The LM-6 A new generation solid-liquid strap-on launch vehicle has the structural dynamic characteristics of lower frequencies,denser modes and coupling modes in longitudinal,bending and torsion modal space.During the...The LM-6 A new generation solid-liquid strap-on launch vehicle has the structural dynamic characteristics of lower frequencies,denser modes and coupling modes in longitudinal,bending and torsion modal space.During the development phase of LM-6 A,modal tests of partial stacks and the full vehicle were designed to obtain the structural dynamic properties.The structural dynamic models using the finite element method(FEM)have been verified and calibrated based on the modal test data.This paper describes the pre-test predictions and test execution,and details the comparison between the pre-test predictions and the test data.The successful maiden flight of LM-6 A further confirmed the effectiveness of structural dynamic modeling and modal test for LM-6 A.展开更多
采用ADAMS/View提供的参数化建模及参数化分析方法,对6×6越野汽车前独立悬架进行了参数化设计,并对悬架主要的几何参数进行了分析,得出了较好的分析仿真结果.整个过程首先根据整车设计条件确定悬架的尺寸参数和车轮的定位参数,然...采用ADAMS/View提供的参数化建模及参数化分析方法,对6×6越野汽车前独立悬架进行了参数化设计,并对悬架主要的几何参数进行了分析,得出了较好的分析仿真结果.整个过程首先根据整车设计条件确定悬架的尺寸参数和车轮的定位参数,然后利用AD-AMS/View建立悬架的虚拟样机模型,最后对所建立的模型进行设计研究(design study)和试验设计DOE(Design of Experiments).通过分析得出随下摆臂的长度值增大和下摆臂的安装倾角的减小,车轮侧向滑移量有大幅减小的趋势.因此选择下摆臂的长度值及其安装倾角为设计变量,以车轮侧向滑移量为设计对象,在ADAMS/Insight中进行了参数优选,得出的仿真结果能够满足设计要求.该方法提高了悬架的设计速度与质量,可为今后设计高性能的悬架系统提供借鉴.展开更多
采用ADAMS/View提供的参数化建模及参数化分析方法,对6×6越野汽车前独立悬架进行参数化设计,并分析悬架主要的评价指标,得出较好的实验结果。整个过程首先根据整车设计条件确定悬架的尺寸参数和车轮的定位参数,然后利用ADAMS/View...采用ADAMS/View提供的参数化建模及参数化分析方法,对6×6越野汽车前独立悬架进行参数化设计,并分析悬架主要的评价指标,得出较好的实验结果。整个过程首先根据整车设计条件确定悬架的尺寸参数和车轮的定位参数,然后利用ADAMS/View建立悬架的虚拟样机模型,最后对所建立的模型进行设计研究(Design Study)和试验设计(De-sign of Experiments,DOE)。通过分析得出随下摆臂的长度值增大和下摆臂的安装倾角的减小,车轮侧向滑移量有大幅度减小的趋势。因此选择下摆臂的长度值及其安装倾角为设计变量,以车轮侧向滑移量为设计对象,在ADAMS/Insight中进行了参数优化,得出的实验结果达到了预期的目标。该方法提高了悬架的设计速度与质量,为以后设计高性能的悬架系统提供了方法保证。展开更多
With technological advancements in 6G and Internet of Things(IoT), the incorporation of Unmanned Aerial Vehicles (UAVs) and cellularnetworks has become a hot research topic. At present, the proficient evolution of 6G ...With technological advancements in 6G and Internet of Things(IoT), the incorporation of Unmanned Aerial Vehicles (UAVs) and cellularnetworks has become a hot research topic. At present, the proficient evolution of 6G networks allows the UAVs to offer cost-effective and timelysolutions for real-time applications such as medicine, tracking, surveillance,etc. Energy efficiency, data collection, and route planning are crucial processesto improve the network communication. These processes are highly difficultowing to high mobility, presence of non-stationary links, dynamic topology,and energy-restricted UAVs. With this motivation, the current research paperpresents a novel Energy Aware Data Collection with Routing Planning for6G-enabled UAV communication (EADCRP-6G) technique. The goal of theproposed EADCRP-6G technique is to conduct energy-efficient cluster-baseddata collection and optimal route planning for 6G-enabled UAV networks.EADCRP-6G technique deploys Improved Red Deer Algorithm-based Clustering (IRDAC) technique to elect an optimal set of Cluster Heads (CH) andorganize these clusters. Besides, Artificial Fish Swarm-based Route Planning(AFSRP) technique is applied to choose an optimum set of routes for UAVcommunication in 6G networks. In order to validated whether the proposedEADCRP-6G technique enhances the performance, a series of simulationswas performed and the outcomes were investigated under different dimensions.The experimental results showcase that the proposed model outperformed allother existing models under different evaluation parameters.展开更多
In recent times,sixth generation(6G)communication technologies have become a hot research topic because of maximum throughput and low delay services for mobile users.It encompasses several heterogeneous resource and c...In recent times,sixth generation(6G)communication technologies have become a hot research topic because of maximum throughput and low delay services for mobile users.It encompasses several heterogeneous resource and communication standard in ensuring incessant availability of service.At the same time,the development of 6G enables the Unmanned Aerial Vehicles(UAVs)in offering cost and time-efficient solution to several applications like healthcare,surveillance,disaster management,etc.In UAV networks,energy efficiency and data collection are considered the major process for high quality network communication.But these procedures are found to be challenging because of maximum mobility,unstable links,dynamic topology,and energy restricted UAVs.These issues are solved by the use of artificial intelligence(AI)and energy efficient clustering techniques for UAVs in the 6G environment.With this inspiration,this work designs an artificial intelligence enabled cooperative cluster-based data collection technique for unmanned aerial vehicles(AECCDC-UAV)in 6G environment.The proposed AECCDC-UAV technique purposes for dividing the UAV network as to different clusters and allocate a cluster head(CH)to each cluster in such a way that the energy consumption(ECM)gets minimized.The presented AECCDC-UAV technique involves a quasi-oppositional shuffled shepherd optimization(QOSSO)algorithm for selecting the CHs and construct clusters.The QOSSO algorithm derives a fitness function involving three input parameters residual energy of UAVs,distance to neighboring UAVs,and degree of UAVs.The performance of the AECCDC-UAV technique is validated in many aspects and the obtained experimental values demonstration promising results over the recent state of art methods.展开更多
采用碳酸盐共沉淀法和高温烧结工艺将一定量的Mo^(6+)掺杂到Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料中。利用XRD、SEM、EDS和恒流测试仪研究Mo^(6+)掺杂对Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料的晶体结构、...采用碳酸盐共沉淀法和高温烧结工艺将一定量的Mo^(6+)掺杂到Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料中。利用XRD、SEM、EDS和恒流测试仪研究Mo^(6+)掺杂对Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料的晶体结构、微观形貌和电化学性能的影响。结果显示,Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)表现出更低的阳离子混排和优异的电化学性能。经过Mo^(6+)掺杂后的正极,由于Li^(+)高速的迁移速率,使得首次不可逆容量损失降低,并展现出更好的高倍率性能和优异的循环稳定性。在0.5C倍率下循环100周后,Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)的容量保持率达到92.2%,远远大于Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)的87.5%。另外,当放电倍率增大到5C时,Li_(1.2)0Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)的放电比容量要比Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)低21.0 m A·h/g。因此,采用Mo^(6+)掺杂改性Li_(1.2)0Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料,可以有效提高锂电池的循环保持率和高倍率放电性能。展开更多
Unmanned aerial vehicles(UAVs)have attracted growing research interests in recent years,which can be used as cost-effective aerial platforms to transmit collected data packets to ground access points(APs).Thus,it is c...Unmanned aerial vehicles(UAVs)have attracted growing research interests in recent years,which can be used as cost-effective aerial platforms to transmit collected data packets to ground access points(APs).Thus,it is crucial to investigate robust airto-ground(A2G)wireless links for high-speed UAVs.However,the A2G wireless link is unstable as it suffers from large path-loss and severe Doppler effect due to the high mobility of UAVs.In order to meet these challenges,we propose an orthogonal time frequency space(OTFS)-based UAV communication system to relief the Doppler effect.Besides,considering that the energy of UAV is limited,we optimize the trajectory planning of UAV to minimize the energy consumption under the constraints of bit error rate(BER)and transmission rate,where the Doppler compensation is taken into account.Simulation results show that the performance of OTFS-based UAV system is superior to orthogonal frequency division multiplexing(OFDM)-based UAV systems,which can accomplish transmission tasks over shorter distances with lower energy consumption.展开更多
文摘The LM-6 A new generation solid-liquid strap-on launch vehicle has the structural dynamic characteristics of lower frequencies,denser modes and coupling modes in longitudinal,bending and torsion modal space.During the development phase of LM-6 A,modal tests of partial stacks and the full vehicle were designed to obtain the structural dynamic properties.The structural dynamic models using the finite element method(FEM)have been verified and calibrated based on the modal test data.This paper describes the pre-test predictions and test execution,and details the comparison between the pre-test predictions and the test data.The successful maiden flight of LM-6 A further confirmed the effectiveness of structural dynamic modeling and modal test for LM-6 A.
文摘采用ADAMS/View提供的参数化建模及参数化分析方法,对6×6越野汽车前独立悬架进行了参数化设计,并对悬架主要的几何参数进行了分析,得出了较好的分析仿真结果.整个过程首先根据整车设计条件确定悬架的尺寸参数和车轮的定位参数,然后利用AD-AMS/View建立悬架的虚拟样机模型,最后对所建立的模型进行设计研究(design study)和试验设计DOE(Design of Experiments).通过分析得出随下摆臂的长度值增大和下摆臂的安装倾角的减小,车轮侧向滑移量有大幅减小的趋势.因此选择下摆臂的长度值及其安装倾角为设计变量,以车轮侧向滑移量为设计对象,在ADAMS/Insight中进行了参数优选,得出的仿真结果能够满足设计要求.该方法提高了悬架的设计速度与质量,可为今后设计高性能的悬架系统提供借鉴.
文摘采用ADAMS/View提供的参数化建模及参数化分析方法,对6×6越野汽车前独立悬架进行参数化设计,并分析悬架主要的评价指标,得出较好的实验结果。整个过程首先根据整车设计条件确定悬架的尺寸参数和车轮的定位参数,然后利用ADAMS/View建立悬架的虚拟样机模型,最后对所建立的模型进行设计研究(Design Study)和试验设计(De-sign of Experiments,DOE)。通过分析得出随下摆臂的长度值增大和下摆臂的安装倾角的减小,车轮侧向滑移量有大幅度减小的趋势。因此选择下摆臂的长度值及其安装倾角为设计变量,以车轮侧向滑移量为设计对象,在ADAMS/Insight中进行了参数优化,得出的实验结果达到了预期的目标。该方法提高了悬架的设计速度与质量,为以后设计高性能的悬架系统提供了方法保证。
文摘With technological advancements in 6G and Internet of Things(IoT), the incorporation of Unmanned Aerial Vehicles (UAVs) and cellularnetworks has become a hot research topic. At present, the proficient evolution of 6G networks allows the UAVs to offer cost-effective and timelysolutions for real-time applications such as medicine, tracking, surveillance,etc. Energy efficiency, data collection, and route planning are crucial processesto improve the network communication. These processes are highly difficultowing to high mobility, presence of non-stationary links, dynamic topology,and energy-restricted UAVs. With this motivation, the current research paperpresents a novel Energy Aware Data Collection with Routing Planning for6G-enabled UAV communication (EADCRP-6G) technique. The goal of theproposed EADCRP-6G technique is to conduct energy-efficient cluster-baseddata collection and optimal route planning for 6G-enabled UAV networks.EADCRP-6G technique deploys Improved Red Deer Algorithm-based Clustering (IRDAC) technique to elect an optimal set of Cluster Heads (CH) andorganize these clusters. Besides, Artificial Fish Swarm-based Route Planning(AFSRP) technique is applied to choose an optimum set of routes for UAVcommunication in 6G networks. In order to validated whether the proposedEADCRP-6G technique enhances the performance, a series of simulationswas performed and the outcomes were investigated under different dimensions.The experimental results showcase that the proposed model outperformed allother existing models under different evaluation parameters.
基金This work was supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2021R1F1A1063319).
文摘In recent times,sixth generation(6G)communication technologies have become a hot research topic because of maximum throughput and low delay services for mobile users.It encompasses several heterogeneous resource and communication standard in ensuring incessant availability of service.At the same time,the development of 6G enables the Unmanned Aerial Vehicles(UAVs)in offering cost and time-efficient solution to several applications like healthcare,surveillance,disaster management,etc.In UAV networks,energy efficiency and data collection are considered the major process for high quality network communication.But these procedures are found to be challenging because of maximum mobility,unstable links,dynamic topology,and energy restricted UAVs.These issues are solved by the use of artificial intelligence(AI)and energy efficient clustering techniques for UAVs in the 6G environment.With this inspiration,this work designs an artificial intelligence enabled cooperative cluster-based data collection technique for unmanned aerial vehicles(AECCDC-UAV)in 6G environment.The proposed AECCDC-UAV technique purposes for dividing the UAV network as to different clusters and allocate a cluster head(CH)to each cluster in such a way that the energy consumption(ECM)gets minimized.The presented AECCDC-UAV technique involves a quasi-oppositional shuffled shepherd optimization(QOSSO)algorithm for selecting the CHs and construct clusters.The QOSSO algorithm derives a fitness function involving three input parameters residual energy of UAVs,distance to neighboring UAVs,and degree of UAVs.The performance of the AECCDC-UAV technique is validated in many aspects and the obtained experimental values demonstration promising results over the recent state of art methods.
文摘采用碳酸盐共沉淀法和高温烧结工艺将一定量的Mo^(6+)掺杂到Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料中。利用XRD、SEM、EDS和恒流测试仪研究Mo^(6+)掺杂对Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料的晶体结构、微观形貌和电化学性能的影响。结果显示,Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)表现出更低的阳离子混排和优异的电化学性能。经过Mo^(6+)掺杂后的正极,由于Li^(+)高速的迁移速率,使得首次不可逆容量损失降低,并展现出更好的高倍率性能和优异的循环稳定性。在0.5C倍率下循环100周后,Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)的容量保持率达到92.2%,远远大于Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)的87.5%。另外,当放电倍率增大到5C时,Li_(1.2)0Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)的放电比容量要比Li_(1.20)Mn_(0.52)Ni_(0.13)Co_(0.13)Mo_(0.02)O_(2)低21.0 m A·h/g。因此,采用Mo^(6+)掺杂改性Li_(1.2)0Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)正极材料,可以有效提高锂电池的循环保持率和高倍率放电性能。
基金supported by the National Key Research and Development Program of China(Grant 2020YFB1804800)the National Natural Science Foundation of China(Grant U22B2008 and Grant 61922010)the Beijing Natural Science Foundation(Grant JQ20019)。
文摘Unmanned aerial vehicles(UAVs)have attracted growing research interests in recent years,which can be used as cost-effective aerial platforms to transmit collected data packets to ground access points(APs).Thus,it is crucial to investigate robust airto-ground(A2G)wireless links for high-speed UAVs.However,the A2G wireless link is unstable as it suffers from large path-loss and severe Doppler effect due to the high mobility of UAVs.In order to meet these challenges,we propose an orthogonal time frequency space(OTFS)-based UAV communication system to relief the Doppler effect.Besides,considering that the energy of UAV is limited,we optimize the trajectory planning of UAV to minimize the energy consumption under the constraints of bit error rate(BER)and transmission rate,where the Doppler compensation is taken into account.Simulation results show that the performance of OTFS-based UAV system is superior to orthogonal frequency division multiplexing(OFDM)-based UAV systems,which can accomplish transmission tasks over shorter distances with lower energy consumption.
