针对单目同时定位与地图构建(simultan-eous localization and mapping,SLAM)技术存在的尺度不确定性问题,提出一种结合深度预测网络来估计绝对尺度的单目SLAM算法。利用MonoDepth网络对单目图像进行深度预测,与从单目图像中提取的ORB...针对单目同时定位与地图构建(simultan-eous localization and mapping,SLAM)技术存在的尺度不确定性问题,提出一种结合深度预测网络来估计绝对尺度的单目SLAM算法。利用MonoDepth网络对单目图像进行深度预测,与从单目图像中提取的ORB特征点进行深度值的数据关联,通过设定深度阈值的方法剔除具有不可靠深度值的特征点,恢复单目的绝对尺度,根据特征点的真实深度信息,通过光束法平差优化位姿图,校正尺度漂移,减少累积误差。通过室外KITTI数据集进行对比实验,其结果表明,该方法能够获得更高的定位精度。展开更多
In this study,the impact of environmental factors on tropical cyclone(TC)outer-core size was investigated for both migrating and local TCs in the South China Sea during the period 2001–2019.Among all the thermodynami...In this study,the impact of environmental factors on tropical cyclone(TC)outer-core size was investigated for both migrating and local TCs in the South China Sea during the period 2001–2019.Among all the thermodynamic and dynamic factors,the low-level environmental helicity showed the strongest positive correlation with TC outer-core size.Large helicity favors the development and organization of convection in TCs,and the corresponding strong inflow and large angular momentum fluxes into the system is beneficial for the maintenance and enlargement of TC outer-core size.Besides,the asymmetric distribution of helicity may account for the asymmetry of TC outer-core size.Therefore,the environmental helicity,as an integrated dynamic factor,can provide an alternative view on TC outer-core size.展开更多
文摘针对单目同时定位与地图构建(simultan-eous localization and mapping,SLAM)技术存在的尺度不确定性问题,提出一种结合深度预测网络来估计绝对尺度的单目SLAM算法。利用MonoDepth网络对单目图像进行深度预测,与从单目图像中提取的ORB特征点进行深度值的数据关联,通过设定深度阈值的方法剔除具有不可靠深度值的特征点,恢复单目的绝对尺度,根据特征点的真实深度信息,通过光束法平差优化位姿图,校正尺度漂移,减少累积误差。通过室外KITTI数据集进行对比实验,其结果表明,该方法能够获得更高的定位精度。
基金This work was supported by the National Key Research and Development Program of China[grant number 2017YFC1501603]the National Natural Science Foundation of China[grant numbers 41675053,42175062,and 61827091].
文摘In this study,the impact of environmental factors on tropical cyclone(TC)outer-core size was investigated for both migrating and local TCs in the South China Sea during the period 2001–2019.Among all the thermodynamic and dynamic factors,the low-level environmental helicity showed the strongest positive correlation with TC outer-core size.Large helicity favors the development and organization of convection in TCs,and the corresponding strong inflow and large angular momentum fluxes into the system is beneficial for the maintenance and enlargement of TC outer-core size.Besides,the asymmetric distribution of helicity may account for the asymmetry of TC outer-core size.Therefore,the environmental helicity,as an integrated dynamic factor,can provide an alternative view on TC outer-core size.
