在我国科学技术迅速发展的今天,移动机器人的智能程度在不断提升。同步定位与建图(Simultaneous Localization and Mapping,SLAM)算法是移动机器人自主导航实现的前提与关键。文章在ROS系统基础上分析了基于滤波器与基于图优化方法的SLA...在我国科学技术迅速发展的今天,移动机器人的智能程度在不断提升。同步定位与建图(Simultaneous Localization and Mapping,SLAM)算法是移动机器人自主导航实现的前提与关键。文章在ROS系统基础上分析了基于滤波器与基于图优化方法的SLAM算法原理,利用基于Jetson Nano硬件平台的移动机器人进行SLAM算法建图。文章针对建图中产生的地图错位漂移等问题进行研究讨论,分析得出Cartographer算法可在室内复杂环境下构建出误差低、精度高的2D栅格地图,验证了该算法在室内环境较其他算法的优异性,为移动机器人在室内SLAM建图提供更可靠的解决方案。展开更多
This study's goal is to present a dynamic portrait of the farm-buildings environment in Occitania,in Southern France,in order to better identify the transitions underway in agri-food chains.To this end,we undertoo...This study's goal is to present a dynamic portrait of the farm-buildings environment in Occitania,in Southern France,in order to better identify the transitions underway in agri-food chains.To this end,we undertook a ter-ritorial diagnosis based on actor statements,using 28 semi-structured interviews across Occitania.This diagnosis was enriched by graphic modelling,which enabled the spatialization of the dynamics described.We show that the process of standardisation of farm buildings prevails in the majority of the territories studied.This phenomenon has intensified in recent years with the development of vast photovoltaic-roofed sheds,accentuating the farm-land conversion and soil sealing.At the same time,in areas with strong environmental,landscape and heritage contexts,a'new adventure in farm buildings'(2022 survey)is taking shape.It is primarily driven by local short food chains,which rely on self-construction,repurposing and refurbishment,the sharing of tools and equipment,and which favour the use and reuse of local resources.This study shows that farm-buildings dynamics crystallise many challenges confronting the reterritorialisation of agriculture and food production.展开更多
针对Cartographer算法在激光雷达的数据处理中存在的点云特征丢失的问题和低帧率激光雷达导致的运动畸变问题,提出一种改进激光同步定位与地图构建(simultaneous localization and mapping, SLAM)算法。采用k邻域搜索邻近点降采样的体...针对Cartographer算法在激光雷达的数据处理中存在的点云特征丢失的问题和低帧率激光雷达导致的运动畸变问题,提出一种改进激光同步定位与地图构建(simultaneous localization and mapping, SLAM)算法。采用k邻域搜索邻近点降采样的体素滤波方法代替Cartographer算法中的传统体素滤波方法,在不丢失点云特征的情况下提升计算速率;嵌入轮式里程计辅助模块去除激光雷达运动畸变,减少机器人的位姿累积误差,从而改善建图效果;最后,增加了边约束条件改善回环检测效果。通过在机器人操作系统中的gazebo搭建仿真环境进行模拟实验,对比两种算法,实验结果显示改进算法的建图轨迹误差更小。展开更多
This paper puts forword 11 cartographic generalization operator models and introduces their mathematical definitions,and thus a precise mathematical form and quantitative description has been given to these formerly l...This paper puts forword 11 cartographic generalization operator models and introduces their mathematical definitions,and thus a precise mathematical form and quantitative description has been given to these formerly limited qualitative concepts.The meaning of mathematical definition of operators for cartographic generalization and the application prospect in computer_aided cartography (CAC) is stated.ract The Jurassic strata in Jingyan of Sichuan containing the Mamenchinsaurus fauna are dealt with and divided in this paper. The Mamenchisaurus fossils contained there are compared in morphological features and stratigraphically with other types of the genus on by one. The comprehensive analysis show that the Mamenchisaurus fauna of Jingyan appeared in the early Late Jurassic and is primitive in morphology. The results of the morphological identification and stratigraphical study agree with each other. Their evolutionary processes in different apoches of the Late Jurassic also made clear. Key words Jingyan, Sichuan, Mamenchisaurus Fauna, stratigraphy, evolution展开更多
文摘在我国科学技术迅速发展的今天,移动机器人的智能程度在不断提升。同步定位与建图(Simultaneous Localization and Mapping,SLAM)算法是移动机器人自主导航实现的前提与关键。文章在ROS系统基础上分析了基于滤波器与基于图优化方法的SLAM算法原理,利用基于Jetson Nano硬件平台的移动机器人进行SLAM算法建图。文章针对建图中产生的地图错位漂移等问题进行研究讨论,分析得出Cartographer算法可在室内复杂环境下构建出误差低、精度高的2D栅格地图,验证了该算法在室内环境较其他算法的优异性,为移动机器人在室内SLAM建图提供更可靠的解决方案。
文摘This study's goal is to present a dynamic portrait of the farm-buildings environment in Occitania,in Southern France,in order to better identify the transitions underway in agri-food chains.To this end,we undertook a ter-ritorial diagnosis based on actor statements,using 28 semi-structured interviews across Occitania.This diagnosis was enriched by graphic modelling,which enabled the spatialization of the dynamics described.We show that the process of standardisation of farm buildings prevails in the majority of the territories studied.This phenomenon has intensified in recent years with the development of vast photovoltaic-roofed sheds,accentuating the farm-land conversion and soil sealing.At the same time,in areas with strong environmental,landscape and heritage contexts,a'new adventure in farm buildings'(2022 survey)is taking shape.It is primarily driven by local short food chains,which rely on self-construction,repurposing and refurbishment,the sharing of tools and equipment,and which favour the use and reuse of local resources.This study shows that farm-buildings dynamics crystallise many challenges confronting the reterritorialisation of agriculture and food production.
文摘针对Cartographer算法在激光雷达的数据处理中存在的点云特征丢失的问题和低帧率激光雷达导致的运动畸变问题,提出一种改进激光同步定位与地图构建(simultaneous localization and mapping, SLAM)算法。采用k邻域搜索邻近点降采样的体素滤波方法代替Cartographer算法中的传统体素滤波方法,在不丢失点云特征的情况下提升计算速率;嵌入轮式里程计辅助模块去除激光雷达运动畸变,减少机器人的位姿累积误差,从而改善建图效果;最后,增加了边约束条件改善回环检测效果。通过在机器人操作系统中的gazebo搭建仿真环境进行模拟实验,对比两种算法,实验结果显示改进算法的建图轨迹误差更小。
文摘This paper puts forword 11 cartographic generalization operator models and introduces their mathematical definitions,and thus a precise mathematical form and quantitative description has been given to these formerly limited qualitative concepts.The meaning of mathematical definition of operators for cartographic generalization and the application prospect in computer_aided cartography (CAC) is stated.ract The Jurassic strata in Jingyan of Sichuan containing the Mamenchinsaurus fauna are dealt with and divided in this paper. The Mamenchisaurus fossils contained there are compared in morphological features and stratigraphically with other types of the genus on by one. The comprehensive analysis show that the Mamenchisaurus fauna of Jingyan appeared in the early Late Jurassic and is primitive in morphology. The results of the morphological identification and stratigraphical study agree with each other. Their evolutionary processes in different apoches of the Late Jurassic also made clear. Key words Jingyan, Sichuan, Mamenchisaurus Fauna, stratigraphy, evolution