On-board Subsystem Research Articles

CANSat-IDS: An adaptive distributed Intrusion Detection System for satellites, based on combined classification of CAN traffic

The increasing dependence on satellite technology for critical applications, such as telecommunications, Earth observation, and navigation, underscores the need for robust security measures to safeguard these assets from potential cyber threats. Moreover, as many satellite systems rely on the Controller Area Network (CAN) protocol for efficient data exchange among onboard subsystems, they become prime targets for cyberattacks. While contributions present various options for detecting attacks in the CAN bus, no one proposes an architecture suitable for satellite systems. To address this concern, this paper presents a novel approach to develop an adaptive distributed Intrusion Detection System (IDS) for satellites, which integrates machine and deep learning techniques for the classification of CAN frames. This system is specifically designed to overcome the inherent power and computational challenges of satellite operations by executing time-based anomaly detection on board, and content-based detection at the ground segment. To evaluate the effectiveness of the proposed solution, experiments are conducted using representative Datasets. The obtained results demonstrate that the distributed IDS presented in this research offers a promising solution to improve the security of satellite systems by achieving high detection rates ranging from 91.12% to 99.86% (F1-score).

Swarm of lightsail nanosatellites for Solar System exploration

This paper presents a study for the realization of a space mission which employs nanosatellites driven by an external laser source impinging on an optimized lightsail, as a valuable technology to launch swarms of spacecrafts into the Solar System. Nanosatellites propelled by laser can be useful for heliosphere exploration and for planetary observation, if suitably equipped with sensors, or be adopted for the establishment of network systems when placed into specific orbits. By varying the area-to-mass ratio (i.e. the ratio between the sail area and the payload weight) and the laser power, it is possible to insert nanosatellites into different hyperbolic orbits with respect to Earth, thus reaching the target by means of controlled trajectories in a relatively short amount of time. A mission involving nanosatellites of the order of 1 kg of mass is envisioned, by describing all the on-board subsystems and satisfying all the requirements in terms of power and mass budget. Particular attention is paid to the telecommunication subsystem, which must offer all the necessary functionalities. To fabricate the lightsail, the thin films technology has been considered, by verifying the sail’s thermal stability during the thrust phase. Moreover, the problem of mechanical stability of the lightsail has been tackled, showing that the distance between the ligthsail structure and the payload plays a pivotal role. Some potential applications of the proposed technology are discussed, such as the mapping of the heliospheric environment.

Enhancing accuracy of information processing in onboard subsystems of UAVs

The object of research is the onboard subsystems of Unmanned Aerial Vehicles (UAVs). The research is aimed at analyzing UAVs, specifically the integration and enhancement of satellite-based positioning systems, including Global Navigation Satellite Systems (GNSS) and Inertial Navigation Systems (INS). The problem concerns traditional satellite-based positioning services, especially those relying solely on medium earth orbit (MEO) satellites, which are insufficient for specific requirements. The study aims to address the limitations of these systems on onboard subsystems of UAVs, especially in challenging environments laden with jammers and interference, and to provide a more accurate, robust, and continuous positioning solution. The research proposes a «multilayer system of systems» approach that integrates signals from various sources, including low Earth orbit (LEO) satellites, ground-based positioning, navigation, and timing (PNT) systems, and user-centric sensors. The combined approach, termed LeGNSS/INS, leverages the strengths of each component, providing redundancy and enhanced accuracy. The system's performance was evaluated using pseudo-real output data, demonstrating its ability to generate quasi-real dynamic trajectories for UAV flight. The error analysis showed that the proposed method consistently outperforms traditional GNSS systems, especially in challenging environments. The enhanced performance of the LeGNSS/INS system can be attributed to integrating multiple satellite systems with INS and applying optimal filtering techniques. The research also employed mathematical modeling to represent the dependencies and interactions when combining data from different sources, such as GPS, LEO, and INS. The Kalman filter is a mechanism to fuse data from multiple sources optimally. The insights from this study apply to various sectors, including aviation, maritime navigation, autonomous drones, and defense. The enhanced positioning accuracy can significantly improve safety, navigation precision, and operational efficiency. However, the study assumes idealized conditions for satellite signal reception, which might not always be accurate in real-world scenarios. Challenges, such as the martial law conditions in Ukraine affecting data collection and potential satellite signal restrictions, were also highlighted. Further research can delve into the impact of more complex environmental factors and the integration of additional satellite systems or sensors to enhance accuracy further.

Statistical Decomposition and Machine Learning to Clean In Situ Spaceflight Magnetic Field Measurements

AbstractRobust in situ magnetic field measurements are critical to understanding the various mechanisms that couple mass, momentum, and energy throughout our solar system. However, the spacecraft on which magnetometers are often deployed contaminate the magnetic field measurements via onboard subsystems including reaction wheels and magnetorquers. Two magnetometers can be deployed at different distances from the spacecraft to determine an approximation of the interfering field for subsequent removal, but constant data streams from both magnetometers can be impractical due to power and telemetry limitations. Here we propose a method to identify and remove time‐varying magnetic interference from sources such as reaction wheels using statistical decomposition and convolutional neural networks, providing high‐fidelity magnetic field data even in cases where dual‐sensor measurements are not constantly available. For example, a measurement interval from the Parker Solar Probe outboard magnetometer experienced a 95.1% reduction in reaction wheel interference following application of the proposed technique.

Retrospective Proposals for the Orbital Correction of GSAT0201 & GSAT0202

On August 22, 2014, the first two Full Operational Capacity satellites of the Galileo constellation were launched from Kourou on a Soyuz ST-B rocket. Shortly after the insertion into the final orbit, the on-board telemetry showed the achieved orbit was different from the target highly inclined circular orbit, due to a failure in the Fregat upper stage attitude control system. This anomaly precluded nominal operations in the Galileo constellation, as well as introducing limitations in the use of several of on-board subsystems. A recovery campaign took place in the winter of 2014 to change the two satellites’ trajectories, so to reduce the entity of operative constraints and provide better communication with the ground segment. With no dedicated orbital thruster available, attitude thrusters were used effectively to modify and enhance the orbit and recover from a multi-system failure, making reinsertion in a GNSS constellation possible. This work investigates, by means of a numerical model, the best combination and sequence of maneuvers that could have been implemented in the recovery campaign to satisfy most proposed drivers with the given Delta v budget. The results show that different final orbits with the same resonance but lower eccentricity could have been achieved.

НАЗЕМНО-БОРТОВІ СИСТЕМИ ВИПРОБУВАНЬ ТА ДІАГНОСТИКИ ВЕРТОЛІТНИХ РЕДУКТОРІВ

The article is an overview and information. An effective direction of operational diagnostics of the most stressed units - gear drives of GTE gearboxes are methods for analyzing vibration signals of the engine casing.The theoretical and experimental substantiation of vibration diagnostics of GTE gears and helicopter gearboxes in-dicates that the main function that characterizes the energy efficiency of torque transmission and is sensitive to the initiation of defects in gear teeth can be considered the deviation of the parameter of the first derivative of the angular velocity of re-coupling of the teeth.The system for collecting and processing flight information is divided into onboard and ground parts. The onboard sub-system in the form of hardware and software systems provides for the collection and preliminary processing of primary infor-mation - vibration signals, synchronization, temperature, etc. It interacts with the standard equipment of the helicopter to obtain information regarding the modes of operation and flight of the helicopter. The on-board subsystem, as a rule, contains vibration sensors, speed sensors and accumulation and pre-processing blocks.The ground subsystem is a set of hardware and software tools that provide automatic express analysis and extended analysis of information recorded on board. The ground subsystem of the diagnostic system can be divided into local and central (support center). The local part is the software for processing the information accumulated during the flight and the database, which are hosted by the organization operating the helicopters.At present, methods are already being used for servicing machines according to the actual state or identifying parts without disassembling them based on vibration diagnostic tests. Their use allows to simultaneously reduce the cost of adjust-ment work and improve their quality, since not only the condition of the parts of the product is checked, but also how they are assembled, whether there are misalignments of bearings or gears during assembly.After the flight, the accumulated data is transferred to the ground subsystem of the operating organization, where post-flight analysis is carried out, processing results are issued and the results are stored in a local database. Further, the processing results are synchronized with the database of the support center to provide information on the technical condition to the devel-opers of helicopters and their units, as well as to operating organizations

Development and Implementation of a Remote-Control System for an Unmanned Research Small Vessel

The paper presents the results of the development and implementation of a remote-control system for an unmanned research small vessel, consisting of onboard and coastal control subsystems. The developed system was installed and tested on a small vessel manufactured at the Sevastopol State University. The control system allows the navigator to control the vessel at a distance of 1-2 km, to carry out video surveillance of the situation around the vessel, to control the orientation and location of the vessel. Wi-Fi technology is used to connect the coastal and onboard subsystems. Also, the navigator has the opportunity to control the vessel using a portable hand control panel.

Research, development and production costs prediction parametric model for future civil hypersonic aircraft

Assessing the economic viability of new high-speed systems concepts since the early design phases is crucial for the success of future hypersonic vehicles including cruisers, reusable access-to-space and re-entry systems. Besides literature reports few parametric cost models for high-speed vehicles, all of them makes exclusively use of mass as parameter and none of the models moves beyond the vehicle level. This paper describes a new parametric cost estimation model which moves beyond the state-of-the-art methodologies (1) by integrating vehicle design and operational parameters (in addition to the mass) as cost drivers for the prediction of the vehicle life-cycle cost, (2) by introducing prediction margins accounting for the uncertainties on the data-driven correlations, (3) by providing a first estimate of the costs of every on-board subsystem, including combined cycle engines and multi-functional subsystems, (4) by increasing the granularity of the analysis up to technology level, thus providing a valuable support to Technology Roadmaping activities. The parametric cost estimation model has been refined and exploited in the context of the Horizon 2020 STRATOFLY project, where the technological, operational, environmental, and economic viability of a Mach 8 waverider concept have been investigated.

Towards a formalized model-based process for the design of high-speed aircraft and related subsystems

Increasing complexity associated to advanced aircraft concepts for high-speed flight is pushing the limit of engineering practices concerning design phases of products lifecycle. Specific methodologies aimed at managing requirements over the entire vehicle architecture definition shall then be properly formalized and supported by means of standardized processes and languages in order to be effective. The approaches suggested by the Systems Engineering practices, especially when considering the model-based environments as main tools for systems design, can be exploited to face these challenges, if properly tailored to suit the specific engineering field considered. This paper aims at proposing a model-based process for the design of high-speed aircraft exploiting a formalized methodology and the typical tools of Systems Engineering. A conceptual design exercise, based on the STRATOFLY MR3 hypersonic cruiser case study, is performed from high-level stakeholder objectives to vehicle performance estimations, passing through functional and interface analyses. Additionally, some insights concerning on-board subsystems sizing activities are provided in terms of integration within the high-level design process. The whole work highlights the capability of performing a seamless requirements management and development within the design procedure, particularly focussing on the relationships among the different stages of the workflow.

Artificial vision algorithm for earth station location from CubeSats in narrow beam optical communications

The use of CubeSats promises several advantages within a low economical budget margin for different missions. Nowadays, data transfer through optical channels (lasercom) is considered a potential technology for satellite wireless communications, providing several advantages in terms of data transfer rate with lower energy consumption. However, a main drawback is the location of the Optical Ground Station (OGS). Therefore, an artificial vision algorithm for the processing of images captured by the camera of a CubeSat is proposed in this work, in order to carry out the identification and recognition of an OGS by means of a beacon signal, to aid the Pointing, Acquisition and Tracking (PAT) onboard subsystem for the communication’s stage.

Research on reliability analysis strategy of high-speed train ATP on-board equipment under uncertain information

In view of the incomplete knowledge and lack of data, the system has epistemic uncertainties. This paper uses Bayesian network fusion evidence theory to analyze the reliability of high-speed railway ATP on-board equipment. According to the requirements of safety-critical system reliability analysis, this paper starts with the analysis of system structure and unit module status, comprehensively considering the influence of uncertain information, common cause failure, recovery mechanism, and degraded operation on system reliability. In this paper, with the advantage of the Bayesian network in the description of events in multiple states, evidence theory is used to reason about the system under incomplete information conditions, obtain the availability interval of on-board subsystems and discuss the impact of the degraded operation on system availability. The [Formula: see text] factor model is used to analyze common cause failures, and then the Bayesian network modeling of common cause failures is realized by adding common cause failure nodes. The results show that the method enhances the Bayesian network’s ability to process uncertain information, and the common cause failure data of the train control on-board subsystem is continuously accumulated. The factor model can be used to obtain a more practical common cause failure rate.

Integration Tests of ETCS On-board Subsystems Based on the Requirements of the Technical Specifications for Interoperability of the ‘Control-Command and Signalling’ Subsystem

Achieving the interoperability of the European rail system in each Member State requires many measures to standardise the adopted technical solutions and relevant regulations. However, it is likely that there may be some incompatibilities between individual subsystems, even if these subsystems are designed in accordance with standardised requirements. Interoperable rolling stock may be unable to move freely over an interoperable railway line due to some incompatibilities and differences in the versions of the installed firmware in the ETCS system devices. The article discusses the compliance tests of the proper integration of the on-board subsystem with the trackside subsystem, carried out by the Railway Research Institute. Keywords: interoperability, control-command and signalling, ERTMS, ETCS, TSI, CCS

Metamaterial array based meander line planar antenna for cube satellite communication

This research article presents a design and performance analysis of a metamaterial inspired ultra-high frequency (UHF) compact planar patch antenna for the CubeSat communication system that could be smoothly integrated with commercially available 2U Cube Satellite structure and onboard subsystem. The proposed antenna consists of two layers, one is two different width meander line antenna patch with partial ground plane and another layer is 3 × 2 near-zero-indexed metamaterial (NZIM) metamaterial array structure with ground plane. The NZIM array layer has been utilized to minimize the coupling effect with Cube Satellite structure and improve the frequency stability with enhanced antenna gain and efficiency. The fabricated antenna can operate within the lower UHF frequency band of 443.5–455 MHz. with an average peak gain of 2.5 dB. The designed antenna impedance stability characteristic has been explored after integration with the 2U Cube Satellite body layout. Besides, the antenna communication performance has been verified using 2U Cube Satellite free space path loss investigation. Small antenna volume with trade-off between the antenna size and performance are the key advantages of the proposed design, as the antenna occupies only 80 × 40 × 3.35 mm3 space of the 2U Cube Satellite body structure and the geometrical parameters can be designed to provide the best performance between 449 and 468.5 MHz.

Reliability analysis on the train control system in the CTCS-3 operating mode

Purpose This paper aims to study the reliability of the high-speed train operation control system in the Chinese Train Control System Level 3 (CTCS-3) operating mode. Design/methodology/approach Dynamic fault tree and Bayesian network method are adopted to analyze the reliability and weakness of the CTCS-3 system. Findings First, a physical architecture and data flow diagram of the CTCS-3 system are established according to the typical structure and functions of the CTCS-3 system. Second, the dynamic fault tree of the CTCS-3 system is constructed. Considering the prior probability of the bottom event and the existence of dynamic redundancy, the dynamic fault tree is transformed into a Bayesian net. The reliability of the CTCS-3 system is carried out based on the prior probability and the weakness that affects the reliability of the system based on the posterior probability is also analyzed by the Bayesian network. Finally, it is disclosed that the impact of the on-board subsystem on the reliability of the CTCS-3 system is generally greater than that of the ground subsystem. The two weakest modules in the onboard subsystem are the driver-machine interface (DMI) and balise transmission module (BTM) and the weakest one in the ground subsystem is Balise. The analysis results are generally consistent with the malfunctions in the field operation of China’s high-speed railway. Originality/value (1) By reasoning, the reliability of the train operation control system in the CTCS-3 operating mode meets the standard requirements. (2) Through backward reasoning, it is found that the failure of the onboard subsystem leads to a greater probability of failure of the train control system. (3) The DMI, BTM and automatic train protection computer unit modules are weak components in the onboard subsystem. Vital digit input&output, train interface unit and train security gateway are rarely involved in previous research, the result in this paper shows that these three modules are also weak components in the subsystem, which requires attention.

Developing the concept of autonomous control of the quarry vehicles movement

Introduction. The article presents the results of studies related to the description of the synthesis and further analysis of the dynamic behavior of unmanned vehicles (UMVs) operating at coal opencast mines and other mining enterprises. The relevance of the research topic is dictated by the need to create safe and effective conditions for overburden / mining and mining transportation operations. This is ensured, among other things, by the operation of unmanned heavy-duty dump trucks. Purpose of the work: in the course of the research, a concept was developed for the formation of route parameters and models of the dynamics of movement of UMVs along technological routes. Methodology. The paper describes the technology for generating and processing signals in control subsystems as part of an automated dispatching system and an on-board subsystem for autonomous control of the UMV. Research methods include the study of the shapes and characteristics of current trajectories (CT) in relation to a nominal axial trajectory (NAT). In this case, a current trajectory of the UMV is considered within the framework of the so-called S-frames, which are formed as geolocations on a certain working UMV route from a bench face to the place of unloading and vice versa. As a variable characterizing the UMV behavior on a current trajectory, a 1D-signal with a time dependent frequency is adopted, the nature of the change of which is determined by the CT dynamic shape relative to the NAT. Results. Such chirp signals – together with the wavelet transforms technique introduced into consideration – allow us in a semantically transparent and information-rich videographic form to display and subject to further processing signals characterizing the current behavior of a UMV on a route. The resulting parameters of such secondary wavelet representations of the current UMV dynamics (wavelet maps) are further planned to be used in the subsystem of dynamic modal control of the UMV movement in the open pit. Conclusions. The results of the studies carried out make it possible to form current routes of UMV movement according to the models generated based on the analytical tools accompanying the dynamics of the UMVs, proposed in the work.

Accounting of the magnetic field of the power supply system of a power-capacitive technical object

The paper shows the approach and the result of taking into account the mutual influence of on-board subsystems of a complex technical object along the DC power supply circuits. Technical objects are understood as a mobile, energy-intensive vehicle, such as an aircraft, a surface or submarine vessel, or a railway locomotive with strong magnetic fields. The aim of the work is to create a simple and intuitive tool for mathematical modeling of the magnetic field vector at an arbitrarily specified observation point. The task is being solved in order to improve the accuracy of magnetic measurements on board, in particular, in navigation problems. On-board DC networks are considered, to which the approach of mathematical modeling is applied. The disadvantages of commercial programs of a similar purpose are noted. The binding of the objects under consideration to the general coordinate system is described. An analytical algorithm for calculating the magnetic field vector from the on-board cable network with a pronounced 3D trajectory is shown. Examples of visualization of the simulation results are given. An algorithm for calculating the induction vector based on the Biot-Savard law is considered. The algorithm for the analytical solution of the problem is described in detail. A specific power cable of the on-board network is considered. The cable is given by a set of straight conductors with current. The ways of future improvement of the created product with the transition from one observation point to the field map in a given three-dimensional zone of arbitrary position, volume and orientation are outlined. The obtained result is considered as an element of the procedure for achieving electromagnetic compatibility of energy-intensive and highly sensitive subsystems of a modern complex technical object.

Thrust Validation of Rotating Detonation Engine System by Moving Rocket Sled Test

This Paper presents the results of a rotating detonation engine rocket sled test demonstration on a 127 mm gauge rail at 100 m long high-speed running track test equipment to evaluate the thrust performance of a stand-alone rotating detonation engine propulsion system. The developed sled test demonstrator contained all onboard subsystems, including engine, gas cylinders, valves, controller, and a data logger. The sled test demonstrator successfully generated thrust, and three or four detonation waves of 1460 to were observed during the 2.0 s burn time. The measured specific impulse in the sled test was 144 s as estimated from the acceleration of the demonstrator and the mass decrease in the onboard cylinders. The test results were compared with the data from a laboratory-stand firing test using a load cell, and the specific impulses of the sled test were found to be comparable to the results of the stand firing test.

Design and Implementation of High Reliability Electrical Power System for 2U NutSat

This article proposes the design and implementation of an electrical power system (EPS) for 2U CubeSat using a single-ended primary-inductor converter (SEPIC) along with the perturbed and observe method for the maximum power point tracking (MPPT). SEPIC converters have the advantages of input current continuity, voltage boosting and bucking, short-circuit protection, low-side driver, and noninverted input and output voltages. When the battery voltage is too low, by adding a low power consumption latching relay to develop a novel topology, the battery can be directly charged with solar panels without the MPPT algorithm and to improve the system reliability. In addition to the on-board computer subsystem, we can independently control whether to turn on the power according to the battery capacity and importance priority for each subsystem of CubeSat. The satellite is operated in outer space that the environment is wide temperature variation, vacuum, and high electromagnetic radiation. Therefore, the satellite was subjected to various types of tests, such as vacuum, thermal cycling, and radiation tests, to verify the system's capacity for enduring the aforementioned environmental changes. Finally, implementations and various tests were carried out to verify the viability and the accuracy, and reliability of the EPS of the satellite.

Selected Aspects of Control-Command and Signalling On-Board Subsystem Verification

This article describes the procedures, standard parameters and control requirements to be performed in order to achieve EC verification of a Control-Command and Signalling On-board Subsystem. An analysis of issues related to the assessment of the on-board subsystem is presented in terms of the necessary checks that must be performed by a notified body and the issues of interoperability tests of the on-board ERTMS with track-side infrastructure. Providing railway interoperability is strictly related to the introduction of unified rules for the assessment and verification of the ETCS and GSM-R subsystems that are part of the European Rail Traffic Management System (ERTMS). The article describes procedures, standard parameters, requirements and necessary controls that must be implemented to carry out EC Verification of a Control-Command and Signalling On-board Subsystem. Reference is also made to the issues of ERTMS on-board compatibility tests with track-side infrastructure. Keywords: TSI, CCO, ERTMS, conformity assessment, interoperability

Research on the fault prediction method of an on-board subsystem in high-speed train control systems

The train control system is the “nerve center” of the high-speed train information system, which is large-scale and comprises various components. The on-board subsystem is the core of the train control system and is key to ensuring traffic safety and improving operating efficiency. Currently, the fault data processing methods of the on-board subsystem remain manual, which primarily realizes the fault detection and location. It is difficult to achieve the fault mechanism level, and fault prediction cannot be realized effectively. In this paper, the on-board subsystem structure and the fault disposal status were analyzed. The existing problems have been summarized, and some concepts and algorithms to predict faults were introduced. Based on the on-board subsystem structure and each modules performance parameters, the system-level fault prediction model was established. Based on the practical operational data sets, the fault prediction based on the Bayesian network was carried out and verified under 20, 200, 2000 and 20000 sets, respectively. The prediction accuracy was 5%, 27%, 92% and 96.3%, respectively, under the condition of 2000 data sets. The hidden Markov model and neural network-based fault prediction solutions were compared with the proposed method. The results demonstrate the advanced performance of the Bayesian network-based solution in system-level fault prediction.