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
A single-/dual-wavelength switchable and tunable erbium-doped fiber laser(EDFL) with super-narrow linewidth has been proposed and experimentally demonstrated at room temperature. The fiber laser is based on a compound...A single-/dual-wavelength switchable and tunable erbium-doped fiber laser(EDFL) with super-narrow linewidth has been proposed and experimentally demonstrated at room temperature. The fiber laser is based on a compound cavity simply composed of a ring main cavity and a two-ring subring cavity(TR-SC). Regardless of single- or dual-wavelength operation, the EDFL could always work well in single-longitudinal-mode(SLM) state at every oscillating wavelength. In dual-wavelength operation, the spacing could be tuned from 0 nm to 4.83 nm. In single-wavelength operation, the EDFL could lase at a fixed wavelength of 1 543.65 nm or another wavelength with a tunable range of 4.83 nm. The super-narrow linewidths of 550 Hz and 600 Hz for two wavelengths are obtained. The proposed EDFL has potential applications in microwave/terahertz-wave generation and high-precision distributed fiber optical sensing.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supported by the Youth Foundation of Hebei Educational Committee(No.QN2015235)the Technology Foundation for Selected Overseas Chinese Scholar of Ministry of Human Resources and Social Security of China(No.CG2015003006)the Special Funding of Comprehensive Capability Enhancement Program from Hebei University
文摘A single-/dual-wavelength switchable and tunable erbium-doped fiber laser(EDFL) with super-narrow linewidth has been proposed and experimentally demonstrated at room temperature. The fiber laser is based on a compound cavity simply composed of a ring main cavity and a two-ring subring cavity(TR-SC). Regardless of single- or dual-wavelength operation, the EDFL could always work well in single-longitudinal-mode(SLM) state at every oscillating wavelength. In dual-wavelength operation, the spacing could be tuned from 0 nm to 4.83 nm. In single-wavelength operation, the EDFL could lase at a fixed wavelength of 1 543.65 nm or another wavelength with a tunable range of 4.83 nm. The super-narrow linewidths of 550 Hz and 600 Hz for two wavelengths are obtained. The proposed EDFL has potential applications in microwave/terahertz-wave generation and high-precision distributed fiber optical sensing.
