The limited energy and high mobility of unmanned aerial vehicles(UAVs)lead to drastic topology changes in UAV formation.The existing routing protocols necessitate a large number of messages for route discovery and mai...The limited energy and high mobility of unmanned aerial vehicles(UAVs)lead to drastic topology changes in UAV formation.The existing routing protocols necessitate a large number of messages for route discovery and maintenance,greatly increasing network delay and control overhead.A energyefficient routing method based on the discrete timeaggregated graph(TAG)theory is proposed since UAV formation is a defined time-varying network.The network is characterized using the TAG,which utilizes the prior knowledge in UAV formation.An energyefficient routing algorithm is designed based on TAG,considering the link delay,relative mobility,and residual energy of UAVs.The routing path is determined with global network information before requesting communication.Simulation results demonstrate that the routing method can improve the end-to-end delay,packet delivery ratio,routing control overhead,and residual energy.Consequently,introducing timevarying graphs to design routing algorithms is more effective for UAV formation.展开更多
The reduction of energy consumption is an increasingly important topic of the railway system.Energy-efficient train control(EETC)is one solution,which refers to mathematically computing when to accelerate,which cruisi...The reduction of energy consumption is an increasingly important topic of the railway system.Energy-efficient train control(EETC)is one solution,which refers to mathematically computing when to accelerate,which cruising speed to hold,how long one should coast over a suitable space,and when to brake.Most approaches in literature and industry greatly simplify a lot of nonlinear effects,such that they ignore mostly the losses due to energy conversion in traction components and auxiliaries.To fill this research gap,a series of increasingly detailed nonlinear losses is described and modelled.We categorize an increasing detail in this representation as four levels.We study the impact of those levels of detail on the energy optimal speed trajectory.To do this,a standard approach based on dynamic programming is used,given constraints on total travel time.This evaluation of multiple test cases highlights the influence of the dynamic losses and the power consumption of auxiliary components on railway trajectories,also compared to multiple benchmarks.The results show how the losses can make up 50%of the total energy consumption for an exemplary trip.Ignoring them would though result in consistent but limited errors in the optimal trajectory.Overall,more complex trajectories can result in less energy consumption when including the complexity of nonlinear losses than when a simpler model is considered.Those effects are stronger when the trajectory includes many acceleration and braking phases.展开更多
介绍了INS/DR/MM车辆组合导航系统以及系统的部件组成,对系统的软硬件结构进行了分析。结合目前各主流嵌入式平台的性能,利用Windows XP Embedded(XPE)嵌入式操作系统体积小和易扩展的优势,选用Windows XP Embedded作为车辆组合导航系...介绍了INS/DR/MM车辆组合导航系统以及系统的部件组成,对系统的软硬件结构进行了分析。结合目前各主流嵌入式平台的性能,利用Windows XP Embedded(XPE)嵌入式操作系统体积小和易扩展的优势,选用Windows XP Embedded作为车辆组合导航系统的开发平台。为了满足车辆导航实时、快速的要求,设计了基于模糊逻辑的地图匹配算法。经过多次实际跑车试验证明,该嵌入式车辆导航系统可以正确实时地将地图匹配后的位置信息显示在电子地图上。展开更多
设计了一款基于ARM & Windows CE及FFT算法的锚杆无损检测系统,介绍了硬件电路设计方法,包括信号采集模块、A/D转换模块、液晶显示模块、电源模块;在软件设计中,完成了Windows CE操作系统的定制以及应用程序设计,并对设计方法和数据...设计了一款基于ARM & Windows CE及FFT算法的锚杆无损检测系统,介绍了硬件电路设计方法,包括信号采集模块、A/D转换模块、液晶显示模块、电源模块;在软件设计中,完成了Windows CE操作系统的定制以及应用程序设计,并对设计方法和数据FFT分析方法进行了阐述。展开更多
基金supported in part by the National Natural Science Foundation of China under Grants 62171154in part by the National Natural Science Foundation of Shandong Province under Grant ZR2020MF007+1 种基金in part by the Research Fund Program of Guangdong Key Laboratory of Aerospace Communication and Networking Technology under Grant 2018B030322004in part by the Fundamental Research Funds for the Central Universities under Grant HIT.OCEF.2023030。
文摘The limited energy and high mobility of unmanned aerial vehicles(UAVs)lead to drastic topology changes in UAV formation.The existing routing protocols necessitate a large number of messages for route discovery and maintenance,greatly increasing network delay and control overhead.A energyefficient routing method based on the discrete timeaggregated graph(TAG)theory is proposed since UAV formation is a defined time-varying network.The network is characterized using the TAG,which utilizes the prior knowledge in UAV formation.An energyefficient routing algorithm is designed based on TAG,considering the link delay,relative mobility,and residual energy of UAVs.The routing path is determined with global network information before requesting communication.Simulation results demonstrate that the routing method can improve the end-to-end delay,packet delivery ratio,routing control overhead,and residual energy.Consequently,introducing timevarying graphs to design routing algorithms is more effective for UAV formation.
基金supported by Swiss Federal Office of Transport,the ETH foundation and via the grant RAILPOWER.
文摘The reduction of energy consumption is an increasingly important topic of the railway system.Energy-efficient train control(EETC)is one solution,which refers to mathematically computing when to accelerate,which cruising speed to hold,how long one should coast over a suitable space,and when to brake.Most approaches in literature and industry greatly simplify a lot of nonlinear effects,such that they ignore mostly the losses due to energy conversion in traction components and auxiliaries.To fill this research gap,a series of increasingly detailed nonlinear losses is described and modelled.We categorize an increasing detail in this representation as four levels.We study the impact of those levels of detail on the energy optimal speed trajectory.To do this,a standard approach based on dynamic programming is used,given constraints on total travel time.This evaluation of multiple test cases highlights the influence of the dynamic losses and the power consumption of auxiliary components on railway trajectories,also compared to multiple benchmarks.The results show how the losses can make up 50%of the total energy consumption for an exemplary trip.Ignoring them would though result in consistent but limited errors in the optimal trajectory.Overall,more complex trajectories can result in less energy consumption when including the complexity of nonlinear losses than when a simpler model is considered.Those effects are stronger when the trajectory includes many acceleration and braking phases.
文摘介绍了INS/DR/MM车辆组合导航系统以及系统的部件组成,对系统的软硬件结构进行了分析。结合目前各主流嵌入式平台的性能,利用Windows XP Embedded(XPE)嵌入式操作系统体积小和易扩展的优势,选用Windows XP Embedded作为车辆组合导航系统的开发平台。为了满足车辆导航实时、快速的要求,设计了基于模糊逻辑的地图匹配算法。经过多次实际跑车试验证明,该嵌入式车辆导航系统可以正确实时地将地图匹配后的位置信息显示在电子地图上。
