Pub Date : 2023-08-25DOI: 10.3390/aerospace10090755
Jiacheng Li, Hanlin Sheng, J. Zhang, Haibo Zhang
In the coverage path planning (CPP) problem of an agricultural spraying UAV, a margin reduction algorithm was designed first to address special situations such as ditches and channels within the operational terrain. Regarding the particularity of a concave polygon area, an algorithm based on topology mapping was developed to judge the concave points of the concave polygon area, and the path with special concave points was scheduled. For the evaluation of the pesticide spraying mission, the flight distance and extra coverage ratio were the most appropriate optimization objectives. Therefore, this paper selected these two indicators to form a fitness function, then found the optimal operating heading angle of the mission after iterative optimization. Finally, the CPP for an agricultural spraying UAV in an arbitrary polygon area under the optimal heading angle was realized. The simulation and flight test results showed that the CPP method could significantly shorten the flight distance and reduce additional coverage, then avoid energy consumption and pesticide waste. In addition, the engineering practicability of the method was verified in this paper. This method can be popularized and widely used for an agricultural spraying UAV, which has great engineering application value.
{"title":"Coverage Path Planning Method for Agricultural Spraying UAV in Arbitrary Polygon Area","authors":"Jiacheng Li, Hanlin Sheng, J. Zhang, Haibo Zhang","doi":"10.3390/aerospace10090755","DOIUrl":"https://doi.org/10.3390/aerospace10090755","url":null,"abstract":"In the coverage path planning (CPP) problem of an agricultural spraying UAV, a margin reduction algorithm was designed first to address special situations such as ditches and channels within the operational terrain. Regarding the particularity of a concave polygon area, an algorithm based on topology mapping was developed to judge the concave points of the concave polygon area, and the path with special concave points was scheduled. For the evaluation of the pesticide spraying mission, the flight distance and extra coverage ratio were the most appropriate optimization objectives. Therefore, this paper selected these two indicators to form a fitness function, then found the optimal operating heading angle of the mission after iterative optimization. Finally, the CPP for an agricultural spraying UAV in an arbitrary polygon area under the optimal heading angle was realized. The simulation and flight test results showed that the CPP method could significantly shorten the flight distance and reduce additional coverage, then avoid energy consumption and pesticide waste. In addition, the engineering practicability of the method was verified in this paper. This method can be popularized and widely used for an agricultural spraying UAV, which has great engineering application value.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77913748","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 : 2023-08-25DOI: 10.3390/aerospace10090750
Xiaoyuan Zheng, Cheng Zhang, Yifang Lou, Guangming Xue, H. Bai
Active vibration control shows excellent performance in vibration isolation. In this work, the finite element model of a toothed electromagnetic spring (TES) is established using ANSYS Maxwell software. Subsequently, a static characteristic experiment of the TES is carried out, and the validity of the model is verified. Based on the established finite element model, the influence of key structural parameters on the static characteristics of the electromagnetic spring is analyzed. The results show that the parameters of the magnetic teeth have a significant impact on the performance of the electromagnetic spring. As the number of teeth increases, the electromagnetic force first increases and then decreases. With the increase in the tooth height or width, the maximum electromagnetic force gradually increases to the maximum value and then stabilizes. It should be noted that the tooth width simultaneously affects the maximum electromagnetic force, stiffness characteristics, and effective working range of the TES. This work provides a basis for further exploring the application of electromagnetic springs within the field of active vibration control.
{"title":"Parametric Analysis of the Toothed Electromagnetic Spring Based on the Finite Element Model","authors":"Xiaoyuan Zheng, Cheng Zhang, Yifang Lou, Guangming Xue, H. Bai","doi":"10.3390/aerospace10090750","DOIUrl":"https://doi.org/10.3390/aerospace10090750","url":null,"abstract":"Active vibration control shows excellent performance in vibration isolation. In this work, the finite element model of a toothed electromagnetic spring (TES) is established using ANSYS Maxwell software. Subsequently, a static characteristic experiment of the TES is carried out, and the validity of the model is verified. Based on the established finite element model, the influence of key structural parameters on the static characteristics of the electromagnetic spring is analyzed. The results show that the parameters of the magnetic teeth have a significant impact on the performance of the electromagnetic spring. As the number of teeth increases, the electromagnetic force first increases and then decreases. With the increase in the tooth height or width, the maximum electromagnetic force gradually increases to the maximum value and then stabilizes. It should be noted that the tooth width simultaneously affects the maximum electromagnetic force, stiffness characteristics, and effective working range of the TES. This work provides a basis for further exploring the application of electromagnetic springs within the field of active vibration control.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89351554","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 : 2023-08-24DOI: 10.3390/aerospace10090749
Yongchang Huang, Xiangying Guo, D. Cao
Z-shaped folding wings have the potential to enhance the flight performance of an aircraft, contingent upon its mission requirements. However, the current scope of research on unmanned aerial vehicles (UAVs) with Z-shaped folding wings primarily focuses on the analysis of their folding structure and aeroelasticity-related vibrations. Computational fluid dynamics methods and dynamic meshing are employed to examine the folding process of Z-shaped folding wings. By comparing the steady aerodynamic characteristics of Z-shaped folding wings with those of conventional wings, this investigation explores the dynamic aerodynamic properties of Z-shaped folding wings at varying upward folding speeds. The numerical findings reveal that the folding of Z-shaped folding wings reduces the lift-to-drag ratio, yet simultaneously diminishes the nose-down pitching moment, thereby augmenting maneuverability. Concerning unsteady aerodynamics, the transient lift and drag coefficients of the folded wing initially increase and subsequently decrease as the folding angle increases at small angles of attack. Likewise, the nose-down pitching moment exhibits the same pattern in response to the folding angle. Additionally, the aerodynamic coefficients experience a slight decrease during the initial half of the folding process with increasing folding speed. Once the wing reaches approximately 40°~45° of folding, there is an abrupt change in the transient aerodynamic coefficients. Notably, this abrupt change is delayed with higher folding speeds, eventually converging to similar values across different folding speeds.
{"title":"Aerodynamic Characteristics of a Z-Shaped Folding Wing","authors":"Yongchang Huang, Xiangying Guo, D. Cao","doi":"10.3390/aerospace10090749","DOIUrl":"https://doi.org/10.3390/aerospace10090749","url":null,"abstract":"Z-shaped folding wings have the potential to enhance the flight performance of an aircraft, contingent upon its mission requirements. However, the current scope of research on unmanned aerial vehicles (UAVs) with Z-shaped folding wings primarily focuses on the analysis of their folding structure and aeroelasticity-related vibrations. Computational fluid dynamics methods and dynamic meshing are employed to examine the folding process of Z-shaped folding wings. By comparing the steady aerodynamic characteristics of Z-shaped folding wings with those of conventional wings, this investigation explores the dynamic aerodynamic properties of Z-shaped folding wings at varying upward folding speeds. The numerical findings reveal that the folding of Z-shaped folding wings reduces the lift-to-drag ratio, yet simultaneously diminishes the nose-down pitching moment, thereby augmenting maneuverability. Concerning unsteady aerodynamics, the transient lift and drag coefficients of the folded wing initially increase and subsequently decrease as the folding angle increases at small angles of attack. Likewise, the nose-down pitching moment exhibits the same pattern in response to the folding angle. Additionally, the aerodynamic coefficients experience a slight decrease during the initial half of the folding process with increasing folding speed. Once the wing reaches approximately 40°~45° of folding, there is an abrupt change in the transient aerodynamic coefficients. Notably, this abrupt change is delayed with higher folding speeds, eventually converging to similar values across different folding speeds.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75233207","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 : 2023-08-24DOI: 10.3390/aerospace10090748
Gustavo E. Ramos-Alcaraz, Miguel A. Alonso-Arévalo, J. M. Nuñez-Alfonso
Accurate attitude determination is crucial for satellites and spacecraft. Among attitude determination devices, star sensors are the most accurate. Solving the lost-in-space problem is the most critical function of the star sensor. Our research introduces a novel star-identification system that utilizes a polygon-recognition algorithm to assign a unique complex number to polygons created by stars. This system aims to solve the lost-in-space problem. Our system includes a full solution with a lens, image sensor, processing unit, and algorithm implementation. To test the system’s performance, we analyzed 100 night sky images that resembled what a real star sensor in orbit would experience. We used a k-d tree algorithm to accelerate the search in the star catalog of complex numbers. We implemented various verification methods, including internal polygon verification and a voting mechanism, to ensure the system’s reliability. We obtained the star database used as a reference from the Gaia DR2 catalog, which we filtered, to eliminate irrelevant stars, and which we arranged by apparent magnitude. Despite manually introducing up to three false stars, the system successfully identified at least one star in 97% of the analyzed images.
{"title":"Star-Identification System Based on Polygon Recognition","authors":"Gustavo E. Ramos-Alcaraz, Miguel A. Alonso-Arévalo, J. M. Nuñez-Alfonso","doi":"10.3390/aerospace10090748","DOIUrl":"https://doi.org/10.3390/aerospace10090748","url":null,"abstract":"Accurate attitude determination is crucial for satellites and spacecraft. Among attitude determination devices, star sensors are the most accurate. Solving the lost-in-space problem is the most critical function of the star sensor. Our research introduces a novel star-identification system that utilizes a polygon-recognition algorithm to assign a unique complex number to polygons created by stars. This system aims to solve the lost-in-space problem. Our system includes a full solution with a lens, image sensor, processing unit, and algorithm implementation. To test the system’s performance, we analyzed 100 night sky images that resembled what a real star sensor in orbit would experience. We used a k-d tree algorithm to accelerate the search in the star catalog of complex numbers. We implemented various verification methods, including internal polygon verification and a voting mechanism, to ensure the system’s reliability. We obtained the star database used as a reference from the Gaia DR2 catalog, which we filtered, to eliminate irrelevant stars, and which we arranged by apparent magnitude. Despite manually introducing up to three false stars, the system successfully identified at least one star in 97% of the analyzed images.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91034604","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 : 2023-08-23DOI: 10.3390/aerospace10090747
Xudong Han, Y. Fu, Yan Wang, Mingkang Wang, Deming Zhu
The control accuracy and stability of the electrohydrostatic actuator (EHA) are directly impacted by parameter uncertainty, disturbance uncertainty, and non-matching disturbance, which negatively impacts aircraft rudder maneuvering performance and even results in rudder chatter. A dynamic surface-based adaptive active disturbance rejection control (DSAADRC) is proposed as a solution for these issues. It does this by developing a novel parametric adaptive law driven by the combination of tracking error, parameter estimation error, and state estimation error to estimate the unknown parameters, using three low-order ESOs to estimate and compensate the uncertain disturbances online, and employing a dynamic surface method to obtain the differential values of virtual control signals in the backstepping method to deal with non-matching disturbances. In this research, a Lyapunov stability analysis demonstrates that the method can achieve the position tracking accuracy of the EHA under time-varying external disturbances after first establishing an EHA dynamics model with nonlinearity and uncertainty, followed by the design of an adaptive active disturbance rejection control method based on dynamic surfaces for the uncertainties and perturbations. In contrast to control strategies like Robust Control (RC) and Adaptive Robust Control (ARC), simulation and experiment comparison shows that the method has stronger anti-disturbance under time-varying external disturbances.
{"title":"Dynamic Surface-Based Adaptive Active Disturbance Rejection Control of Electrohydrostatic Actuators","authors":"Xudong Han, Y. Fu, Yan Wang, Mingkang Wang, Deming Zhu","doi":"10.3390/aerospace10090747","DOIUrl":"https://doi.org/10.3390/aerospace10090747","url":null,"abstract":"The control accuracy and stability of the electrohydrostatic actuator (EHA) are directly impacted by parameter uncertainty, disturbance uncertainty, and non-matching disturbance, which negatively impacts aircraft rudder maneuvering performance and even results in rudder chatter. A dynamic surface-based adaptive active disturbance rejection control (DSAADRC) is proposed as a solution for these issues. It does this by developing a novel parametric adaptive law driven by the combination of tracking error, parameter estimation error, and state estimation error to estimate the unknown parameters, using three low-order ESOs to estimate and compensate the uncertain disturbances online, and employing a dynamic surface method to obtain the differential values of virtual control signals in the backstepping method to deal with non-matching disturbances. In this research, a Lyapunov stability analysis demonstrates that the method can achieve the position tracking accuracy of the EHA under time-varying external disturbances after first establishing an EHA dynamics model with nonlinearity and uncertainty, followed by the design of an adaptive active disturbance rejection control method based on dynamic surfaces for the uncertainties and perturbations. In contrast to control strategies like Robust Control (RC) and Adaptive Robust Control (ARC), simulation and experiment comparison shows that the method has stronger anti-disturbance under time-varying external disturbances.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80380714","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 : 2023-08-23DOI: 10.3390/aerospace10090745
Maria Coutinho, F. Afonso, Alain Souza, David Bento, Ricardo Gandolfi, Felipe R. Barbosa, F. Lau, A. Suleman
The electrification of an aircraft’s propulsive system is identified as a potential solution towards a lower carbon footprint in the aviation industry. One of the effects of increased electrification is the generation of a large amount of waste heat that needs to be removed. As high-power systems must be cooled to avoid performance deterioration such as battery thermal runaway, a suitable thermal management system is required to regulate the temperature of the powertrain components. With this in mind, the main objective of this research is to identify promising heat transfer technologies to be integrated into a thermal management system (TMS) such that power, mass, and drag can be minimised for a parallel hybrid–electric regional aircraft in the context of the EU-funded FutPrInt50 project. Five different TMS architectures are modelled using the Matlab/Simulink environment based on thermodynamic principles, heat transfer fundamentals, and fluid flow equations. The systems are a combination of a closed-loop liquid cooling integrated with different heat dissipation components, namely ram air heat exchanger, skin heat exchanger, and fuel. Their cooling capacity and overall aircraft performance penalties under different flight conditions are estimated and compared to each other. Then, a parametric study is conducted, followed by a multi-objective optimisation analysis with the aim of minimising the TMS impact. As expected, none of the investigated architectures exhibit an ideal performance across the range of the studied metrics. The research revealed that, while planning the TMS for future hybrid–electric aircraft, alternative architectures will have to be developed and studied in light of the power requirements.
{"title":"A Study on Thermal Management Systems for Hybrid–Electric Aircraft","authors":"Maria Coutinho, F. Afonso, Alain Souza, David Bento, Ricardo Gandolfi, Felipe R. Barbosa, F. Lau, A. Suleman","doi":"10.3390/aerospace10090745","DOIUrl":"https://doi.org/10.3390/aerospace10090745","url":null,"abstract":"The electrification of an aircraft’s propulsive system is identified as a potential solution towards a lower carbon footprint in the aviation industry. One of the effects of increased electrification is the generation of a large amount of waste heat that needs to be removed. As high-power systems must be cooled to avoid performance deterioration such as battery thermal runaway, a suitable thermal management system is required to regulate the temperature of the powertrain components. With this in mind, the main objective of this research is to identify promising heat transfer technologies to be integrated into a thermal management system (TMS) such that power, mass, and drag can be minimised for a parallel hybrid–electric regional aircraft in the context of the EU-funded FutPrInt50 project. Five different TMS architectures are modelled using the Matlab/Simulink environment based on thermodynamic principles, heat transfer fundamentals, and fluid flow equations. The systems are a combination of a closed-loop liquid cooling integrated with different heat dissipation components, namely ram air heat exchanger, skin heat exchanger, and fuel. Their cooling capacity and overall aircraft performance penalties under different flight conditions are estimated and compared to each other. Then, a parametric study is conducted, followed by a multi-objective optimisation analysis with the aim of minimising the TMS impact. As expected, none of the investigated architectures exhibit an ideal performance across the range of the studied metrics. The research revealed that, while planning the TMS for future hybrid–electric aircraft, alternative architectures will have to be developed and studied in light of the power requirements.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90282712","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 : 2023-08-23DOI: 10.3390/aerospace10090746
N. Giannelis, Tamas Bykerk, G. Vio
This paper introduces a generic model for the study of aerodynamic behaviour relevant to fifth-generation high-performance aircraft. The model design is presented, outlining simplifications made to retain the key features of modern high-performance vehicles while ensuring a manufacturable geometry. Subsonic wind tunnel tests were performed with force and moment balance measurements used to develop a database of experimental validation data for the platform at a freestream velocity of 20 m/s. Numerical simulations are also presented and validated by the experiments and further employed to ensure the vortex behaviour is consistent with contemporary high-performance platforms. A sensitivity study of the computational predictions from the turbulence modelling approach is also presented. This geometry is the first in a suite of representative aircraft geometries (the Sydney Standard Aerodynamic Models), in which all geometries, computational models, and experimental data are made openly available to the research community (accessible via this link: https://zenodo.org/communities/ssam_gen5/) to serve as validation test cases and promote best practices in aerodynamic modelling.
{"title":"A Generic Model for Benchmark Aerodynamic Analysis of Fifth-Generation High-Performance Aircraft","authors":"N. Giannelis, Tamas Bykerk, G. Vio","doi":"10.3390/aerospace10090746","DOIUrl":"https://doi.org/10.3390/aerospace10090746","url":null,"abstract":"This paper introduces a generic model for the study of aerodynamic behaviour relevant to fifth-generation high-performance aircraft. The model design is presented, outlining simplifications made to retain the key features of modern high-performance vehicles while ensuring a manufacturable geometry. Subsonic wind tunnel tests were performed with force and moment balance measurements used to develop a database of experimental validation data for the platform at a freestream velocity of 20 m/s. Numerical simulations are also presented and validated by the experiments and further employed to ensure the vortex behaviour is consistent with contemporary high-performance platforms. A sensitivity study of the computational predictions from the turbulence modelling approach is also presented. This geometry is the first in a suite of representative aircraft geometries (the Sydney Standard Aerodynamic Models), in which all geometries, computational models, and experimental data are made openly available to the research community (accessible via this link: https://zenodo.org/communities/ssam_gen5/) to serve as validation test cases and promote best practices in aerodynamic modelling.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75122932","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 : 2023-08-23DOI: 10.3390/aerospace10090744
O. Boucher, N. Bellouin, H. Clark, E. Gryspeerdt, Julien Karadayi
Airlines optimize flight trajectories in order to minimize their operational costs, of which fuel consumption is a large contributor. It is known that flight trajectories are not fuel-optimal because of airspace congestion and restrictions, safety regulations, bad weather and other operational constraints. However, the extent to which trajectories are not fuel-optimal (and therefore CO2-optimal) is not well known. In this study, we present two methods for optimizing the flight cruising time by taking best advantage of the wind pattern at a given flight level and for constant airspeed. We test these methods against actual flight trajectories recorded under the In-service Aircraft for a Global Observing System (IAGOS) programme. One method is more robust than the other (computationally faster) method, but when successful, the two methods agree very well with each other, with optima generally within the order of 0.1%. The IAGOS actual cruising trajectories are on average 1% longer than the computed optimal for the transatlantic route, which leaves little room for improvement given that by construction the actual trajectory cannot be better than our optimum. The average degree of non-optimality is larger for some other routes and can be up to 10%. On some routes, there are also outlier flights that are not well optimized; however, the reason for this is not known.
{"title":"Comparison of Actual and Time-Optimized Flight Trajectories in the Context of the In-Service Aircraft for a Global Observing System (IAGOS) Programme","authors":"O. Boucher, N. Bellouin, H. Clark, E. Gryspeerdt, Julien Karadayi","doi":"10.3390/aerospace10090744","DOIUrl":"https://doi.org/10.3390/aerospace10090744","url":null,"abstract":"Airlines optimize flight trajectories in order to minimize their operational costs, of which fuel consumption is a large contributor. It is known that flight trajectories are not fuel-optimal because of airspace congestion and restrictions, safety regulations, bad weather and other operational constraints. However, the extent to which trajectories are not fuel-optimal (and therefore CO2-optimal) is not well known. In this study, we present two methods for optimizing the flight cruising time by taking best advantage of the wind pattern at a given flight level and for constant airspeed. We test these methods against actual flight trajectories recorded under the In-service Aircraft for a Global Observing System (IAGOS) programme. One method is more robust than the other (computationally faster) method, but when successful, the two methods agree very well with each other, with optima generally within the order of 0.1%. The IAGOS actual cruising trajectories are on average 1% longer than the computed optimal for the transatlantic route, which leaves little room for improvement given that by construction the actual trajectory cannot be better than our optimum. The average degree of non-optimality is larger for some other routes and can be up to 10%. On some routes, there are also outlier flights that are not well optimized; however, the reason for this is not known.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77385759","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 : 2023-08-22DOI: 10.3390/aerospace10090737
Ui-Jeong Lee, S. Ahn, Dong-Young Choi, Sang-Min Chin, Dae-Sung Jang
As the usability of and demand for unmanned aerial vehicles (UAVs) have increased, it has become necessary to establish a UAS traffic management (UTM) system for efficient UAV operations at low altitudes. To avoid collisions with ground obstacles, other UAVs, and manned aircraft, in building a safe path, the UTM needs to determine the time and space allocated to each flight. Ideas for discretizing and structuring airspace in various forms have been proposed to enhance the efficiency of system operation and improve traffic congestion through effectual airspace allocation. Additionally, various methods of allocating UAVs to structured unit spaces have been studied in the literature. In this paper, the methods and structural designs for allocating airspace that have appeared in related studies are classified into several types, and their strengths and weaknesses are analyzed. The structured airspace designs are categorized into three models: Air-Matrix, Air-Network, and Air-Tube, and analyzed according to their sub-structures and temporal allocation methods. In addition, a quantitative analysis is conducted by re-categorizing the structured airspace and operation methods and building their combinations.
{"title":"Airspace Designs and Operations for UAS Traffic Management at Low Altitude","authors":"Ui-Jeong Lee, S. Ahn, Dong-Young Choi, Sang-Min Chin, Dae-Sung Jang","doi":"10.3390/aerospace10090737","DOIUrl":"https://doi.org/10.3390/aerospace10090737","url":null,"abstract":"As the usability of and demand for unmanned aerial vehicles (UAVs) have increased, it has become necessary to establish a UAS traffic management (UTM) system for efficient UAV operations at low altitudes. To avoid collisions with ground obstacles, other UAVs, and manned aircraft, in building a safe path, the UTM needs to determine the time and space allocated to each flight. Ideas for discretizing and structuring airspace in various forms have been proposed to enhance the efficiency of system operation and improve traffic congestion through effectual airspace allocation. Additionally, various methods of allocating UAVs to structured unit spaces have been studied in the literature. In this paper, the methods and structural designs for allocating airspace that have appeared in related studies are classified into several types, and their strengths and weaknesses are analyzed. The structured airspace designs are categorized into three models: Air-Matrix, Air-Network, and Air-Tube, and analyzed according to their sub-structures and temporal allocation methods. In addition, a quantitative analysis is conducted by re-categorizing the structured airspace and operation methods and building their combinations.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72562432","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 : 2023-08-22DOI: 10.3390/aerospace10090740
Weijun Pan, Liru Qin, Qinyue He, Yuanjing Huang
This paper presents a conflict detection and resolution method based on a velocity obstacle method for flight conflicts in a three-dimensional space. With the location and speed information of the two aircraft, the optimal relief strategy is obtained using particle swarm optimization. Aiming at the problem of excessive computational complexity in solving flight conflicts in a three-dimensional space with a cylindrical flight protection zone, an improved method for narrowing the search range is proposed to achieve a rapid solution by simplifying the complicated three-dimensional problem into a two-dimensional problem. The generality and flexibility of the method is effectively verified through simulations in flight conflict scenarios which almost cover all common situations. The experimental results show that the method can accurately determine the conflict time and generate the optimal relief strategy for different scenarios. The improved method of optimizing-search-range can significantly improve the computational efficiency, taking about 0.4 s to find the optimal solution, which can be used in real-time conflict resolution. The study provides a new solution for the flight conflict resolution problem.
{"title":"Three-Dimensional Flight Conflict Detection and Resolution Based on Particle Swarm Optimization","authors":"Weijun Pan, Liru Qin, Qinyue He, Yuanjing Huang","doi":"10.3390/aerospace10090740","DOIUrl":"https://doi.org/10.3390/aerospace10090740","url":null,"abstract":"This paper presents a conflict detection and resolution method based on a velocity obstacle method for flight conflicts in a three-dimensional space. With the location and speed information of the two aircraft, the optimal relief strategy is obtained using particle swarm optimization. Aiming at the problem of excessive computational complexity in solving flight conflicts in a three-dimensional space with a cylindrical flight protection zone, an improved method for narrowing the search range is proposed to achieve a rapid solution by simplifying the complicated three-dimensional problem into a two-dimensional problem. The generality and flexibility of the method is effectively verified through simulations in flight conflict scenarios which almost cover all common situations. The experimental results show that the method can accurately determine the conflict time and generate the optimal relief strategy for different scenarios. The improved method of optimizing-search-range can significantly improve the computational efficiency, taking about 0.4 s to find the optimal solution, which can be used in real-time conflict resolution. The study provides a new solution for the flight conflict resolution problem.","PeriodicalId":50845,"journal":{"name":"Aerospace America","volume":null,"pages":null},"PeriodicalIF":0.1,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73970270","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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