To overcome the shortcomings of the traditional passive ranging technology based on image, such as poor ranging accuracy, low reliability and complex system, a new visual passive ranging method based on re-entrant coa...To overcome the shortcomings of the traditional passive ranging technology based on image, such as poor ranging accuracy, low reliability and complex system, a new visual passive ranging method based on re-entrant coaxial optical path is presented. The target image is obtained using double cameras with coaxial optical path. Since there is imaging optical path difference between the cameras, the images are different. In comparison of the image differences, the target range could be reversed. The principle of the ranging method and the ranging model are described. The relationship among parameters in the ranging process is analyzed quantitatively. Meanwhile,the system composition and technical realization scheme are also presented. Also, the principle of the method is verified by the equivalent experiment. The experimental results show that the design scheme is correct and feasible with good robustness. Generally, the ranging error is less than 10% with good convergence. The optical path is designed in a re-entrant mode to reduce the volume and weight of the system. Through the coaxial design,the visual passive range of the targets with any posture can be obtained in real time. The system can be widely used in electro-optical countermeasure and concealed photoelectric detection.展开更多
Abstract： There is a high demand for unmanned aerial vehicle （UAV） flight stability when using vi- sion as a detection method for navigation control. To meet such demand, a new path planning meth- od for controllin...Abstract： There is a high demand for unmanned aerial vehicle （UAV） flight stability when using vi- sion as a detection method for navigation control. To meet such demand, a new path planning meth- od for controlling multi-UAVs is studied to reach multi-waypoints simultaneously under the view of visual navigation technology. A model based on the stable-shortest pythagorean-hodograph （PH） curve is established, which could not only satisfy the demands of visual navigation and control law, but also be easy to compute. Based on the model, a planning algorithm to guide multi-UAVs to reach multi-waypoints at the same time without collisions is developed. The simulation results show that the paths have shorter distance and smaller curvature than traditional methods, which could help to avoid collisions.展开更多
视觉导航作为移动机器人自主运行的核心技术支撑,其性能直接决定移动机器人的环境感知精度、定位建图可靠性与路径规划的合理性。文章系统综述移动机器人视觉导航的研究进展,围绕视觉传感器、同步定位与地图构建(Simultaneous Localizat...视觉导航作为移动机器人自主运行的核心技术支撑,其性能直接决定移动机器人的环境感知精度、定位建图可靠性与路径规划的合理性。文章系统综述移动机器人视觉导航的研究进展,围绕视觉传感器、同步定位与地图构建(Simultaneous Localization and Mapping,SLAM)和路径规划三大核心环节展开分析:在视觉传感器层面,重点探讨单模态、多模态融合视觉传感器和新型视觉传感器的技术特性与适配场景;在SLAM层面,总结传统几何SLAM、多模态融合SLAM以及神经隐式SLAM的技术演进与性能优势;在路径规划层面,重点介绍传统算法与生物启发算法的特点与适用场景。最后,总结当前技术面临的挑战,并对未来研究方向进行展望,为视觉导航技术的进一步发展提供参考。展开更多
The Drovers’ Paths are remnants of important land access roads from Rio Grande do Sul to São Paulo at the time of Colonial Brazil. They were built and used between the 18th and 20th centuries, particularly i...The Drovers’ Paths are remnants of important land access roads from Rio Grande do Sul to São Paulo at the time of Colonial Brazil. They were built and used between the 18th and 20th centuries, particularly in the region of Coxilha Rica. The main objective of this research is to develop a method for decision-making applied to the territorial landscape management in the Coxilha Rica. The method consisted of generating criteria to map the visibility spot reached from the main selected points;define the human visual acuity, realize bibliographic research, use cartographic and historical documents, inter-views, as well as field surveys that enabled the identification, characterization and mapping of historical farms and drovers’ paths. After data processing, the information was entered into the cartographic database;the data were cross-checked and analysis was made of the visibility of the surrounding farms and stone-walled corridors. Quality assessments showed that, with the visibility polygons, and through the use of cartographic tools, we could cross-check between different levels of information and analyze landscape intervention alternatives in order to minimize environmental impacts. When applying the method in the Coxilha Rica it was possible mapping the visibility polygon, taking human visual acuity into consideration, based on historical farms and stone-walled corridors;and making spatial analyses to explore alternatives to intervention (installation of power transmission systems) in order to preserve the scenic environment of the region. In the end, the decision was by does not construct the system.展开更多
为了解体育支教研究的历史脉络与未来趋势,探究助力体育支教研究不断紧跟时代的研究路径,运用Cite Space 6.4.R1可视化软件对知网上检索到的“体育支教”相关文献进行可视化分析,对其关键词进行数据聚合运算。研究结果显示,体育支教领...为了解体育支教研究的历史脉络与未来趋势,探究助力体育支教研究不断紧跟时代的研究路径,运用Cite Space 6.4.R1可视化软件对知网上检索到的“体育支教”相关文献进行可视化分析,对其关键词进行数据聚合运算。研究结果显示,体育支教领域研究已经形成了有一定社会影响力的教育实施模式,但对体育支教的创新对策研究数量明显偏少,对现有的体育支教行动策略进行不断的完善发展方面有待深入研究。近几年,关于体育支教研究的前沿与趋势同乡村振兴发展有着密切联系。总体上,国内关于体育支教研究宏观角度与微观角度并存,始终围绕关键问题并紧跟国家政策变化,未来研究应扩大文献样本与数据来源,以便更全面地描绘该领域的研究现状与趋势。展开更多
基金Supported by the National Basic Research Program of China under Grant No 2014CB340102
文摘To overcome the shortcomings of the traditional passive ranging technology based on image, such as poor ranging accuracy, low reliability and complex system, a new visual passive ranging method based on re-entrant coaxial optical path is presented. The target image is obtained using double cameras with coaxial optical path. Since there is imaging optical path difference between the cameras, the images are different. In comparison of the image differences, the target range could be reversed. The principle of the ranging method and the ranging model are described. The relationship among parameters in the ranging process is analyzed quantitatively. Meanwhile,the system composition and technical realization scheme are also presented. Also, the principle of the method is verified by the equivalent experiment. The experimental results show that the design scheme is correct and feasible with good robustness. Generally, the ranging error is less than 10% with good convergence. The optical path is designed in a re-entrant mode to reduce the volume and weight of the system. Through the coaxial design,the visual passive range of the targets with any posture can be obtained in real time. The system can be widely used in electro-optical countermeasure and concealed photoelectric detection.
文摘Abstract： There is a high demand for unmanned aerial vehicle （UAV） flight stability when using vi- sion as a detection method for navigation control. To meet such demand, a new path planning meth- od for controlling multi-UAVs is studied to reach multi-waypoints simultaneously under the view of visual navigation technology. A model based on the stable-shortest pythagorean-hodograph （PH） curve is established, which could not only satisfy the demands of visual navigation and control law, but also be easy to compute. Based on the model, a planning algorithm to guide multi-UAVs to reach multi-waypoints at the same time without collisions is developed. The simulation results show that the paths have shorter distance and smaller curvature than traditional methods, which could help to avoid collisions.
文摘视觉导航作为移动机器人自主运行的核心技术支撑,其性能直接决定移动机器人的环境感知精度、定位建图可靠性与路径规划的合理性。文章系统综述移动机器人视觉导航的研究进展,围绕视觉传感器、同步定位与地图构建(Simultaneous Localization and Mapping,SLAM)和路径规划三大核心环节展开分析:在视觉传感器层面,重点探讨单模态、多模态融合视觉传感器和新型视觉传感器的技术特性与适配场景;在SLAM层面,总结传统几何SLAM、多模态融合SLAM以及神经隐式SLAM的技术演进与性能优势;在路径规划层面,重点介绍传统算法与生物启发算法的特点与适用场景。最后,总结当前技术面临的挑战,并对未来研究方向进行展望,为视觉导航技术的进一步发展提供参考。
基金Supported by National Natural Science Foundation of China（60873032, 61105095, 61203361） Doctoral Program Foundation of Ministry of Education of China （20100142110020）+3 种基金 the Specialized Research Fund for the Doctoral Program of Higher Education of China （20100073120020） Postdoctoral Science Foundation of China （2012M511095） Shanghai Municipal Natural Science Foundation （11ZR1418400） Shanghai Postdoctoral Science Foundation（12R21414200）
文摘The Drovers’ Paths are remnants of important land access roads from Rio Grande do Sul to São Paulo at the time of Colonial Brazil. They were built and used between the 18th and 20th centuries, particularly in the region of Coxilha Rica. The main objective of this research is to develop a method for decision-making applied to the territorial landscape management in the Coxilha Rica. The method consisted of generating criteria to map the visibility spot reached from the main selected points;define the human visual acuity, realize bibliographic research, use cartographic and historical documents, inter-views, as well as field surveys that enabled the identification, characterization and mapping of historical farms and drovers’ paths. After data processing, the information was entered into the cartographic database;the data were cross-checked and analysis was made of the visibility of the surrounding farms and stone-walled corridors. Quality assessments showed that, with the visibility polygons, and through the use of cartographic tools, we could cross-check between different levels of information and analyze landscape intervention alternatives in order to minimize environmental impacts. When applying the method in the Coxilha Rica it was possible mapping the visibility polygon, taking human visual acuity into consideration, based on historical farms and stone-walled corridors;and making spatial analyses to explore alternatives to intervention (installation of power transmission systems) in order to preserve the scenic environment of the region. In the end, the decision was by does not construct the system.
文摘为了解体育支教研究的历史脉络与未来趋势,探究助力体育支教研究不断紧跟时代的研究路径,运用Cite Space 6.4.R1可视化软件对知网上检索到的“体育支教”相关文献进行可视化分析,对其关键词进行数据聚合运算。研究结果显示,体育支教领域研究已经形成了有一定社会影响力的教育实施模式,但对体育支教的创新对策研究数量明显偏少,对现有的体育支教行动策略进行不断的完善发展方面有待深入研究。近几年,关于体育支教研究的前沿与趋势同乡村振兴发展有着密切联系。总体上,国内关于体育支教研究宏观角度与微观角度并存,始终围绕关键问题并紧跟国家政策变化,未来研究应扩大文献样本与数据来源,以便更全面地描绘该领域的研究现状与趋势。
