In the narrow, submarine, unstructured environment, the present localization approaches, such as GPS measurement, dead?rcckoning, acoustic positioning, artificial landmarks-based method, are hard to be used for multip...In the narrow, submarine, unstructured environment, the present localization approaches, such as GPS measurement, dead?rcckoning, acoustic positioning, artificial landmarks-based method, are hard to be used for multiple small-scale underwater robots. Therefore, this paper proposes a novel RGB-D camera and Inertial Measurement Unit (IMU) fusion-based cooperative and relative close-range localization approach for special environments, such as underwater caves. Owing to the rotation movement with zero-radius, the cooperative localization of Multiple Turtle-inspired Amphibious Spherical Robot (MTASRs) is realized. Firstly, we present an efficient Histogram of Oriented Gradient (HOG) and Color Names (CNs) fusion feature extracted from color images ofTASRs. Then, by training Support Vector Machine (SVM) classifier with this fusion feature, an automatic recognition method of TASRs is developed. Secondly, RGB-D camerabased measurement model is obtained by the depth map In order to realize the cooperative and relative close-range localization of MTASRs, the MTASRs model is established with RGB-D camera and IMU. Finally, the depth measurement in water is corrected and the efficiency of RGB-D camera for underwater application is validated. Then experiments of our proposed localization method with three robots were conducted and the results verified the feasibility of the proposed method for MTASRs.展开更多
Long-range olefin isomerization could lead to the remote functionalization of hydrocarbon chains,which is advantageous with regards to atom-,step-,and redox economy.However,present methodologies for long-range olefin ...Long-range olefin isomerization could lead to the remote functionalization of hydrocarbon chains,which is advantageous with regards to atom-,step-,and redox economy.However,present methodologies for long-range olefin isomerization are mainly focused on heteroatom directed remote olefin migration;studies using aryl groups as the directing group are limited.The limited examples either utilize aryl olefins with special substituted groups on a benzene ring,or use elaborately optimized ligands or co-catalysts to accelerate the isomerization.A more simple catalytic system for general aryl olefins,without the need for special ligands or co-catalysts,was to be developed.Herein,we report a Pd-catalyzed long-range olefin isomerization(up to 15 units)for general aryl olefins via a 1,2-hydrogen shift mechanism.This methodology provides a simple pathway to long-range olefin isomerization without the participation of special ligands or co-catalysts.展开更多
基金the National Natural Science Foundation of China (Nos. 61773064, 61503028)Graduate Technological Innovation Project of Beijing Institute of Technology (No. 2018CX10022)National High Tech. Research and Development Program of China (No. 2015AA043202).
文摘In the narrow, submarine, unstructured environment, the present localization approaches, such as GPS measurement, dead?rcckoning, acoustic positioning, artificial landmarks-based method, are hard to be used for multiple small-scale underwater robots. Therefore, this paper proposes a novel RGB-D camera and Inertial Measurement Unit (IMU) fusion-based cooperative and relative close-range localization approach for special environments, such as underwater caves. Owing to the rotation movement with zero-radius, the cooperative localization of Multiple Turtle-inspired Amphibious Spherical Robot (MTASRs) is realized. Firstly, we present an efficient Histogram of Oriented Gradient (HOG) and Color Names (CNs) fusion feature extracted from color images ofTASRs. Then, by training Support Vector Machine (SVM) classifier with this fusion feature, an automatic recognition method of TASRs is developed. Secondly, RGB-D camerabased measurement model is obtained by the depth map In order to realize the cooperative and relative close-range localization of MTASRs, the MTASRs model is established with RGB-D camera and IMU. Finally, the depth measurement in water is corrected and the efficiency of RGB-D camera for underwater application is validated. Then experiments of our proposed localization method with three robots were conducted and the results verified the feasibility of the proposed method for MTASRs.
基金We would like to thank the Research Foundation of Education Bureau of Hunan Province(No.19K079)the National Key R&D Program of China(No.2018YFE0126800)for financial support.We thank the Instrumental Analysis Center of SJTU for characterza-tion.
文摘Long-range olefin isomerization could lead to the remote functionalization of hydrocarbon chains,which is advantageous with regards to atom-,step-,and redox economy.However,present methodologies for long-range olefin isomerization are mainly focused on heteroatom directed remote olefin migration;studies using aryl groups as the directing group are limited.The limited examples either utilize aryl olefins with special substituted groups on a benzene ring,or use elaborately optimized ligands or co-catalysts to accelerate the isomerization.A more simple catalytic system for general aryl olefins,without the need for special ligands or co-catalysts,was to be developed.Herein,we report a Pd-catalyzed long-range olefin isomerization(up to 15 units)for general aryl olefins via a 1,2-hydrogen shift mechanism.This methodology provides a simple pathway to long-range olefin isomerization without the participation of special ligands or co-catalysts.
