Aerospace Systems Research Articles

The role of Industrial Resources in Reconfigurable Aerospace Production Systems: A Preliminary Literature Review

Today, aerospace products need to be developed following economic and environmental drivers. Aerospace production systems must adapt to novel products that reuse current industrial resources to accommodate new scenarios. Reconfigurable Production Systems (RPS) or Reconfigurable Manufacturing Systems (RMS) is the answer. This paper aims to perform a preliminary review of the literature to answer the following research question. What is the current application of Reconfigurable Manufacturing Systems in the aerospace industry? This preliminary literature review is focused on the role of industrial resources in the design of RMS at the conceptual stage and the application or applicability of RMS in the aerospace industry. The objective of this paper is to provide the research community with a preliminary review of research trends in the field of industrial resources and RMS systems in aerospace.

Aerospace Systems "Aerial Launch" at the Modern Stage

The need for the emergence and use of aerospace systems (ASS) "Aerial launch" by the leading countries has been formulated. The types of ASS and the types of military space systems are revealed, as well as the connection between them. The functioning and perspective ASS "Aerial launch" with civil and military applications is analyzed. Based on a systematic analysis, a structure of ASS "Aerial launch" for the conditions of the Republic of Bulgaria, its advantages, disadvantages and main properties is proposed. Based on the performed modeling, a scheme of operation of ASS "Aerial launch" and stages of the flight of the MiG-29UB carrier aircraft for launching a nanosatellite (nanosatellites) into orbit in the conditions of our country is proposed.

Applications of Intelligent Optimization Algorithms and Fuzzy Logic Systems in Aerospace: A Review

Applications of Intelligent Optimization Algorithms and Fuzzy Logic Systems in Aerospace: A Review

Modeling Rainfall–Runoff Responses and Antecedent Moisture Effects Using Principles of System Identification

Rainfall–runoff dynamics of surface water, combined sewer, and separate sewer systems can be highly impacted by antecedent moisture conditions, or the relative wetness or dryness of the system. Accurately simulating these dynamics is critical for developing predictive models of systems that are sensitive to antecedent moisture. This paper presents the results of 25 years of work formulating, applying and refining a hydrologic model that addresses the impacts of antecedent moisture conditions on the rainfall–runoff process. The development, process and equations of the model are presented. The model was derived using the principles of system identification from the field of aerospace control systems to find the simplest mathematical model that accurately describes the relationship between system inputs and the flow output. Developing and testing the model was done primarily from observations in the U.S. Midwest. where both preceding rainfall and seasonal hydrologic conditions impact antecedent moisture dynamics. For these systems, the model described here is perhaps the most parsimonious that can accurately simulate these dynamics. This provides several advantages to the modeler, including ease of use, fewer parameters to calibrate, ability to quickly identify optimal parameters, and ease of representation in a numerical computer routine. Physical interpretation of the model structure and parameters is possible, providing the modeler with useful insights into the physical processes driving the rainfall–runoff dynamics.

Review Article on Condition Assessment of Structures Using Electro-Mechanical Impedance Technique

Structural health monitoring (SHM) is a process for determination of presence, location, severity of damages and remaining life of the infrastructures. SHM is widely applied in aerospace, mechanical and civil engineering systems to assess the conditions of structures to improve the operation, safety, serviceability and reliability, respectively. There are various SHM techniques for monitoring the health of structures such as global response based and local techniques. Damages occur in the structures due to its inability to withstand intended design loadings, physical environment and chemical environment. Therefore, damage identification is necessary to improve the durability of the structures for protection against catastrophic failure. The research paper is focused on electro-mechanical impedance (EMI) technique which is one of the techniques based on smart materials. The smart materials are utilized for monitoring the health of the structures. These are used for damage determination and its quantification for the interrogated structures. Variation in admittance or impedance signature shows the existence of damage in the structures. Furthermore, the different statistical methods viz., root mean square deviation (RMSD), mean absolute percentage deviation (MAPD), covariance (Cov), and correlation coefficient (CC) are used for the quantification of damage. Smart material such as piezoelectric materials, its properties and applications are also considered. In this paper, the implementation of EMI technique based on different recent advances in smart materials and their appropriateness have been described. Subsequently, the reviewed investigations are significant for the monitoring of real-life infrastructures. The presented paper is the compact state-of-the-art for EMI technique which is used for SHM. This examination will be valuable to infrastructural health monitoring and engineering applications in respect to innovative research directions.

Simulation models as a unified source of knowledge for safety assessments of aerospace systems

Simulation models as a unified source of knowledge for safety assessments of aerospace systems

Simulation models as a unified source of knowledge for safety assessments of aerospace systems

Simulation models as a unified source of knowledge for safety assessments of aerospace systems

Research of propulsion system’s engines for the carrier aircraft of an advanced reusable two-stage aerospace system

Research of propulsion system’s engines for the carrier aircraft of an advanced reusable two-stage aerospace system

Online structural integrity monitoring of high-performance composite rocket motor casing

Solid rocket motor (SRM) is one of the significant sub-systems for aerospace launch vehicles. The requirements of high range and high payload capabilities in aerospace systems demand the usage of high specific strength and high specific stiffness materials for rocket motor casings to minimize the inert weights. The present state-of-the-art technology is to realize stages of missile systems/launch vehicles with Composite Rocket Motor Casing (CRMC) to have a high-performance factor. CRMC is being designed with a marginal Factor of Safety (FOS) and mostly for a one-time use during its service life. CRMC is pressure tested to verify leak containment and its ability to sustain the Maximum Expected Operating Pressure (MEOP). Acoustic Emission Testing (AET), an online and global Structural Health Monitoring (SHM) technique along with strain and dilation measurement is used for observing the dynamic behavior of CRMC during the pressure test. Conventional Non-destructive Testing (NDT) such as Ultrasonic (UT) and Radiographic testing (RT) are employed to identify the type of defects. This unique capability of monitoring the dynamic behavior of active defects during real-time is of great significance for the acceptance of CRMC. The evolution of such an online system requires, first, identification of an appropriate process and next its adoption to meet the challenges posed by composite materials. There are various steps involved in the online SHM of CRMC. In this paper, various test practices, requirements, test parameters along with the details of strain and dilation measurements are given. This online inspection methodology and strain-dilation measurement during the Proof Pressure Test (PPT), along with a series of other inspection methods form the basis of CRMC acceptance for further use.

Digital Twin in Aerospace Industry: A Gentle Introduction

Digital twin (DT), primarily a virtual replica of any conceivable physical entity, is a highly transformative technology with profound implications. Whether it be product development, design optimisation, performance improvement, or predictive maintenance, digital twins are changing the ways work is undertaken in various industries with multifarious business applications. Aerospace industry, including its manufacturing base, is one such keen adopter of digital twins with an unprecedented interest in their bespoke design, development, and implementation across wider operations and critical functions. This, however, comes with some misconceptions about the digital twin technology and lack of understanding with respect to its optimal implementation. For instance, equating a digital twin to an intelligent model while ignoring the essential components of data acquisition and visualisation, misleads the creators into building digital shadow or digital models, instead of the actual digital twin. This paper unfolds such intricacies of digital twin technology for the aerospace community in particular and others in general so as to remove the fallacies that affect their effective realisation for safety-critical systems. It comprises a comprehensive survey of digital twins and their constituent elements. Elaborating their characteristic state-of-the-art composition along with corresponding limitations, three dimensions of the future digital twins for the aerospace sector, termed as aero-Digital Twins (aero-DTs), are proposed as an outcome of this survey. These include the interactive, standardisation, and cognitive dimensions of digital twins, which if leveraged diligently could help the aero-DT research and development community quadruple the efficiency of existing and future aerospace systems as well as their associated processes.

Assurance of electronic parts for aerospace system reliability: Past, present, and future

Over the last two to three decades, the balance of influence within the electronics industry has shifted decisively toward the consumer electronics and information technology products, away from the defense or aerospace markets. This shift toward the commercial markets has changed certain ground rules in the electronics industry. Reliance of the aerospace industry, in particular, on components from supply chains dedicated to other products, or cross-vertical product integration, creates a supply web and introduces significant risks that are not necessarily present for volume-driven electronic products. Many of the unique risks in the aerospace industry emanate from the key characteristics of this industry. Although selection and usage of commercial electronics in NASA flight hardware is possible at a comparable (and in many cases lower) level of risk to that of employing parts that are screened to military or NASA specifications, for a large majority of flight projects it is difficult to distinguish the difference in on-orbit performance or reliability for parts screened at any level, or commercial parts that have no additional screening performed by the government. This paper identifies several bases for establishing context and developing unique or alternative approaches for successful parts selection and application within NASA and across the commercial space community.

An evidential network-based hierarchical method for system reliability analysis with common cause failures and mixed uncertainties

Redundant design has been widely used in aerospace systems, nuclear systems, etc. which calls for particular attention to common cause failure problems in such systems with various kinds of redundant mechanisms. Besides, imprecision and epistemic uncertainties also need to be taken into account for system reliability modeling and assessment. In this paper, a comprehensive study based on the evidential network is performed for the reliability analysis of complex systems with common cause failures and mixed uncertainties. The decomposed partial α-factor is used to separate the contribution of independent parts and common cause parts of basic failure events. Mixed uncertainties are quantified and expressed by the D-S evidence theory, and the system reliability with uncertainties is modeled by evidential network. Furthermore, two layers, i.e. a decomposed event layer and coupling layer, are embedded into the evidential network of the system, and, as a result, the hierarchical structure of system reliability is constructed. The importance and sensitivities of various component types and their impact on system reliability are detected. The presented evidential network-based hierarchical method is applied to analyze the reliability of an auxiliary power supply system of a train and the results demonstrate the effectiveness of this method.

Failure behavior analysis of phased-mission systems considering functional and physical isolation effects

Phased-Mission Systems (PMS) are widely applied in aerospace, telecommunication and intelligent systems for multiple, consecutive and non-overlapping phases of missions. The phase-dependent stresses and system structure cause some difficulties to the reliability analysis of PMSs. In this paper, we analyze the physical isolation effects on the degradation speeds and across-phase damage accumulations of failure mechanisms. And, some corresponding reliability and unreliability formulas are derived. Besides, a hierarchical Binary Decision Diagram (BDD)-based modeling method is proposed for incorporating functional and physical isolation effects into BDD models, and the analytical method with phase algebras is introduced for studying the failure behavior of PMS with functional dependence. In the case study, we evaluate the collision avoidance system of a fixed-wing unmanned aerial vehicle as an example to demonstrate the proposed modeling and analysis method. Results show that the physical isolation effects have significant influences on the degradations of components, which deserves detailed analysis for a more practical and realistic PMS’s failure behavior.

Nickel hydrogen gas batteries: From aerospace to grid-scale energy storage applications

The challenging requirements of high safety, low-cost, all-climate and long lifespan restrict most battery technologies for grid-scale energy storage. Historically, owing to stable electrode reactions and robust battery chemistry, aqueous nickel–hydrogen gas (Ni–H2) batteries with outstanding durability and safety have been served in aerospace and satellite systems for over three decades ever since their first development in the 1970s. Despite their satisfactory performances, this technology has difficulty to be applied for grid-scale energy storage primarily because of their high cost resulting from the utilization of expensive platinum as anode hydrogen catalyst. In recent years, with the extensive exploration of inexpensive hydrogen evolution/oxidation reaction catalysts, advanced Ni–H2 batteries have been revived as promising battery chemistry for grid-scale energy storage applications. This mini-review provides an overview of the development activities of Ni–H2 batteries and highlights the recent advances in the application of advanced Ni–H2 batteries for grid-scale energy storage. New cost-effective hydrogen evolution/oxidation reactions catalysts, novel cathode materials, and advanced Ni–H2 battery designs toward further development of Ni–H2 batteries are discussed. The renaissance of advanced Ni–H2 battery technology is particularly attractive for future grid-scale energy storage applications.

Aerospace System Engineering Model in the New Era

In the face of emerging opportunities of building a space power, the new challenges of complex international situations, and the new requirements put forward by the development of information technology to the modernization of national defense and the army, aerospace equipment presents a systematic development trend and requires that the theories and management methods guiding system engineering must change and follow the trend. By summarizing and judging the current research status of system engineering at home and abroad, based on the practice of aerospace system engineering, this paper designs a dynamic evolution process of system engineering, constructs the evolution, process and management model of system engineering, and puts forward some suggestions for further optimization of the practice of system engineering to provide reference for solving complex system engineering problems and enriching the theory of system engineering.

Hardware-Assisted Security Monitoring Unit for Real-Time Ensuring Secure Instruction Execution and Data Processing in Embedded Systems.

The hardware security of embedded systems is raising more and more concerns in numerous safety-critical applications, such as in the automotive, aerospace, avionic, and railway systems. Embedded systems are gaining popularity in these safety-sensitive sectors with high performance, low power, and great reliability, which are ideal control platforms for executing instruction operation and data processing. However, modern embedded systems are still exposing many potential hardware vulnerabilities to malicious attacks, including software-level and hardware-level attacks; these can cause program execution failure and confidential data leakage. For this reason, this paper presents a novel embedded system by integrating a hardware-assisted security monitoring unit (SMU), for achieving a reinforced system-on-chip (SoC) on ensuring program execution and data processing security. This architecture design was implemented and evaluated on a Xilinx Virtex-5 FPGA development board. Based on the evaluation of the SMU hardware implementation in terms of performance overhead, security capability, and resource consumption, the experimental results indicate that the SMU does not lead to a significant speed degradation to processor while executing different benchmarks, and its average performance overhead reduces to 2.18% on typical 8-KB I/D-Caches. Security capability evaluation confirms the monitoring effectiveness of SMU against both instruction and data tampering attacks. Meanwhile, the SoC satisfies a good balance between high-security and resource overhead.

Forward Design Method of Avionics System Based on Communication

With the rapid development of computer technology, electronic technology, and control technology, communication-based avionics systems can provide greater potential for the improvement of aircraft combat capabilities. Moreover, during the flight, passengers have an increasing demand for space communications. How to provide passengers with a communication-based aerospace electronic system that is indistinguishable from the ground during the flight is a problem that needs to be solved urgently. The research on the forward design method of this system has been highly valued by experts at home and abroad. This article is a communication-based forward design method for avionics systems. Based on the development of aerospace data communication technology, this article discusses the advantages of the application of the CCSDS (Consultative Committee for Space Data Systems) protocol in the design of aerospace electronic communication systems. This research designs the technical scheme of the entire aerospace communication electronic system and refers to the relevant CCSDS protocol to complete the design of the distributor’s fast transmission telemetry package and the distributor’s slow transmission telemetry package. This article introduces the two existing architectures of the integrated avionics system, compares and analyzes them, and then elaborates the integrated avionics system architecture based on trusted computing and the trust chain transfer mechanism. The experimental results show that the method designed in this paper uses the NBSP basic protocol in an aeronautical communication environment with a nesting depth of 2 s. When the data transmission delay is 2 s, the NBSP scheme is 0.9 and the NERON scheme is 0.4. This shows that the design method of this study is able to meet the requirements of the system and technical indicators.

Reliability Assessment of Space Station Based on Multi-Layer and Multi-Type Risks

A space station is a typical phased-mission system, and assessing its reliability during its configuration is an important engineering action. Traditional methods usually require extensive data to carry out a layered reliability assessment from components to the system. These methods suffer from lack of sufficient test data, and the assessment process becomes very difficult, especially in the early stage of the configuration. This paper proposes a reliability assessment method for the space station configuration mission, using multi-layer and multi-type risks. Firstly, the risk layer and the risk type for the space station configuration are defined and identified. Then, the key configuration risks are identified comprehensively, considering their occurrence likelihood and consequence severity. High load risks are identified through risk propagation feature analysis. Finally, the configuration reliability model is built and the state probabilities are computed, based on the probabilistic risk propagation assessment (PRPA) method using the assessment probability data. Two issues are addressed in this paper: (1) how to build the configuration reliability model with three layers and four types of risks in the early stage of the configuration; (2) how to quantitatively assess the configuration mission reliability using data from the existing operational database and data describing the propagation features. The proposed method could be a useful tool for the complex aerospace system reliability assessment in the early stage.

Testing Setup and Delay Compensation in HILS of Aerospace Systems

Hardware In-Loop Simulation (HILS) test setup is a highly essential tool in the design and development of Aerospace vehicle subsystems. The performance evaluation of vehicle subsystems in real-time scenario helps a lot in achieving successful flight tests and minimizing the number of trials. The HILS testbed suffering from inherent delay during testing and resulted in unwanted diverging oscillations, which limits the HILS testbed effectiveness. The deep insight into the HILS testbed is presented here. The available delay compensation methods were studied, and a suitable compensation method was implemented. The adverse effectiveness of delay compensation was also discussed.

A Case for User-Centered Design in Satellite Command and Control

The prevalence of unique, disparate satellite command and control (SATC2) systems in current satellite operations is problematic. As such, the United States Air Force aims to consolidate SATC2 systems into an enterprise solution that utilizes a common Human–Machine Interface (HMI). We employed a User-Centered Design (UCD) approach including a variety of methods from design thinking and human factors engineering to develop a solution that is effective, efficient, and meets operator needs. During a summative test event, we found that users had significantly higher situation awareness, lower workload, and higher subjective usability while using the HMI developed via UCD over the existing, or legacy, HMI. This case study serves as evidence to support the assertion that involving users early and often has positive and tangible effects on the development of aerospace systems.