Purpose of research is to increase productivity when cutting hard-to-work steels by integrated use of chip breaking tool geometry and cutting modes, which reduce the viscous properties of the chips and the processed material. The article discusses the problems of mechanical processing of parts of oil production equipment at enterprises in Western Siberia. It is presented the main condition for ensuring chip crushing and revealed the problem of low efficiency of existing methods in modern industry, to one degree or another guiding, curling and chip-cutting method.

Methods. Simulation modeling, calculation of chip direction and crushing were performed; effective methods for solving the problem of chip crushing during the machining of parts made of materials with corrosion-resistant, heat-resistant properties were identified; laboratory, persistent tests of the complex method were carried out.

Results of studying the mechanism of chip formation during processing by cutting heat-resistant and corrosionresistant alloys are given here. To solve the problem, we have formulated two tasks that were solved using information taken from the theory of material resistance, tensile diagrams when testing samples of corrosionresistant, heat-resistant materials with high operational properties. A chip breaking exchangeable insert with a variable rake angle is designed and presented. The results and analysis of laboratory test data, in which a plate with chip breaking geometry of the front surface is used, are presented, the operating conditions of effective chip breaking are shown. The conclusions on the solution of the first problem are formulated, it is shown that the determining factor in chip breaking is the physical and mechanical characteristics of the processed material, which vary with different cutting conditions.

Conclusion. The work shows that chip removal from the cutting zone prevents it from entering the cutting edge area, reducing impact loads on it and improving the quality of machining. It is possible to form stress concentrators in the chips, leading to chip self-destruction even when processing viscous heat-resistant alloys. The hypothesis is used that the temperature conditions for the maximum workability of heat-resistant and corrosion-resistant steels and alloys correspond to the conditions of high-temperature embrittlement, with the help of which it is possible to create conditions for effective chip crushing and conditions for maximum workability when cutting heat-resistant steels and alloys.

Purpose of research. The study is devoted to improving the resistance characteristics of an interlocking side milling cutter with a constructive radial feed when processing extended RK profile shafts while maintaining the required quality of surface treatment.

Methods. Forming of RK profiles by milling with a disk cutter with a constructive radial feed allows you to obtain the required surface quality with high processing productivity. Due to the fact that the processing conditions for each cutting insert are different, it is necessary to study the resistance of interchangeable polyhedral inserts (IPI) and to search for structural solutions to reduce the range of change in resistance, while maintaining the quality of surface treatment of the PK profile. The influence of the use of an uneven pitch of location both on the quality of processing and on the resistance of each individual insert is studied.

Results. The paper presents a method for calculating the resistance of an IPI of a interlocking side milling cutter during processing of an extended RK profile of a shaft, taking into account the individual conditions of their operation, namely: cutting speed, feed to the tooth, milling width and the diametrical position of the IPI

Conclusion. The analysis of the influence of the structural parameters of the cutter on changing the range of values of the resistance of IPI is made, and recommendations for its reduction are proposed. The main design parameters that affect the change in the resistance range are also identified.

Today, when machining domestic-made worm milling cutter according to GOST 9324-80, a problem arises in their durability at the roughing stage. Russian tool companies engaged in the manufacture of metal cutting tools do not currently offer prefabricated worm tools with cutting elements made of hard alloy tools for machining large-modular gears.

Purpose of research. Creation of prefabricated structures for machine-building enterprises with replaceable cutting carbide plates (RCHAP). Due to this, the productivity of equipment already available at the enterprise is increased several times, the economic efficiency of introducing high-quality metal-cutting tools makes it possible to purchase modern equipment and make the work of machine operators at machine-building enterprises more efficient and less time-consuming. In this paper, we propose a fundamentally new technical solution, which makes it possible to increase the efficiency of machining gears with a metal-cutting tool, with the arrangement of replaceable carbide cutting plates in the prefabricated initial contour of the manufacturing rail in worm milling cutters.

Methods. The research method is the use of graphic simulation, which allows you to determine the size of the crosssectional area of the cut layer for the cutting elements of the worm tool.

Results. Improving the processing efficiency will be achieved by implementing a group cutting scheme in a prefabricated worm milling cutter by using a larger number of main and side carbide cutting inserts on an Archimedean tool worm, which allow sequentially cutting the machining allowance and reducing the feed rate to the cutting insert, to ensure milling uniformity throughout the processing stage, and also reduce the magnitude of shock loads on cutting carbide elements of a precast tool.

Conclusion. The use of replaceable carbide plates in a group cutting scheme increases the durability and reliability of a precast worm cutter.

Purpose of research is to develop a methodology that allows designing EDM electrodes applying advanced computer-aided design (CAD) systems by forming the tool’s working surface with geometry which is inverse equidistant to the geometry of a given workpiece taking into account the EDM gap, working translation or translation-rotational motion of EDM electrodes, the value of the layer of conductive coating based on the technological parameters of the processing procedure. It is also necessary to propose, implement and formulate technological guidelines for manufacturing EDM electrodes from dielectric materials by additive techniques with the subsequent formation of a conductive layer on them; the value of the layer should ensure the flow of working electrical processes in the EDM gap and the necessary tool life. This will make it possible to expand the scope of application of combination EDM electrodes as applied to combined processing techniques which are characterized by a wide variety of working surface shapes, which correspond to the geometry of the workpiece, which is not limited by the degree of curvature, has by far lower cost and high processability when creating a special tool for pilot and single manufacturing.

Methods. When carrying out the work, theory of the classical laws of mechanical engineering technology, electrical processing techniques, the known laws of rapid prototyping and additive technologies were used.

Results. The theoretical foundations and the technology for manufacturing combination EDM electrodes by rapid prototyping have been developed and a methodology for calculating and designing the working part of EDM electrodes has been proposed taking into account the geometric parameters of the machined surface and a variable EDM gap value.

Conclusion. The mechanism of EDM electrode design by means of digital prototyping in modern CAD systems is justified taking into account the features of the workpiece geometry, EDM gap and metallization material.

Purpose of reseach. The article deals with the study of the operation of the extended Kalman filter (EKF), supplemented with an adaptive digital filter in order to compensate for the error in the operation of the EKF when performing data integration of the mobile robot control system.

Methods. The adaptive digital filter (ADF) is a self-tuning filter that iteratively changes its variable parameters to achieve the optimal desired values of the output data. The EKF supplemented with the ADF with the NLMS adaptation algorithm will be called the EKF–ADF system or the EKF+NLMS digital filter. An important task is the selection of the number of frames and ADF weighting coefficients at which the optimum quality of noise suppression and the convergence rate of the adaptation algorithm are achieved.

Results. With various options of organizing the operation of the ADF buffer memory, the adjusted values for assessing the state of the ‘mobile robot–environment’ system may differ. When the number of input data frames and ADF weighting coefficients are small, low quality noise suppression will be observed. With an increase in the number of frames and weighting coefficients, the quality of noise suppression is improved, and the convergence rate of the adaptation algorithm decreases.

Conclusion. The EKF+NLMS digital filter algorithm takes an intermediate place between the EKF algorithm and the serial filtering of the EKF and ADF signals with the NLMS algorithm according to the criteria for estimating the mean square error, mean absolute error, signal-to-noise ratio, and convergence rate.

Purpose of research is to study cheaper composite materials for building structures such as cement-free ones without heat treatment, which will undoubtedly allow finding their application in building industry. To achieve this goal it is necessary to identify patterns of structure formation of clinker-free contact condensation hardening composite materials in which portlandite crystals act as a matrix, and the physicochemical active component of natural origin acts as a filler.

Methods. In accordance with the purpose set, one of the main tasks of the work was to be solved; it involved study-ing the patterns of structure formation of contact-condensation hardening systems relying on the basic principles of materials science, which include studying the influence of the composition, structure and state of the starting com-ponents on the properties of a composite material. In this work, we studied the role of the physicochemical activity of raw materials and the possibility of ‘combining’ a portlandite matrix with filling mechano-physicochemical active raw materials capable of producing new structures. To form the composite material, a compaction pressing technique at elevated specific pressures was used, which made it possible to implement the mechanisms of contact condensation technology of structure formation. The formation of physicochemical bonds of portlandite and aluminosilicate filler of various types is also possible with certain ratios of their mass fractions and V/I ratios the optimization of which was one of our objectives.

Results. The result of this work is to assess the impact of raw material characteristics and technology parameters on the properties of the resulting material, namely, the improvement of the compacting pressure and the amount of filler when getting a compacted composite.

Conclusion. The development of a technology of producing clinker-free contact condensation composites based on portlandite with aluminosilicate filler will expand the raw material base of local building materials, reduce their cost and energy consumption, that is, solve key issues of resource saving in the building materials production.

Purpose of research. Analysis is done on the basis of experimental data of loading level impact on deformability of beams with steel and composite fiberglass reinforcement at prolonged loads.

Methods. Experimental studies of concrete bending elements of two series were carried out: the first is reinforced with composite fiberglass reinforcement of ASK class, the second is reinforced with steel reinforcement of А400 class. Studies of experimental samples were carried out under long-term loads. The structures were under different loads during the experiment: at design load, at 1.2 level from design load and at 1.5 from the design load. Concrete deformations and deflections of experimental beams of two series were fixed.

Results. Dependence on time of concrete deformations of experimental samples of two series at different loading levels, dependence of deflection growth on load application level, influence dependence of loading level of elements on speed and intensity of creep deformation growth of beams with fiberglass and steel reinforcement are stated on the basis of experimental data. In particular, the bends of all samples with fiberglass reinforcement exceeded the maximum permissible value, while the maximum deflection of reinforced concrete beams in the middle of the section did not exceed maximum permissible value.

Conclusion. On the basis of the obtained data, conclusions are drawn on the nature and magnitude of long-term deformations of beams with fiberglass and steel reinforcement at different levels of long-term loads. This conclusion is significant in practical sense when using concrete structures with composite reinforcement taking into account a small number of research data.

Рurpose of research. Situations that reduce the accuracy of links positioning often arise due to the drab of contacts during the operation of robot manipulator. One of this problem solutions is signal filtering. Modern digital filtering algorithms have a rather complex mathematical structure. Data processing in such filters takes long time. So the purpose of this work is to develop fast-acting fuzzy digital filter device capable to eliminate the problem of contact scrapping when positioning the links of robot manipulator.

Methods. Generalized mathematical model was used in the development of digital filter device. This model is implemented by using fuzzy logic theory. Generalized mathematical model of the fuzzy digital filter includes a model determining a support of fuzzy output variable, a model for determining coefficients of fuzzy digital filter and a model for converting the output voltage into a rotation angle of robot manipulator servo drive. This mathematical model makes it possible to recalculate the voltage supplied to the input of fuzzy digital filter using two control coefficients thereby improving the positioning accuracy of robot manipulator links.

Results. During experimental studies, comparative analysis of developed fast-acting device of fuzzy digital filter with Kalman filter was carried out. The RMSE standard error for two filters was calculated. The average RMSE value of the fuzzy digital filter was 0.0185 of Kallman's filter was 0.0193.

Conclusion. Generalized mathematical model of fuzzy digital filter device consisting of three models is described. Device implementing determination of caliper of fuzzy output variable, experimental model of robot manipulator, experimental research and proposed mathematical model are presented.

Purpose of research. The current task is to monitor ships using video surveillance cameras installed along the canal. It is important for information communication support for navigation of the Moscow Canal. The main subtask is direct recognition of ships in an image or video. Implementation of a neural network is perspectively.

Methods. Various neural network are described. images of ships are an input data for the network. The learning sample uses CIFAR-10 dataset. The network is built and trained by using Keras and TensorFlow machine learning libraries.

Results. Implementation of curving artificial neural networks for problems of image recognition is described. Advantages of such architecture when working with images are also described. The selection of Python language for neural network implementation is justified. The main used libraries of machine learning, such as TensorFlow and Keras are described. An experiment has been conducted to train swirl neural networks with different architectures based on Google collaboratoty service. The effectiveness of different architectures was evaluated as a percentage of correct pattern recognition in the test sample. Conclusions have been drawn about parameters influence of screwing neural network on showing its effectiveness.

Conclusion. The network with a single curl layer in each cascade showed insufficient results, so three-stage curls with two and three curl layers in each cascade were used. Feature map extension has the greatest impact on the accuracy of image recognition. The increase in cascades' number has less noticeable effect and the increase in the number of screwdriver layers in each cascade does not always have an increase in the accuracy of the neural network. During the study, a three-frame network with two buckling layers in each cascade and 128 feature maps is defined as an optimal architecture of neural network under described conditions. operability checking of architecture's part under consideration on random images of ships confirmed the correctness of optimal architecture choosing.

Purpose of research is to develop an image segmentation algorithm based on the persistent homology for solving problems of searching and classifying defects. The algorithm is aimed at improving the quality of products at enterprises with continuous production (metallurgy, woodworking, and others).

Methods. To segment an image, it is proposed to specify links between pixels in the image. In the future, during the iterative breaking of links, as their weights increase, pixels will be combined into groups called holes. Pixels that are in a single group have both their original characteristics and characteristics common for the entire group, and they also change the weights of their links with representatives of other groups. This creates a history of the formation of separate groups of pixels which can be specified as segments with a time-based characteristic of the change.

Results. The result of the research is the development of an algorithm designed to search for and classify defects in various materials. The optimal algorithm for applying the principle of persistent homology to images has been developed, and factors determining the transition boundaries of image objects have been analyzed and selected. The segmentation algorithm was tested on metal images obtained from sheet rolling equipment. The results of comparing the proposed algorithm with the K-means and Mean-Shift segmentation algorithms for different parameters are provided in the article.

Conclusion. Using persistent homology in image segmentation tasks can enable creating a tool that can be applied to materials with different structures without any need for significant changes. The software implementation of the segmentation process based on the principles of computer topology has shown high flexibility due to the storing of the history of segment changes.

Purpose of reseach is to develop a method for generating training data to enable the use of artificial neural networks (ANN) method in gas analyzer systems. The problem of increasing the accuracy of separate determination of gas concentrations in multicomponent mixtures under conditions of environmental parameters changes is considered. It is proposed to increase the accuracy of determining target gas concentrations by using the ANN method for joint processing of sensor signals.

Methods: Training data for the neural network were generated using numerical experiments and mathematical simulation methods. To assess the accuracy of training, the standard deviation (SD) was used and the relative error was calculated. ANN training and research were conducted in the MATLAB environment (the Neural Networks Toolbox application). When developing mathematical models of gas sensors, the theory of electrical circuits, electronic theory of chemisorption and the adsorption theory of heterogeneous catalysis were applied.

Results: A method for generating training data sets using mathematical models of gas sensors is described. The proposed training method has been tested on a specific task, in particular, a decision-making device based on ANN for a four-component gas analyzer has been developed. The efficiency of using neural networks for tuning out from the mutual cross-sensitivity of sensors was evaluated.

Conclusion: A method for generating training data using simulation models is proposed, which allows automazing the process of training, research, choosing the architecture and structure of ANN and their testing. The method was tested. Based on the analysis of the obtained errors, conclusions are made about the efficiency of using neural networks to reduce errors caused by cross sensitivity at different concentrations of the main and interfering gases.

Purpose of research. Currently, various technologies and methods are used to control the integrity and authenticity of data transmitted through open communication channels. One of them is the technology for transmitting sequences of information packets connected to each other in chains using certain cryptographic algorithms. Similar approaches are used in the well-known blockchain technology and are focused on large volumes of transmitted and protected information and large sizes of additional service information fields. The purpose of this article is to study the characteristics of systems, transmission of small information packets in comparison with traditional size frames of TCP/IP stack, in which the broken packet sequence order is restored using the chain method, by analyzing hash sequences available in each of such packets.

Methods. In this article, simulation modeling, system analysis method, method of systematization and ranking of the obtained results are used.

Results. It is shown that increasing the size of the additional field with the hash of the previous message from 4 to 6 bits has a significant effect on reducing the probability of erroneous restore of the order of information packets. Further increasing the length of the hash field reduces the probability of error by only 2 to 5 % for each additional bit of the hash field for any length of the chain being restored. It is shown that the coefficient of the usage of the communication channel (the ratio of useful chain of packets to the volume of information transmitted through the communication channel) is maximum when the length of the hash field is 6 in the whole range of sizes of the field information part of the data packet.

Conclusion. The paper shows that the chain method is applicable for restoring the original sequence of information packets transmitted from the source to the receiver in systems where the preservation of the sequence of packets is not guaranteed. The obtained values of the transmission system parameters allow us to ensure acceptable reliability of data transmission with a minimum amount of additional service information, and achieve information redundancy less than that in similar ones by 10-15.

Thermocatalytic sensors are widely used in gas analysis systems and have high reliability and low cost. However, errors in measuring the concentration of combustible gases related to the non-linearity of the conversion characteristic and the influence of ambient temperature fluctuations significantly limit the scope of their application.

Purpose of reseach. Development of a method for measuring gas concentration by thermocatalytic sensors, which allows reducing measurement errors by tuning out due to ambient temperature influence and linearization of the conversion characteristic.

Problems. They are as follows: to develop a method for temperature stabilization of a thermocatalytic sensor; to make a structural and functional scheme for the sensor activation; to obtain a mathematical description of the method and substantitation for tuning out as a result of temperature influence; to experimentally confirm the possibility of linearization of the sensor conversion function in the thermal stabilization mode.

Methods. The mathematical description of the method applies the theory of heat transfer and the theory of electrical circuits with discrete signals. When analyzing existing solutions and synthesizing the device, methods for calculating circuits with nonlinear elements and the theory of measurement systems have been used. The real conversion function has been obtained through an experimental method.

Results. A method for measuring gas concentration by a thermocatalytic sensor with the use of a microcontroller and PWM has been developed. It allows reducing errors due to tuning out as a result of ambient temperature influence. A mathematical description of the method has been given. An experiment has been performed. It demonstrates the effectiveness of using temperature stabilization to linearize the conversion characteristic.

Conclusion. The paper proposes a method for temperature stabilization of thermocatalytic gas sensors. The method makes it possible to increase the accuracy of measurements by tuning out due to the influence of temperature fluctuations and linearization of the conversion function. The possibility of linearization of the sensor function has been experimentally confirmed. It characterizes the dependence of the output signal on the concentration of combustible gas. Using this method allows you to reduce the cost of the sensor, improve the quality factors of the sensor, such as the reliability and stability of parameters.

Purpose of research. The present paper conserns the problem of using reaction predictors in the control system of bipedal walking robots. The main advantage of using predictors is the ability to exclude unknown reaction forces from the dynamics equations and, consequently, from the robot control problem statements based on the model. An additional advantage of predictor setting of control tasks is also discussed in the paper, namely the possibility of its use to predict changes in contact interaction modes, such as slipping motion or foot lifting from the supporting surface.

Methods. The following methods are used in the research: the method of dynamics of multi-mass systems is necessary for developing a mathematical model of the behavior of a walking robot and describing its contact interaction with the support surface, the method of neural networks is used to develop a predictor that allows one to forecast the values of reactions between the robot’s foot and the surface.

Results. The paper shows that there is a connection between the frequencies of the harmonic components of robot movements (the ratio p of these frequencies in the experiment and the training sample) and the quality of reactions predictor operation of the support surface. This indicates the importance of applying a representative spectrum of walking robot movement frequencies in forming a training sample, and the poor generalizability of the predictor in relation to movement frequency.

Conclusion. The paper has considered the use of a reaction predictor to identify the possibility of changing the mode of contact interaction, based on the measurement of discrepancies between local linearizations for various discrete steps. The results obtained in this work will be used in the development of a motion control system for a bipedal walking robot, which allows the device to adapt to the parameters of the support surface on which the movement occurs.