Vol 32, No 4 (2022)

Introduction. The paper considers the problem of improving the efficiency of self-propelled small-sized tillage cutters by adapting to changing environments, and in particular, to changing physical and mechanical properties of the soil. The aim of the research is to develop a methodology for designing self-propelled small-sized tillage cutters.
Materials and Methods. The study used the basic provisions of the theory of mechanisms and machines and the design theory in mechanical engineering. The main attention is paid to the general scientific principle of adaptation in designing self-propelled small-sized tillage cutters. The authors understand this principle as the ability to automatically provide the required mode of machine operation in relation to the soil conditions.
Results. The results presented in the article made it possible to propose a methodological approach to designing efficient self-propelled small-sized tillage cutters with an ability to adapt them to changing environments. The results of the study are a methodology for designing tillage cutters and a new technical solution for their adaptation to soil conditions. On the basis of patents for inventions and utility models, in which this method is implemented, there was developed a prototype tillage cutter, which automatically covers the full range of required operating modes.
Discussion and Conclusion. Compared to the known tillage cutters, the proposed technical solution for the soil tillage cutter design allows improving the quality of soil tillage. This is due to the fact that the value of the kinematic index is in the required range, and the agrotechnical requirements for tillage are met.

Introduction. Developing and adapting domestic technologies aimed at the maintenance and repair of foreign equipment is impossible without design documentation. The object of the study was the volumetric hydraulic drive Sauer-Danfoss of 90 series consisting of a hydraulic pump 90R100 and a hydraulic motor 90M100. The purpose of the study is to determine the nominal dimensions and permissible variations in dimensions of critical parts that affect efficiency of the foreign hydraulic drive.
Materials and Methods. The first series of bench tests was devoted to finding the ranges of variation of significant factors influencing the volumetric efficiency. In the second series, there were constructed regression models and by using the steepest ascend method, there were determined the values of critical parts wear and clearances in the critical parts connections affecting efficiency of the hydraulic drive Sauer-Danfoss.
Results. The bench tests made it possible to determine the ranges of changes in critical parts wear and clearances in the critical parts connections of volumetric hydraulic drives that affect the volumetric efficiency. There has been proposed and implemented a comprehensive approach to determining the nominal dimensions and permissible variations
in dimensions of critical parts of foreign equipment units. This approach suggests a combination of experimental studies (bench tests) and the method of dimensional analysis. For the new volumetric hydraulic drive Sauer-Danfoss series 90 the following values are received: diameter of a hole in the cylinder block under the piston 22.7+0,006 mm, piston diameter 22.7–0,004 mm, diameter of a hole in the rear cover under the spool 9.5+0,004 mm, spool diameter 9.5–0,0025 mm.Discussion and Conclusion. There have been determined the nominal values of dimensions, permissible variations in dimensions of critical parts, and the values of technological clearances in the critical parts connections of the new volumetric hydraulic drive Sauer-Danfoss series 90 that affect its efficiency. 

Introduction. The article presents the solution of the problem of identifying the subject area “Preliminary adjustment of the working elements of the combine harvester cutting unitˮ. The correct choice of parameter values of the cutting unit as the most important element of a combine harvester is one of the main conditions for providing high quality harvesting. 
Materials and Methods. Decisions on the values of technological parameters of the harvester, which is a complex hierarchical system, are made on the basis of information about the external environment and the machine technical state. The incoming data are quantitative, qualitative and evaluative in nature. Taking into account the heterogeneity and vagueness of the information, the decisions are made through using intelligent information systems, which are based on the fuzzy logic programming and use a linguistic approach to describe the subject area. 
Results. The subject area “Preliminary adjustment of the combine harvester cutting unit parametersˮ has been investigated. The formal-logical scheme for selecting the values of adjustable parameters of the combine harvester cutting unit is described in detail. The main factors influencing the values of the combine harvester cutting unit adjustable parameters are defined, their linguistic description is given, the corresponding input and output linguistic variables are introduced, and the membership functions are built on the basis of expert information. The agreement analysis of the presented information has been carried out and optimal models have been selected. 
Discussion and Conclusion. The proposed approach and created fuzzy knowledge base can be used as the basis for an intelligent decision-making system for adjusting combine parameters. Using this system in the field in combination with sensors for continuous monitoring of harvesting conditions and an automated image analysis system will allow responding quickly to changing conditions, will significantly improve operational efficiency
and reduce decision-making time.

Introduction. We consider a weakly conductive gradient fiber in the single-mode regime and solve the equation for the electric field in the core of this fiber in a general form in the first approximation. The aim of this study is to study the field and energy in the core of a weakly conductive gradient fiber without taking into account the polarization in the single-mode regime in the case of a power-law (generally) refractive index profile.
Materials and Methods. From Maxwell’s equations for dielectric media, there was derived an equation for the field in a fiber with gradient refractive index profile. Making the appropriate substitutions, replacing the zero-order Bessel function with a Gaussian function, and making the necessary approximation of the resulting equation, we arrive at an equation that we solve by the Wentzel – Kramers – Brillouin method and obtain analytical expressions for the field and energy inside waveguide for an arbitrary degree of the refractive index.
Results. There was obtained a solution of the equation for the field in fiber with a powerlaw refractive index profile. Numerical calculations were carried out. A graph of the dependence of a dimensionless quantity – “normalized” energy – on the waveguide parameter for the first five powers of the profile (n = 1, 2, 3, 4, 5) was plotted.
Discussion and Conclusion. It is shown that the energy increases faster for the profile with n = 1, and after this value, the energy for the profile with n = 1 increases sharply, and for n > 1, the energy growth decreases with increasing n. The results obtained in this work can be used for creating an energy-efficient core, for carrying out a possible analysis of information transmission, and for designing waveguides taking into account specific applications.

Introduction. Ensuring the required parameters and characteristics of electromagnetic radiation of lighting irradiation facilities for greenhouses is an important task to improve the efficiency of energy use and the characteristics of crop production. The aim of the work is to determine the effective operation mode of technological irradiation scheme with separation of energy flows in lighting systems of industrial greenhouses.
Materials and Methods. In the developed model of the irradiation technological scheme, constructive decisions make it possible to divide the energy flows into components and to control these flows. It has been proposed that separate regulation of the voltage on the irradiator and the fan can be used to create conditions for changing the values of separate spectral lines of radiation in order to further assess the effect of these changes.
Results. We obtained the results on the change of PPFD distribution depending on the voltage on the greenhouse irradiator from 198 to 242 V and the air temperature near the lamp from 38 to 47°C. The comparison of averaged PPFD values in the studied modes with the PPFD value in the nominal mode for these ranges allowed determining the mode at voltage 220 V and the air temperature near the lamp from 43 to 47°C as a rational for practical use in technological irradiation schemes with energy flows separation in the lighting systems of industrial greenhouses.
Discussion and Conclusion. The development and application of rational modes for operation of greenhouse irradiators, taking into account the modes of network and lamp is the basis for greenhouse production with the use of alternative thermal energy.