In order to improve the problem of overly relying on situational information, high computational power requirements, and weak adaptability of traditional maneuver methods used by hypersonic vehicles (HV), an intelligent maneuver strategy combining deep reinforcement learning (DRL) and deep neural network (DNN) is proposed to solve the hypersonic pursuit–evasion (PE) game problem under tough head-on situations. The twin delayed deep deterministic (TD3) gradient strategy algorithm is utilized to explore potential maneuver instructions, the DNN is used to fit to broaden application scenarios, and the intelligent maneuver strategy is generated with the initial situation of both the pursuit and evasion sides as the input and the maneuver game overload of the HV as the output. In addition, the experience pool classification strategy is proposed to improve the training convergence and rate of the TD3 algorithm. A set of reward functions is designed to achieve adaptive adjustment of evasion miss distance and energy consumption under different initial situations. The simulation results verify the feasibility and effectiveness of the above intelligent maneuver strategy in dealing with the PE game problem of HV under difficult situations, and the proposed improvement strategies are validated as well.
{"title":"Intelligent Maneuver Strategy for a Hypersonic Pursuit-Evasion Game Based on Deep Reinforcement Learning","authors":"Yunhe Guo, Zijian Jiang, Hanqiao Huang, Hongjia Fan, Weiye Weng","doi":"10.3390/aerospace10090783","DOIUrl":"https://doi.org/10.3390/aerospace10090783","url":null,"abstract":"In order to improve the problem of overly relying on situational information, high computational power requirements, and weak adaptability of traditional maneuver methods used by hypersonic vehicles (HV), an intelligent maneuver strategy combining deep reinforcement learning (DRL) and deep neural network (DNN) is proposed to solve the hypersonic pursuit–evasion (PE) game problem under tough head-on situations. The twin delayed deep deterministic (TD3) gradient strategy algorithm is utilized to explore potential maneuver instructions, the DNN is used to fit to broaden application scenarios, and the intelligent maneuver strategy is generated with the initial situation of both the pursuit and evasion sides as the input and the maneuver game overload of the HV as the output. In addition, the experience pool classification strategy is proposed to improve the training convergence and rate of the TD3 algorithm. A set of reward functions is designed to achieve adaptive adjustment of evasion miss distance and energy consumption under different initial situations. The simulation results verify the feasibility and effectiveness of the above intelligent maneuver strategy in dealing with the PE game problem of HV under difficult situations, and the proposed improvement strategies are validated as well.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"25 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78275619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.3390/aerospace10090780
Daiwu Zhu, Zehui Chen, Xiaofan Xie, Jiuhao Chen
With the increase in airspace flow, the complexity of the airspace operation environment has also increased. Against this backdrop, improving the operational efficiency of airspace is crucial to ensure its efficient operation. The discrete division of controlled airspace represents a novel methodology for achieving this end. This approach involves visualizing the use of the airspace, quantifying and evaluating the operational efficiencies of airspace environments, and assessing specific metrics during an allocated time period. In this study, a discrete unit model was constructed to hierarchically subdivide complex airspace into static obstacles and aircraft-occupied space units, which facilitated the optimization of decision-making operations for multiple aircraft in airspace using the discrete method. Furthermore, busy airspace units could be effectively avoided. Finally, by using the extended analytic hierarchy process, we evaluated the threshold value of airspace operational efficiency improvement when operation efficiency metrics were enhanced via discrete approaches. The results indicated that the threshold value was 0.02168, classified as “good”, which represented an improvement in comparison with the original value of airspace operational efficiency (0.03173). These findings demonstrated that the application of the discrete division methodology significantly improved the overall operational efficiency of the airspace.
{"title":"Discretization Method to Improve the Efficiency of Complex Airspace Operation","authors":"Daiwu Zhu, Zehui Chen, Xiaofan Xie, Jiuhao Chen","doi":"10.3390/aerospace10090780","DOIUrl":"https://doi.org/10.3390/aerospace10090780","url":null,"abstract":"With the increase in airspace flow, the complexity of the airspace operation environment has also increased. Against this backdrop, improving the operational efficiency of airspace is crucial to ensure its efficient operation. The discrete division of controlled airspace represents a novel methodology for achieving this end. This approach involves visualizing the use of the airspace, quantifying and evaluating the operational efficiencies of airspace environments, and assessing specific metrics during an allocated time period. In this study, a discrete unit model was constructed to hierarchically subdivide complex airspace into static obstacles and aircraft-occupied space units, which facilitated the optimization of decision-making operations for multiple aircraft in airspace using the discrete method. Furthermore, busy airspace units could be effectively avoided. Finally, by using the extended analytic hierarchy process, we evaluated the threshold value of airspace operational efficiency improvement when operation efficiency metrics were enhanced via discrete approaches. The results indicated that the threshold value was 0.02168, classified as “good”, which represented an improvement in comparison with the original value of airspace operational efficiency (0.03173). These findings demonstrated that the application of the discrete division methodology significantly improved the overall operational efficiency of the airspace.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"72 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86573900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.3390/aerospace10090781
Bona P. Fitrikananda, Y. I. Jenie, R. A. Sasongko, Hari Muhammad
The rise in Unmanned Aerial Vehicle (UAV) usage has opened exciting possibilities but has also introduced risks, particularly in aviation, with instances of UAVs flying dangerously close to commercial airplanes. The potential for accidents underscores the urgent need for effective measures to mitigate mid-air collision risks. This research aims to assess the effectiveness of the Sense and Avoid (SAA) system during operation by providing a rating system to quantify its parameters and operational risk, ultimately enabling authorities, developers, and operators to make informed decisions to reach a certain level of safety. Seven parameters are quantified in this research: the SAA’s detection range, field of view, sensor accuracy, measurement rate, system integration, and the intruder’s range and closing speed. While prior studies have addressed these parameter quantifications separately, this research’s main contribution is the comprehensive method that integrates them all within a simple five-level risk rating system. This quantification is complemented by a risk assessment simulator capable of testing a UAV’s risk rating within a large sample of arbitrary flight traffic in a Monte Carlo simulation setup, which ultimately derives its maximum risk rating. The simulation results demonstrated safety improvements using the SAA system, shown by the combined maximum risk rating value. Among the contributing factors, the detection range and sensor accuracy of the SAA system stand out as the primary drivers of this improvement. This conclusion is consistent even in more regulated air traffic imposed with five or three mandatory routes. Interestingly, increasing the number of intruders to 50 does not alter the results, as the intruders’ probability of being detected remains almost the same. On the other hand, improving SAA radar capability has a more significant effect on risk rating than enforcing regulations or limiting intruders.
{"title":"Risk Assessment Method for UAV’s Sense and Avoid System Based on Multi-Parameter Quantification and Monte Carlo Simulation","authors":"Bona P. Fitrikananda, Y. I. Jenie, R. A. Sasongko, Hari Muhammad","doi":"10.3390/aerospace10090781","DOIUrl":"https://doi.org/10.3390/aerospace10090781","url":null,"abstract":"The rise in Unmanned Aerial Vehicle (UAV) usage has opened exciting possibilities but has also introduced risks, particularly in aviation, with instances of UAVs flying dangerously close to commercial airplanes. The potential for accidents underscores the urgent need for effective measures to mitigate mid-air collision risks. This research aims to assess the effectiveness of the Sense and Avoid (SAA) system during operation by providing a rating system to quantify its parameters and operational risk, ultimately enabling authorities, developers, and operators to make informed decisions to reach a certain level of safety. Seven parameters are quantified in this research: the SAA’s detection range, field of view, sensor accuracy, measurement rate, system integration, and the intruder’s range and closing speed. While prior studies have addressed these parameter quantifications separately, this research’s main contribution is the comprehensive method that integrates them all within a simple five-level risk rating system. This quantification is complemented by a risk assessment simulator capable of testing a UAV’s risk rating within a large sample of arbitrary flight traffic in a Monte Carlo simulation setup, which ultimately derives its maximum risk rating. The simulation results demonstrated safety improvements using the SAA system, shown by the combined maximum risk rating value. Among the contributing factors, the detection range and sensor accuracy of the SAA system stand out as the primary drivers of this improvement. This conclusion is consistent even in more regulated air traffic imposed with five or three mandatory routes. Interestingly, increasing the number of intruders to 50 does not alter the results, as the intruders’ probability of being detected remains almost the same. On the other hand, improving SAA radar capability has a more significant effect on risk rating than enforcing regulations or limiting intruders.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"12 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91110111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Endurance is a critical factor for solar-powered unmanned aerial vehicles (SUAVs). Taking inspiration from birds, SUAVs have the ability to harvest extra energy from atmospheric thermal updrafts to extend their endurance. Though recent research has mainly focused on estimating the characteristics of thermal updrafts, there is a noticeable dearth of studies investigating the energy performance of SUAVs during soaring under different conditions. To begin with, this work establishes a thermal updraft and SUAV energy model. In addition, it introduces an integrated guidance and control process to achieve static soaring within thermal for SUAVs. Numerical simulations are implemented to analyze the electric energy performance at different solar irradiation levels, SUAV velocities and thermal strengths. Several remarkable conclusions are drawn from the simulations, which could provide significant insights for SUAVs to further exploit thermal energy.
{"title":"Energy Analysis for Solar-Powered Unmanned Aerial Vehicle under Static Soaring","authors":"Yansen Wu, Ke Li, Anmin Zhao, Haobo Liu, Yuan-Bo Li, Dongsheng Wen","doi":"10.3390/aerospace10090779","DOIUrl":"https://doi.org/10.3390/aerospace10090779","url":null,"abstract":"Endurance is a critical factor for solar-powered unmanned aerial vehicles (SUAVs). Taking inspiration from birds, SUAVs have the ability to harvest extra energy from atmospheric thermal updrafts to extend their endurance. Though recent research has mainly focused on estimating the characteristics of thermal updrafts, there is a noticeable dearth of studies investigating the energy performance of SUAVs during soaring under different conditions. To begin with, this work establishes a thermal updraft and SUAV energy model. In addition, it introduces an integrated guidance and control process to achieve static soaring within thermal for SUAVs. Numerical simulations are implemented to analyze the electric energy performance at different solar irradiation levels, SUAV velocities and thermal strengths. Several remarkable conclusions are drawn from the simulations, which could provide significant insights for SUAVs to further exploit thermal energy.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"51 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79318002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-31DOI: 10.3390/aerospace10090770
Archana Tikayat Ray, Anirudh Prabhakara Bhat, Ryan T. White, Van Minh Nguyen, Olivia J. Pinon Fischer, D. Mavris
This research investigates the potential application of generative language models, especially ChatGPT, in aviation safety analysis as a means to enhance the efficiency of safety analyses and accelerate the time it takes to process incident reports. In particular, ChatGPT was leveraged to generate incident synopses from narratives, which were subsequently compared with ground-truth synopses from the Aviation Safety Reporting System (ASRS) dataset. The comparison was facilitated by using embeddings from Large Language Models (LLMs), with aeroBERT demonstrating the highest similarity due to its aerospace-specific fine-tuning. A positive correlation was observed between the synopsis length and its cosine similarity. In a subsequent phase, human factors issues involved in incidents, as identified by ChatGPT, were compared to human factors issues identified by safety analysts. The precision was found to be 0.61, with ChatGPT demonstrating a cautious approach toward attributing human factors issues. Finally, the model was utilized to execute an evaluation of accountability. As no dedicated ground-truth column existed for this task, a manual evaluation was conducted to compare the quality of outputs provided by ChatGPT to the ground truths provided by safety analysts. This study discusses the advantages and pitfalls of generative language models in the context of aviation safety analysis and proposes a human-in-the-loop system to ensure responsible and effective utilization of such models, leading to continuous improvement and fostering a collaborative approach in the aviation safety domain.
{"title":"Examining the Potential of Generative Language Models for Aviation Safety Analysis: Case Study and Insights Using the Aviation Safety Reporting System (ASRS)","authors":"Archana Tikayat Ray, Anirudh Prabhakara Bhat, Ryan T. White, Van Minh Nguyen, Olivia J. Pinon Fischer, D. Mavris","doi":"10.3390/aerospace10090770","DOIUrl":"https://doi.org/10.3390/aerospace10090770","url":null,"abstract":"This research investigates the potential application of generative language models, especially ChatGPT, in aviation safety analysis as a means to enhance the efficiency of safety analyses and accelerate the time it takes to process incident reports. In particular, ChatGPT was leveraged to generate incident synopses from narratives, which were subsequently compared with ground-truth synopses from the Aviation Safety Reporting System (ASRS) dataset. The comparison was facilitated by using embeddings from Large Language Models (LLMs), with aeroBERT demonstrating the highest similarity due to its aerospace-specific fine-tuning. A positive correlation was observed between the synopsis length and its cosine similarity. In a subsequent phase, human factors issues involved in incidents, as identified by ChatGPT, were compared to human factors issues identified by safety analysts. The precision was found to be 0.61, with ChatGPT demonstrating a cautious approach toward attributing human factors issues. Finally, the model was utilized to execute an evaluation of accountability. As no dedicated ground-truth column existed for this task, a manual evaluation was conducted to compare the quality of outputs provided by ChatGPT to the ground truths provided by safety analysts. This study discusses the advantages and pitfalls of generative language models in the context of aviation safety analysis and proposes a human-in-the-loop system to ensure responsible and effective utilization of such models, leading to continuous improvement and fostering a collaborative approach in the aviation safety domain.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"13 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88468281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-31DOI: 10.3390/aerospace10090771
Katerina Bernardova Sykorova
TOPIC: The task of the 21st century is the implementation of manned flights in Earth’s orbit with the view to building orbital and planetary bases. This requires addressing the impacts on people and small social groups in terms of psychological, psychosocial, physiological and health. The author presents her own comprehensive research and intervention approach to exploring and supporting the operation of the space crew in the four-month isolation period of “SIRIUS-18/19”, which can be used in the future for manned flights into deep space. GOAL: The main goal is to present three main areas, within the implementation of social research, designed to analyze the operation of the crew in a simulated space flight: 1. WORKING CONDITIONS, WORKING ENVIRONMENT AND SOCIAL ATMOSPHERE; 2. the STRUCTURE AND DYNAMICS OF RELATIONSHIPS and TIES; 3. a set of other specific areas. The key outputs of the comprehensive analysis of the “SIRIUS-19” crew operations concerning the level of satisfaction with the working environment and conditions, the structure and dynamics of relationships and other specific areas are presented. The suitability of the implementation of intervention activities for isolated crews is pointed out. The purpose is to contribute to the preparation of human crews for manned flights in deep space and to reduce the risks of damage to human biopsychosocial health. METHODS: For a comprehensive analysis, a set of the author’s own questionnaire methods, verified over 25 years in the normal and extremely demanding conditions of specific professions, was used. The diagnostic and intervention method sociomapping, based on fuzzy theory and the mathematical modeling of outputs, was used for the analysis of the structure and dynamics of relationships as it is a technique suitable for the analysis of nonlinear dynamical systems. The methodology enabled the author to obtain a comprehensive view of the experimental situation from a psychosocial and sociological point of view. RESULTS: The model of the author’s analytical approach confirmed the legitimacy of its implementation in the case of isolation experiments. A comprehensive analysis of the “SIRIUS-18/19” crew’s work environment yielded outputs from the 10 main and 48 sub-areas analyzed. The analysis of the six-member, gender-mixed, multicultural crew in the area of structure and dynamics of relationships focused on 35 areas; a total of 344 sociomaps were created. The files were analyzed qualitatively and quantitatively using control diagrams. CONCLUSIONS: Outputs have the potential to be used in other isolation experiments as sociotechnical measures for project organizers and as verification of the need to introduce work with the crew in the form of development workshops using the sociomapping method.
{"title":"Application of a Psychosocial Approach to the Identification and Strengthening of Adaptation Mechanisms of Humans and a Small Social Group during the Isolation Experiment “SIRIUS 2017–2023”","authors":"Katerina Bernardova Sykorova","doi":"10.3390/aerospace10090771","DOIUrl":"https://doi.org/10.3390/aerospace10090771","url":null,"abstract":"TOPIC: The task of the 21st century is the implementation of manned flights in Earth’s orbit with the view to building orbital and planetary bases. This requires addressing the impacts on people and small social groups in terms of psychological, psychosocial, physiological and health. The author presents her own comprehensive research and intervention approach to exploring and supporting the operation of the space crew in the four-month isolation period of “SIRIUS-18/19”, which can be used in the future for manned flights into deep space. GOAL: The main goal is to present three main areas, within the implementation of social research, designed to analyze the operation of the crew in a simulated space flight: 1. WORKING CONDITIONS, WORKING ENVIRONMENT AND SOCIAL ATMOSPHERE; 2. the STRUCTURE AND DYNAMICS OF RELATIONSHIPS and TIES; 3. a set of other specific areas. The key outputs of the comprehensive analysis of the “SIRIUS-19” crew operations concerning the level of satisfaction with the working environment and conditions, the structure and dynamics of relationships and other specific areas are presented. The suitability of the implementation of intervention activities for isolated crews is pointed out. The purpose is to contribute to the preparation of human crews for manned flights in deep space and to reduce the risks of damage to human biopsychosocial health. METHODS: For a comprehensive analysis, a set of the author’s own questionnaire methods, verified over 25 years in the normal and extremely demanding conditions of specific professions, was used. The diagnostic and intervention method sociomapping, based on fuzzy theory and the mathematical modeling of outputs, was used for the analysis of the structure and dynamics of relationships as it is a technique suitable for the analysis of nonlinear dynamical systems. The methodology enabled the author to obtain a comprehensive view of the experimental situation from a psychosocial and sociological point of view. RESULTS: The model of the author’s analytical approach confirmed the legitimacy of its implementation in the case of isolation experiments. A comprehensive analysis of the “SIRIUS-18/19” crew’s work environment yielded outputs from the 10 main and 48 sub-areas analyzed. The analysis of the six-member, gender-mixed, multicultural crew in the area of structure and dynamics of relationships focused on 35 areas; a total of 344 sociomaps were created. The files were analyzed qualitatively and quantitatively using control diagrams. CONCLUSIONS: Outputs have the potential to be used in other isolation experiments as sociotechnical measures for project organizers and as verification of the need to introduce work with the crew in the form of development workshops using the sociomapping method.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"36 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87945538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-31DOI: 10.3390/aerospace10090773
S. Proskurov, M. Lummer, J. Delfs, R. Ewert, J. Kirz, M. Plohr, Robert Jaron
Overcoming the problem of excessive engine noise at low altitudes is a formidable task on the way to developing a supersonic passenger aircraft. The focus of this paper is on the fan noise shielding during take-off, investigated as part of the DLR project ELTON SST (estimation of landing and take-off noise of supersonic transport) for an in-house aircraft design. The supersonic inlet is required to provide the proper quantity and uniformity of air to the engine over a wider range of flight conditions than the subsonic inlet. For passenger aircraft, the noise problem influences engine integration and placement, and the new generation of supersonic transport would require innovative engineering solutions in order to come up with an efficient low-noise design. Potential solutions are evaluated using DLR tools capable of accurate source generation and noise propagation to the far-field. For low-speed aircraft operation, the method of choice is a strongly coupled volume-resolving discontinuous Galerkin (DG) and fast multipole boundary element method (FM-BEM) which is applied due to a large disparity between the Mach numbers on the interior and exterior of the inlet. The method is used for obtaining the acoustic signature of the full-scale model at realistic flight points, including the application of the programmed lapse rate (PLR), which involves simulations at higher pitch angles than for the reference flight path. The results show that the proposed method is highly suitable for obtaining accurate noise footprints during the low-speed phase and could be used to assist with certification procedures of future supersonic aircraft.
{"title":"Installed Fan Noise Simulation of a Supersonic Business Aircraft","authors":"S. Proskurov, M. Lummer, J. Delfs, R. Ewert, J. Kirz, M. Plohr, Robert Jaron","doi":"10.3390/aerospace10090773","DOIUrl":"https://doi.org/10.3390/aerospace10090773","url":null,"abstract":"Overcoming the problem of excessive engine noise at low altitudes is a formidable task on the way to developing a supersonic passenger aircraft. The focus of this paper is on the fan noise shielding during take-off, investigated as part of the DLR project ELTON SST (estimation of landing and take-off noise of supersonic transport) for an in-house aircraft design. The supersonic inlet is required to provide the proper quantity and uniformity of air to the engine over a wider range of flight conditions than the subsonic inlet. For passenger aircraft, the noise problem influences engine integration and placement, and the new generation of supersonic transport would require innovative engineering solutions in order to come up with an efficient low-noise design. Potential solutions are evaluated using DLR tools capable of accurate source generation and noise propagation to the far-field. For low-speed aircraft operation, the method of choice is a strongly coupled volume-resolving discontinuous Galerkin (DG) and fast multipole boundary element method (FM-BEM) which is applied due to a large disparity between the Mach numbers on the interior and exterior of the inlet. The method is used for obtaining the acoustic signature of the full-scale model at realistic flight points, including the application of the programmed lapse rate (PLR), which involves simulations at higher pitch angles than for the reference flight path. The results show that the proposed method is highly suitable for obtaining accurate noise footprints during the low-speed phase and could be used to assist with certification procedures of future supersonic aircraft.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"1 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84278590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-31DOI: 10.3390/aerospace10090776
Xiancheng Gu, Linghua Dong, Tong Li, Weidong Yang
An active rotor with trailing-edge flaps (TEFs) is an effective active vibration control method for helicopters. Blade flapping dynamic characteristics have a significant effect on the active vibration control performance of an active rotor. In this study, an aeroelastic model is developed using the Hamilton principle, and a quasi-steady Theodorsen model for the airfoil with a TEF is utilized to calculate the aerodynamic loads induced by the dynamic deflection of TEFs. The accuracy of this model is validated through a comparison with the CAMRAD calculation and flight test results of a SA349/2 helicopter. Based on the modal orthogonality and the equilibrium equation of the blade flapping motion, the method of changing the blade flapping dynamic characteristics is obtained. Blade sectional characteristics are adjusted to study the effect of blade flapping dynamics on the vibration control authority of an active rotor. The simulation results demonstrate that if the modal frequency of second-order flap is tuned to close to the rotor passage frequency, the flapping dynamic characteristics are capable of enhancing the vibration control performance of the active rotor.
{"title":"A Study on Influence of Flapping Dynamic Characteristics on Vibration Control of Active Rotor with Trailing-Edge Flaps","authors":"Xiancheng Gu, Linghua Dong, Tong Li, Weidong Yang","doi":"10.3390/aerospace10090776","DOIUrl":"https://doi.org/10.3390/aerospace10090776","url":null,"abstract":"An active rotor with trailing-edge flaps (TEFs) is an effective active vibration control method for helicopters. Blade flapping dynamic characteristics have a significant effect on the active vibration control performance of an active rotor. In this study, an aeroelastic model is developed using the Hamilton principle, and a quasi-steady Theodorsen model for the airfoil with a TEF is utilized to calculate the aerodynamic loads induced by the dynamic deflection of TEFs. The accuracy of this model is validated through a comparison with the CAMRAD calculation and flight test results of a SA349/2 helicopter. Based on the modal orthogonality and the equilibrium equation of the blade flapping motion, the method of changing the blade flapping dynamic characteristics is obtained. Blade sectional characteristics are adjusted to study the effect of blade flapping dynamics on the vibration control authority of an active rotor. The simulation results demonstrate that if the modal frequency of second-order flap is tuned to close to the rotor passage frequency, the flapping dynamic characteristics are capable of enhancing the vibration control performance of the active rotor.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"123 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85272553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-31DOI: 10.3390/aerospace10090775
Arinc Tutku Altun, M. Hasanzade, Emre Saldiran, Guney Guner, Mevlut Uzun, Rodolphe Fremond, Yiwen Tang, Prithiviraj Bhundoo, Yu Su, Yan Xu, G. Inalhan, Michael W. Hardt, A. Fransoy, A. Modha, Jose Antonio Tena, Cesar Nieto, M. Vilaplana, M. Tojal, V. Gordo, Pablo Menendez, A. Gonzalez
Advanced Air Mobility (AAM) is a concept that is expected to transform the current air transportation system and provide more flexibility, agility, and accessibility by extending the operations to urban environments. This study focuses on flight test, integration, and analysis considerations for the feasibility of the future AAM concept and showcases the outputs of the Air Mobility Urban-Large Experimental Demonstration (AMU-LED) project demonstrations at Cranfield University. The purpose of the Cranfield demonstrations is to explore the integrated decentralized architecture of the AAM concept with layered airspace structure through various use cases within a co-simulation environment consisting of real and simulated standard-performing vehicle (SPV) and high-performing vehicle (HPV) flights, manned, and general aviation flights. Throughout the real and simulated flights, advanced U-space services are demonstrated and contingency management activities, including emergency operations and landing, are tested within the developed co-simulation environment. Moreover, flight tests are verified and validated through key performance indicator analysis, along with a social acceptance study. Future recommendations on relevant industrial and regulative activities are provided.
{"title":"AMU-LED Cranfield Flight Trials for Demonstrating the Advanced Air Mobility Concept","authors":"Arinc Tutku Altun, M. Hasanzade, Emre Saldiran, Guney Guner, Mevlut Uzun, Rodolphe Fremond, Yiwen Tang, Prithiviraj Bhundoo, Yu Su, Yan Xu, G. Inalhan, Michael W. Hardt, A. Fransoy, A. Modha, Jose Antonio Tena, Cesar Nieto, M. Vilaplana, M. Tojal, V. Gordo, Pablo Menendez, A. Gonzalez","doi":"10.3390/aerospace10090775","DOIUrl":"https://doi.org/10.3390/aerospace10090775","url":null,"abstract":"Advanced Air Mobility (AAM) is a concept that is expected to transform the current air transportation system and provide more flexibility, agility, and accessibility by extending the operations to urban environments. This study focuses on flight test, integration, and analysis considerations for the feasibility of the future AAM concept and showcases the outputs of the Air Mobility Urban-Large Experimental Demonstration (AMU-LED) project demonstrations at Cranfield University. The purpose of the Cranfield demonstrations is to explore the integrated decentralized architecture of the AAM concept with layered airspace structure through various use cases within a co-simulation environment consisting of real and simulated standard-performing vehicle (SPV) and high-performing vehicle (HPV) flights, manned, and general aviation flights. Throughout the real and simulated flights, advanced U-space services are demonstrated and contingency management activities, including emergency operations and landing, are tested within the developed co-simulation environment. Moreover, flight tests are verified and validated through key performance indicator analysis, along with a social acceptance study. Future recommendations on relevant industrial and regulative activities are provided.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"75 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80670396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, an adaptive neural network global fractional order fast terminal sliding mode model-free intelligent PID control strategy (termed as TDE-ANNGFOFTSMC-MFIPIDC) is proposed for the hypersonic vehicle ground thermal environment simulation test device (GTESTD). Firstly, the mathematical model of the GTESTD is transformed into an ultra-local model to ensure that the control strategy design process does not rely on the potentially inaccurate dynamic GTESTD model. Meanwhile, time delay estimation (TDE) is employed to estimate the unknown terms of the ultra-local model. Next, a global fractional-order fast terminal sliding mode surface (GFOFTSMS) is introduced to effectively reduce the estimation error generated by TDE. It also eliminates arrival time, accelerates the convergence speed of the sliding phase, guarantees finite time arrival, avoids the singularity phenomenon, and bolsters robustness. Then, as the upper bound of the disturbance error is unknown, an adaptive neural network (ANN) control is designed to approximate the upper bound of the estimation error closely and mitigate the chattering phenomenon. Furthermore, the stability of the control system and the convergence time are proven by the Lyapunov stability theorem and are calculated, respectively. Finally, simulation results are conducted to validate the efficacy of the proposed control strategy.
{"title":"Adaptive Neural Network Global Fractional Order Fast Terminal Sliding Mode Model-Free Intelligent PID Control for Hypersonic Vehicle’s Ground Thermal Environment","authors":"Xiaodong Lv, Guangming Zhang, Z. Bai, Xiaoxiong Zhou, Zhihan Shi, Mingxiang Zhu","doi":"10.3390/aerospace10090777","DOIUrl":"https://doi.org/10.3390/aerospace10090777","url":null,"abstract":"In this paper, an adaptive neural network global fractional order fast terminal sliding mode model-free intelligent PID control strategy (termed as TDE-ANNGFOFTSMC-MFIPIDC) is proposed for the hypersonic vehicle ground thermal environment simulation test device (GTESTD). Firstly, the mathematical model of the GTESTD is transformed into an ultra-local model to ensure that the control strategy design process does not rely on the potentially inaccurate dynamic GTESTD model. Meanwhile, time delay estimation (TDE) is employed to estimate the unknown terms of the ultra-local model. Next, a global fractional-order fast terminal sliding mode surface (GFOFTSMS) is introduced to effectively reduce the estimation error generated by TDE. It also eliminates arrival time, accelerates the convergence speed of the sliding phase, guarantees finite time arrival, avoids the singularity phenomenon, and bolsters robustness. Then, as the upper bound of the disturbance error is unknown, an adaptive neural network (ANN) control is designed to approximate the upper bound of the estimation error closely and mitigate the chattering phenomenon. Furthermore, the stability of the control system and the convergence time are proven by the Lyapunov stability theorem and are calculated, respectively. Finally, simulation results are conducted to validate the efficacy of the proposed control strategy.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":"1 1","pages":""},"PeriodicalIF":0.1,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89168956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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