The article discusses the requirements for automated control systems in the production of Earth orientation devices. Various types of interferometers are analyzed for use in an automated control system for the manufacture of optical instruments for orientation of spacecraft on the Earth. An overview of the most common interferometer models is given, the characteristics and features of their schemes, development trends and manufacturers are discussed in detail. A comparison was made of the parameters of a number of imported and domestic interferometers suitable for use in an automated control system. The advantages and disadvantages of interferometers according to the schemes of Jamen, Mach-Zehnder, Sagnac, Michelson and Fizeau are considered. The Jamen interferometer was invented for the first time in 1856, to measure small refractive indices of gases. The Mach-Zehnder interferometer was developed on a similar principle, its main feature is that the beams of the rays obtained can be separated at a sufficiently large distance using a semitransparent mirror. In 1913, the Sagnac interferometer was invented; in its design, the light is divided by a semitransparent plate-divider into two beams, which propagate in a circle and are reduced by mirrors back to the divider. Albert Michelson in 1890 proposed an interferometer scheme, the basis of which is a light-splitting mirror. One of the most common is the Fizeau interferometer scheme, proposed in 1868. In this type of device, interference occurs in the gap between two reflecting surfaces. Based on the parameters of the problem under study, the choice in favor of the interferometer configuration according to the Fizeau scheme is justified. Interferometer OptoTL-60/125 from LLC "Optical laboratory" meets all the requirements.
Keywords: automated control system, laser interferometer, Fizeau interferometer, optics, photonics, optical production, interferometry
The article describes the simulation in the Simulink environment of the operation of a stepper motor used as an electric drive of the scanning mechanism for the Earth orientation device. The purpose of the study is to determine the minimum power consumption in each range of values for inductance and resistance. If the model is found to be inoperable above certain values of the specified parameters, the measurement range narrows to an area where there is enough energy to properly work out a given angle. The simulation is based on the parameters of NEMA17 engines, in particular, NEMA 17HS3410. Voltage control in the system is carried out by means of a PI controller, the influence of the regulator on the energy consumption of the system is shown. The regularities of the formation of angular velocity of various amplitudes when working out a turn in open and closed control systems are noted. The range of electrical parameters at which the engine operates with almost the same power consumption is determined. The lowest power values at which the engine is operable are found. The results of the work are visualized in the form of three-dimensional surfaces, recommendations for the continuation of research are developed.
Keywords: stepper motor, simulation, Earth orientation device, power consumption
Recognition of radiation from celestial bodies by technical means is an important task in the orientation of spacecraft. For a device that is part of the Earth orientation device, a variant of modeling an electronic signal amplifier received from a pyroelectric sensor is studied. On the recommendation of the developers, the properties of trans-impedance operational amplifiers were studied, and suitable coefficients for the negative feedback circuit were selected. The type of output signal of the model is studied in comparison with the recording of values taken from a real photodetector. The preferred design of the model in the Matlab Simulink environment is shown – a model defined by an electrical circuit using the Simscape Electrical library.
Keywords: simulation of electric circuits, space orientation, photodetecting device, transimpedance amplifier, optoelectronic devices, space instrumentation
The article reveals the results of the work carried out on modeling the dynamic model of the electric drive of the scanning mechanism of the Earth orientation device, which is based on a hybrid stepping motor. The simulation is based on NEMA 17HS3410 motor parameters. A brief description and features of hybrid stepper motors are provided. The simplest model of an electric drive is considered, in which there is a rigidly set moment of force, a moment of inertia of the rotor of an electric motor, and also the moments of dry friction and the moment of liquid friction are taken into account. It is shown how the change in the value of fluid friction affects the general behavior of the mathematical model of a hybrid electric motor. The behavior of a single-pole stepper drive is simulated. The relationship of the value of the moment of force acting on the rotor with the passport characteristics of the investigated electric motor is considered. The possibility of controlling the scanning mechanism based on P- and PI-controllers is estimated.
Keywords: electrodive, Simulink, moment of force, inetria moment, liquid fricton
The article discusses the aspects of coordination of the file formats used for recording biological signals. The primary attention is paid to the data structure and the conversions of its own format to standard formats and vice versa when conducting state tests and certification of a medical device.
Keywords: ECG, EKS, EDF, MIT-BIH, data format, data format conversion, electrocardiogram
in article the algorithm of a posteriori calculation of heart rate on record EX. The algorithm produces the allocation of QRS complex for R-teeth, the classification of complexes into two types: normal and artifact complexes. It is proposed to classify the analysis of contours and measurement of interference at the frequency of 50 Hz. This classification can significantly improve the measurement accuracy of the instantaneous heart rate compared to the moving average
Keywords: frequency of cardiac abbreviations, RR interval, QRS complex, Holter monitoring, selection of artifacts of the FORMER, the algorithm for calculating heart rate, contour, RR–interferometry
The article describes the role of reduced order models (ROM) in MEMS design & testing, reflects their advantages in comparison with the finite element method (FEM) full models for real-time behavioral modeling of MEMS dynamic characteristics and versatile research of the objects' properties. The mathematical interpretation of the procedure for reducing the system dynamics equations order by switching from the full model presented in the form of state variables equations to the ROM state variables equations is given, the four existing scientific methods for reducing the FEM model order are presented in generalized form. The particularities of embedded ANSYS software capabilities application to automatically generate the ROM from the original full FEM model with lower computer power requirements and the preservation of the original model accuracy in the presence of only the structural mechanics are set out in details. Two equal algorithms for further work with the ROM in MatLab software in order to simulate the MEMS dynamics and study time and frequency properties of the model are presented: by designing the scheme consisting of prearranged Simulink function blocks and by writing an M-file program listing using the special MatLab programming language. Scientific novelty of the results is the combination of the methods for MEMS design (system of partial differential equations, ANSYS program) and behavioral modeling (system of ordinary differential equations, MatLab program) that can significantly reduce the complexity of the FEM model adaptation to the real-time modeling and eliminate computation errors.
Keywords: micro-electro-mechanical system, finite element method, behavioral modeling, reduced order model, ANSYS, MatLab
The article describes the slow flying drones with reference to problems of aerial photography. As an alternative to multicopter proposed aerodynamic design, elliptical flying wing. It has been shown that this scheme allows ensure uniform distribution of lifting force along the wing span, respectively, does not allow on loss of unmanned speed bogged down into a tailspin. The results of mathematical modeling and flight test a prototype of this type of UAV.
Keywords: unmanned aerial vehicle; elliptical wing; control laws; mathematic modeling; drone aircraft
The solution of the navigation problem on the basis of integration of inertial-satellite navigation systems, complexed with odometer, in the general case - without simplifying assumptions about the object model of its trajectory, etc. The effectiveness of the solution with the loss of satellite signals is illustrated by numerical experiment.
Keywords: tight integration, inertial - satellite navigation systems, odometer, nonlinear Kalman filter, continuous-discrete filtering
Solution of the problem of navigation on the basis of integration of inertial-satellite navigation systems, complexed with odometer, and the approximation of the trajectory of motion of the object by means of electronic charts (EC) set of great circle paths. Given the discrete nature of satellite measurements of the parameters of motion estimation is carried out by successive application of two non-linear Gaussian filters: continuous - the interval between satellite measurements (including at their failure) and discrete-continuous - when they occur. Thus obtained estimates of the parameters of motion implemented in the great circle path, having a minimum dimension, provide fundamentally accurate snap estimated coordinates to the true path of movement defined by the EC.
Keywords: tight integration, inertial-satellite navigation systems, odometer, e-cards, great circle path, a Gaussian filter
This article deals with the problem of adaptive threshold for the allocation of R-wave with Holter. Considered one of the embodiments of the microcontroller detection algorithm R-wave. Based on this algorithm, the analysis of the stability at two variants prediction threshold and different coefficients. Obtained plots of the stability of the algorithm on the selected coefficients.
Keywords: microcontroller, Holter ECG, QRS - complex ehlektrokardiosignala, adaptive threshold, the allocation of R-wave, electrocardiography, the algorithm adjust the threshold.
The article deals with interference suppression algorithms that arise in the ECG signal by moving of the electrodes due to the motion of the object. It is proposed to use an adaptive filter, which reference signal is provided by the data triaxial accelerometer.
Keywords: electrocardiogram, adaptive filtering, motion artifacts, electrophysiological signal adaptation algorithm
In this paper we consider the application of digital signal processing techniques to clean them from interference and to present in a special basis, which allows the detection of events related to the manifestation of the functioning of a functional system in health and disease. Implemented mathematical foundation and rapid synthesis methods for converting the signals used in electrophysiology based on the discrete wavelet and Gabor transforms. Filter synthesis using Filter Desing ToolBox package MatLab was observed.
Keywords: digital signal processing techniques, rapid synthesis methods, discrete wavelet transform, Gabor transform