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基于改进SIFT和多约束的UAV影像匹配方法
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作者 何明磊 王中元 +2 位作者 戚铭心 杨振宇 袁芳 《合肥工业大学学报(自然科学版)》 北大核心 2025年第2期212-219,共8页
针对尺度不变特征转换(scale invariant feature transform,SIFT)算法在无人机(unmanned aerial vehicle,UAV)影像的匹配过程中存在特征点稳定性差和误匹配多的问题,文章提出一种基于改进SIFT和多约束的UAV影像匹配方法。首先,在对影像... 针对尺度不变特征转换(scale invariant feature transform,SIFT)算法在无人机(unmanned aerial vehicle,UAV)影像的匹配过程中存在特征点稳定性差和误匹配多的问题,文章提出一种基于改进SIFT和多约束的UAV影像匹配方法。首先,在对影像降采样后,综合采用SIFT算法和Scharr-ORB(oriented brief)算法共同进行特征点检测和描述;然后,使用最近邻距离比值法(nearest neighbor distance ratio,NNDR)、双向约束匹配和余弦相似度约束匹配的多约束方法进行特征点的粗匹配;最后,使用最小中值(least median of squares,LMedS)算法计算基础矩阵和随机抽样一致性(random sample consensus,RANSAC)算法计算单应矩阵的多约束方法进行特征点的精匹配,进一步提高匹配精度。结果表明,该方法在获得更多特征点和匹配对数的同时,能够剔除较多的误匹配,使其具有较高的匹配正确率和匹配精度。 展开更多
关键词 无人机(uav)影像 影像匹配 边缘检测 多约束方法 基础矩阵
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基于UAV影像点云密度的植被稀疏区DEM精度分析
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作者 戴志林 郭辉 包勤跃 《北京测绘》 2025年第3期316-321,共6页
本文以无人机(UAV)倾斜摄影影像点云为数据源,通过对构建植被稀疏区数字高程模型(DEM)的最佳点云密度进行分析研究,从中选取出最佳点云密度,以实现高效、快速获取DEM数据。使用随机采样算法将原始点云以10%~90%密度进行抽稀,同时采用中... 本文以无人机(UAV)倾斜摄影影像点云为数据源,通过对构建植被稀疏区数字高程模型(DEM)的最佳点云密度进行分析研究,从中选取出最佳点云密度,以实现高效、快速获取DEM数据。使用随机采样算法将原始点云以10%~90%密度进行抽稀,同时采用中误差对生成的DEM进行精度评价分析。结果显示:①在点云抽稀10%~40%时,中误差随着点云密度的减小而增大,同时在点云抽稀30%时中误差与原始点云几乎相似;②在点云抽稀40%~60%时,中误差变化较为平缓,但总体呈上升趋势;③在点云抽稀60%~90%时,随着点云密度的进一步减小,中误差随着点云密度的减小而迅速增大。得出结论,点云密度与DEM精度呈正相关,抽稀30%的点云成为在同类型条件植被稀疏区UAV倾斜摄影点云生成DEM的最佳点云密度。 展开更多
关键词 无人机(uav)倾斜摄影 影像点云 点云密度 抽稀 数字高程模型(DEM)
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基于深度强化学习的UAV-RIS辅助鲁棒海上无线通信
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作者 夏薇 唐冬 《计算机应用文摘》 2025年第6期73-77,共5页
随着我国综合实力的提升,海上紧急救援、科研考察及军事行动对无线通信的需求日益增长,提升海上通信系统的可靠性尤为重要。为模拟实际海况,在基站到RIS再到用户的级联信道信息不完美的假设下,文章提出了一种UAV-RIS辅助的海上无线通信... 随着我国综合实力的提升,海上紧急救援、科研考察及军事行动对无线通信的需求日益增长,提升海上通信系统的可靠性尤为重要。为模拟实际海况,在基站到RIS再到用户的级联信道信息不完美的假设下,文章提出了一种UAV-RIS辅助的海上无线通信系统,旨在改善非固定海上用户(OMU)的服务质量。通过DRL算法联合优化MU-MISO系统中的无人机轨迹、波束成形矩阵及RIS相移,以最大化下行链路速率。 展开更多
关键词 uav-RIS 海上通信 深度强化学习 无人机轨迹
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Geomorphometric Analysis of the Kshetrapal Landslide in Chamoli, Uttarakhand, India Using the White Box Tool (WBT) and QGIS by Comparing various DEMs Obtained from UAV and TLS
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作者 Ashok Anand 《International Journal of Geosciences》 2025年第1期31-60,共30页
Utilizing multispectral satellite data and digital elevation models (DEMs) has emerged as the primary approach for cartographically representing landforms. By using high-resolution satellite photos that capture spatia... Utilizing multispectral satellite data and digital elevation models (DEMs) has emerged as the primary approach for cartographically representing landforms. By using high-resolution satellite photos that capture spatial, temporal, spectral, and radiometric data, one may get a fresh comprehension of the geomorphology of a particular area by recognizing its landforms. In addition, a synergistic method is used by using data produced from digital elevation models (DEMs) such as Slope, Aspect, Hillshade, Curvature, Contour Patterns, and 3-D Flythrough Visuals. The increasing use of UAV (drone) technology for obtaining high-resolution digital images and elevation models has become an essential element in developing complete topographic models in landslide scars that are very unstable and prone to erosion. Comparison (differences in values) of seven (7) different DEMs between two algorithms used, i.e., QGIS and White Box Tool (WBT), were successfully attempted in the present research. The TLS, UAV and Satellite data of the study area—Kshetrapal Landslide, Chamoli (District), Uttarakhand (State), India was subjected to two different algorithms (QGIS and WBT) to evaluate and differentiate seven different DEMs (CARTOSAT, ASTER, SRTM, Alos 3D, TanDEM, MERIT, and FabDEM/FATHOM) taking into consideration various parameters viz. Aspect, Hillshade, Slope, Mean Curvature, Plan Curvature, Profile Curvature and Total Curvature. The different values of aforesaid parameters of various DEMs evaluated (using algorithms QIGS and WBT) reveal that only three parameters, i.e., Aspect, Hillshade, and Slope, show results. In contrast, the remaining ones do not show any meaningful results, and therefore, the comparison was possible only with regard to these three parameters. The comparison is drawn by comparing minimum, maximum, and elevation values (by subtracting WBT values from QGIS values) regarding Aspect, Hillshade, and Slope, arranging the differences in values as per their importance. (Increasing or decreasing order), assigning merit scores individually, and then cumulatively, and ascertaining the order of application suitability of various Dems, which stand in the order of (CARTOSAT, ASTER, SRTM, Alos 3D, TanDEM, and MERIT, and FabDEM/FATHOM). 展开更多
关键词 LANDSLIDE Morphometric Analysis Digital Elevation Models (DEMs) TLS uav (Drone) QGIS WBT
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基于DRL的UAV辅助海上物联网联合卸载和资源分配
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作者 李予诺 魏泽 何荣希 《现代电子技术》 北大核心 2025年第3期141-148,共8页
针对多无人机辅助海上物联网搜救场景,为了使无人机能处理无人船卸载的更多计算任务,同时尽可能减少无人机的能量浪费,文中提出一种基于深度确定性策略梯度(DDPG)的任务感知联合卸载和资源分配算法。首先,考虑无人机可自适应调整时隙内... 针对多无人机辅助海上物联网搜救场景,为了使无人机能处理无人船卸载的更多计算任务,同时尽可能减少无人机的能量浪费,文中提出一种基于深度确定性策略梯度(DDPG)的任务感知联合卸载和资源分配算法。首先,考虑无人机可自适应调整时隙内飞行时间以及无人船卸载任务在无人机排队计算的实际情况,建立了通信模型、计算模型和能耗模型。其次,通过联合考虑卸载决策、功率分配以及无人机飞行轨迹规划和速度调整,构建最大化所有无人机平均收益的优化问题;然后将该问题转化为马尔科夫决策过程,确立了对应的状态空间、动作空间和奖励函数,并通过DDPG算法求解出最优策略。仿真结果表明,与其他基准算法相比,所提算法可以有效提高无人机的平均收益。 展开更多
关键词 移动边缘计算 无人机 深度强化学习 计算卸载 功率分配 轨迹规划
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UAV-Mounted Intelligent Reflecting Surface in Maritime Wireless Powered Communication Network
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作者 Liu Yuan Han Fengxia Zhao Shengjie 《China Communications》 2025年第3期254-269,共16页
Intelligent reflecting surface(IRS)assisted with the wireless powered communication network(WPCN)can enhance the desired signal energy and carry out the power-sustaining problem in ocean monitoring systems.In this pap... Intelligent reflecting surface(IRS)assisted with the wireless powered communication network(WPCN)can enhance the desired signal energy and carry out the power-sustaining problem in ocean monitoring systems.In this paper,we investigate a reliable communication structure where multiple buoys transmit data to a base station(BS)with the help of the unmanned aerial vehicle(UAV)-mounted IRS and harvest energy from the base station simultaneously.To organically combine WPCN with maritime data collection scenario,a scheduling protocol that employs the time division multiple access(TDMA)is proposed to serve multiple buoys for uplink data transmission.Furthermore,we compare the full-duplex(FD)and half-duplex(HD)mechanisms in the maritime data collection system to illustrate different performances under these two modes.To maximize the fair energy efficiency under the energy harvesting constraints,a joint optimization problem on user association,BS transmit power,UAV’s trajectory and IRS’s phase shift is formulated.To solve the non-convex problem,the original problem is decoupled into several subproblems,and successive convex optimization and block coordinate descent(BCD)methods are employed obtain the near-optimal solutions alternatively.Simulation results demonstrate that the UAV-mounted IRS can significantly improve energy efficiency in our considered system. 展开更多
关键词 full-duplex IRS joint optimization TDMA uav WPCN
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光学智能反射表面辅助的UAV群分布式光移动通信
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作者 王海卜 张在琛 +1 位作者 葛荧萌 曾涵 《电子与信息学报》 北大核心 2025年第1期48-56,共9页
随着无人机(UAV)系统的规模持续扩大以及对更高通信速率的需求增长,UAV光移动通信(UAV-OMC)已经成为一个有前景的技术方向。然而,传统的UAV-OMC难以支持多UAV之间的通信。该文基于光学智能反射表面(OIRS)技术,提出一个适用于UAV群的分布... 随着无人机(UAV)系统的规模持续扩大以及对更高通信速率的需求增长,UAV光移动通信(UAV-OMC)已经成为一个有前景的技术方向。然而,传统的UAV-OMC难以支持多UAV之间的通信。该文基于光学智能反射表面(OIRS)技术,提出一个适用于UAV群的分布式OMC系统。通过在特定的UAV上设置OIRS,利用OIRS将光信号从单个UAV节点扩散到多个UAV节点。这一系统在保留UAV-OMC系统的高能效和高速度的同时,能够支持分布式UAV群的通信。对所提出的系统进行了数学建模,考虑了一系列现实因素,如OIRS的光束控制、UAV之间的相对运动和UAV的抖动等,这些因素都符合实际系统的特点。此外,该文还推导出了系统的误比特率(BER)和渐进中断概率的闭式表达式。基于理论分析和模拟结果,讨论了各个参数和系统设计的影响。 展开更多
关键词 光移动通信 光学智能反射表面 无人机 性能分析
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Energy Consumption Minimization for NOMA-Based Secure UAV-MEC Network
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作者 Zhang Hao Huang Yuzhen +1 位作者 Zhang Zhi Lu Xingbo 《China Communications》 2025年第3期202-216,共15页
Applying non-orthogonal multiple access(NOMA)to the mobile edge computing(MEC)network supported by unmanned aerial vehicles(UAVs)can improve spectral efficiency and achieve massive user access on the basis of solving ... Applying non-orthogonal multiple access(NOMA)to the mobile edge computing(MEC)network supported by unmanned aerial vehicles(UAVs)can improve spectral efficiency and achieve massive user access on the basis of solving computing resource constraints and coverage problems.However,the UAV-enabled network has a serious risk of information leakage on account of the openness of wireless channel.This paper considers a UAV-MEC secure network based on NOMA technology,which aims to minimize the UAV energy consumption.To achieve the purpose while meeting the security and users’latency requirements,we formulate an optimization problem that jointly optimizes the UAV trajectory and the allocation of network resources.Given that the original problem is non-convex and multivariate coupled,we proposed an effective algorithm to decouple the nonconvex problem into independent user relation coefficients and subproblems based on successive convex approximation(SCA)and block coordinate descent(BCD).The simulation results showcase the performance of our optimization scheme across various parameter settings and confirm its superiority over other benchmarks with respect to energy consumption. 展开更多
关键词 MEC NOMA resource optimization secure transmission trajectory optimization uav
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Joint User Association,Resource Allocation and Trajectory Design for Multi-UAV-Aided NOMA Wireless Communication Systems
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作者 Yin Sixing Qu Zhaowei Yu Peng 《China Communications》 2025年第3期217-233,共17页
In this paper,we investigate a multi-UAV aided NOMA communication system,where multiple UAV-mounted aerial base stations are employed to serve ground users in the downlink NOMA communication,and each UAV serves its as... In this paper,we investigate a multi-UAV aided NOMA communication system,where multiple UAV-mounted aerial base stations are employed to serve ground users in the downlink NOMA communication,and each UAV serves its associated users on its own bandwidth.We aim at maximizing the overall common throughput in a finite time period.Such a problem is a typical mixed integer nonlinear problem,which involves both continuous-variable and combinatorial optimizations.To efficiently solve this problem,we propose a two-layer algorithm,which separately tackles continuous-variable and combinatorial optimization.Specifically,in the inner layer given one user association scheme,subproblems of bandwidth allocation,power allocation and trajectory design are solved based on alternating optimization.In the outer layer,a small number of candidate user association schemes are generated from an initial scheme and the best solution can be determined by comparing all the candidate schemes.In particular,a clustering algorithm based on K-means is applied to produce all candidate user association schemes,the successive convex optimization technique is adopted in the power allocation subproblem and a logistic function approximation approach is employed in the trajectory design subproblem.Simulation results show that the proposed NOMA scheme outperforms three baseline schemes in downlink common throughput,including one solution proposed in an existing literature. 展开更多
关键词 NOMA resource allocation trajectory design uav communications user association
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Integrating Image Processing Technology and Deep Learning to Identify Crops in UAV Orthoimages
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作者 Ching-Lung Fan Yu-Jen Chung 《Computers, Materials & Continua》 2025年第2期1925-1945,共21页
This study aims to enhance automated crop detection using high-resolution Unmanned Aerial Vehicle(UAV)imagery by integrating the Visible Atmospherically Resistant Index(VARI)with deep learning models.The primary chall... This study aims to enhance automated crop detection using high-resolution Unmanned Aerial Vehicle(UAV)imagery by integrating the Visible Atmospherically Resistant Index(VARI)with deep learning models.The primary challenge addressed is the detection of bananas interplanted with betel nuts,a scenario where traditional image processing techniques struggle due to color similarities and canopy overlap.The research explores the effectiveness of three deep learning models—Single Shot MultiBox Detector(SSD),You Only Look Once version 3(YOLOv3),and Faster Region-Based Convolutional Neural Network(Faster RCNN)—using Red,Green,Blue(RGB)and VARI images for banana detection.Results show that VARI significantly improves detection accuracy,with YOLOv3 achieving the best performance,achieving a precision of 73.77%,recall of 100%,and reduced training time by 95 seconds.Additionally,the average Intersection over Union(IoU)increased by 4%–25%across models with VARI-enhanced images.This study confirms that incorporating VARI improves the performance of deep learning models,offering a promising solution for precise crop detection in complex agricultural environments. 展开更多
关键词 uav RGB image deep learning visible atmospherically resistant index CROP
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A general methodological framework for hazard assessment in remote mountain areas combining geomorphological mapping with UAV survey
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作者 Elena GAROVA Bogdan CHADROMTSEV +6 位作者 Alexander PEDANOV Pavel GREBENNIKOV Igor ILTUGANOV Pavel LOBANOV Pavel PONOMARJOVS Felix DRAESNER Sven FUCHS 《Journal of Mountain Science》 2025年第3期763-775,共13页
This paper presents a standardised workflow for conducting hazard assessments of mass wasting processes in remote mountain areas with limited data.The methodology integrates geomorphological mapping and remote sensing... This paper presents a standardised workflow for conducting hazard assessments of mass wasting processes in remote mountain areas with limited data.The methodology integrates geomorphological mapping and remote sensing techniques and is adaptable to different national standards,thus ensuring its applicability in a variety of contexts.The principal objective is to guarantee the safety of mountainous regions,particularly in the vicinity of essential infrastructure,where the scope for implementing structural measures is restricted.The framework commences with comprehensive geomorphological mapping,which facilitates the identification of past hazardous processes and potential future hazards.New technologies,such as uncrewed aerial vehicles(UAVs),are employed to create high-resolution DEMs,which are particularly beneficial in regions with limited data availability.These models facilitate the assessment of potential hazards and inform decisions regarding protective measures.The utilisation of UAVs enhances the accuracy and efficiency of data collection,particularly in remote mountainous regions where alternative remotely sensed information may be unavailable.The integration of modern approaches into traditional hazard assessment methods allows for a comprehensive analysis of the spatial distribution of factors driving mass wasting processes.This workflow provides valuable insights that assist in the prioritisation of interventions and the optimisation of risk reduction in high mountainous areas. 展开更多
关键词 Geomorphological mapping Hazard assessment uav Remote mountain areas Mitigation planning
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基于UAV激光雷达+InSAR技术+关键区域GNSS连续观测的矿地表沉陷监测方案研究
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作者 乔元锋 何龙 《黑龙江环境通报》 2025年第2期85-87,共3页
煤炭开采势必会造成地表沉陷,而对地表沉陷规律进行研究,可以对地表建筑物的保护做到有的放矢。以往传统的沉陷规律研究通常采取布设常规沉陷观测站,借助全站仪进行数据采集。针对常规观测站观测存在的观测周期长、外业劳动强度大、固... 煤炭开采势必会造成地表沉陷,而对地表沉陷规律进行研究,可以对地表建筑物的保护做到有的放矢。以往传统的沉陷规律研究通常采取布设常规沉陷观测站,借助全站仪进行数据采集。针对常规观测站观测存在的观测周期长、外业劳动强度大、固定测点不易保护等不足,各个矿区均在寻求更合适的监测手段。随着测绘新技术的不断出现,一些新的测量方法也被应用于矿山监测,如InSAR技术、无人机激光雷达技术等。基于此,本文结合传统地表移动观测站,利用无人机激光雷达技术和InSAR技术对某矿煤矿3112工作面开采地表沉陷进行全面监测。 展开更多
关键词 开采沉陷 uav激光雷达 INSAR技术 GNSS连续观测
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Resilient multi-objective mission planning for UAV formation:A unified framework integrating task pre-and re-assignment
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作者 Xinwei Wang Xiaohua Gao +4 位作者 Lei Wang Xichao Su Junhong Jin Xuanbo Liu Zhilong Deng 《Defence Technology(防务技术)》 2025年第3期203-226,共24页
Combat effectiveness of unmanned aerial vehicle(UAV)formations can be severely affected by the mission execution reliability.During the practical execution phase,there are inevitable risks where UAVs being destroyed o... Combat effectiveness of unmanned aerial vehicle(UAV)formations can be severely affected by the mission execution reliability.During the practical execution phase,there are inevitable risks where UAVs being destroyed or targets failed to be executed.To improve the mission reliability,a resilient mission planning framework integrates task pre-and re-assignment modules is developed in this paper.In the task pre-assignment phase,to guarantee the mission reliability,probability constraints regarding the minimum mission success rate are imposed to establish a multi-objective optimization model.And an improved genetic algorithm with the multi-population mechanism and specifically designed evolutionary operators is used for efficient solution.As in the task-reassignment phase,possible trigger events are first analyzed.A real-time contract net protocol-based algorithm is then proposed to address the corresponding emergency scenario.And the dual objective used in the former phase is adapted into a single objective to keep a consistent combat intention.Three cases of different scales demonstrate that the two modules cooperate well with each other.On the one hand,the pre-assignment module can generate high-reliability mission schedules as an elaborate mathematical model is introduced.On the other hand,the re-assignment module can efficiently respond to various emergencies and adjust the original schedule within a millisecond.The corresponding animation is accessible at bilibili.com/video/BV12t421w7EE for better illustration. 展开更多
关键词 Cooperative mission planning uav formation Mission reliability Evolutionary algorithm Contract net protocol
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Air-to-ground reconnaissance-attack task allocation for heterogeneous UAV swarm
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作者 LUO Yuelong JIANG Xiuqiang +1 位作者 ZHONG Suchuan JI Yuandong 《Journal of Systems Engineering and Electronics》 2025年第1期155-175,共21页
A task allocation problem for the heterogeneous unmanned aerial vehicle (UAV) swarm in unknown environments is studied in this paper.Considering that the actual mission environment information may be unknown,the UAV s... A task allocation problem for the heterogeneous unmanned aerial vehicle (UAV) swarm in unknown environments is studied in this paper.Considering that the actual mission environment information may be unknown,the UAV swarm needs to detect the environment first and then attack the detected targets.The heterogeneity of UAVs,multiple types of tasks,and the dynamic nature of task environment lead to uneven load and time sequence problems.This paper proposes an improved contract net protocol (CNP) based task allocation scheme,which effectively balances the load of UAVs and improves the task efficiency.Firstly,two types of task models are established,including regional reconnaissance tasks and target attack tasks.Secondly,for regional reconnaissance tasks,an improved CNP algorithm using the uncertain contract is developed.Through uncertain contracts,the area size of the regional reconnaissance task is determined adaptively after this task assignment,which can improve reconnaissance efficiency and resource utilization.Thirdly,for target attack tasks,an improved CNP algorithm using the fuzzy integrated evaluation and the double-layer negotiation is presented to enhance collaborative attack efficiency through adjusting the assignment sequence adaptively and multi-layer allocation.Finally,the effectiveness and advantages of the improved method are verified through comparison simulations. 展开更多
关键词 unmanned aerial vehicle(uav)swarm reconnaissance-attack coupled task allocation contract net protocol(CNP) fuzzy integrated evaluation double-layer negotiation
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基于OFDM信号的UAV测控数据链通信稳定性研究
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作者 王委 《信息记录材料》 2025年第1期212-215,共4页
无人机数据链通信的稳定性成为制约无人机性能的重要因素之一,若能够在测控数据采集处理过程中对数据精度进行优化处理,将极大地提高数据通信稳定性。为此,本研究结合正交频分复用信号的基本原理和特点,提出了一种新的测角算法。该算法... 无人机数据链通信的稳定性成为制约无人机性能的重要因素之一,若能够在测控数据采集处理过程中对数据精度进行优化处理,将极大地提高数据通信稳定性。为此,本研究结合正交频分复用信号的基本原理和特点,提出了一种新的测角算法。该算法通过设置对应的列阵雷达、差波生成方法对无人机角度估计。然后在测角结果的基础上,利用卷积神经网络和应答机制对测控数据进行优化处理,进一步校正数据误差。实验结果表明:本文的设计方法在无人机测控数据链通信稳定性方面具有显著优势,能够提供更加准确有效的测控数据,为无人机操作提供有效依据。研究结果也可以为其他无线通信系统的稳定性和可靠性问题提供有益的参考和借鉴。 展开更多
关键词 正交频分复用(OFDM)信号 无人机(uav) 测控数据链 通信稳定性
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Vehicle and onboard UAV collaborative delivery route planning:considering energy function with wind and payload
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作者 GUO Jingfeng SONG Rui HE Shiwei 《Journal of Systems Engineering and Electronics》 2025年第1期194-208,共15页
The rapid evolution of unmanned aerial vehicle(UAV)technology and autonomous capabilities has positioned UAV as promising last-mile delivery means.Vehicle and onboard UAV collaborative delivery is introduced as a nove... The rapid evolution of unmanned aerial vehicle(UAV)technology and autonomous capabilities has positioned UAV as promising last-mile delivery means.Vehicle and onboard UAV collaborative delivery is introduced as a novel delivery mode.Spatiotemporal collaboration,along with energy consumption with payload and wind conditions play important roles in delivery route planning.This paper introduces the traveling salesman problem with time window and onboard UAV(TSPTWOUAV)and emphasizes the consideration of real-world scenarios,focusing on time collaboration and energy consumption with wind and payload.To address this,a mixed integer linear programming(MILP)model is formulated to minimize the energy consumption costs of vehicle and UAV.Furthermore,an adaptive large neighborhood search(ALNS)algorithm is applied to identify high-quality solutions efficiently.The effectiveness of the proposed model and algorithm is validated through numerical tests on real geographic instances and sensitivity analysis of key parameters is conducted. 展开更多
关键词 vehicle and onboard unmanned aerial vehicle(uav)collaborative delivery energy consumption function route planning mixed integer linear programming model adaptive large neighborhood search(ALNS)algorithm
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基于多密度流聚类的UAV-NOMA用户分簇与功率分配算法 被引量:1
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作者 杨青青 韩卓廷 +1 位作者 彭艺 吴桐 《湖南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第6期86-97,共12页
针对无人机(Unmanned Aerial Vehicle,UAV)辅助非正交多址(Non-Orthogonal Multiple Access,NOMA)下行通信系统,提出了最大化和速率的用户动态分簇与功率分配方案.考虑用户服务质量与UAV位置约束,建立了和速率最大化的优化问题.由于目... 针对无人机(Unmanned Aerial Vehicle,UAV)辅助非正交多址(Non-Orthogonal Multiple Access,NOMA)下行通信系统,提出了最大化和速率的用户动态分簇与功率分配方案.考虑用户服务质量与UAV位置约束,建立了和速率最大化的优化问题.由于目标函数的非凸性,将原问题解耦为三个子问题,分别优化UAV位置部署与用户连接、用户动态分簇、功率分配以提高系统性能.首先,基于K-means算法设计了UAV位置部署与用户连接方案,以减小路损为目的确定UAV最佳部署位置,同时选择其服务的最优用户群;其次,改进多密度流聚类(Multi-Density Stream Clustering, MDSC)算法,提出了单UAV下用户静态与动态分簇方案,静态分簇方案可自适应平衡簇数与簇用户数,并获得较大的簇内用户信道增益差异,动态分簇方案则针对用户移动属性,制定了即时更新策略;最后,使用分式规划(Fractional Programming,FP)二次变换的方法,引入辅助变量将原非凸问题变换为凸问题,交替优化辅助变量与功率分配因子,获得原非凸问题的次优解.仿真结果表明,与其他算法相比,本文分簇方案能获得更大的簇内信道差异与更小的簇内用户数标准差,同时用户系统性能也获得了显著提升. 展开更多
关键词 无人机 非正交多址 位置部署 动态分簇 功率分配
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OFDM-UAV中继广播通信系统航迹优化方法
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作者 李冬霞 孟燕 +1 位作者 黄庚铭 刘海涛 《西安电子科技大学学报》 EI CAS CSCD 北大核心 2024年第4期91-101,共11页
为了提高无人机中继广播通信系统的性能,针对频率选择性衰落信道,考虑基站到无人机以及无人机到用户的全通信链路,提出了基于正交频分复用(OFDM)技术的无人机中继广播通信系统航迹优化方法。首先提出了基于OFDM的无人机中继广播通信传... 为了提高无人机中继广播通信系统的性能,针对频率选择性衰落信道,考虑基站到无人机以及无人机到用户的全通信链路,提出了基于正交频分复用(OFDM)技术的无人机中继广播通信系统航迹优化方法。首先提出了基于OFDM的无人机中继广播通信传输模型,对单用户节点中断概率和系统平均中断概率进行理论分析并给出近似计算公式;然后以平均中断概率最小化和最大用户中断概率最小化为优化准则,提出无人机的航迹优化方法并分析了各因素对系统中断性能的影响;最后通过计算机仿真,证明了所提航迹优化方法正确有效。研究表明:在多径信道下,基于OFDM的无人机中继广播通信系统能有效克服频率选择性衰落,且译码转发方式下的连通性优于放大转发方式;基于平均中断概率最小化准则得到的系统中断性能优于最大用户中断概率最小化准则。 展开更多
关键词 无人机中继 广播通信 正交频分复用 航迹优化 中断概率
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基于UAV成像技术的‘高原红’海棠花期物候监测研究 被引量:3
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作者 范俊俊 姜文龙 +3 位作者 刘星辰 夏重立 张往祥 黄俊 《北方园艺》 CAS 北大核心 2024年第10期47-54,共8页
以‘高原红’海棠(Malus‘Prairifire’)为试材,基于UAV成像技术采集物候期内图像样本并提取色彩参数值(CIE L^(*)a^(*)b^(*)),计算不同采样点及不同物候期的色差值(△E),通过对比△E的变化情况实现海棠物候的动态监测,为实时掌握海棠... 以‘高原红’海棠(Malus‘Prairifire’)为试材,基于UAV成像技术采集物候期内图像样本并提取色彩参数值(CIE L^(*)a^(*)b^(*)),计算不同采样点及不同物候期的色差值(△E),通过对比△E的变化情况实现海棠物候的动态监测,为实时掌握海棠物候动态变化情况,适时作出调整策略提供技术参考,同时也为开展花期物候调控相关研究提供参考依据。结果表明:1)利用Photoshop提取航拍图像色彩参数,并基于物候色彩参数进行聚类分析,将其物候划分为萌芽期、展叶期、蕾期、初花期、盛花期、末花期、落叶期、结果期、休眠期,建立了‘高原红’海棠物候色彩参数库;2)计算‘高原红’海棠各物候期内色差△E_(1)及不同物候期间色差△E_(2)范围,并基于各物候期内最大色差△E_(1max)′及不同物候期间最小色差△E_(2min)′,建立了基于色差参数的物候判别方法;3)随机提取了2个日期(3月22日、4月10日)的‘高原红’海棠物候图像色彩参数,通过聚类分析判定2个日期物候图分别处于蕾期和盛花期,结果与实际相符;2个日期物候图间色差(△E_(2)′=21.8)大于蕾期至初花期最小色差(△E_(2min)=9.6),表明此时物候期跨度较大,结果与实际相符。综上,该方法可便捷高效判断海棠花期等物候期情况。 展开更多
关键词 uav成像技术 ‘高原红’海棠 花期物候 色彩参数 监测
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基于DPBBO算法的智慧云仓UAV盘库作业优化
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作者 张富强 温博强 惠记庄 《北京工业大学学报》 CAS CSCD 北大核心 2024年第8期921-929,共9页
针对智慧云仓货物信息量大、易出现账物不符等库存管理问题,迫切需要将无人机(unmanned aerial vehicle, UAV)和工业物联网(industrial Internet of things, IIoT)集成起来,为仓储精细化管理提供解决方案。首先,分析盘库作业数据采集与... 针对智慧云仓货物信息量大、易出现账物不符等库存管理问题,迫切需要将无人机(unmanned aerial vehicle, UAV)和工业物联网(industrial Internet of things, IIoT)集成起来,为仓储精细化管理提供解决方案。首先,分析盘库作业数据采集与信息交互运行机制,以危险避障和数据采集为约束函数,考虑了UAV在加速、减速、匀速、转角等飞行条件下的能耗差异,并以能耗最低和时间最短为目标函数构造UAV盘库作业数学模型;然后,设计了差分迁移-分段变异生物地理学优化(differential migration-piecewise mutation-biogeography-based optimization, DPBBO)算法对上述模型进行优化解算;最后,进行了仿真实验验证。结果表明:DPBBO算法对解决该盘库作业问题的效果较优,可以提升库存抽检任务的时效性和库存管理的准确性。 展开更多
关键词 智慧云仓 盘库作业 无人机 差分迁移-分段变异生物地理学优化算法 射频识别技术 工业物联网
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