cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.7507754
title: Finite Element Analysis of Pilot’s Helmet Design Using Composite Materials for Military Aircraft

description: ABSTRACT The objective of this research was to design pilot helmets and to perform analysis of designed ballistic helmet against impact strength of bullet in Solidworks and Laminator software. The material used for construction of the helmet is fiber reinforced polymer matrix composite in which polymer matrix is made of nylon, a thermoset resin, and the fibers are aramid, an aromatic polymide resin developed by E.I. duPont de Nemours and Company and sold under the trademarks “Kevlar®” and “Nomex®”. The design of the helmet is done by deciding the stacking sequence of various laminae which are oriented with main material directions at different angles to the global laminate axes in order to produce a structural element in the form of a shell. The simulation of the helmet in Solidworks and Laminator is done with an 8-g AK 47 bullet, hitting it with a velocity of 710 m/s. The model is validated against published data and a good correlation is observed. The result of this project is that a 1.30 kg helmet with shell thickness of 7 mm is obtained, which is economical, light weight and is able to give high-performance protection against ballistic shrapnel and bullets.
DOI: 10.6084/m9.figshare.7506698
title: Structure Synthesis and Optimization of Feed Support Mechanisms for a Deployable Parabolic Antenna

description: ABSTRACT In this paper, a systematic method to synthesize parallel mechanisms for feed support mechanisms based on screw theory is proposed. First, the motion requirement of the feed support mechanism is studied. Then, a class of parallel mechanisms having a translational motion with different degrees of freedom is synthesized based on the constraint-synthesis method. Then, these parallel mechanisms are modified based on the specificities of deployable mechanisms, and two kinds of mechanisms are selected as the unit for the feed support mechanism. Finally, the deployment ratio of two kinds of mechanisms is optimized. The configurations obtained in this paper can enrich the types of feed support mechanisms.
DOI: 10.6084/m9.figshare.7506698.v1
title: Structure Synthesis and Optimization of Feed Support Mechanisms for a Deployable Parabolic Antenna

description: ABSTRACT In this paper, a systematic method to synthesize parallel mechanisms for feed support mechanisms based on screw theory is proposed. First, the motion requirement of the feed support mechanism is studied. Then, a class of parallel mechanisms having a translational motion with different degrees of freedom is synthesized based on the constraint-synthesis method. Then, these parallel mechanisms are modified based on the specificities of deployable mechanisms, and two kinds of mechanisms are selected as the unit for the feed support mechanism. Finally, the deployment ratio of two kinds of mechanisms is optimized. The configurations obtained in this paper can enrich the types of feed support mechanisms.
DOI: 10.6084/m9.figshare.7511897
title: Experimental Magnetometer Calibration for Nanosatellites’ Navigation System

description: ABSTRACT This article deals with the problem of Earth’s magnetic field sensors calibration in the context of low-cost nanosatellites’ navigation systems. The attitude of space vehicles can be determined from the state estimation using information from three-axis inertial and non-inertial sensors. This study considers a three-axis solid-state magnetometer. In the vehicle itself, the presence of ferrous materials and electronic devices creates disturbances, distorting the measured field. The sensor precision can be enhanced through calibration methods which calculate the systematic error. The objective here is to study and implement calibration combining a geometric method and the TWOSTEP algorithm. The methodology is based on numerical simulations, with the development of a database of the Earth’s magnetic field along the vehicle orbit, and experimental tests using a nanosatellite mockup, containing an embedded processor Arduino MEGA 2560 platform and the magnetometer HMC5843.
DOI: 10.6084/m9.figshare.7519442.v1
title: Performance Comparison of the IMMPDAF Algorithm Using Real and Simulated Radar Measurements

description: ABSTRACT Performance indexes obtained in idealized simulated scenarios are the primary source of data for evaluating different target tracking algorithms in most researches presented in the literature. Despite the convenience of simulation, ultimate evaluation of a tracking algorithm must be made in real scenarios. Unfortunately, real radar measurements as well as accurate aircraft position, necessary for calculating tracking errors, are not easily available. In this paper, we present an evaluation of the well-known Interacting Multiple-Model with Probabilistic Data Association Filtering algorithm using data obtained from a flight inspection of a Brazilian Air Force ground-based long-range surveillance radar. The presented results show that, in this scenario the Interacting Multiple-Model with Probabilistic Data Association Filtering algorithm performance using real data is worse compared to simulation. Statistical properties of the real radar measurements are also investigated, and some evidence is found that embedded noise is not well modeled as perfectly white.
DOI: 10.6084/m9.figshare.7519442
title: Performance Comparison of the IMMPDAF Algorithm Using Real and Simulated Radar Measurements

description: ABSTRACT Performance indexes obtained in idealized simulated scenarios are the primary source of data for evaluating different target tracking algorithms in most researches presented in the literature. Despite the convenience of simulation, ultimate evaluation of a tracking algorithm must be made in real scenarios. Unfortunately, real radar measurements as well as accurate aircraft position, necessary for calculating tracking errors, are not easily available. In this paper, we present an evaluation of the well-known Interacting Multiple-Model with Probabilistic Data Association Filtering algorithm using data obtained from a flight inspection of a Brazilian Air Force ground-based long-range surveillance radar. The presented results show that, in this scenario the Interacting Multiple-Model with Probabilistic Data Association Filtering algorithm performance using real data is worse compared to simulation. Statistical properties of the real radar measurements are also investigated, and some evidence is found that embedded noise is not well modeled as perfectly white.
DOI: 10.6084/m9.figshare.7510172
title: Formation Flight Control of Multi-UAV System with Communication Constraints

description: ABSTRACT Three dimensional formation control problem of multi-UAV system with communication constraints of non-uniform time delays and jointly-connected topologies is investigated. No explicit leader exists in the formation team, and, therefore, a consensus-based distributed formation control protocol which requires only the local neighbor-toneighbor information between the UAVs is proposed for the system. The stability analysis of the proposed formation control protocol is also performed. The research suggests that, when the time delay, communication topology, and control protocol satisfy the stability condition, the formation control protocol will guide the multi-UAV system to asymptotically converge to the desired velocity and shape the expected formation team, respectively. Numerical simulations verify the effectiveness of the formation control system.
DOI: 10.6084/m9.figshare.7510172.v1
title: Formation Flight Control of Multi-UAV System with Communication Constraints

description: ABSTRACT Three dimensional formation control problem of multi-UAV system with communication constraints of non-uniform time delays and jointly-connected topologies is investigated. No explicit leader exists in the formation team, and, therefore, a consensus-based distributed formation control protocol which requires only the local neighbor-toneighbor information between the UAVs is proposed for the system. The stability analysis of the proposed formation control protocol is also performed. The research suggests that, when the time delay, communication topology, and control protocol satisfy the stability condition, the formation control protocol will guide the multi-UAV system to asymptotically converge to the desired velocity and shape the expected formation team, respectively. Numerical simulations verify the effectiveness of the formation control system.
DOI: 10.6084/m9.figshare.7516490
title: Micro-motion Recognition of Spatial Cone Target Based on ISAR Image Sequences

description: ABSTRACT The accurate micro-motions recognition of spatial cone target is the foundation of the characteristic parameter acquisition. For this reason, a micro-motion recognition method based on the distinguishing characteristics extracted from the Inverse Synthetic Aperture Radar (ISAR) sequences is proposed in this paper. The projection trajectory formula of cone node strong scattering source and cone bottom sliptype strong scattering sources, which are located on the spatial cone target, are deduced under three micro-motion types including nutation, precession, and spinning, and the correctness is verified by the electromagnetic simulation. By comparison, differences are found among the projection of the scattering sources with different micro-motions, the coordinate information of the scattering sources in the Inverse Synthetic Aperture Radar sequences is extracted by the CLEAN algorithm, and the spinning is recognized by setting the threshold value of Doppler. The double observation points Interacting Multiple Model Kalman Filter is used to separate the scattering sources projection of the nutation target or precession target, and the cross point number of each scattering source’s projection track is used to classify the nutation or precession. Finally, the electromagnetic simulation data are used to verify the effectiveness of the micro-motion recognition method.
DOI: 10.6084/m9.figshare.7516634
title: Anticipating the Need for New Skills for the Future Aerospace and Aviation Professionals

description: ABSTRACT This study aims to translate needed future skills to the university classroom for the aerospace and aviation industry personnel, given the fast-paced change taking place in both the industry and the education sectors. A synopsis of the current challenges faced in the educational field is outlined, followed by a mapping of the future of both education and air platforms, in an attempt to set the basis of the needed skills framework. The Assessment and Teaching of 21st Century Skills Project is used as a baseline for the definition of the future “critical” skill set, which is considered well aligned with the future needs of the aerospace industry. It is suggested that this critical skill set can be translated to the higher education environment through an effective redesign of the existing teaching and learning philosophy and the practices.
DOI: 10.6084/m9.figshare.7516634.v1
title: Anticipating the Need for New Skills for the Future Aerospace and Aviation Professionals

description: ABSTRACT This study aims to translate needed future skills to the university classroom for the aerospace and aviation industry personnel, given the fast-paced change taking place in both the industry and the education sectors. A synopsis of the current challenges faced in the educational field is outlined, followed by a mapping of the future of both education and air platforms, in an attempt to set the basis of the needed skills framework. The Assessment and Teaching of 21st Century Skills Project is used as a baseline for the definition of the future “critical” skill set, which is considered well aligned with the future needs of the aerospace industry. It is suggested that this critical skill set can be translated to the higher education environment through an effective redesign of the existing teaching and learning philosophy and the practices.
DOI: 10.6084/m9.figshare.7517078
title: Design of a Nanosatellite Ground Monitoring and Control Software – a Case Study

description: ABSTRACT The growing countries that have carried out the development of CubeSat missions for academic purposes do not offer aerospace engineering programs at their universities. This causes difficulties for traditional engineers upon the formal use of different standards and frameworks for aerospace development, such as the European Cooperation for Space Standardization and Space Mission Analysis and Design . One way in which traditional software engineers can easily understand the structure of an aerospace framework, in order to apply it on the development of CubeSat mission software parts, is comparing its most important elements in relation to the elements suggested by a more familiar method. In this paper, we present a hybrid framework between the ECSS-E-ST-40C standard and the Rational Unified Process, which can be used by traditional software engineers as a guide model for the development of software elements in academic nanosatellite missions. The model integrates the processes and documentation suggested by the ECSS-E-ST-40C with the disciplines, workflows and artifacts suggested in Rational Unified Process. This simplifies the structure of ECSS-E-ST-40C and allows traditional software engineers to easily understand its work elements. The paper describes as study case the implementation of the hybrid model in the analysis and design of ground monitoring and control software for the Libertad-2 satellite mission, which is currently being developed by the Universidad Sergio Arboleda in Colombia.
DOI: 10.6084/m9.figshare.7517078.v1
title: Design of a Nanosatellite Ground Monitoring and Control Software – a Case Study

description: ABSTRACT The growing countries that have carried out the development of CubeSat missions for academic purposes do not offer aerospace engineering programs at their universities. This causes difficulties for traditional engineers upon the formal use of different standards and frameworks for aerospace development, such as the European Cooperation for Space Standardization and Space Mission Analysis and Design . One way in which traditional software engineers can easily understand the structure of an aerospace framework, in order to apply it on the development of CubeSat mission software parts, is comparing its most important elements in relation to the elements suggested by a more familiar method. In this paper, we present a hybrid framework between the ECSS-E-ST-40C standard and the Rational Unified Process, which can be used by traditional software engineers as a guide model for the development of software elements in academic nanosatellite missions. The model integrates the processes and documentation suggested by the ECSS-E-ST-40C with the disciplines, workflows and artifacts suggested in Rational Unified Process. This simplifies the structure of ECSS-E-ST-40C and allows traditional software engineers to easily understand its work elements. The paper describes as study case the implementation of the hybrid model in the analysis and design of ground monitoring and control software for the Libertad-2 satellite mission, which is currently being developed by the Universidad Sergio Arboleda in Colombia.
DOI: 10.6084/m9.figshare.7517942
title: Knowledge Management Patterns Model for a Flight Test Environment

description: ABSTRACT This paper investigates how Knowledge Management patterns in a Brazilian Air Force flight test environment can be simulated using a System Dynamics approach. The research has been conducted initially by a literature review on the main Knowledge Management and System Dynamics theories. Data for this research has been collected in a previous study consisted of documental research regarding the flight test environment Knowledge Management and a questionnaire-based survey which identified both a low Knowledge Management maturity level and the flight test core competence as the capability of performing flight test campaigns. The issued problem was the tradeoff between actions focused on performing flight test campaigns versus Knowledge Management to transfer the core competence inside organization in order to keep it in a high level. A system dynamics quantitative model has been developed as a result of this research. Fluxes and stokes were identified within the model and the relation between them emerged by identifying systemic feedback loops that may compromise the Knowledge Management and the core competence transferring. These features enable a holistic visualization and better understanding of the problem as well as the possibilities of identifying ways of improvement.
DOI: 10.6084/m9.figshare.7517942.v1
title: Knowledge Management Patterns Model for a Flight Test Environment

description: ABSTRACT This paper investigates how Knowledge Management patterns in a Brazilian Air Force flight test environment can be simulated using a System Dynamics approach. The research has been conducted initially by a literature review on the main Knowledge Management and System Dynamics theories. Data for this research has been collected in a previous study consisted of documental research regarding the flight test environment Knowledge Management and a questionnaire-based survey which identified both a low Knowledge Management maturity level and the flight test core competence as the capability of performing flight test campaigns. The issued problem was the tradeoff between actions focused on performing flight test campaigns versus Knowledge Management to transfer the core competence inside organization in order to keep it in a high level. A system dynamics quantitative model has been developed as a result of this research. Fluxes and stokes were identified within the model and the relation between them emerged by identifying systemic feedback loops that may compromise the Knowledge Management and the core competence transferring. These features enable a holistic visualization and better understanding of the problem as well as the possibilities of identifying ways of improvement.
DOI: 10.6084/m9.figshare.7519403
title: Management Process of a Frequency Response Flight Test for Rotorcraft Flying Qualities Evaluation

description: ABSTRACT This paper applies the frequency response methodology to characterize and analyze the flying qualities of longitudinal and lateral axes of a rotary-wing aircraft, AS355-F2. Using the results, it is possible to check the suitability of the aircraft in accordance with ADS-33E-PRF standard, whose flying qualities specifications criteria are based on parameters in the frequency domain. The key steps addressed in the study involve getting, by means of flight test data, the closed-loop dynamic responses including the design of the instrumentation and specification of the sensors to be used in the flight test campaign, the definition of the appropriate maneuvers characteristics for excitation of the aircraft, the planning and execution of the flight test to collect the data, and the proper data treatment, processing and analysis after the flight. After treatment of the collected data, single input-single output spectral analysis is performed. The results permit the analysis of the flying qualities characteristics, anticipation of the demands to which the pilot will be subjected during closed-loop evaluations and check of compliance with the aforementioned standard, within the range of consistent excitation frequencies for flight tests, setting the agility level of the test aircraft.
DOI: 10.6084/m9.figshare.7519403.v1
title: Management Process of a Frequency Response Flight Test for Rotorcraft Flying Qualities Evaluation

description: ABSTRACT This paper applies the frequency response methodology to characterize and analyze the flying qualities of longitudinal and lateral axes of a rotary-wing aircraft, AS355-F2. Using the results, it is possible to check the suitability of the aircraft in accordance with ADS-33E-PRF standard, whose flying qualities specifications criteria are based on parameters in the frequency domain. The key steps addressed in the study involve getting, by means of flight test data, the closed-loop dynamic responses including the design of the instrumentation and specification of the sensors to be used in the flight test campaign, the definition of the appropriate maneuvers characteristics for excitation of the aircraft, the planning and execution of the flight test to collect the data, and the proper data treatment, processing and analysis after the flight. After treatment of the collected data, single input-single output spectral analysis is performed. The results permit the analysis of the flying qualities characteristics, anticipation of the demands to which the pilot will be subjected during closed-loop evaluations and check of compliance with the aforementioned standard, within the range of consistent excitation frequencies for flight tests, setting the agility level of the test aircraft.
DOI: 10.6084/m9.figshare.7509833
title: The Control of Asymmetric Rolling Missiles Based on Improved Trajectory Linearization Control Method

description: ABSTRACT According to motion characteristic of an asymmetric rolling missile with damage fin, a three-channel controlled model is established. The controller which is used to realize non-linear tracking and decoupling control of the roll and angle motion is introduced based on an improved trajectory linearization control method. The improved method is composed of the classic trajectory linearization control method and a compensation control law. The classic trajectory linearization control method is implemented in the time-scale separation principle. The Lipschitz non-linear state observer systematically obtained by solving the linear matrix inequality approach is provided to estimate state variables and unknown parameters, and then the compensation control law utilizing the estimated unknown parameters improves the TLC method. Simulation experiments show that the adaptive decoupling control ensure tracking performance, and the robustness and accuracy of missile attitude control are ensured under the condition of the system parameters uncertainty, random observation noise and external disturbance caused by damage fin.
DOI: 10.6084/m9.figshare.7509833.v1
title: The Control of Asymmetric Rolling Missiles Based on Improved Trajectory Linearization Control Method

description: ABSTRACT According to motion characteristic of an asymmetric rolling missile with damage fin, a three-channel controlled model is established. The controller which is used to realize non-linear tracking and decoupling control of the roll and angle motion is introduced based on an improved trajectory linearization control method. The improved method is composed of the classic trajectory linearization control method and a compensation control law. The classic trajectory linearization control method is implemented in the time-scale separation principle. The Lipschitz non-linear state observer systematically obtained by solving the linear matrix inequality approach is provided to estimate state variables and unknown parameters, and then the compensation control law utilizing the estimated unknown parameters improves the TLC method. Simulation experiments show that the adaptive decoupling control ensure tracking performance, and the robustness and accuracy of missile attitude control are ensured under the condition of the system parameters uncertainty, random observation noise and external disturbance caused by damage fin.