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A review of aerial manipulation of small-scale rotorcraft unmanned robotic systems
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作者 Xilun DING Pin GUO +1 位作者 Kun XU Yushu YU 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第1期200-214,共15页
Small-scale rotorcraft unmanned robotic systems(SRURSs) are a kind of unmanned rotorcraft with manipulating devices. This review aims to provide an overview on aerial manipulation of SRURSs nowadays and promote relati... Small-scale rotorcraft unmanned robotic systems(SRURSs) are a kind of unmanned rotorcraft with manipulating devices. This review aims to provide an overview on aerial manipulation of SRURSs nowadays and promote relative research in the future. In the past decade, aerial manipulation of SRURSs has attracted the interest of researchers globally. This paper provides a literature review of the last 10 years(2008–2017) on SRURSs, and details achievements and challenges. Firstly, the definition, current state, development, classification, and challenges of SRURSs are introduced. Then, related papers are organized into two topical categories: mechanical structure design, and modeling and control. Following this, research groups involved in SRURS research and their major achievements are summarized and classified in the form of tables. The research groups are introduced in detail from seven parts. Finally, trends and challenges are compiled and presented to serve as a resource for researchers interested in aerial manipulation of SRURSs. The problem,trends, and challenges are described from three aspects. Conclusions of the paper are presented,and the future of SRURSs is discussed to enable further research interests. 展开更多
关键词 AERIAL MANIPULATION Mechanical structure design Modeling and control Research GROUPS SMALL-SCALE ROTORCRAFT unmanned AERIAL systems TRENDS and challenges
MAV/UAV task coalition phased-formation method 预览
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作者 JIAO Zhiqiang YAO Peiyang +2 位作者 ZHANG Jieyong ZHONG Yun WANG Xun 《系统工程与电子技术:英文版》 SCIE EI CSCD 2019年第2期402-414,共13页
The formation of the manned aerial vehicle/unmanned aerial vehicle(MAV/UAV) task coalition is considered. To reduce the scale of the problem, the formation progress is divided into three phases. For the task clusterin... The formation of the manned aerial vehicle/unmanned aerial vehicle(MAV/UAV) task coalition is considered. To reduce the scale of the problem, the formation progress is divided into three phases. For the task clustering phase, the geographical position of tasks is taken into consideration and a cluster method is proposed. For the UAV allocation phase, the UAV requirement for both constrained and unconstrained resources is introduced, and a multi-objective optimal algorithm is proposed to solve the allocation problem. For the MAV allocation phase, the optimal model is firstly constructed and it is decomposed according to the ideal of greed to reduce the time complexity of the algorithm. Based on the above phases, the MAV/UAV task coalition formation method is proposed and the effectiveness and practicability are demonstrated by simulation examples. 展开更多
关键词 TASK coalition formation TASK clustering unmanned AERIAL VEHICLE (UAV) ALLOCATION manned AERIAL VEHICLE (MAV) ALLOCATION
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A two-stage optimization method for unmanned aerial vehicle inspection of an oil and gas pipeline network
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作者 Yamin Yan Yongtu Liang +4 位作者 Haoran Zhang Wan Zhang Huixia Feng Bohong Wang Qi Liao 《石油科学:英文版》 SCIE CAS CSCD 2019年第2期458-468,共11页
Oil and gas pipeline networks are a key link in the coordinated development of oil and gas both upstream and downstream.To improve the reliability and safety of the oil and gas pipeline network, inspections are implem... Oil and gas pipeline networks are a key link in the coordinated development of oil and gas both upstream and downstream.To improve the reliability and safety of the oil and gas pipeline network, inspections are implemented to minimize the risk of leakage, spill and theft, as well as documenting actual incidents. In recent years, unmanned aerial vehicles have been recognized as a promising option for inspection due to their high efficiency. However, the integrated optimization of unmanned aerial vehicle inspection for oil and gas pipeline networks, including physical feasibility, the performance of mission, cooperation, real-time implementation and three-dimensional(3-D) space, is a strategic problem due to its large-scale,complexity as well as the need for efficiency. In this work, a novel mixed-integer nonlinear programming model is proposed that takes into account the constraints of the mission scenario and the safety performance of unmanned aerial vehicles. To minimize the total length of the inspection path, the model is solved by a two-stage solution method. Finally, a virtual pipeline network and a practical pipeline network are set as two examples to demonstrate the performance of the optimization schemes. Moreover, compared with the traditional genetic algorithm and simulated annealing algorithm, the self-adaptive genetic simulated annealing algorithm proposed in this paper provides strong stability. 展开更多
关键词 PIPELINE network Unmanned AERIAL VEHICLE inspection MIXED-INTEGER nonlinear PROGRAMMING TWO-STAGE solution
UAV’s Coverage Search Planning Algorithm Based on Action Combinations
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作者 陈仔荣 鲁亚飞 +1 位作者 侯中喜 王俊伟 《上海交通大学学报:英文版》 EI 2019年第1期48-57,共10页
The autonomous route planning in coverage search is an important subject of unmanned aerial vehicle(UAV) mission planning. Pre-planning is simple and feasible for the coverage search mission of single UAV in regular a... The autonomous route planning in coverage search is an important subject of unmanned aerial vehicle(UAV) mission planning. Pre-planning is simple and feasible for the coverage search mission of single UAV in regular areas. As to the dynamic mission in complicated environment of multi-UAV, the route planning will encounter the difficulties of reasonable task distribution and the real-time environment changes which include the changes of the mission area, the detection of threat area, the interference of communication and so on. At this point, making the UAV to do real-time autonomous planning is necessary. However, it is hard to fulfil requirements of real-time, autonomous and efficient at the same time. According to a scalable knowledge base,this paper proposes a coverage search algorithm which is based on the mapping between the basic behavior combination and surroundings. A UAV’s coverage search simulation model with random shapes is built with a discrete map to update the environment and the changes of the mission on time. Comparison of the simulation analysis and the dynamic programming shows that the method has amazing expandability and can change the search strategy feasibly. It is efficient, and the ratio of coverage redundancy can be decreased to 1.21. It also has the potentiality in real-time calculation, and the computing time can be shortened to about 2 s. 展开更多
关键词 unmanned AERIAL vehicle(UAV) COVERAGE SEARCH action COMBINATIONS SEARCH strategy dynamic programming
Distributed Transmit Beamforming for UAV to Base Communications 预览
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作者 Yin Lu Jun Fang +1 位作者 Zhong Guo J.Andrew Zhang 《中国通信:英文版》 SCIE CSCD 2019年第1期15-25,共11页
Distributed transmit beamforming(DTB)is very efficient for extending the communication distance between a swarm of UAVs and the base,particularly when considering the constraints in weight and battery life for payload... Distributed transmit beamforming(DTB)is very efficient for extending the communication distance between a swarm of UAVs and the base,particularly when considering the constraints in weight and battery life for payloads on UAVs.In this paper,we review major function modules and potential solutions in realizing DTB in UAV systems,such as timing and carrier synchronization,phase drift tracking and compensation,and beamforming vector generation and updating.We then focus on beamforming vector generation and updating,and introduce a concatenated training scheme,together with a recursive channel estimation and updating algorithm.We also propose three approaches for tracking the variation of channels and updating the vectors.The effectiveness of these approaches is validated by simulation results. 展开更多
关键词 unmanned AERIAL vehicle DISTRIBUTED transmit BEAMFORMING BEAMFORMING VECTOR generation and updating channel prediction
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Optimized deployment of a radar network based on an improved firefly algorithm
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作者 Xuc-jun ZHANG Wei JIA +3 位作者 Xiang-min GUAN Guo-qiang XU Jun CHEN Yan-bo ZHU 《信息与电子工程前沿:英文版》 SCIE EI CSCD 2019年第3期425-437,共13页
The threats and challenges of unmanned aerial vehicle(UAV) invasion defense due to rapid UAV development have attracted increased attention recently. One of the important UAV invasion defense methods is radar network ... The threats and challenges of unmanned aerial vehicle(UAV) invasion defense due to rapid UAV development have attracted increased attention recently. One of the important UAV invasion defense methods is radar network detection. To form a tight and reliable radar surveillance network with limited resources, it is essential to investigate optimized radar network deployment. This optimization problem is difficult to solve due to its nonlinear features and strong coupling of multiple constraints. To address these issues, we propose an improved firefly algorithm that employs a neighborhood learning strategy with a feedback mechanism and chaotic local search by elite fireflies to obtain a trade-off between exploration and exploitation abilities. Moreover, a chaotic sequence is used to generate initial firefly positions to improve population diversity. Experiments have been conducted on 12 famous benchmark functions and in a classical radar deployment scenario. Results indicate that our approach achieves much better performance than the classical firefly algorithm(FA) and four recently proposed FA variants. 展开更多
关键词 IMPROVED FIREFLY algorithm Radar surveillance network DEPLOYMENT optimization Unmanned AERIAL vehicle (UAV) INVASION defense
Human-Robot Interface for Unmanned Aerial Vehicle via a Leap Motion 预览
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作者 Mingxuan Chen Caibing Liu +1 位作者 Guanglong Du Ping Zhang 《北京理工大学学报:英文版》 EI CAS 2019年第1期1-7,共7页
The unmanned aircraft vehicles industry is in the ascendant while traditional interaction ways for an unmanned aerial vehicle(UAV)are not intuitive enough.It is difficult for a beginner to control a UAV,therefore natu... The unmanned aircraft vehicles industry is in the ascendant while traditional interaction ways for an unmanned aerial vehicle(UAV)are not intuitive enough.It is difficult for a beginner to control a UAV,therefore natural interaction methods are preferred.This paper presents a novel interactive control method for a UAV through operator's gesture,and explores the natural interaction method for the UAV.The proposed system uses the leap motion controller as an input device acquiring the gesture position and orientation data.It is found that the proposed human-robot interface can track the movement of the operator with satisfactory accuracy.The biggest advantage of the proposed method is its capability to control the UAV by just one hand instead of a joystick.A series of experiments verified the feasibility of the proposed human-robot interface.The results demonstrate that non-professional operators can easily operate a remote UAV by just using this system. 展开更多
关键词 human-robot interface unmanned AERIAL vehicle(UAV) GESTURE control scheme autoadaption leap MOTION
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Land of Hopes
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《北京周报:英文版》 2019年第20期4-5,共2页
Aerial photo taken on September 12,2018 shows the ripe rice fields at Nanniwan in Yan'an, northwest Chinas Shaanxi Province. Yanan, which hosted the then headquarters of the Communist Party of China from 1935 to 1... Aerial photo taken on September 12,2018 shows the ripe rice fields at Nanniwan in Yan'an, northwest Chinas Shaanxi Province. Yanan, which hosted the then headquarters of the Communist Party of China from 1935 to 1948, has eliminated absolute poverty after its Last two impoverished counties met the country's requirement to cast off the tide, the Shaanxi Provincial Government said on May 7. 展开更多
关键词 AERIAL PHOTO impoverished counties PROVINCIAL GOVERNMENT
Stability Analysis and Structural Parameters Optimization of Quadrotor Unmanned Aerial Vehicles 预览
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作者 CHEN Cheng ZHANG Liru +2 位作者 ZHANG Cheng FU Weijie LIU Na 《国际设备工程与管理:英文版》 2019年第1期19-29,共11页
To increase dynamic stability of the quadrotor unmanned aerial vehicles in varying mechanical structure.The qualitative analysis is considered the main methods for analyzing the dynamic stability,while the index of qu... To increase dynamic stability of the quadrotor unmanned aerial vehicles in varying mechanical structure.The qualitative analysis is considered the main methods for analyzing the dynamic stability,while the index of qualitative analysis of the structural stability and the dynamic stability are still hard to establish.Therefore,the process during rolling or pitching is selected for investigating in the present papers,the method of Lyapunov exponent is adopted for establishing the quantification relationship of between structural parameters of quadrotor unmanned aerial vehicles and dynamic stability,and its dynamic stability for guiding the design of the vehicle′s mechanical structure and the optimization of its stability control by using the relationship.As compared to its counterpart of Lyapunov′s second method,the main advantage of the concept of Lyapunov exponents is that the methods for calculating the exponent process are constructive which makes the stability analysis of complex nonlinear systems possible. 展开更多
关键词 QUADROTOR unmanned AERIAL vehicles structure optimization DYNAMIC model DYNAMIC stability LYAPUNOV EXPONENT
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Motion planning of a quadrotor robot game using a simulation-based projected policy iteration method
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作者 Li-dong ZHANG Ban WANG +2 位作者 Zhi-xiang LIU You-min ZHANG Jian-liang AI 《信息与电子工程前沿:英文版》 SCIE EI CSCD 2019年第4期525-537,共13页
Making rational decisions for sequential decision problems in complex environments has been challenging researchers in various fields for decades. Such problems consist of state transition dynamics, stochastic uncerta... Making rational decisions for sequential decision problems in complex environments has been challenging researchers in various fields for decades. Such problems consist of state transition dynamics, stochastic uncertainties,long-term utilities, and other factors that assemble high barriers including the curse of dimensionality. Recently, the state-of-the-art algorithms in reinforcement learning studies have been developed, providing a strong potential to efficiently break the barriers and make it possible to deal with complex and practical decision problems with decent performance. We propose a formulation of a velocity varying one-on-one quadrotor robot game problem in the threedimensional space and an approximate dynamic programming approach using a projected policy iteration method for learning the utilities of game states and improving motion policies. In addition, a simulation-based iterative scheme is employed to overcome the curse of dimensionality. Simulation results demonstrate that the proposed decision strategy can generate effective and efficient motion policies that can contend with the opponent quadrotor and gather advantaged status during the game. Flight experiments, which are conducted in the Networked Autonomous Vehicles(NAV) Lab at the Concordia University, have further validated the performance of the proposed decision strategy in the real-time environment. 展开更多
关键词 Reinforcement learning APPROXIMATE dynamic PROGRAMMING Decision making Motion planning Unmanned AERIAL vehicle
Reliable flight performance assessment of multirotor based on interacting multiple model particle filter and health degree
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作者 Zhiyao ZHAO Peng YAO +3 位作者 Xiaoyi WANG Jiping XU Li WANG Jiabin YU 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第2期444-453,共10页
Multirotor has been applied to many military and civilian mission scenarios. From the perspective of reliability, it is difficult to ensure that multirotors do not generate hardware and software failures or performanc... Multirotor has been applied to many military and civilian mission scenarios. From the perspective of reliability, it is difficult to ensure that multirotors do not generate hardware and software failures or performance anomalies during the flight process. These failures and anomalies may result in mission interruptions, crashes, and even threats to the lives and property of human beings.Thus, the study of flight reliability problems of multirotors is conductive to the development of the drone industry and has theoretical significance and engineering value. This paper proposes a reliable flight performance assessment method of multirotors based on an Interacting Multiple Model Particle Filter(IMMPF) algorithm and health degree as the performance indicator. First, the multirotor is modeled by the Stochastic Hybrid System(SHS) model, and the problem of reliable flight performance assessment is formulated. In order to solve the problem, the IMMPF algorithm is presented to estimate the real-time probability distribution of hybrid state of the established SHS-based multirotor model, since it can decrease estimation errors compared with the standard interacting multiple model algorithm based on extended Kalman filter. Then, the reliable flight performance is assessed with health degree based on the estimation result. Finally, a case study of a multirotor suffering from sensor anomalies is presented to validate the effectiveness of the proposed method. 展开更多
关键词 HEALTH DEGREE INTERACTING multiple model Multirotor Particle filter Reliability and safety RELIABLE flight performance Unmanned AERIAL vehicles
Geographic,Geometrical and Semantic Reconstruction of Urban Scene from High Resolution Oblique Aerial Images 预览
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作者 Xiaofeng Sun Shuhan Shen +2 位作者 Hainan Cui Lihua Hu Zhanyi Hu 《自动化学报:英文版》 CSCD 2019年第1期118-130,共13页
An effective approach is proposed for 3D urban scene reconstruction in the form of point cloud with semantic labeling. Starting from high resolution oblique aerial images,our approach proceeds through three main stage... An effective approach is proposed for 3D urban scene reconstruction in the form of point cloud with semantic labeling. Starting from high resolution oblique aerial images,our approach proceeds through three main stages: geographic reconstruction, geometrical reconstruction and semantic reconstruction. The absolute position and orientation of all the cameras relative to the real world are recovered in the geographic reconstruction stage. Then, in the geometrical reconstruction stage,an improved multi-view stereo matching method is employed to produce 3D dense points with color and normal information by taking into account the prior knowledge of aerial imagery.Finally the point cloud is classified into three classes(building,vegetation, and ground) by a rule-based hierarchical approach in the semantic reconstruction step. Experiments on complex urban scene show that our proposed 3-stage approach could generate reasonable reconstruction result robustly and efficiently.By comparing our final semantic reconstruction result with the manually labeled ground truth, classification accuracies from86.75% to 93.02% are obtained. 展开更多
关键词 OBLIQUE aerial image point cloud SEMANTIC LABELING urban RECONSTRUCTION
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An execution control method for the Aerostack aerial robotics framework
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作者 Martin MOLINA Alberto CAMPORREDONDO +2 位作者 Hriday BAVLE AlejANDro RODRIGUEZ-RAMOS Pascual CAMPOY 《信息与电子工程前沿:英文版》 SCIE EI CSCD 2019年第1期60-75,共16页
Execution control is a critical task of robot architectures which has a deep impact on the quality of the final system. In this study, we describe a general method for execution control, which is a part of the Aerosta... Execution control is a critical task of robot architectures which has a deep impact on the quality of the final system. In this study, we describe a general method for execution control, which is a part of the Aerostack software framework for aerial robotics, and present technical challenges for execution control and design decisions to develop the method. The proposed method has an original design combining a distributed approach for execution control of behaviors(such as situation checking and performance monitoring) and centralizes coordination to ensure consistency of the concurrent execution. We conduct experiments to evaluate the method. The experimental results show that the method is general and usable with acceptable development efforts to efficiently work on different types of aerial missions. The method is supported by standards based on a robot operating system(ROS) contributing to its general use, and an open-source project is integrated in the Aerostack framework. Therefore, its technical details are fully accessible to developers and freely available to be used in the development of new aerial robotic systems. 展开更多
关键词 AERIAL ROBOTICS CONTROL ARCHITECTURE Behavior-based CONTROL EXECUTIVE system
Modeling novel methodologies for unmanned aerial systems–Applications to the UAS-S4 Ehecatl and the UAS-S45 Bálaam
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作者 Maxime Alex Junior KUITCHE Ruxandra Mihaela BOTEZ 《中国航空学报:英文版》 SCIE EI CAS CSCD 2019年第1期58-77,共20页
The rising demand for Unmanned Aerial Systems(UASs) to perform tasks in hostile environments has emphasized the need for their simulation models for the preliminary evaluations of their missions. The efficiency of the... The rising demand for Unmanned Aerial Systems(UASs) to perform tasks in hostile environments has emphasized the need for their simulation models for the preliminary evaluations of their missions. The efficiency of the UAS model is directly related to its capacity to estimate its flight dynamics with minimum computational resources. The literature describes several techniques to estimate accurate aircraft flight dynamics. Most of them are based on system identification. This paper presents an alternative methodology to obtain complete model of the S4 and S45 unmanned aerial systems. The UAS-S4 and the UAS-S45 models were divided into four sub-models, each corresponding to a specific discipline: aerodynamics, propulsion, mass and inertia, and actuator. The‘‘aerodynamic” sub-model was built using the Fderivatives in-house code, which is an improvement of the classical DATCOM procedure. The ‘‘propulsion” sub-model was obtained by coupling a two-stroke engine model based on the ideal Otto cycle and a Blade Element Theory(BET) analysis of the propeller. The ‘‘mass and the inertia” sub-model was designed utilizing the Raymer and DATCOM methodologies. A sub-model of an actuator using servomotor characteristics was employed to complete the model. The total model was then checked by validation of each submodel with numerical and experimental data. The results indicate that the obtained model was accurate and could be used to design a flight simulator. 展开更多
关键词 AERODYNAMICS Aerospace PROPULSION Flight dynamics Unmanned aerial vehicles MODELING
Energy efficient and delay aware ternary-state transceivers for aerial base stations 预览
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作者 Nahina Islam Kandeepan Sithamparanathan +2 位作者 Karina Gomez Chavez James Scott Hamid Eltom 《数字通信与网络:英文版》 2019年第1期40-50,共11页
In recent times, Aerial Base Stations(AeBSs) are being investigated to provide wireless coverage to terrestrial radio terminals. There are many advantages of using aerial platforms to provide wireless coverage, includ... In recent times, Aerial Base Stations(AeBSs) are being investigated to provide wireless coverage to terrestrial radio terminals. There are many advantages of using aerial platforms to provide wireless coverage, including larger coverage in remote areas and better line-of-sight conditions, etc. Energy is a scarce resource for the AeBSs, hence the wise management of energy is quite beneficial for the aerial network. In this context, we study the means of reducing the total energy consumption by designing and implementing an energy efficient AeBSs as presented in this paper. Implementing the sleep mode in the Base Stations (BSs) has been proven to be a very good approach for improving the energy efficiency and we propose a novel strategy for further improving energy efficiency by considering ternary state transceivers for AeBSs. Using the three state model, we propose a Markov Decision Process (MDP) based algorithm, which intelligently switches among three states of the transceivers based on the offered traffic meanwhile maintaining a prescribed minimum channel rate per user. We define a reward function for the MDP, which helps us to get an optimal policy for selecting a particular mode for the transceivers of the AeBS. Considering an AeBS with transceivers whose states are changeable, we perform simulations to analyse the performance of the algorithm. Our results show that, compared with the always active model, around 40% gain in the energy efficiency is achieved by using our proposed MDP algorithm together with the three-state transceivers model. We also show the energy-delay tradeoff in order to design an efficient AeBS. 展开更多
关键词 AERIAL base station UAV Green communication SLEEP mode Markov decision process ENERGY efficiency ENERGY DELAY TRADEOFF
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Safe navigation of quadrotors with jerk limited trajectory
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作者 Shu-peng LAI Meng-lu LAN +1 位作者 Ya-xuan LI Ben M.CHEN 《信息与电子工程前沿:英文版》 SCIE EI CSCD 2019年第1期107-119,共13页
Many aerial applications require unmanned aerial systems operate in safe zones because of the presence of obstacles or security regulations. It is a non-trivial task to generate a smooth trajectory satisfying both dyn... Many aerial applications require unmanned aerial systems operate in safe zones because of the presence of obstacles or security regulations. It is a non-trivial task to generate a smooth trajectory satisfying both dynamic constraints and motion limits of the unmanned vehicles while being inside the safe zones. Then the task becomes even more challenging for real-time applications, for which computational efficiency is crucial. In this study, we present a safe flying corridor navigation method, which combines jerk limited trajectories with an efficient testing method to update the position setpoints in real time. Trajectories are generated online and incrementally with a cycle time smaller than 10 μs, which is exceptionally suitable for vehicles with limited onboard computational capability. Safe zones are represented with multiple interconnected bounding boxes which can be arbitrarily oriented.The jerk limited trajectory generation algorithm has been extended to cover the cases with asymmetrical motion limits. The proposed method has been successfully tested and verified in flight simulations and actual experiments. 展开更多
关键词 QUADROTOR Unmanned AERIAL VEHICLE Motion planning
Comparative Analysis of Fractional Vegetation Cover Estimation Based on Multi-sensor Data in a Semi-arid Sandy Area 预览
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作者 LIU Qiuyu ZHANG Tinglong +3 位作者 LI Yizhe LI Ying BU Chongfeng ZHANG Qingfeng 《中国地理科学:英文版》 SCIE CSCD 2019年第1期166-180,共15页
The estimation of fractional vegetation cover(FVC) is important for identifying and monitoring desertification, especially in arid and semiarid regions. By using regression and pixel dichotomy models, we present the c... The estimation of fractional vegetation cover(FVC) is important for identifying and monitoring desertification, especially in arid and semiarid regions. By using regression and pixel dichotomy models, we present the comparison of Sentinel-2A(S2) multispectral instrument(MSI) and Landsat 8(L8) operational land imager(OLI) data regarding the retrieval of FVC in a semi-arid sandy area(Mu Us Sandland, China, in August 2016). A combination of unmanned aerial vehicle(UAV) high-spatial-resolution images and field plots were used to produce verified data. Based on a normalized difference vegetation index(NDVI) regression model, the results showed that, compared with that of L8, the coefficient of determination(R2) of S2 increased by 26.0%, and the root mean square error(RMSE) and the sum of absolute error(SAE) decreased by 3.0% and 11.4%, respectively. For the ratio vegetation index(RVI) regression model, compared with that of L8, the R2 of S2 increased by 26.0%, and the RMSE and SAE decreased by 8.0% and 20.0%, respectively. When the pixel dichotomy model was used, compared with that of L8, the RMSE of S2 decreased by 21.3%, and the SAE decreased by 26.9%. Overall, S2 performed better than L8 in terms of FVC inversion. Additionally, in this paper, we develop a verified scheme based on UAV data in combination with the object-based classification method. This scheme is feasible and sufficiently robust for building relationships between field data and inversion results from satellite data. Further, the synergy of multi-source sensors(especially UAVs and satellites) is a potential effective way to estimate and evaluate regional ecological environmental parameters(FVC). 展开更多
关键词 fractional vegetation cover (FVC) Sentinel-2A (S2) unmanned AERIAL vehicle (UAV)image PIXEL DICHOTOMY MODEL regression MODEL
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An automatic method for road centerline extraction from post-earthquake aerial images
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作者 Zhumei Liu Jingfa Zhang Xue Li 《大地测量与地球动力学:英文版》 2019年第1期10-16,共7页
Road vector database plays an important role in post-earthquake relief,rescue and reconstruction.However,due to data privacy policy,it is difficult for general users to obtain high-precision and complete vector data o... Road vector database plays an important role in post-earthquake relief,rescue and reconstruction.However,due to data privacy policy,it is difficult for general users to obtain high-precision and complete vector data of road network.The OpenStreetMap(OSM)project provides an open-source,global free road dataset,but there are inevitable geo-localization/projection errors,which will lead to large errors in hazard survey analysis.In this paper,we proposed a road centerline correction method using postearthquake aerial images.Under the constraint of the vector road map(OpenStreetMap),we rectified the centerline by the context feature and spectral gradient feature of post-event images automatically.The experiment implemented on 0.5 m/pixel post-event aerial images of Haiti,2010,showed that the completeness and extraction quality of proposed method were over 90%and 80%without any manual intervention. 展开更多
关键词 OpenStreetMap MORPHOLOGICAL GRADIENT ROAD CENTERLINE extraction AERIAL image
Fixed-wing UAV guidance law for ground target over-flight tracking 预览
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作者 ZHANG Min ZHENG Chenming HUANG Kun 《系统工程与电子技术:英文版》 SCIE EI CSCD 2019年第2期384-392,共9页
This paper studies the problem of tracking a ground target for a fixed-wing unmanned aerial vehicle(UAV) based on the proposed guidance law. The algorithm ensures that a UAV continuously overflies the target whether i... This paper studies the problem of tracking a ground target for a fixed-wing unmanned aerial vehicle(UAV) based on the proposed guidance law. The algorithm ensures that a UAV continuously overflies the target whether it is fixed or moving. The requirements of the UAV flight constraints such as bounded airspeed and acceleration are considered. A Lyapunov function is constructed to prove the stability of the proposed guidance law,and parameter design criteria have been developed. Considering the fixed and moving ground targets, numerical simulations are performed to verify the feasibility and benefits of the proposed guidance algorithm. 展开更多
关键词 unmanned AERIAL vehicle (UAV) ground TARGET guidance LAW over-flight stability
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Aircraft robust multidisciplinary design optimization methodology based on fuzzy preference function
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作者 Ali Reza BABAEI Mohammad Reza SETAYANDEH Hamid FARROKHFAL 《中国航空学报:英文版》 SCIE EI CAS CSCD 2018年第12期2248-2259,共12页
This paper presents a Fuzzy Preference Function-based Robust Multidisciplinary Design Optimization(FPF-RMDO) methodology. This method is an effective approach to multidisciplinary systems, which can be used to designe... This paper presents a Fuzzy Preference Function-based Robust Multidisciplinary Design Optimization(FPF-RMDO) methodology. This method is an effective approach to multidisciplinary systems, which can be used to designer experiences during the design optimization process by fuzzy preference functions. In this study, two optimizations are done for Predator MQ-1 Unmanned Aerial Vehicle(UAV):(A) deterministic optimization and(B) robust optimization. In both problems, minimization of takeoff weight and drag is considered as objective functions, which have been optimized using Non-dominated Sorting Genetic Algorithm(NSGA). In the robust design optimization, cruise altitude and velocity are considered as uncertainties that are modeled by the Monte Carlo Simulation(MCS) method. Aerodynamics, stability and control, mass properties, performance, and center of gravity are used for multidisciplinary analysis. Robust design optimization results show 46% and 42% robustness improvement for takeoff weight and cruise drag relative to optimal design respectively. 展开更多
关键词 Fuzzy logic MULTIDISCIPLINARY DESIGN optimization PREFERENCE FUNCTION ROBUST DESIGN Unmanned AERIAL Vehicle (UAV)
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