实现架空输电线路机器人全过程全自主巡检,需要解决机器人自动上下线问题。基于人工辅助上下线方法存在人身安全、工作效率低等问题,探讨几种可行的输电线路巡检机器人自动上下线方法,在此基础上设计研发了一套基于塔身铺设轨道的实用...实现架空输电线路机器人全过程全自主巡检,需要解决机器人自动上下线问题。基于人工辅助上下线方法存在人身安全、工作效率低等问题,探讨几种可行的输电线路巡检机器人自动上下线方法,在此基础上设计研发了一套基于塔身铺设轨道的实用化的机器人自动上下线装置。介绍了该自动上下线装置的工作原理和结构,并对上下线装置的关键技术进行阐述。将该自动上下线装置应用于某500 k V运行线路的机器人巡检试验,试验结果表明该装置能实现机器人自动上、下杆塔地线,具有智能程度高、自主性强、安全性高等优点。展开更多
机巡作业是当前电力巡检的主要发展方向,但与直升机、无人机以及变电站机器人相比,我国输电线路机器人巡检尚未达到实用化水平。为此,对输电线路机器人实用化巡检关键技术开展了研究,建立了机器人典型作业模式,研发了穿越式、跨越式两...机巡作业是当前电力巡检的主要发展方向,但与直升机、无人机以及变电站机器人相比,我国输电线路机器人巡检尚未达到实用化水平。为此,对输电线路机器人实用化巡检关键技术开展了研究,建立了机器人典型作业模式,研发了穿越式、跨越式两类巡检机器人,提出了机器人行走路径改造方法,首次设计了机器人自动上下线装置,并完成了机器人全自主巡检系统的研制。机器人通过了多种复杂自然环境和电磁环境工况的试验考核,以及户外真型线路试验段的功能测试,在500 k V带电运行线路开展示范应用,对线路设备同时进行可见光和红外检测。巡检中暴露了巡检系统存在的问题并进行分析解决,提出了机器人异常情况下的紧急救援措施并成功开展带电救援作业。机器人单次巡检里程达到10 km以上,巡检应用取得良好效果,机器人巡检系统达到一定的实用化水平。展开更多
Traditional cellular network requires that a user equipment(UE) should associate to the same base station(BS) in both the downlink(DL) and the uplink(UL). Based on dual connectivity(DC) introduced in LTE-Advanced R12,...Traditional cellular network requires that a user equipment(UE) should associate to the same base station(BS) in both the downlink(DL) and the uplink(UL). Based on dual connectivity(DC) introduced in LTE-Advanced R12, DL/UL decouple access scheme has been proposed, which is especially suitable for heterogeneous networks(Het Nets). This paper is the pioneer to take the DL/UL decouple access scheme into consideration and develop a novel resource allocation algorithm in a two-tier Het Net to improve the total system throughput in the UL and ease the load imbalance between macro base stations(MBSs) and pico base stations(PBSs). A model is formulated as a nonlinear integer programming, and the proposed algorithm is a sub-optimal algorithm based on the graph theory. First, an undirected and weighted interference graph is obtained. Next, the users are grouped to let users with large mutual interferences to be assigned to different clusters. Then, the users in different clusters are allocated to different resource blocks(RBs) by using the Hungarian algorithm. Simulation results show that the proposed algorithm can provide great promotions for both the total system throughput and the average cell edge user throughput and successfully ease the load imbalance between MBSs and PBSs.展开更多
This paper is devoted to the investigation of the asymptotic behavior for a class of nonlinear parabolic partial functional differential equations. The boundedness and stability of the solutions are established by the...This paper is devoted to the investigation of the asymptotic behavior for a class of nonlinear parabolic partial functional differential equations. The boundedness and stability of the solutions are established by the upper-lower solution method. Some conditions are obtained by using the semigroup theory, the properties of nonnegative matrices and the techniques of inequalities to determine the asymptotically stable region of the equilibrium.展开更多
This study compared two learning strategies (word-part method and context-clue method) for Chinese EFL learners' vocabulary acquisition and retention. The results revealed that the context-clue group yielded signi...This study compared two learning strategies (word-part method and context-clue method) for Chinese EFL learners' vocabulary acquisition and retention. The results revealed that the context-clue group yielded significantly higher scores on the immediate posttests than the word-part group. The context-clue group outperformed on the immediate and delayed fill-in-the-blank posttests than the word-part group. As regards gender effects, no overall differences were found between male and female students. Additionally, the pretest had positive effects on two posttests for the female students, but negative effects for the male students. In educational settings, the context-clue method is highly suggested for explicit vocabulary instruction.展开更多
文摘实现架空输电线路机器人全过程全自主巡检,需要解决机器人自动上下线问题。基于人工辅助上下线方法存在人身安全、工作效率低等问题,探讨几种可行的输电线路巡检机器人自动上下线方法,在此基础上设计研发了一套基于塔身铺设轨道的实用化的机器人自动上下线装置。介绍了该自动上下线装置的工作原理和结构,并对上下线装置的关键技术进行阐述。将该自动上下线装置应用于某500 k V运行线路的机器人巡检试验,试验结果表明该装置能实现机器人自动上、下杆塔地线,具有智能程度高、自主性强、安全性高等优点。
文摘机巡作业是当前电力巡检的主要发展方向,但与直升机、无人机以及变电站机器人相比,我国输电线路机器人巡检尚未达到实用化水平。为此,对输电线路机器人实用化巡检关键技术开展了研究,建立了机器人典型作业模式,研发了穿越式、跨越式两类巡检机器人,提出了机器人行走路径改造方法,首次设计了机器人自动上下线装置,并完成了机器人全自主巡检系统的研制。机器人通过了多种复杂自然环境和电磁环境工况的试验考核,以及户外真型线路试验段的功能测试,在500 k V带电运行线路开展示范应用,对线路设备同时进行可见光和红外检测。巡检中暴露了巡检系统存在的问题并进行分析解决,提出了机器人异常情况下的紧急救援措施并成功开展带电救援作业。机器人单次巡检里程达到10 km以上,巡检应用取得良好效果,机器人巡检系统达到一定的实用化水平。
基金supported by the National Natural Science Foundation General Program of China under Grant No.61171110the National Basic Research Program of China under Grant No.2013CB329003
文摘Traditional cellular network requires that a user equipment(UE) should associate to the same base station(BS) in both the downlink(DL) and the uplink(UL). Based on dual connectivity(DC) introduced in LTE-Advanced R12, DL/UL decouple access scheme has been proposed, which is especially suitable for heterogeneous networks(Het Nets). This paper is the pioneer to take the DL/UL decouple access scheme into consideration and develop a novel resource allocation algorithm in a two-tier Het Net to improve the total system throughput in the UL and ease the load imbalance between macro base stations(MBSs) and pico base stations(PBSs). A model is formulated as a nonlinear integer programming, and the proposed algorithm is a sub-optimal algorithm based on the graph theory. First, an undirected and weighted interference graph is obtained. Next, the users are grouped to let users with large mutual interferences to be assigned to different clusters. Then, the users in different clusters are allocated to different resource blocks(RBs) by using the Hungarian algorithm. Simulation results show that the proposed algorithm can provide great promotions for both the total system throughput and the average cell edge user throughput and successfully ease the load imbalance between MBSs and PBSs.
基金Supported by NNSFC(19971059)Education Burean of Sichuan Province(01LA43)
文摘This paper is devoted to the investigation of the asymptotic behavior for a class of nonlinear parabolic partial functional differential equations. The boundedness and stability of the solutions are established by the upper-lower solution method. Some conditions are obtained by using the semigroup theory, the properties of nonnegative matrices and the techniques of inequalities to determine the asymptotically stable region of the equilibrium.
文摘This study compared two learning strategies (word-part method and context-clue method) for Chinese EFL learners' vocabulary acquisition and retention. The results revealed that the context-clue group yielded significantly higher scores on the immediate posttests than the word-part group. The context-clue group outperformed on the immediate and delayed fill-in-the-blank posttests than the word-part group. As regards gender effects, no overall differences were found between male and female students. Additionally, the pretest had positive effects on two posttests for the female students, but negative effects for the male students. In educational settings, the context-clue method is highly suggested for explicit vocabulary instruction.
