With the wide application of laser in the field of skin plastic surgery, micro laser galvanometer scanner has made great progress in this field with its portability. However, the measurement method used to measure the...With the wide application of laser in the field of skin plastic surgery, micro laser galvanometer scanner has made great progress in this field with its portability. However, the measurement method used to measure the deflection angle of laser galvanometer in the narrow space of scanner with high precision remains to be studied. In this paper, an angle measurement method based on magnetic field is proposed, and the effect of the shapes of permanent magnets(PMs) on the measurement is studied by theoretical and experimental study under the condition that the maximum available space for the PMs is a 10 mm side cube. An angle measuring experimental device is set up, and the contrast experiment is carried out with different PMs which are the same as simulation. The experimental results show that cylindrical PM is more suitable than other PMs, which is consistent with the simulation results, and the maximum nonlinearity error is 0.562%. This method has the advantages of small volume,non-contact measurement, small moment of inertia, good dynamic response and no external excitation for the PMs, so it has a broad application prospect in micro laser galvanometer scanner.展开更多
Narrow space manipulations are crucial for equipment maintenance,as they eliminate the need for disassembly,thus reducing costs and increasing efficiency.Cable-driven flexible robots possess exceptional capabilities i...Narrow space manipulations are crucial for equipment maintenance,as they eliminate the need for disassembly,thus reducing costs and increasing efficiency.Cable-driven flexible robots possess exceptional capabilities in maneuvering through narrow spaces,thanks to their interaction compliance and distal dexterity.However,their inherent low stiffness causes a decline in the location accuracy of the robot and could even lead to manipulation failure.To address this challenge,this paper proposes a novel type of rigid-flexible coupling robot,which increases the stiffness of the robot while ensuring the reachability within a narrow space.To achieve high-accuracy location in a narrow space,kinematic and control methods are proposed.Specifically,the robot forward kinematics are uniformly represented,and the closed-form inverse kinematics solution is derived.Furthermore,in cases where the robot's structure fails to align with Pieper's solution,a two-stage search strategy is utilized to solve the inverse kinematics,resulting in a high success rate of 99.1%.Based on the proposed kinematics,a rigid-dominated control method is then proposed to facilitate localization and pose alignment of target objects in narrow spaces.The practical comparative experiments show that the proposed robot has the capability of high accuracy control in narrow spaces.展开更多
A case of brachial plexus neuropraxia occurring during CT-guided radiofrequency ablation is reported in a patient with a narrow costoclavicular space. We discuss clinical methods of identifying patients with a narrow ...A case of brachial plexus neuropraxia occurring during CT-guided radiofrequency ablation is reported in a patient with a narrow costoclavicular space. We discuss clinical methods of identifying patients with a narrow costoclavicular space who are at risk of position-related injury of the brachial plexus during anaesthesia. Identifying high risk patients and proper positioning during anaesthesia are hallmarks of preventing such injuries.展开更多
The discovery of the momentum space crystal based on the alkaline-earth atom ^(88)Sr in narrow-line cooling has paved the way to explore this novel physical phenomenon in other cold atom systems. In this paper, a mome...The discovery of the momentum space crystal based on the alkaline-earth atom ^(88)Sr in narrow-line cooling has paved the way to explore this novel physical phenomenon in other cold atom systems. In this paper, a momentum space crystal based on the fermions ^(87)Sr in narrow-line cooling of transition^1S_0–~3P_1 is demonstrated. We theoretically analyze and compare the formation principle of the narrow-line with that of broad-line cooling, and achieve the momentum space crystal in experiment. Beyond that we present a series of numerical calculations of those important parameters which influence the distribution and size of the momentum space crystal. Correspondingly, we vary the values of these parameters in experiment to observe the momentum space crystal evolution and distribution. The experimental results are in conformity with the results of the theoretically numerical calculations. These results and analyses provide a detailed supplementary study on the formation and evolution of momentum space crystal. In addition, this work could also give a guideline on atomic manipulation by narrow-line cooling.展开更多
针对在狭长空间下传统的行人航迹推算(Pedestrian Dead Reckoning,PDR)方法易受传感器扰动与环境干扰,导致传感器数据存在误差累积无法实现行人位置精确估计的问题,结合室内走廊狭长空间典型场景下北斗伪卫星(Pseudosatellite,PL)的信...针对在狭长空间下传统的行人航迹推算(Pedestrian Dead Reckoning,PDR)方法易受传感器扰动与环境干扰,导致传感器数据存在误差累积无法实现行人位置精确估计的问题,结合室内走廊狭长空间典型场景下北斗伪卫星(Pseudosatellite,PL)的信号特征,提出了一种基于北斗信标辅助的PDR狭长空间定位方法。通过提取空间下确定性位置PL观测量数据特征,建立了数据特征与空间位置的指纹位置对应关系。设计了一种北斗PL与PDR组合的拐点检测方法。以北斗信标节点为基础,结合PDR适用范围大与应用性强的特性,将方向信息组合到卡尔曼滤波算法中完成设计。通过实测验证,与PDR定位方法相比,在室内狭长空间情况下组合系统的均方根误差(Root Mean Squared Error,RMSE)定位精度提高了54%。展开更多
基金supported by the Aeronautical Science Foundation of China [grant numbers 20175748009]。
文摘With the wide application of laser in the field of skin plastic surgery, micro laser galvanometer scanner has made great progress in this field with its portability. However, the measurement method used to measure the deflection angle of laser galvanometer in the narrow space of scanner with high precision remains to be studied. In this paper, an angle measurement method based on magnetic field is proposed, and the effect of the shapes of permanent magnets(PMs) on the measurement is studied by theoretical and experimental study under the condition that the maximum available space for the PMs is a 10 mm side cube. An angle measuring experimental device is set up, and the contrast experiment is carried out with different PMs which are the same as simulation. The experimental results show that cylindrical PM is more suitable than other PMs, which is consistent with the simulation results, and the maximum nonlinearity error is 0.562%. This method has the advantages of small volume,non-contact measurement, small moment of inertia, good dynamic response and no external excitation for the PMs, so it has a broad application prospect in micro laser galvanometer scanner.
基金supported by the National Natural Science Foundation of China(Grant Nos.52188102,52090054,52205521)the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(Grant No.GZC20240539).
文摘Narrow space manipulations are crucial for equipment maintenance,as they eliminate the need for disassembly,thus reducing costs and increasing efficiency.Cable-driven flexible robots possess exceptional capabilities in maneuvering through narrow spaces,thanks to their interaction compliance and distal dexterity.However,their inherent low stiffness causes a decline in the location accuracy of the robot and could even lead to manipulation failure.To address this challenge,this paper proposes a novel type of rigid-flexible coupling robot,which increases the stiffness of the robot while ensuring the reachability within a narrow space.To achieve high-accuracy location in a narrow space,kinematic and control methods are proposed.Specifically,the robot forward kinematics are uniformly represented,and the closed-form inverse kinematics solution is derived.Furthermore,in cases where the robot's structure fails to align with Pieper's solution,a two-stage search strategy is utilized to solve the inverse kinematics,resulting in a high success rate of 99.1%.Based on the proposed kinematics,a rigid-dominated control method is then proposed to facilitate localization and pose alignment of target objects in narrow spaces.The practical comparative experiments show that the proposed robot has the capability of high accuracy control in narrow spaces.
文摘A case of brachial plexus neuropraxia occurring during CT-guided radiofrequency ablation is reported in a patient with a narrow costoclavicular space. We discuss clinical methods of identifying patients with a narrow costoclavicular space who are at risk of position-related injury of the brachial plexus during anaesthesia. Identifying high risk patients and proper positioning during anaesthesia are hallmarks of preventing such injuries.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11474282 and 61775220)the Key Research Project of Frontier Science of the Chinese Academy of Sciences(Grant No.QYZDB-SSW-JSC004)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB21030100)
文摘The discovery of the momentum space crystal based on the alkaline-earth atom ^(88)Sr in narrow-line cooling has paved the way to explore this novel physical phenomenon in other cold atom systems. In this paper, a momentum space crystal based on the fermions ^(87)Sr in narrow-line cooling of transition^1S_0–~3P_1 is demonstrated. We theoretically analyze and compare the formation principle of the narrow-line with that of broad-line cooling, and achieve the momentum space crystal in experiment. Beyond that we present a series of numerical calculations of those important parameters which influence the distribution and size of the momentum space crystal. Correspondingly, we vary the values of these parameters in experiment to observe the momentum space crystal evolution and distribution. The experimental results are in conformity with the results of the theoretically numerical calculations. These results and analyses provide a detailed supplementary study on the formation and evolution of momentum space crystal. In addition, this work could also give a guideline on atomic manipulation by narrow-line cooling.
文摘针对在狭长空间下传统的行人航迹推算(Pedestrian Dead Reckoning,PDR)方法易受传感器扰动与环境干扰,导致传感器数据存在误差累积无法实现行人位置精确估计的问题,结合室内走廊狭长空间典型场景下北斗伪卫星(Pseudosatellite,PL)的信号特征,提出了一种基于北斗信标辅助的PDR狭长空间定位方法。通过提取空间下确定性位置PL观测量数据特征,建立了数据特征与空间位置的指纹位置对应关系。设计了一种北斗PL与PDR组合的拐点检测方法。以北斗信标节点为基础,结合PDR适用范围大与应用性强的特性,将方向信息组合到卡尔曼滤波算法中完成设计。通过实测验证,与PDR定位方法相比,在室内狭长空间情况下组合系统的均方根误差(Root Mean Squared Error,RMSE)定位精度提高了54%。
