURAL ELEMENTS OF GAS TURBINE ENGINES AT THE REPAIR STAGE

Vibration diagnostics of damage belongs to the class of non-destructive methods, which usually do not take long time. However, the main problem of vibration diagnostics is relatively low sensitivity to the critical damage of fatigue crack type, which arises because of long time accumulation of plastic deformation. To improve the sensitivity and reliability of vibration diagnostics of damage two methods were considered. First method was based on the fact, that a characteristic feature of vibrations of structural elements with fatigue crack is the occurrence of non-linear resonances (sub- and super-harmonic) and significant non-linearity of vibration response at these resonances. Secon one – on the fact, that quite noticeable in certain cases increase of damping characteristic caused by a crack can be observed. Analytical and experimental studies of these methods were carried out as applied to the blades of aircraft gas turbine engines. As a result of the studies, the intensity of change in parameter of super-harmonic resonance and in damping characteristics at different parameters of crack was determined. Besides, the experimental techniques for vibration testing of turbine blades were developed. There was demonstrated, that the sensitivity of both considered methods of vibration diagnostics is several orders of magnitude higher than the sensitivity of conventional methods based on the change in natural frequencies and mode shapes, and they can be effectively used for the diagnostics of blades on the stage of engine repair. All the other conditions being equal, second-order superharmonic resonance demonstrates a higher sensitivity to the presence of cracks than the damping characteristic. The smallest crack with an area of 0.2% considered in the work causes a reliably recorded non-linearity of vibration response at superharmonic resonance of order of 2/1. At this the change of damping characteristic slightly exceeds the error of experiment.

PROMISING PULSE AND VIBRATION SHOCK DEVICE FOR UNLOADING OF TRAILERVEHICLES

Due to the growth of bulk cargo transportation by road, it is necessary to increase the level of mechanization and automation of loading and unloading operations. In recent years, various powerful high-performance unloading machines of original designs (car tippers, vibrating platforms, elevators, etc.) have been created to mechanize unloading processes. This makes it possible to speed up unloading, reduce costs and reduce excessive downtime of dump trucks under unloading. However, the use of such machines is cost-effective at unloading points with a turnover of more than 30 dump trucks per day. Therefore, the problem of creating simple and cheap equipment that ensures efficient unloading of dump trucks with bulk cargo, as well as cleaning of rolling stock from cargo residues, as regardless of the type and composition of cargo, some of them are delayed on the floor, in stamped ribs. pockets of all-metal body walls. The largest amount of cargo remains on the hatch covers, the angle of which is on average 300, while the angle of the actual slope of the cargo reaches 450 and more. Due to this ratio of angles, even dry material cannot fall out completely through the hatch opening, let alone moistened or viscous bulk cargoes. The amount of bulk cargo residues depends on many factors (type of cargo, its humidity, size of pieces, air temperature, distance of transportation, method of unloading) and can be from 2 to 30% of the total weight of the cargo [1]. The use of useful vibrations allows to solve this problem the most expediently. Therefore, the development of a vibratory shock device for unloading vehicles is a promising and urgent task.

DEVELOPMENT AND RESEARCH OF A HIGH-PERFORMANCE ELECTRONIC DEVICE FOR OZONE SYNTHESIS IN A VIBRATION DRYER

The article analyzes the features of drying grain raw materials using a vibrating dryer, in which the drying agent is a mixture of heated air in combination with ozone of a certain concentration. Based on the analysis to intensify this process, we propose to develop a high-performance electronic device for ozone synthesis. The scientific study considers oscillations that increase and update the heat transfer surface regardless of the method of supply of the drying agent. Due to this, the removal of moisture intensifies, the drying speed increases. Having conducted a search and analyzed the process of vibration drying, we can say that in the future will progress two main trends in their development. This is the use of vibration in combination with the action of ozone on the raw material entering the drying. Ozone interacts with the membrane structure of bacteria, fungi, the structural unit of viruses, which leads to a violation of its barrier function and their death. The bactericidal effect of ozonation is superior to the effect of ultraviolet quartz radiation. Bactericidal effect from quartz irradiation for 60 minutes identical to the bactericidal effect of ozone for 3 minutes Ozone has a high penetrating ability and also shows antibacterial activity against gram-positive flora, Escherichia coli, epidermal staphylococcus. This method is the most effective general method of controlling the dynamic state of the processed raw materials. The analysis allows us to suggest possible solutions for the use of low-frequency oscillations for separation processes and outline the prospects for their application. It is proved that the existing equipment is used with significant energy consumption and high cost. The constructions and technologies considered in the work do not completely exhaust the possibilities of using vibration and ozone, although they testify to the expediency of their application and combination not only in agricultural production, but also in other industries in order to intensify processes and obtain quality products.

DETERMINATION OF THE MODE OF FUNCTIONING OF THE CENTRIFUGAL-GRAVITATIONAL SEPARATOR OF THE GRINDING DEVICE

The peculiarity of harvesting legumes is the need to process their heap on grater devices with subsequent separation. To improve the technical and economic performance of seed heap processing equipment, it is advisable to combine wiping and separation operations by combining a grater working body and a separating rotating sieve of cylindrical or conical shape. The analysis of influence of geometry of rotary sieve drums allows to define the rational form and parameters of work of the separating device which will provide the necessary quality of seed material. Analysis of the literature on the processes of sieve separation of grain and seed mixtures showed the advantages of centrifugal separators with a rotating sieve surface. Improving the efficiency of separation of mixtures by rotary sieves is achieved by the simultaneous use of centrifugal, Coriolis and gravitational forces. The aim of the study is to increase the efficiency of separation of seed heaps of legumes after treatment with a grater device by determining the trajectory of the seeds along the rotational surfaces. Earlier, the authors developed a grater-separating unit in which a cylindrical perforated drum is used to remove unworn seeds. This design does not use the surface of the sieve effectively enough. To increase the uniformity of the load on the steaming surface of the rotary drum, it is advisable to reduce its area in the direction of seed movement. To do this, use a conical separating surface to reduce the radius of the cone in the direction of movement of the material. When considering the movement of a particle, it is represented as a material point with mass m moving along a conical surface that rotates around a vertical axis. As a result of theoretical researches the dependence which defines time of stay of a particle on a sieve depending on a coordinate (length of a generating cone) is received. A graphical interpretation of this dependence for certain values of design parameters is also presented. As a result of research, it was found that increasing the residence time of the material on the sieve due to the use of a conical surface increases the yield of pure seeds, and also contributes to the uniform loading of the sieve surface, which improves the quality of the source material.

RESEARCH OF TRANSIENT PROCESSES OF PRESSURE CHANGE WHEN OPERATING A HYDRAULIC SYSTEM WITH FOUR CONNECTED HYDRAULIC MOTORS

The publication is devoted to the study of the quality of the hydraulic system with four series-connected hydraulic motors. These hydraulic systems can be used to drive the working bodies of agricultural machines, have significant advantages in their layout, but at the same time and disadvantages, the elimination of which requires a detailed study of the processes occurring during the operation of this type of system. The analysis of the previous works of scientists in this area allows us to conclude that it is possible to conduct theoretical research in this direction. A mathematical model of the proposed hydraulic system has been developed, which takes into account the effect of external load on the shafts of hydraulic motors, the inertia of the system, the effect of leaks from the connections of the elements of the hydraulic system and possible overflows of the working fluid from the high-pressure zone to the low-pressure zone. At this stage, wave processes occurring in the cavities of the hydraulic system were not taken into account. The solution of the resulting system of differential equations was carried out using the Runge-Kutta-Feldberg method with automatic change of the integration step in the mathematical package MathCad. The resulting transient processes were analyzed for the amplitude of pressure surges and the frequency of its change. Carrying out this analysis allows you to obtain comprehensive information about the nature of transient processes in the hydraulic system in order to find such a ratio of design and technological parameters, in which the system under study met the requirements regarding the quality of work as part of a technological machine. During the research, special attention was paid to the processes occurring at the moment of starting the hydraulic system, and the moment of application of the technological load.

SIMULATION MODELING AND RESEARCH WORKS OF THE HYDRAULIC DRIVE OF THE STEM SEPARATOR FEED FROM TRENCH STORAGE

The issue of accelerated creation of efficient and energy-saving hydraulic drive of stem forage separator from trench storages by simulation modeling of technical systems. It is noted that the use of simulation allows to avoid significant investments required for the manufacture of a prototype of an agricultural machine, provided a detailed study physical model of the hydraulic drive of the stem feed separator. And also allows you to check the adequacy of the results obtained in process of mathematical modeling, and determine the necessary improvement of the proposed hydraulic drive. A fundamentally new constructive-technological scheme is presented stem feed separator from trench storage that allows to carry out process of unloading of a stalk forage from trench storages according to zootechnical requirements. The stand for simulation modeling of transients in the hydraulic drive of the stem forage separator from trench storages is offered. The design of the experimental stand also allows to investigate the hydraulic drive of the stem feed separator in the dynamic mode, when changing the technological load on the working bodies and changing the parameters of the adaptive fluid flow separator and the system in general. As a result of research and analysis of transients in the hydraulic drive, a fairly close coincidence of the results of mathematical and simulation modeling of the hydraulic drive of the stem feed separator, which allows us to recommend obtaining the calculated dependencies for use in the development hydraulic drives of stem feed separators.