In recent years,there has been a surge of interest in air-ground collaborative robotics technologies.Our research group designs a novel combination-separation air-ground robot(CSAGR),which exhibits rapid automatic com...In recent years,there has been a surge of interest in air-ground collaborative robotics technologies.Our research group designs a novel combination-separation air-ground robot(CSAGR),which exhibits rapid automatic combination and separation capabilities.During the combination process,contact effects between robots,as well as between robots and the environment,are unavoidable.Therefore,it is essential to conduct detailed and accurate modeling and analysis of the collision impact intensity and transmission pathways within the robotic system to ensure the successful execution of the combination procedure.This paper addresses the intricate surface geometries and multi-point contact challenges present in the contact regions of dual robots by making appropriate modifications to the traditional continuous contact force model and applying equivalent processing techniques.The validity of the developed model is confirmed through comparisons with results obtained from finite element analysis(FEA),which demonstrates its high fidelity.Additionally,the impact of this model on control performance is analyzed within the flight control system,thereby further ensuring the successful completion of the combination process.This research represents a pioneering application and validation of continuous contact theory in the dynamics of collisions within dual robot systems.展开更多
With the rapid growth of connected devices,traditional edge-cloud systems are under overload pressure.Using mobile edge computing(MEC)to assist unmanned aerial vehicles(UAVs)as low altitude platform stations(LAPS)for ...With the rapid growth of connected devices,traditional edge-cloud systems are under overload pressure.Using mobile edge computing(MEC)to assist unmanned aerial vehicles(UAVs)as low altitude platform stations(LAPS)for communication and computation to build air-ground integrated networks(AGINs)offers a promising solution for seamless network coverage of remote internet of things(IoT)devices in the future.To address the performance demands of future mobile devices(MDs),we proposed an MEC-assisted AGIN system.The goal is to minimize the long-term computational overhead of MDs by jointly optimizing transmission power,flight trajecto-ries,resource allocation,and offloading ratios,while utilizing non-orthogonal multiple access(NOMA)to improve device connectivity of large-scale MDs and spectral efficiency.We first designed an adaptive clustering scheme based on K-Means to cluster MDs and established commu-nication links,improving efficiency and load balancing.Then,considering system dynamics,we introduced a partial computation offloading algorithm based on multi-agent deep deterministic pol-icy gradient(MADDPG),modeling the multi-UAV computation offloading problem as a Markov decision process(MDP).This algorithm optimizes resource allocation through centralized training and distributed execution,reducing computational overhead.Simulation results show that the pro-posed algorithm not only converges stably but also outperforms other benchmark algorithms in han-dling complex scenarios with multiple devices.展开更多
By pushing computation,cache,and network control to the edge,mobile edge computing(MEC)is expected to play a leading role in fifth generation(5G)and future sixth generation(6G).Nevertheless,facing ubiquitous fast-grow...By pushing computation,cache,and network control to the edge,mobile edge computing(MEC)is expected to play a leading role in fifth generation(5G)and future sixth generation(6G).Nevertheless,facing ubiquitous fast-growing computational demands,it is impossible for a single MEC paradigm to effectively support high-quality intelligent services at end user equipments(UEs).To address this issue,we propose an air-ground collaborative MEC(AGCMEC)architecture in this article.The proposed AGCMEC integrates all potentially available MEC servers within air and ground in the envisioned 6G,by a variety of collaborative ways to provide computation services at their best for UEs.Firstly,we introduce the AGC-MEC architecture and elaborate three typical use cases.Then,we discuss four main challenges in the AGC-MEC as well as their potential solutions.Next,we conduct a case study of collaborative service placement for AGC-MEC to validate the effectiveness of the proposed collaborative service placement strategy.Finally,we highlight several potential research directions of the AGC-MEC.展开更多
This paper addresses an unmanned aerial vehicle (UAV) path planning problem for a team of cooperating heterogeneous vehicles composed of one UAV and multiple unmanned ground vehicles (UGVs). The UGVs are used as mobil...This paper addresses an unmanned aerial vehicle (UAV) path planning problem for a team of cooperating heterogeneous vehicles composed of one UAV and multiple unmanned ground vehicles (UGVs). The UGVs are used as mobile actuators and scattered in a large area. To achieve multi-UGV communication and collaboration, the UAV serves as a messenger to fly over all task points to collect the task information and then flies all UGVs to transmit the information about tasks and UGVs. The path planning of messenger UAV is formulated as a precedence-constrained dynamic Dubins traveling salesman problem with neighborhood (PDDTSPN). The goal of this problem is to find the shortest route enabling the UAV to fly over all task points and deliver information to all requested UGVs. When solving this path planning problem, a decoupling strategy is proposed to sequentially and rapidly determine the access sequence in which the UAV visits task points and UGVs as well as the access location of UAV in the com mu nication n eighborhood of each task point and each UGV. The effectiveness of the proposed approach is corroborated through computational experiments on randomly generated instances. The computational results on both small and large in stances dem on strate that the proposed approach can generate high-quality solutions in a reasonable time as compared with two other heuristic algorithms.展开更多
The research of three-dimensional integrated communication technology plays a key role in achieving the ubiquitous connectivity,ultra-high data rates,and emergency communications in the sixth generation(6G)networks.Ae...The research of three-dimensional integrated communication technology plays a key role in achieving the ubiquitous connectivity,ultra-high data rates,and emergency communications in the sixth generation(6G)networks.Aerial networking provides a prom⁃ising solution to flexible,scalable,low-cost and reliable coverage for wireless devices.The integration of aerial network and terrestrial network has been an inevitable paradigm in the 6G era.However,energy-efficient communications and networking among aerial net⁃work and terrestrial network face great challenges.This paper is dedicated to discussing green communications of the air-ground integrated heterogeneous network(AGIHN).We first provide a brief introduction to the characteristics of AGIHN in 6G networks.Further,we analyze the challenges of green AGIHN from the aspects of green terrestrial networks and green aerial networks.Finally,several solutions to and key technologies of the green AGIHN are discussed.展开更多
Refined 3D modeling of mine slopes is pivotal for precise prediction of geological hazards.Aiming at the inadequacy of existing single modeling methods in comprehensively representing the overall and localized charact...Refined 3D modeling of mine slopes is pivotal for precise prediction of geological hazards.Aiming at the inadequacy of existing single modeling methods in comprehensively representing the overall and localized characteristics of mining slopes,this study introduces a new method that fuses model data from Unmanned aerial vehicles(UAV)tilt photogrammetry and 3D laser scanning through a data alignment algorithm based on control points.First,the mini batch K-Medoids algorithm is utilized to cluster the point cloud data from ground 3D laser scanning.Then,the elbow rule is applied to determine the optimal cluster number(K0),and the feature points are extracted.Next,the nearest neighbor point algorithm is employed to match the feature points obtained from UAV tilt photogrammetry,and the internal point coordinates are adjusted through the distanceweighted average to construct a 3D model.Finally,by integrating an engineering case study,the K0 value is determined to be 8,with a matching accuracy between the two model datasets ranging from 0.0669 to 1.0373 mm.Therefore,compared with the modeling method utilizing K-medoids clustering algorithm,the new modeling method significantly enhances the computational efficiency,the accuracy of selecting the optimal number of feature points in 3D laser scanning,and the precision of the 3D model derived from UAV tilt photogrammetry.This method provides a research foundation for constructing mine slope model.展开更多
A self-organized integrated air-ground detection swarmis tentatively applied to achieve reentry vehicle landing detection,such as searching and rescuing a manned spaceship. The detectionswarm consists of multiple unma...A self-organized integrated air-ground detection swarmis tentatively applied to achieve reentry vehicle landing detection,such as searching and rescuing a manned spaceship. The detectionswarm consists of multiple unmanned aerial vehicles （UAVs）and unmanned ground vehicles （UGVs）. The UAVs can accessa detected object quickly for high mobility, while the UGVs cancomprehensively investigate the object due to the variety of carriedequipment. In addition, the integrated air-ground detectionswarm is capable of detecting from the ground and the air simultaneously.To accomplish the coordination of the UGVs andUAVs, they are all regarded as individuals of the artificial swarm.Those individuals make control decisions independently of othersbased on the self-organizing strategy. The overall requirements forthe detection swarm are analyzed, and the theoretical model ofthe self-organizing strategy based on a combined individual andenvironmental virtual function is established. The numerical investigationproves that the self-organizing strategy is suitable andscalable to control the detection swarm. To further inspect the engineeringreliability, an experiment set is established in laboratory,and the experimental demonstration shows that the self-organizingstrategy drives the detection swarm forming a close range and multiangularsurveillance configuration of a landing spot.展开更多
A new type of air-ground communication application framework named FACT(framework for air-ground communication technology with weather-modification aircraft)is presented to track and command weather-modification aircr...A new type of air-ground communication application framework named FACT(framework for air-ground communication technology with weather-modification aircraft)is presented to track and command weather-modification aircraft to perform ideal cloud seeding.FACT provides a set of solutions from three perspectives,namely,onboard,onground and air-to-ground,with the core purpose of solving the problems of the rapid exchange of information,contract analysis and identifying potential seeding areas when flight plans and meteorological conditions change.On board,the observed data are processed centrally and transmitted downward through air-to-ground communication.The real-time application and sharing of aircraft detection data are strengthened on the ground,and potential areas of operation are automatically identified based on ground data.The communication between the air and the ground achieves a technical breakthrough by realizing double satellite links,adaptive data transmission and VPN channel encryption.Additionally,an application based on FACT is designed and implemented for the real-time command of weather-modified aircraft.This approach has become the key air-to-ground communication system support for more than 40 Chinese aircraft and the big data service support center of airborne data to ensure improved operation of weather-modification aircraft in China.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.T2121003 and 91748201).
文摘In recent years,there has been a surge of interest in air-ground collaborative robotics technologies.Our research group designs a novel combination-separation air-ground robot(CSAGR),which exhibits rapid automatic combination and separation capabilities.During the combination process,contact effects between robots,as well as between robots and the environment,are unavoidable.Therefore,it is essential to conduct detailed and accurate modeling and analysis of the collision impact intensity and transmission pathways within the robotic system to ensure the successful execution of the combination procedure.This paper addresses the intricate surface geometries and multi-point contact challenges present in the contact regions of dual robots by making appropriate modifications to the traditional continuous contact force model and applying equivalent processing techniques.The validity of the developed model is confirmed through comparisons with results obtained from finite element analysis(FEA),which demonstrates its high fidelity.Additionally,the impact of this model on control performance is analyzed within the flight control system,thereby further ensuring the successful completion of the combination process.This research represents a pioneering application and validation of continuous contact theory in the dynamics of collisions within dual robot systems.
基金supported by the Gansu Province Key Research and Development Plan(No.23YFGA0062)Gansu Provin-cial Innovation Fund(No.2022A-215).
文摘With the rapid growth of connected devices,traditional edge-cloud systems are under overload pressure.Using mobile edge computing(MEC)to assist unmanned aerial vehicles(UAVs)as low altitude platform stations(LAPS)for communication and computation to build air-ground integrated networks(AGINs)offers a promising solution for seamless network coverage of remote internet of things(IoT)devices in the future.To address the performance demands of future mobile devices(MDs),we proposed an MEC-assisted AGIN system.The goal is to minimize the long-term computational overhead of MDs by jointly optimizing transmission power,flight trajecto-ries,resource allocation,and offloading ratios,while utilizing non-orthogonal multiple access(NOMA)to improve device connectivity of large-scale MDs and spectral efficiency.We first designed an adaptive clustering scheme based on K-Means to cluster MDs and established commu-nication links,improving efficiency and load balancing.Then,considering system dynamics,we introduced a partial computation offloading algorithm based on multi-agent deep deterministic pol-icy gradient(MADDPG),modeling the multi-UAV computation offloading problem as a Markov decision process(MDP).This algorithm optimizes resource allocation through centralized training and distributed execution,reducing computational overhead.Simulation results show that the pro-posed algorithm not only converges stably but also outperforms other benchmark algorithms in han-dling complex scenarios with multiple devices.
基金supported in part by the National Natural Science Foundation of China under Grant 62171465,62072303,62272223,U22A2031。
文摘By pushing computation,cache,and network control to the edge,mobile edge computing(MEC)is expected to play a leading role in fifth generation(5G)and future sixth generation(6G).Nevertheless,facing ubiquitous fast-growing computational demands,it is impossible for a single MEC paradigm to effectively support high-quality intelligent services at end user equipments(UEs).To address this issue,we propose an air-ground collaborative MEC(AGCMEC)architecture in this article.The proposed AGCMEC integrates all potentially available MEC servers within air and ground in the envisioned 6G,by a variety of collaborative ways to provide computation services at their best for UEs.Firstly,we introduce the AGC-MEC architecture and elaborate three typical use cases.Then,we discuss four main challenges in the AGC-MEC as well as their potential solutions.Next,we conduct a case study of collaborative service placement for AGC-MEC to validate the effectiveness of the proposed collaborative service placement strategy.Finally,we highlight several potential research directions of the AGC-MEC.
基金National Outstanding Youth Talents Support Program (No. 61822304)in part by the National Natural Science Foundation of China (No. 61673058)+3 种基金in part by NSFC-Zhejiang Joint Fund for the Integration of Industrialization and Informatization (No. U1609214)in part by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No. 61621063)in part by the Projects of Major International (Regional) Joint Research Program NSFC (No. 61 720106011)in part by International Graduate Exchange Program of Beijing Institute of Technology.
文摘This paper addresses an unmanned aerial vehicle (UAV) path planning problem for a team of cooperating heterogeneous vehicles composed of one UAV and multiple unmanned ground vehicles (UGVs). The UGVs are used as mobile actuators and scattered in a large area. To achieve multi-UGV communication and collaboration, the UAV serves as a messenger to fly over all task points to collect the task information and then flies all UGVs to transmit the information about tasks and UGVs. The path planning of messenger UAV is formulated as a precedence-constrained dynamic Dubins traveling salesman problem with neighborhood (PDDTSPN). The goal of this problem is to find the shortest route enabling the UAV to fly over all task points and deliver information to all requested UGVs. When solving this path planning problem, a decoupling strategy is proposed to sequentially and rapidly determine the access sequence in which the UAV visits task points and UGVs as well as the access location of UAV in the com mu nication n eighborhood of each task point and each UGV. The effectiveness of the proposed approach is corroborated through computational experiments on randomly generated instances. The computational results on both small and large in stances dem on strate that the proposed approach can generate high-quality solutions in a reasonable time as compared with two other heuristic algorithms.
基金This work was supported by National Natural Science Foundation of Chi⁃na under Grant Nos.61901051 and 61932005.
文摘The research of three-dimensional integrated communication technology plays a key role in achieving the ubiquitous connectivity,ultra-high data rates,and emergency communications in the sixth generation(6G)networks.Aerial networking provides a prom⁃ising solution to flexible,scalable,low-cost and reliable coverage for wireless devices.The integration of aerial network and terrestrial network has been an inevitable paradigm in the 6G era.However,energy-efficient communications and networking among aerial net⁃work and terrestrial network face great challenges.This paper is dedicated to discussing green communications of the air-ground integrated heterogeneous network(AGIHN).We first provide a brief introduction to the characteristics of AGIHN in 6G networks.Further,we analyze the challenges of green AGIHN from the aspects of green terrestrial networks and green aerial networks.Finally,several solutions to and key technologies of the green AGIHN are discussed.
基金funded by National Natural Science Foundation of China(Grant Nos.42272333,42277147).
文摘Refined 3D modeling of mine slopes is pivotal for precise prediction of geological hazards.Aiming at the inadequacy of existing single modeling methods in comprehensively representing the overall and localized characteristics of mining slopes,this study introduces a new method that fuses model data from Unmanned aerial vehicles(UAV)tilt photogrammetry and 3D laser scanning through a data alignment algorithm based on control points.First,the mini batch K-Medoids algorithm is utilized to cluster the point cloud data from ground 3D laser scanning.Then,the elbow rule is applied to determine the optimal cluster number(K0),and the feature points are extracted.Next,the nearest neighbor point algorithm is employed to match the feature points obtained from UAV tilt photogrammetry,and the internal point coordinates are adjusted through the distanceweighted average to construct a 3D model.Finally,by integrating an engineering case study,the K0 value is determined to be 8,with a matching accuracy between the two model datasets ranging from 0.0669 to 1.0373 mm.Therefore,compared with the modeling method utilizing K-medoids clustering algorithm,the new modeling method significantly enhances the computational efficiency,the accuracy of selecting the optimal number of feature points in 3D laser scanning,and the precision of the 3D model derived from UAV tilt photogrammetry.This method provides a research foundation for constructing mine slope model.
基金supported by the National Natural Science Foundation of China(11002076)the National High Technology Research and Development Program of China(863 Program)(2014AA7041002)
文摘A self-organized integrated air-ground detection swarmis tentatively applied to achieve reentry vehicle landing detection,such as searching and rescuing a manned spaceship. The detectionswarm consists of multiple unmanned aerial vehicles （UAVs）and unmanned ground vehicles （UGVs）. The UAVs can accessa detected object quickly for high mobility, while the UGVs cancomprehensively investigate the object due to the variety of carriedequipment. In addition, the integrated air-ground detectionswarm is capable of detecting from the ground and the air simultaneously.To accomplish the coordination of the UGVs andUAVs, they are all regarded as individuals of the artificial swarm.Those individuals make control decisions independently of othersbased on the self-organizing strategy. The overall requirements forthe detection swarm are analyzed, and the theoretical model ofthe self-organizing strategy based on a combined individual andenvironmental virtual function is established. The numerical investigationproves that the self-organizing strategy is suitable andscalable to control the detection swarm. To further inspect the engineeringreliability, an experiment set is established in laboratory,and the experimental demonstration shows that the self-organizingstrategy drives the detection swarm forming a close range and multiangularsurveillance configuration of a landing spot.
基金jointly funded by the National Key R&D Program of China(Grant Number 2018YFC1505702)the project of scientific research on weather modification in Northwest China,research for experimental design and application integration(RYSY201909).
文摘A new type of air-ground communication application framework named FACT(framework for air-ground communication technology with weather-modification aircraft)is presented to track and command weather-modification aircraft to perform ideal cloud seeding.FACT provides a set of solutions from three perspectives,namely,onboard,onground and air-to-ground,with the core purpose of solving the problems of the rapid exchange of information,contract analysis and identifying potential seeding areas when flight plans and meteorological conditions change.On board,the observed data are processed centrally and transmitted downward through air-to-ground communication.The real-time application and sharing of aircraft detection data are strengthened on the ground,and potential areas of operation are automatically identified based on ground data.The communication between the air and the ground achieves a technical breakthrough by realizing double satellite links,adaptive data transmission and VPN channel encryption.Additionally,an application based on FACT is designed and implemented for the real-time command of weather-modified aircraft.This approach has become the key air-to-ground communication system support for more than 40 Chinese aircraft and the big data service support center of airborne data to ensure improved operation of weather-modification aircraft in China.
