On-board Equipment Research Articles

Control Systems Synthesis of Maximum Robust Stability Degree Based on Vertex Critical Root Diagrams

The article solves the problem of operative selection of the redundant onboard equipment complex components configuration of the suitable in the current operating conditionаs in the interests of ensuring high fault tolerance of the complex, as well as achieving other operational and technical characteristics. The basis of the redundancy management system of the complex consists of configuration supervisors — as program subjects according to the number of its competitive configurations of heterogeneous and nonuniform equipment worked out in advance. The choice of the preferred configuration is proposed to be carried out by performing multi-level arbitration, which includes two phases of paired arbitration of computers and paired arbitration of configuration. It is proposed to include the means of both types of arbitration in each configuration supervisor, which ensures its self-sufficiency when participating in a competitive selection. The second part of the article is devoted to the computer’s arbitration for the implementation of redundancy management functions. The approach is applicable to a computing environment with many comparable computing devices and contains 2 phases. In the first phase, a preliminary selection of a competing pair of computers — as applicants for the implementation of redundancy management functions in them is carried out. In the break between the phases, the pair computers implement the procedures for pair arbitration of configurations given in the first part of the article. In the second phase, the final choice of the -computer is made, in which the supervisor who won the arbitration will be implemented. In order to achieve the maximum possible centralization of selection procedures and, as a consequence, the exclusion of " bottlenecks" in terms of reliability of places, additionally proposed: the organization of secure data exchange between computers based on distributed registry technology; the procedure of paired arbitration of computers, consisting in mutual cross-validation of dominant supervisors of a pre-allocated pair by comparing preference matrices, including information parcels of arbitration objects. A methodological example that demonstrates the features of the system functioning in the conditions of computers degradation is given. The proposed approach can be used to solve the problems of reconfiguration control of heterogeneous computing facilities of technical objects on-board equipment complexes.

Design and research of train-centric autonomous control CBTC system

Existing CBTC systems suffer from a number of limitations, some of which include convoluted communication between the ground and trains, costly construction, and high costs associated with the installation of ground equipment. The purpose of this study is to further improve the operational efficiency of a train-centric autonomous CBTC system by analyzing the system design, control principles, and module functioning. The planning of ground and onboard equipment will be the main research objects of the novel system. When compared to conventional CBTC systems, the TACS architecture, most notably in the OC and train-train communication modules, changes the control mode from ground-centric to train-centric. This results in an increase in the overall efficiency of the system, and a new train operation scenario of the virtual coupling is introduced to increase the flexibility. The TACS architecture that was designed paves the way for the engineering advancement of the system and establishes the groundwork for it.

METHOD OF CALCULATING THE UNSTATIONARY TEMPERATURE FIELD PARTS OF THE SPHERICAL FORM OF THE STRUCTURE FLIGHT APPARATUS OF UNMANNED AVIATION COMPLEXES

The design of unmanned aircraft vehicles during operation is exposed to significant temperature effects, which causes changes in the dielectric characteristics of radio technical elements and can lead to failures of on-board radio electronic equipment, as a result of which the task of determining the amount of temperature change in the compartments where the radio electronic equipment is located is performed. At the same time, some external elements of the aircraft vehicle can have complex structures with shapes close to spherical and different thicknesses in each cross-sectional structure.
 There is a need to develop a method for calculating the non-stationary temperature field with the purpose of finding out the real conditions in which all the elements of the aircraft structure work, which would help to determine how the temperature of the structure changes during any flight. At the same time, it is necessary to take into account the three dimensions of temperature gradients on spherical parts of structures of various shapes, namely nose part, rounded wing and others. In them, as a rule, each cross-section of the wall has its own thickness and, according to each cross-section, the temperature distribution along the thickness of the wall will correspond, that is, it is necessary to ensure the redistribution of temperature along the structural element, the calculation of which month. In addition, it is necessary to note that the wall of the aircraft can be multi-layered and the properties of its material can change along with the change in temperature. Considering the fact that it is impossible to take into account all the listed features by analytical methods, when choosing a calculation method, it will be advisable to stop at numerical methods.
 One of the most well-known numerical methods is the finite difference method with an implicit calculation scheme, which has an indisputable advantage for modeling - absolute stability with sufficient changes in time and coordinate steps. We will use the level of thermal conductivity in spherical coordinates in order to increase the accuracy of the calculation, for which solution, after finding out the boundary conditions, we will perform a one-dimensional calculation of the temperature by thickness in each mesh section of the structure, and also perform a calculation of the two-dimensional "heat flow" along the solid between the points, that are located on the same thickness, but have a temperature difference. Thus, when calculating the temperature field, the sphericity and multi-lay redness of the structural elements is taken into account, and the property of the material of the aircraft structure changes depending on the temperature.

Virtual sample generation for model-based prognostics and health management of on-board high-speed train control system

In view of class imbalance in data-driven modeling for Prognostics and Health Management (PHM), existing classification methods may fail in generating effective fault prediction models for the on-board high-speed train control equipment. A virtual sample generation solution based on Generative Adversarial Network (GAN) is proposed to overcome this shortcoming. Aiming at augmenting the sample classes with the imbalanced data problem, the GAN-based virtual sample generation strategy is embedded into the establishment of fault prediction models. Under the PHM framework of the on-board train control system, the virtual sample generation principle and the detailed procedures are presented. With the enhanced class-balancing mechanism and the designed sample augmentation logic, the PHM scheme of the on-board train control equipment has powerful data condition adaptability and can effectively predict the fault probability and life cycle status. Practical data from a specific type of on-board train control system is employed for the validation of the presented solution. The comparative results indicate that GAN-based sample augmentation is capable of achieving a desirable sample balancing level and enhancing the performance of correspondingly derived fault prediction models for the Condition-based Maintenance (CBM) operations.

Некоторые выводы по результатам применения конструкторско-технологического анализа надежности для изделий ракетно-космического назначения. Часть 2

The paper generalizes results of introducing procedures of reliability design and technological analysis (RDTA) in the one-time actuation mechanisms of the spacecraft rotary structures (hereinafter referred to as the mechanisms). It provides principles of the mechanisms design and examples of establishing the design documentation requirements in their design process. The differences between processes of the mechanism design and construction are presented, and examples of design and technological factors that could lead to potential failures of such mechanisms are given. Principles of substantiating the spacecraft onboard equipment performance and reliability are considered. Commonality and differences in substantiating performance and reliability of mechanisms and of other onboard equipment of spacecraft are provided. As a result of the RDTA introduction, it was revealed that methods were missing in substantiating performance and reliability of the products for various purposes that were different in form. Only the content of engineering tasks that ensured fulfillment of their service purpose was varying. Moreover, solutions to such problems could be verified using the formalized procedures in reliability design and technological analysis.

Fault classification method for on-board equipment of metro train control system based on BERT-CNN

Fault classification method for on-board equipment of metro train control system based on BERT-CNN

Model for Monitoring the Technical Condition of Onboard Equipment of Space Vehicles Based on the Telemetry Parameters of Transient Processes

Model for Monitoring the Technical Condition of Onboard Equipment of Space Vehicles Based on the Telemetry Parameters of Transient Processes

Using Software-Defined radio receivers for determining the coordinates of low-visible aerial objects

The object of this study is the process of determining the coordinates of low-visible aerial objects. The main hypothesis of the research assumed that the signals emitted by airborne systems of airborne objects that are not visible to radar stations have a greater power than the signal reflected from the airborne object. This, in turn, could improve the signal/noise ratio and, accordingly, the accuracy of determining the coordinates of low-visible aerial objects. It is suggested to use Software-Defined Radio receivers to receive such signals emitted by on-board systems of low-visible aerial objects. It was established that the main sources of signals for Software-Defined Radio receivers are signals of command, telemetry, target channels, manual control channels, and satellite navigation. It was established that an additional distinguishing feature when determining the coordinates of low-visible aerial objects is the uniqueness of their spectra and spectrograms. The method of determining the coordinates of low-visible aerial objects when using Software-Defined Radio receivers has been improved, which, unlike the known ones, involves: – the use as signals for Software-Defined Radio of signal receivers of on-board equipment of low-visible aerial objects; – the use of a priori coordinate values of a low-visible aerial object; – conducting additional spectral analysis of signals of on-board systems of low-visible aerial objects. The spectra and spectrograms of signals of on-board systems of aerial objects when using non-directional and directional antennas were experimentally determined. The experimental studies confirm the possibility of using the Software-Defined Radio receiver to receive signals from airborne equipment and improve the signal-to-noise ratio. The accuracy of determining the coordinates of aerial objects when using Software-Defined Radio receivers was evaluated. A decrease in the error of determining plane coordinates by the Software-Defined Radio system of receivers compared to the accuracy of determining coordinates by the P-19 MA radar station was established by an average of 1.88–2.47 times, depending on the distance to the aerial object

Двукратно резервированный твердотельный усилитель СВЧ-мощности для бортовой аппаратуры космических аппаратов

The paper considers a block diagram, known constructions, and proposed design of a twofold reserved solid-state microwave power amplifier (RSSPA) for space-craft onboard equipment. Modern requirements of the RSSPA to a thermostatically controlled plate (TCP) used to remove heat from only one amplifier of the RSSPA are stated. The advantages and disadvantages of “two-storey” constructions and design with vertical positioning of power amplifier boards with respect to the TCP are shown. The paper proposes the RSSPA, in which its components with a high heat dissipation and the components directly connected with them are placed on the base of the RSSPA case mounted on the TCP via a thermally conductive pad, and all other components are placed on the side walls of the case. Its design is simpler and lighter. The proposed RSSPA is perspective for spacecraft onboard equipment including command and measurement systems.

Mounting Frame Design - an Integrated Approach Through Analysis and Testing

The Mounting frame, a structural unit to house the on-board electronic equipments, has been designed and analyzed. Due to the imposed vibration environment, it is essential to impose constraints of not having any resonance of equipped mounting frame within certain frequency bands. A basic design is evolved and a free vibration analysis using finite element method has been carried out. However results of environmental tests have shown unacceptable grms value, detrimental to certain passengers on the frame. Significant contribution from higher mode to overall grms is observed . Necessary design modifications have been carried out based on analysis and testing. Final design got. validated using environmental testing and is used in the flight analysis and testing. Final design got validated using environmental testing and is used in the flight.

On-Board Multi-Class Geospatial Object Detection Based on Convolutional Neural Network for High Resolution Remote Sensing Images

Multi-class geospatial object detection in high-resolution remote sensing images has significant potential in various domains such as industrial production, military warning, disaster monitoring, and urban planning. However, the traditional process of remote sensing object detection involves several time-consuming steps, including image acquisition, image download, ground processing, and object detection. These steps may not be suitable for tasks with shorter timeliness requirements, such as military warning and disaster monitoring. Additionally, the transmission of massive data from satellites to the ground is limited by bandwidth, resulting in time delays and redundant information, such as cloud coverage images. To address these challenges and achieve efficient utilization of information, this paper proposes a comprehensive on-board multi-class geospatial object detection scheme. The proposed scheme consists of several steps. Firstly, the satellite imagery is sliced, and the PID-Net (Proportional-Integral-Derivative Network) method is employed to detect and filter out cloud-covered tiles. Subsequently, our Manhattan Intersection over Union (MIOU) loss-based YOLO (You Only Look Once) v7-Tiny method is used to detect remote-sensing objects in the remaining tiles. Finally, the detection results are mapped back to the original image, and the truncated NMS (Non-Maximum Suppression) method is utilized to filter out repeated and noisy boxes. To validate the reliability of the scheme, this paper creates a new dataset called DOTA-CD (Dataset for Object Detection in Aerial Images-Cloud Detection). Experiments were conducted on both ground and on-board equipment using the AIR-CD dataset, DOTA dataset, and DOTA-CD dataset. The results demonstrate the effectiveness of our method.

An energy harvesting shock absorber for powering on-board electrical equipment in freight trains

To realize smart detection and safe operation of freight trains, a continuous and stable energy source is required for electrical equipment on the train. It is a feasible scheme to harvest the vibration energy of train suspension to supply power for on-board electrical equipment. This paper presents an energy-harvesting shock absorber (EHSA) based on the slider-crank mechanism and ratchet-pawl mechanism, which provide a vibration reduction effect and renewable electricity. To determine the damping performance and the power generation performance of EHSA, a dynamic model is established based on MATLAB. According to the tests on the mechanical testing and sensing (MTS) bench, the maximum power generation mechanical efficiency of the EHSA is 67.75%, and the maximum output power of the EHSA is 1.65W. In addition, the charging tests on the MTS bench show that the proposed device is applicable to power on-board electrical equipment on freight trains.

APPLICATION OF WIRELESS COMMUNICATION AND TECHNICAL VISION TECHNOLOGIES TO IMPROVE AVIATION SEARCH AND RESCUE OPERATIONS

The subject of research in the article is approaches to improving the onboard equipment of a search and rescue aircraft (AC). The purpose of the study is to develop proposals for improving the technical means of searching for aircraft that have suffered an accident, namely video surveillance systems and information transmission to the control centers (CC) of the search and rescue operation, based on the analysis of the Rules for Search and Rescue Support of Flights of the State Aviation of Ukraine and foreign experience in search and rescue operations. It is proposed to use a light multipurpose helicopter of the Mi-2 type as a search and rescue aircraft (SRAC). The work solves the following problems: studying modern approaches to ensuring aviation search and rescue operations; analyzing technical means of ensuring the search for crashed aircraft; developing proposals for a method of transmitting information from the airborne control center to the ground control center; selecting a suitable carrier for special equipment and individual samples of video surveillance and data transmission systems. The method of comparative analysis is used to solve partial problems. The following results have been obtained: the requirements for the search characteristics of SRAC are determined, in particular, it is proposed to use a light multipurpose helicopter as SRAC; a scheme for organizing communication with the search operation control center using wireless communication technologies is presented; specific requirements for individual components of SRAC onboard special equipment are formulated. Conclusions. The introduction of wireless communication technologies together with thermal imaging equipment will increase the speed and efficiency of searching for crashed aircraft, especially at night and in conditions of limited visibility (fog, smoke). In addition, the range of tasks of light helicopters such as the Mi-2 is expanding, and the number of both onboard and ground operators directly using thermal imaging equipment (infrared camera) to determine the location of the crash is increasing. In this case, the total number of personnel involved in search and rescue operations is not affected.

Fault diagnosis of train control onboard equipment based on Attention-Capsule Network

The onboard equipment of the train is a key component to ensure the safe and efficient operation of the train. Therefore, improving the fault detection ability of onboard equipment is crucial for the safe operation of trains. The driving log record file (AE-LOG) was generated by the CTCS-300T series control system (AE-LOG) as the starting point, and the improved capsule network (CAPSNET) as the research method was studied. By using the capsule network, this model greatly improves the attributes of text characteristics in high-dimensional space and low-dimensional space. At the same time, the routing method of the fusion attention mechanism is used to improve the efficiency of feature selection. Through experimental verification of operating data provided by a certain road bureau, and comparing with traditional models, the accuracy of the model in the control vehicle device fault diagnosis of the control of the vehicle is significantly improved, which shows the effectiveness of the model.

CONSIDERATIONS FOR OPTIMIZING THE FLIGHT PERFORMANCE OF miniUAVs

Unmanned aerial vehicles benefit from a series of mature technologies that transform them into data acquisition, processing and dissemination tools with high levels of impact on areas of interest and great utility for users. The paper exposes the stages of analysis regarding the upgrade process of UAV (ATM-1) from the variant of equipping a target aircraft to a superior variant that can be used for data collection, from areas of interest, in the form of static or dynamic images. The proposed variant has implications both on the air vector balance and on the performance of use due to the new onboard equipment.

DESIGN AND TECHNOLOGY SYSTEM FOR DEVELOPMENT AND OPERATION OF ULTRALIGHT SUBORBITAL ROCKET COMPLEXES

Abstract. Vehicles are called suborbital if they either move along a ballistic trajectory with a flight velocity sufficient to reach altitudes of up to 100 km or more, but insufficient for becoming an orbiter, or fly to altitudes of 100 km or more strictly vertically, but do not become artificial satellites of the planet, even if they reach sufficient velocity at some point. In both the first and second cases, this will be considered a space flight if its height exceeds 100 km (the Kármán line). Despite the active development of the suborbital rocket science in the world as a means of solving many scientific and technical problems in the space and defense industries, scientific research and engineering education, the development of suborbital rocket science in Ukraine has so far remained, at best, at the level of achievements of the 1960s and 1970s and has been supported by numerous amateurs. This article presents the results of the creation and development of a design and technological system for the development and operation of ultralight suborbital rocket systems as the basis for the creation of new models of domestic space rocket systems, rocket and missile weapons systems, the development of innovative technologies in the field of rocket science in general, practical training of highly qualified specialists for the space industry. This paper presents structural and layout diagrams of the developed suborbital rockets, design and technological solutions for the creation of on-board radio-electronic equipment and rocket engines, design modeling, bench and flight tests. The presented design and technological system is already used today at Oles Honchar Dnipro National University for comprehensive practical training of specialists in the field of creation and operation of rocket technology and missile and rocket weapons.

Model for monitoring the technical condition of onboard equipment of space vehicles based on the values of telemetered parameters of transient processes

Model for monitoring the technical condition of onboard equipment of space vehicles based on the values of telemetered parameters of transient processes

Lithium-ion battery state of health estimation based on multi-source health indicators extraction and sparse Bayesian learning

A concise and accurate method for estimating the state of health (SOH) of lithium-ion batteries in the on-board energy management system is critical. However, SOH cannot be directly measured by on-board equipment. To improve the accuracy of SOH estimation for Li-ion batteries, this work proposes an SOH estimation model based on multi-source health indicators (HIs) extraction and sparse Bayesian learning. First, four direct HIs are extracted from the voltage and temperature curves of the batteries during charging and discharging, and two indirect HIs are extracted from the incremental capacity curves in combination with a Gaussian filtering algorithm. Then, the datasets are divided into three different training and test sets, which are used to simulate online SOH estimation under different situations. Finally, the six extracted HIs are selected using the Pearson correlation coefficient method, and the experiment is repeated for one of the situations using the three higher correlation features, and the results before and after selection are compared. The experimental results show that the proposed model can achieve satisfactory results in various simulated online estimation situations on the NASA and Oxford datasets.

A real-time vital control module to increase capabilities of railway control systems in highly automated train operations

Recent advances in technology and railway have led to the introduction of systems and infrastructures capable of driving trains automatically. The Automatic Train Operation (ATO) system has been optimized for active human supervision. The next challenge is to realize ATO systems capable of achieving unsupervised operations on the mainlines. However, at this aim, additional safety functionalities should be provided. In this paper, we propose a pioneer hardware/software Vital Control Module (VCM) architecture capable of expanding the control capabilities of the existing train control system. The VCM includes a Printed Circuit Board (PCB), to be integrated into the cabin equipment, managed by a reliable and safe hard Real-Time Operating System (RTOS). Both hardware and software are developed to be compliant with related safety standards. The VCM integrates an application logic that acts as an on-board equipment control core, assessing the overall operativity in real-time, and promptly issuing emergency brakes if hazardous situations occur. The application logic has been developed with a model-based approach via Simulink/Stateflow tool and implemented as a C-script on the Xilinx Ultrascale + core housed on the PCB. We have used two testbeds to evaluate the VCM performance. Experimental results showed that the Worst-Case Response Time (WCRT) by the application logic is 13.6 times smaller than the most limiting specification-related deadline. The achieved earliness (− 1.8 ms out of 2 ms of deadline) allows for the easy expansion of VCM’s train protection capabilities in the future. Results from the second testbed showed that the VCM can intervene to mitigate hazardous situations ~ 2 times faster than the current automatic train protection systems according to the related standard.

Оценка проектных параметров группировки информационных спутников IoT 5G

The paper presents technique for evaluating design parameters of a satellite constellation operating on the Internet-of-Things principle and making it possible to determine the impact on the constellation general design parameters on characteristics of the fifth generation 5G communication technology used in data transmission between spacecraft, as well as in communication between a spacecraft and the ground stations. Examples of the satellite communication constellation with the data transfer rate of 24 Gbit/s operating in circular orbits with the height of 1000 km are considered. It is shown that the upper limiting parameter for selecting the signal transmission frequency from the satellite to the Earth is the spacecraft power consumption, and the lower limits are the data transfer rate and the signal level. Besides, it is necessary to consider the antenna gain, which depends on the signal transmission frequency and has limitations. Results of studying dependence of the distance between the satellites in the Earth orbit constellation on the power consumed on board the spacecraft are presented. It is shown that with an increase in the number of satellites in constellation and due to a decrease in the onboard equipment power, the mass of a single spacecraft would decrease by 1.4 times. However, total mass of the constellation grows by almost 1.5 times, which potentially increases the project total cost.