Aerospace最新文献_第3页

Safe and Efficient Exploration Path Planning for Unmanned Aerial Vehicle in Forest Environments 无人驾驶飞行器在森林环境中安全高效的探索路径规划

IF 2.1 3区工程技术

Aerospace Pub Date : 2024-07-22 DOI: 10.3390/aerospace11070598

Youkyung Hong, Suseong Kim, Youngsun Kwon, Sanghyouk Choi, Jihun Cha

{"title":"Safe and Efficient Exploration Path Planning for Unmanned Aerial Vehicle in Forest Environments","authors":"Youkyung Hong, Suseong Kim, Youngsun Kwon, Sanghyouk Choi, Jihun Cha","doi":"10.3390/aerospace11070598","DOIUrl":"https://doi.org/10.3390/aerospace11070598","url":null,"abstract":"This study presents an enhanced exploration path planning for unmanned aerial vehicles. The primary goal is to increase the chances of survival of missing people in forest environments. Exploration path planning is an essential methodology for exploring unknown three-dimensional spaces. However, previous studies have mainly focused on underground environments, not forest environments. The existing path planning methods for underground environments are not directly applicable to forest environments. The reason is that multiple open spaces exist with various obstacles, such as trees, foliage, undergrowth, and rocks. This study mainly focused on improving the safety and efficiency to be suitable for forests rather than underground environments. Paths closer to obstacles are penalized to enhance safety, encouraging exploration at a safer distance from obstacles. A potential field function is applied based on explored space to minimize overlapping between existing and new paths to increase efficiency. The proposed exploration path planning method was validated through an extensive simulation analysis and comparison with state-of-the-art sampling-based path planning. Finally, a flight experiment was conducted to verify further the feasibility of the proposed method using onboard real hardware implementation in a cluttered and complex forest environment.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141815522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparative Study on Mechanical Response in Rigid Pavement Structures of Static and Dynamic Finite Element Models 静态和动态有限元模型在刚性路面结构中的机械响应对比研究

IF 2.1 3区工程技术

Aerospace Pub Date : 2024-07-22 DOI: 10.3390/aerospace11070596

Qiao Meng, Ke Zhong, Yuchun Li, Mingzhi Sun

{"title":"Comparative Study on Mechanical Response in Rigid Pavement Structures of Static and Dynamic Finite Element Models","authors":"Qiao Meng, Ke Zhong, Yuchun Li, Mingzhi Sun","doi":"10.3390/aerospace11070596","DOIUrl":"https://doi.org/10.3390/aerospace11070596","url":null,"abstract":"The safety of airport runways is important to guarantee aircraft taking-off, landing, and taxiing, and the comparison of the mechanical response of pavement structures under dynamic and static loading by LS-DYNA has rarely been studied. The purpose of this work is to separate two analysis methods to investigate the mechanical response of rigid airport pavements. Firstly, a tire–road coupling model of an airfield was established to evaluate the suitability of dynamic and static analyses. Then, the effects of landing pitch angles, sinking speeds, and tire pressures on the effective stress, effective strain, and z-displacement of the runway were investigated for both dynamic and static analysis. Finally, the significance of influence factors was analyzed by regression analysis in Statistical Product and Service Solutions (SPSS). The results indicated that the effective stress, effective strain, and z-displacement of the runway increased with a decrease in the landing pitch angle, which also increased with an increase in the sinking speed and tire pressure. It was demonstrated that the difference in pavement mechanical response between dynamic and static analyses progressively widened at high tire pressure and sinking speed. In other words, the static analysis method can be adopted to assess the dynamic mechanical behavior when the landing pitch angle is large and the tire pressure is small. Among the various factors of mechanical response, the effect of tire pressure was the most obvious, followed by sinking speed and landing pitch angle. The work proposes a new approach to understanding the mechanical behavior of runways under complicated and varied conditions, evaluates the applicability of the dynamic and static mechanical analysis methods, identifies key factors in the dynamic and static mechanical analysis of rigid runways, and provides technical support for improving and maintaining the impact resistance of pavement facilities.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141817513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

ATC-SD Net: Radiotelephone Communications Speaker Diarization Network ATC-SD Net：无线电话通信扬声器数字化网络

IF 2.1 3区工程技术

Aerospace Pub Date : 2024-07-22 DOI: 10.3390/aerospace11070599

Weijun Pan, Yidi Wang, Yumei Zhang, Boyuan Han

{"title":"ATC-SD Net: Radiotelephone Communications Speaker Diarization Network","authors":"Weijun Pan, Yidi Wang, Yumei Zhang, Boyuan Han","doi":"10.3390/aerospace11070599","DOIUrl":"https://doi.org/10.3390/aerospace11070599","url":null,"abstract":"This study addresses the challenges that high-noise environments and complex multi-speaker scenarios present in civil aviation radio communications. A novel radiotelephone communications speaker diffraction network is developed specifically for these circumstances. To improve the precision of the speaker diarization network, three core modules are designed: voice activity detection (VAD), end-to-end speaker separation for air–ground communication (EESS), and probabilistic knowledge-based text clustering (PKTC). First, the VAD module uses attention mechanisms to separate silence from irrelevant noise, resulting in pure dialogue commands. Subsequently, the EESS module distinguishes between controllers and pilots by levying voice print differences, resulting in effective speaker segmentation. Finally, the PKTC module addresses the issue of pilot voice print ambiguity using text clustering, introducing a novel flight prior knowledge-based text-related clustering model. To achieve robust speaker diarization in multi-pilot scenarios, this model uses prior knowledge-based graph construction, radar data-based graph correction, and probabilistic optimization. This study also includes the development of the specialized ATCSPEECH dataset, which demonstrates significant performance improvements over both the AMI and ATCO2 PROJECT datasets.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141816683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Case Study of Along-Track Separation Maintenance of Distributed Synthetic Aperture Radar Systems in Low Earth Orbits 低地球轨道分布式合成孔径雷达系统沿轨分离维护案例研究

IF 2.1 3区工程技术

Aerospace Pub Date : 2024-07-22 DOI: 10.3390/aerospace11070600

Marco D’Errico

引用次数: 0

Experimental Study of the Aerodynamic Performance and Flow Characteristics of an Integrated UAV Inlet with Double 90° Bends 带有双 90° 弯道的一体化无人机进气口的空气动力性能和流动特性实验研究

IF 2.1 3区工程技术

Aerospace Pub Date : 2024-07-21 DOI: 10.3390/aerospace11070593

Jiahao Ren, Zhenlong Wu, Huijun Tan, Ziyun Wang, Xiaoming He, Dongpo Li, Yi Zhou

引用次数: 0

Analysis of the Effect of Sampling Probe Geometry on Measurement Accuracy in Supersonic Gas Flow 采样探头几何形状对超音速气体流测量精度的影响分析

IF 2.1 3区工程技术

Aerospace Pub Date : 2024-07-21 DOI: 10.3390/aerospace11070595

Wanlin Zhang, Yingtao Chen, Yanting Ai, Pengpeng Sha, Xinlong Yang

{"title":"Analysis of the Effect of Sampling Probe Geometry on Measurement Accuracy in Supersonic Gas Flow","authors":"Wanlin Zhang, Yingtao Chen, Yanting Ai, Pengpeng Sha, Xinlong Yang","doi":"10.3390/aerospace11070595","DOIUrl":"https://doi.org/10.3390/aerospace11070595","url":null,"abstract":"The accuracy of sampling of gas components has a significant impact on the measurement of various performance parameters in the combustion chamber of an aero-engine. In order to investigate the effect of the probe geometry of a six-point gas sampling probe on sampling accuracy in supersonic gas flow, a three-dimensional probe gas flow characteristic solution model is established through numerical simulation methods of components of transport and fluid–solid coupling. Probes with three angles of 28°, 30°, and 32° and an optimized conical probe are constructed. The sampling accuracy of the probes with different geometries is compared and evaluated by the deviation of the component volume fraction before and after sampling and the resulting combustion efficiency error. This paper presents a set of calculation methods for solving the relative deviation of volume fraction by an iterative method based on the ideal gas law and the Redlich–Kwong equation (R-K equation). The method is designed to solve the exact component volume fraction problem in the simulation calculation. The study results demonstrate that the 28° and optimized conical probes improve sampling accuracy more effectively than the original 30° structure. The deviation of the volume fractions of the two structures is less than 1.7%, and the combustion efficiency error is less than 0.09%. The developed iterative calculation method can significantly reduce the theoretical calculation error to less than 0.06%. The experimental data of the test bench are in good agreement with the simulation results, thereby demonstrating the reliability and accuracy of the sampling probe following structural optimization.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141818728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimization Study of Steady-State Aerial-Towed Cable Circling Strategy Based on BP Neural Network Prediction 基于 BP 神经网络预测的稳态空中牵引电缆绕行策略优化研究

IF 2.1 3区工程技术

Aerospace Pub Date : 2024-07-21 DOI: 10.3390/aerospace11070594

Luqi Feng, Xueqiang Liu, Zi Feng Nio

{"title":"Optimization Study of Steady-State Aerial-Towed Cable Circling Strategy Based on BP Neural Network Prediction","authors":"Luqi Feng, Xueqiang Liu, Zi Feng Nio","doi":"10.3390/aerospace11070594","DOIUrl":"https://doi.org/10.3390/aerospace11070594","url":null,"abstract":"This paper presents models for UAV aerial-towed cables in free-end and fixed-end configurations, crucial for tasks like communication and aerial charging. By establishing a quasi steady-state model, computational results on cable shapes are obtained. To accelerate computations, a backpropagation (BP) neural network prediction model is trained, significantly reducing the computation time. An evaluation function has been developed that integrates both aircraft performance and cable shape considerations to evaluate circling parameters across various states. This function integrates techniques such as BP neural networks and particle swarm optimization (PSO) to refine parameters such as velocities and bank angles for both free-end and fixed-end cables. The results show that the BP neural network accurately predicts cable shapes, achieving a maximum error of 5% in towing force and verticality. Additionally, PSO efficiently optimizes circling parameters, thereby enhancing the effectiveness of the evaluation function in identifying optimal solutions. This approach significantly improves the efficiency of determining optimal circling parameters for UAV aerial-towed cables, thereby contributing to their operational efficacy.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141818753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental Investigation of Runback Water Flow Behavior on Aero-Engine Rotating Spinners with Different Wettabilities 不同润湿性航空发动机旋转纺丝器上回流水流特性的实验研究

IF 2.1 3区工程技术

Aerospace Pub Date : 2024-07-20 DOI: 10.3390/aerospace11070591

Kuiyuan Ma, Guiping Lin, Haichuan Jin, Xiaobin Shen, Xueqin Bu

{"title":"Experimental Investigation of Runback Water Flow Behavior on Aero-Engine Rotating Spinners with Different Wettabilities","authors":"Kuiyuan Ma, Guiping Lin, Haichuan Jin, Xiaobin Shen, Xueqin Bu","doi":"10.3390/aerospace11070591","DOIUrl":"https://doi.org/10.3390/aerospace11070591","url":null,"abstract":"The accumulation of ice on the aero-engine inlet compromises engine safety. Traditional hot air anti-icing systems, which utilize bleed air, require substantial energy, decreasing engine performance and increasing emissions. Superhydrophobic materials have shown potential in reducing energy consumption when combined with these systems. Research indicates that superhydrophobic surfaces on stationary components significantly reduce anti-icing energy consumption by altering runback water flow behavior. However, for rotating aero-engine components, the effectiveness of superhydrophobic surfaces and the influence of surface wettability on runback water flow remain unclear due to centrifugal and Coriolis forces. This study investigates the runback water flow behavior on aero-engine rotating spinner surfaces with varying wettabilities in a straight-flow spray wind tunnel. The results demonstrated that centrifugal force reduces the amount of runback water on the rotating spinner compared to the stationary surface, forming rivulet flows deflected opposite to the direction of rotation. Furthermore, wettability significantly affects the flow characteristics of runback water on rotating surfaces. As the contact angle increases, the liquid water on the rotating spinner transitions from continuous film flow to rivulet and bead-like flows. Notably, the superhydrophobic surface prevents water adhesion, indicating its potential for anti-icing on rotating components. In addition, the interaction between rotational speed and surface wettability enhances the effects, with both increased rotational speed and larger contact angles contributing to higher liquid water flow velocities, promoting the rapid formation and detachment of rivulet and bead-like flows.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141818912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the Generalization Capability of a Data-Driven Turbulence Model by Field Inversion and Machine Learning 通过场反演和机器学习论数据驱动湍流模型的泛化能力

IF 2.1 3区工程技术

Aerospace Pub Date : 2024-07-20 DOI: 10.3390/aerospace11070592

Yasunari Nishi, A. Krumbein, Tobias Knopp, Axel Probst, Cornelia Grabe

引用次数: 0

New Data-Driven Models of Mass Flow Rate and Isentropic Efficiency of Dynamic Compressors 数据驱动的动态压缩机质量流量和等熵效率新模型

IF 2.1 3区工程技术

Aerospace Pub Date : 2024-07-19 DOI: 10.3390/aerospace11070589

Xiande Fang, Yuxiang Fang, Yang Yang, Zhiqiang He, Bei Yang

{"title":"New Data-Driven Models of Mass Flow Rate and Isentropic Efficiency of Dynamic Compressors","authors":"Xiande Fang, Yuxiang Fang, Yang Yang, Zhiqiang He, Bei Yang","doi":"10.3390/aerospace11070589","DOIUrl":"https://doi.org/10.3390/aerospace11070589","url":null,"abstract":"Dynamic compressors are widely used in many industrial sectors, such as air, land, and marine vehicle engines, aircraft environmental control systems (ECS), air-conditioning and refrigeration, gas turbines, gas compression and injection, etc. The data-driven formulas of mass flow rate and isentropic efficiency of dynamic compressors are required for the design, energy analysis, performance simulation, and control- and/or diagnosis-oriented dynamic simulation of such compressors and the related systems. This work develops data-driven models for predicting the performance of dynamic compressors, including empirical models for mass flow rate and isentropic efficiency, which have high prediction accuracy and broad application range. The performance maps of two multi-stage axial compressors of an aero engine and a centrifugal compressor of an aircraft ECS were chosen for evaluation of the existing empirical formulas and testing of the new models. There are 16 empirical models of mass flow rate and 14 empirical models of isentropic efficiency evaluated, and the results show that it is necessary to develop highly accurate empirical formulas both for mass flow rate and isentropic efficiency. With the data-driven method, two empirical models for mass flow rate and one for isentropic efficiency are developed. They are in general form, with some terms removable to make them simple while enhancing their applicability and prediction accuracy. The new models have much higher prediction accuracy than the best existing counterparts. The new mass flow rate models predict for the three compressors a mean absolute relative deviation (MAD) not greater than 1.3%, while the best existing models all have MAD > 2.0%. The new efficiency model predicts for the three compressors an MAD of 1.0%, 0.4%, and 1.9%, respectively, while the best existing model predicts for the three compressors an MAD of 1.8%, 0.8%, and 3.2%, respectively.","PeriodicalId":48525,"journal":{"name":"Aerospace","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141823499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0