Algorithmic support of low-altitude aircraft flight based on the hazard analysis of the flight situation

Low-altitude flight of an aircraft is an effective, but at the same time, a very complex tactical technique, during which the crew does not always have the opportunity to timely recognize the occurrence of an abnormal case, determine the way out of it and counteract an aviation accident development. Despite many advantages of the automatic mode of low-altitude flight performing, its practical implementation is associated with a number of features and disadvantages, which determined the preference for the manual mode of low-altitude flight control. These are the presence of telltale factors, limited ability of performing flights at night and in difficult weather conditions, insufficient reliability etc. The considered features determined the relevance of the of low-altitude flight safety ensuring problem in relation to the manual control mode. As a result of an experimental study of the low-altitude flight performing process in a manual control mode, it was found that when performing manually-controlled low-altitude flight, a hazard assessment of the flight situation becomes pivotal. However the crew being under such conditions is not always able to correctly assess the flight situation hazard due to a combination of objective reasons. The current state of the adaptive and on-board flight safety systems theory makes it possible to increase the safety of the manuallycontrolled low-altitude flight by using adaptive control algorithms based on the flight situation hazard assessment. To solve this problem an adaptive control algorithm is proposed that ensures the formation of a security corridor in the longitudinal control channel, where the upper limit is determined by the critical value of the aircraft detection hazard, and the lower limit is determined by the critical value of the error in maintaining a given flight altitude. For a continuous assessment of the flight situation hazard and the timely formation of control signals the complex information about the current true flight altitude and the foreground is needed. Taking into account the peculiarities of low-altitude flight a digital terrain map containing data on natural and artificial obstacles along the flight route is a more rational source of information, that will make it possible to predict the development of the flight situation hazard. The above reasoning makes it possible to form an aircraft low-altitude flight adaptive control algorithm. A distinctive feature of the proposed algorithm is the implementation of a combined control variety where the pilot is provided with ample manual control opportunities within the security corridor, and the automatic flight control system is assigned the role of a safety subsystem that ensures control and timely return of the flight situation to normal flight conditions. The presented algorithm will allow to increase the crew logical-analytical activity information support during continuous analysis of the existing flight situation due to the formation of protective control actions based on the current flight situation hazard analysis.

Ensuring the secrecy of the radar

The article deals with the issue of stealth of radio-electronic means, energy and structural, radio-electronic masking and ways of its implementation. The structure of the unknown signal for exploration and its parameters, as well as the a posteriori probability of each signal associated with the a priori likelihood function and the cases of its solution. The advantages and disadvantages of broadband signals and their characteristics used in modern radars are considered. On the basis of which conclusions are drawn: LFM radio pulse and a single FCM pulse, used in target tracking modes, has high resolution capabilities in range and radial velocity. The ACF of the FCM pulse has side lobes that raise the target detection threshold, as a result of which radar targets with a weak echo signal can be missed. The considered signals do not provide energy and structural stealth of the radar operation.

Method for building a model of the functioning of the on-board equipment of spacecrafts based on a classification scheme of interactions of subsystems

In this paper, a promising approach to solving the problem of adaptive-distributed control of the technical condition of onboard equipment of spacecraft based on the classification scheme of the mutual influence of subsystems is determined. Purpose is to improve the efficiency of autonomous monitoring of the technical condition of spacecraft on-board equipment. The proposed method for constructing a model of the functioning of onboard equipment of spacecraft made it possible to obtain a classification scheme for the mutual influence of subsystems of onboard equipment, the use of which as a vehicle control model provides semantic compression of telemetric information. The idea of creating a special software for advanced on-board control systems with the function of adaptive-distributed control of technical condition is proposed. The possibility of using the methodology is not excluded when constructing a model of the operation process of on-board equipment for objects of various purposes, including as an element of an artificial intelligence system when solving the problem of monitoring a technical condition.

Structural-parametric synthesis of the tracking filter based on decomposition by the target functional with adaptation to trajectory disturbances

Traditional Kalman-type tracking filters are based on a kinematic motion model, which leads to the occurrence of dynamic errors, which significantly increase during target maneuvering. One of the solutions to this problem is to develop a model of motion dynamics with the ability to adapt its structure to external influences. It is shown that the use of a dynamic model of motion in the filter, which takes into account the inertia of the target and the forces acting on it, makes it possible to significantly increase the efficiency of the state assessment. Purpose is to development of an algorithm for assessing the position of a maneuvering object, effective in terms of accuracy criterion. The use of an adaptive motion model as part of the filter provides an increase in the estimation accuracy in comparison with the classical Kalman filter, which is confirmed by the performed numerical modeling.

Model of the functioning of the optoelectronic information system for detecting space debris

To determine the characteristics of optoelectronic devices, as a rule, models are used that do not take into account the peculiarities of the functioning of information tools, the conditions of visibility and observability, which does not allow to reliably assess their capabilities to obtain coordinate and non-coordinate information. Goal of the work is to investigate the model of an optical-electronic information tool in order to evaluate the characteristics and determine the possibility of obtaining coordinate and non-coordinate information in various conditions. A block model of a system for monitoring space debris in near-earth space by means of optical-electronic information means is considered. A structural diagram of the model's constituent parts is proposed. It is shown that the position of an object in the composition of space debris is determined based on the solution of the above differential equations. The interrelation of the influence of various conditions on the capabilities of optoelectronic information facilities, on the processes of detection and tracking is described. The equations and relationships underlying the model of operation of the optoelectronic information facility are described. The results of modeling are presented, which allow planning the rational placement of optoelectronic information facilities. The presented model makes it possible to obtain initial data for planning the rational placement of optoelectronic information facilities and to substantiate the requirements for their technical characteristics.

Substantiation of selection and dimension reduction of non-centered informative features of signals in information systems of short-range location

In this paper, we consider the issues of selection of informative features, dimension reduction of feature vectors in regression algorithms of detection and recognition of signals and interference, as well as the issues of obtaining informative features using neural network algorithms with ill-conditioned data. The problem is considered in relation to the short-range location, with large dynamic ranges of informative features and small decision intervals, when it is impossible to estimate mathematical expectations, that is, it is impossible to use adaptive algorithms. Regression algorithms for processing non-centered random signals are presented, with a priori unknown mathematical expectations of informative parameters, which consider the specificity of short-range location and use a priori information about the initial regression characteristics of informative features – multiple initial regression coefficients. Unlike it is in traditional regression analysis, the coefficients are determined through the elements of the matrices that are inverse to the matrices of the initial correlation moments. In regression algorithms, it is necessary to calculate the square error of multiple initial regression representations. The residual mean of squares of the initial regression representations are used to justify the methods for selection and dimension reduction of informative features of signals in the problems of detection and recognition of signals and interference. We give examples of application of the proposed methods for the problems of detection and recognition of a helicopter and airplane by acoustic signals when processing histograms of the distributions of the durations of intervals between zeros, samples of envelopes and samples of local extrema of the power spectral density. Good separability of the {airplane} and {helicopter} classes in the space of non-centered parameters of signals (features) is shown. The issue of obtaining regression statistical characteristics with illconditioned data is considered. If the matrices of the correlation moments of the informative features of signals and noise are illconditioned, it becomes impossible to obtain a priori information about the multiple initial regression coefficients. The possibility of using neural network algorithms to obtain estimates of the residual mean squares of regression representations and multiple initial regression coefficients through the weight coefficients on the inputs of neurons with ill-conditioned data is shown. The results can be used in short-range location systems with a large dynamic range of non-centered informative parameters, when it is not possible to estimate the mathematical expectations of the signal parameters due to the limited observation interval.

Peculiarities of making decisions on the choice of the composition of the main hardware equipment of aviation multifunctional simulators

The current stage of training aircraft crews (AC) is characterized by the predominance of training tasks solved with the help of aviation multifunctional simulators (AMT). AMT covers a wide range of aviation simulators designed to solve problems of planning and managing the use of hardware and software resources in solving various training tasks in the interests of training aircraft crews. Based on this, AMT are characterized by a variety of hardware that ensure the implementation of technological operations and processes for analyzing and processing information when performing educational tasks, which determined the relevance of the task of choosing their optimal composition. Purpose of the work is to develop a model for choosing the composition of hardware equipment (HSS) in the AMT structure for solving training tasks in the interests of training aircraft crews. The solution to the optimization problem of substantiating the CAO is based on the analysis of the features of the application and development of AMT based on the modernization of obsolete and new hardware equipment. The complexity of the task is due to significant computational difficulties arising from the need to provide various technological operations and cycles of information flows in the form of a certain set of elementary operations and the presence of “individual” quality criteria for each educational task. To solve it, the technological process of solving educational AMT is represented by an oriented graph, the vertices of which are the tasks to be solved, and the arcs connecting them are elementary technological operations implemented by hardware. The fulfillment of each educational task is based on the fulfillment of a certain set of elementary streams based on the implementation of the compared CAO options in the AMT structure. The search for a solution is carried out on the graph using a three-level model based on finding optimal solutions to cover the educational tasks to be solved with the available means of obsolete hardware equipment, justifying the required number of new (developed) tools and choosing their optimal composition in the AMT structure as a whole, taking into account the preferences of the persons taking decision (decision maker). The proposed methodological approach and the model for choosing the CAO that implements it provide a sequential and level-bylevel solution of optimization problems with extreme variables for a reasonable choice of the decision maker of the optimal composition of hardware in the AMT structure in the interests of solving a variety of diverse training tasks for training aircraft crews.

A mathematical model of the functional reliability of radio electronic means, taking into account their predicted technical condition

The requirement for the adaptability of mathematical models of systems for processing technical information and functionality (SOTIF) of radio electronic means (RES) should be understood as the need to take into account the main features of the RES in the system model, as well as the complexity (a large number of elements, multi-mode, etc.) and a significant difference in elements RES by the nature of the degradation processes occurring in them, manifested in the differences in their probabilistic characteristics of reliability. The mathematical model of SOTIF RES should take into account the fact that, on the one hand, the real properties of the reliability of the RES may change in the process of targeted use under the influence of external factors, and on the other hand, the available information on the reliability of the RES is always incomplete and inaccurate. Therefore, it is necessary that the mathematical model of the system provides for the possibility of entering additional (a posteriori) information and recalculating the previously found optimal terms and volumes of technical impacts. Goal of the work is to form a reflective model of the change in the state of the RES with the features and at the same time the difficulties of the need to use the composition of the distribution laws, including the a priori and empirical (a posteriori) components. An approach is proposed, according to which, as elements of the REM sample, parts of the equipment are distinguished, which are covered by the influence of given preventive operations. The distribution laws of the operating time to failure of the selected elements can be specified by any functions corresponding to increasing (or increasing on average) functions of the failure rates. In the developed model, the empirical component, in turn, includes two components due to structural and parametric failures (structural and parametric components). A mathematical model of the functional reliability of the RES has been developed and the information-significant characteristics of the reliability of the RES have been demonstrated.

Model of classification of observation objects under conditions of intersection of their motion paths based on joint analysis of trajectory and polarization information

Currently, one of the topical issues arising in the functioning of radar stations for various purposes is the issue of tracking complex targets, namely the case of crossing the trajectories of several observation objects. When intersecting trajectories of objects, there is uncertainty in the presence of numerous elevations caused by reflections from a plurality of reflecting surfaces or areas of space, which leads to entanglement of trajectories, that is, the detected object is accompanied by a radar along the trajectory of another object. It is also possible to trace the second object along the trajectory of the first. This case is a special difficulty, as it leads to maintenance disruptions, loss of objects and their omission. At the same time, at the classification stage, an object can be assigned to a class to which it does not belong. Therefore, how to achieve a reliable classification of objects requires the development of methods for assessing its performance. To do this, a scientific and methodological apparatus for checking the quality of radar operation was developed (in which only trajectory information was analyzed at the first stage, and joint analysis of trajectory and polarization information was carried out at the second stage), which is a simulation model implemented in the software environment MathCad 15.0. The simulation results show that with an increase in the number of tracked objects and a decrease in the distance between them, the value of the classification quality indicator decreases. This indicates a contradiction between existing processing methods and classification quality requirements and indicates the need to develop new methods that provide a given quality indicator. A possible tool to resolve the contradiction may be the use of polarization information in order to ensure the required probability of correct classification of objects, namely, when identifying elevations and extrapolating trajectories at the stage of tracking objects of observation. In order to solve the problem, the initial data for the model of classification of objects were polarization scattering matrices, on the basis of which polarization parameters were calculated and object features were formed. The results of the simulation show that the use of polarization information when tracking a large number of objects (from 10 trajectories and their intersection) provides the required level of classification quality for existing algorithms. The increase in the probability of correct classification ranged from 8% (at the edges of the radar viewing area) to 12% (in the center of the directional pattern).

Application of the augmented reality method in training of radio engineering students

Third quarter of 2021 was marked by the appearance of technologically mature augmented reality (AR) equipment, which is positioned by the leaders of all leading IT companies as the next wave of radical changes in digital technology after the spread of smartphones. The process is accompanied by the beginning of the introduction of AR in education, applications of this kind are becoming widespread. Due to the comparative novelty and attractiveness for users, the educational practice of AR is ahead of the accompanying research activity. Despite the already existing large volume of publications on this topic, most of them are preliminary, dedicated to certain private aspects. A very problematic, although natural for a new technology, circumstance is the lack of publications on the consequences of long-term use of this tool in training. At the same time, there is no doubt that there is a significant potential for improving the efficiency of educational processes via AR, especially in university practice and when teaching students of radio engineering specialties. In the Russian Federation, there is a noticeable lag in the application of augmented reality technology in educational practice for students of specialties that are not directly related to software development. The purpose of this paper is to fill in this didactic gap in radio engineering education. The paper highlights the practice of using an augmented reality application for smartphones in the educational process for three months in 2021 at Moscow State Technical University of Civil Aviation. The specific capabilities of virtual and augmented reality technologies are correlated, the expediency of their use in education compared. The results of a long-term educational application of augmented reality are shown. The paper allows to identify promising problems of using augmented reality technology in radio engineering education from a research perspective, as well as to formulate didactic recommendations.