Automatic Control System of Vacuum Nano Coating Based on AVR Single Chip Microcomputer

Aiming at the problems of long response time and poor anti-interference ability of traditional vacuum nano-coating automatic control system, a design of vacuum nano-coating automatic control system based on AVR single-chip microcomputer is proposed. The use of ATmega128L microcontroller and Harvard architecture improves the parallel processing efficiency of the microcontroller. Select the transient voltage suppression diode to protect the power supply of the single-chip microcomputer, optimize the communication circuit, connect an external encryptor to realize the data encryption function, increase the filtering program and optimize the binary code processing function. Using PID (Packet Identifier) control algorithm, the design of nano-coating vacuum automatic control system based on AVR single-chip microcomputer is realized. Compared with the traditional system, when the simulation model and system parameters of the control system constructed in the environment change, the proposed system can be stabilized within 15 seconds, and can be stabilized for 13 seconds after the interference signal is added. The response time of the system is longer. Shorter, stronger anti-interference ability, more suitable for automatic control of vacuum nano-coating.

Optimization of the precision gear grinding operation based on integrated information system

In accordance with the principles of hierarchical management, a comprehensive two-level management system is presented for the development and manufacturing of products for the stages of pre-production (the upper level of the management hierarchy) and for the actual production stage (the lower level of the management hierarchy). At the stage of pre-production, the gear grinding operation design on the “MAAG” type machines was carried out. For this purpose, a technique for optimizing the gear grinding parameters for a two dish-wheel rolling scheme has been developed, a mathematical optimization model containing an objective function with restrictions imposed on it has been created. The objective function is the gear grinding machine time, which depends on the operation parameters (gear grinding stock allowance, cutting modes, grinding wheel specification, part material) and the design features of the gears being ground (module, diameter, number of teeth, radius of curvature of the involutes). The article shows that at the stage of pre-production, the gear grinding optimization is a method of operation design. At the stage of actual production, a closed-loop automatic control system with feedback on the deviation of the adjustable value (gear grinding power) automatically supports the numerical power values that were found at the operation design stage, taking into account ensuring defect-free high-performance gear grinding (minimum number of working strokes and maximum longitudinal feeds). At this stage, i.e. when a robust longitudinal feed automatic control system is operating, the optimization carried out at the previous stage (pre-production) sets the functioning algorithm for the adaptive system with corresponding control algorithm. Thus, at the production stage (when the gear grinding machine is running), the operation optimization is a control method. Therefore, it is shown that with two-level control, the gear grinding operation optimization performs a dual function. On the one hand, it is a design method (at the pre-production stage), and on the other – a management method (at the actual production stage). With this approach, i.e. with the integration of production and its preparation based on a single two-level management, the efficiency of a single integrated design and production automation system is significantly higher due to general (unified) optimization, rather than partial one.

Application of the ARMA Model to Describe and Forecast the Flotation Feed Solids Flow Rate

The flow rate of solids is subject to random disturbances of the changing feed and can significantly affect the quantitative and qualitative parameters of the coal flotation products. This quantity can be described as a stochastic process. The paper presents the results of the solids flow rate model for coal flotation identification calculations, treated as a disturbance to the process. This is an innovative approach to modelling those quantitative parameters of the flotation feed that are measurably available and whose random changes have a significant impact on the enhancement process under industrial conditions. These include the volumetric flow rate of the feed and, in particular, concentration of solids in the feed. Therefore, it is suggested that random changes of these two parameters of the feed should be mapped using a model of one quantity—the flow rate of solids. This solution is advantageous because this quantity, as a quantitative parameter of the feed, has a significant impact on the course of the coal flotation process. The model is necessary in the process of designing an automatic control system through simulation tests. It allows us to generate a data string simulating random changes to this quantitative parameter of the feed. On this basis, in the simulation model, the correct functioning of the automatic control system is tested, the task of which is to compensate the influence of this disturbance. To determine the empirical model of the feed solids flow rate, measurement data obtained during the registration of the solids concentration and volumetric flow rate of the feed were used in four consecutive periods of operation of an industrial facility of one of the Polish coal processing plants. The time courses of the solids flow rate in the feed were described by ARMA (autoregressive–moving-average model) means, and the two-stage least squares method was used to estimate the model parameters. The results of the identification and verification of the designated model showed the correctness of adopting the third-order ARMA model, with parameters a1 = −1.0682, a2 = −0.2931, a3 = 0.3807, c1 = −0.1588, c2 = −0.2301, c3 = 0.1037, and variance σ2ε = 0.0891, white noise sequence εt, determined on the basis of a series of residuals described by the fifth-order model. It has been shown that the identified model of the flow rate of solids of the feed to flotation as disturbances can be used to develop a predictive model that allows forecasting the modelled quantity with a prediction horizon equal to the sampling period. One-step forecasting based on the determined predictor equation was found to give results consistent with the recorded values of the solid part flow rate of the feed and the extreme values of the prediction error are within the range from −1.08 to 2.90 kg/s.

Power Equipment Defects Prediction Based on the Joint Solution of Classification and Regression Problems Using Machine Learning Methods

Our paper proposes a method for constructing a system for predicting defects and failures of power equipment and the time of their occurrence based on the joint solution of regression and classification problems using machine learning methods. A distinctive feature of this method is the use of the equipment’s technical condition index as an informative parameter. The results of calculating and visualizing the technical condition index in relation to the electro-hydraulic automatic control system of hydropower turbine when predicting the defect “clogging of drainage channels” showed that its determination both for an equipment and for a group of its functional units allows one to quickly and with the required accuracy assess the arising technological disturbances in the operation of power equipment. In order to predict the behavior of the technical condition index of the automatic control system of the turbine, the optimal tuning of the LSTM model of the recurrent neural network was developed and carried out. The result of the application of the model was the forecast of the technical condition index achievement and the limiting characteristic according to the current time data on its values. The developed model accurately predicted the behavior of the technical condition index at time intervals of 3 and 10 h, which made it possible to draw a conclusion about its applicability for early identification of the investigated defect in the automatic control system of the turbine. Thus, we can conclude that the joint solution of regression and classification problems using an information parameter in the form of a technical condition index allows one to develop systems for predicting defects, one significant advantage of which is the ability to early determine the development of degradation phenomena in power equipment.

SYNTHESIS OF CONTROL SYSTEM OF ENERGY CONSUMING TECHNOLOGICAL PROCESS BASED ON D PARTITIONING

The work is aimed at solving the applied problem of developing an automatic control system for the evaporator using the principle of D-partition. Since there is always uncertainty in real problems, the solution of the problem of synthesis of the control system is reduced to the synthesis of a robust regulator. As a result, the area of robust stability of the object was obtained and an array of PI controller settings was formed, which ensures the stability of the object in the entire range of uncertainty.

Modeling of automatic control system for air supply to a bio-reactor using fuzzy control

The stages of modeling the automatic control system (ACS) for air supply to aeration with the use of fuzzy control are considered. The investigated control algorithm is based on the combination of a nonlinear controller with approximating control (CAC), whose parameters are corrected using fuzzy logic. The algorithm for correcting the CAC parameters for transient and steady state modes is based on the application of two simple rulebases (RB) with three and five linguistic terms, respectively. As a result, the required speed in the transient mode and accuracy in the steady state mode are provided. It is proved that switching the RB according to the logic of the multi-mode system is less demanding on the number of rules, structure and setting parameters of the membership function than using the extended RB. The differences between the proposed ACS with different BP for the main operating modes of the system are shown. These include: improvement of quality indicators due to the implementation of different BP in different modes; more rigorous justification of the mechanism for ensuring insensitivity to the switching moments of BP when changing modes due to the CAC of the direct circuit of the ACS. Effective implementation of the stages of ACS modeling and fuzzy controller design is possible using the Fuzzy Logic Toolbox system of the Simulink MATLAB modeling environment.

INVESTIGATION OF ADDITIONAL LOSSES OF FIBER-OPTIC CONDUCTORS OF TYPE G-652 THAT OCCUR DURING BENDING

One of the problems of modern information transmission systems is the introduction of new methods of protecting information transmitted over fiber-optic transmission lines. Currently, new methods of unauthorized access are emerging, which are being improved and developed every year. Within the framework of this work, studies of additional losses during bending of the optical fiber were carried out in order to create an automatic control system for additional losses that occur during mechanical action leading to its bending. For this purpose, practical experiments were conducted to measure losses in optical fiber with multiple bends and a computer program was created based on the data obtained. With the help of this program, it is possible to estimate additional losses in the optical fiber when the wavelength changes from 1310 to 1625 nm and the bending angle indicators from 45 to 135 degrees. The program also allows you to automatically approximate the values of additional losses occurring in the optical fiber with different variations of different bending angles and their number. The study of additional losses will allow in the future to develop an automatic control system based on changes in the indicators of additional losses and, when they change, issue a warning signal about possible unauthorized connection to a fiber-optic cable.