最新刊期
卷 32 ， 期 19 ， 2024
- “在深腔狭小空间手术领域，专家提出了入路姿态光纤导航的经鼻柔性手术机器人，实现了手术机器人术中形位高精度自感知，验证了其有效性和可行性。”摘要：To address the challenges of limited dexterity in traditional transnasal surgery and inadequate intraoperative guidance， a flexible transnasal surgical robot with fiber-optic navigation is developed. The design features a flexible manipulator with spherical hinges and pin-slot configuration for enhanced dexterity and resistance to torsional disturbances. The robot's forward and inverse kinematics are modeled using geometric analysis and the D-H parameter method. Embedded with two fiber-optic sensors at 90° intervals in each manipulator， a data-driven posture calibration using binocular vision and extreme learning avoids errors from traditional offline calibration and mitigates error accumulation in differential geometry posture estimation. This enhances high-precision perception of the robot's shape and position. Experiments demonstrate the manipulator's bending angle can reach 105°， with a load capacity of 0.9 N at 80°. Using fiber-optic navigation， maximum position prediction errors are 0.920 mm in free environments and 1.635 mm with obstacles， confirming the robot's effectiveness and feasibility.关键词：Fiber-optic navigation;Flexible surgical robot;extreme learning machine;position tracking
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发布时间：2024-11-20 - “在空间高功率激光领域，专家建立了相变热控系统，为快速散热提供解决方案。”摘要：To achieve effective heat dissipation for a space high-power laser diode pumping source array， a phase change thermal control system has been developed. Key components like thermal interface materials （TIM）， copper heat sinks， phase-change materials， reinforcing materials， active heaters， and space radiators have been designed and evaluated. Initially， the thermal specifications of the laser diode pumping array are outlined， followed by the thermal control design concepts. A detailed design of the thermal control system was developed， and two thermal control schemes were formulated with and without copper foam filling. Then， the two different schemes were analyzed using NX software. The first scheme reaches a peak temperature of 59.98 ℃ in 800 s， with the phase-change material surface at 47.12 ℃. The second scheme achieves a maximum temperature of 38.35℃ in 200 s and maintains thermal congruence with the phase-change temperature after 360 s， meeting the 10-40 ℃ specification. Consequently， the thermal control system for the laser diode pumping source is designed and manufactured based on the second scheme， ensuring efficient heat dissipation.关键词：space high-power laser;laser diode;pumping source array;phase change thermal control system
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发布时间：2024-11-20 -
Femtosecond laser annealing of 4H-SiC interfaces and optimization of their electrical performance AI导读
“在高频高功率器件领域，通过飞秒激光退火优化SiC界面电学性能，实现了肖特基势垒和载流子浓度的显著变化。”摘要：Enhancing the electrical contact properties between SiC and metal interfaces is crucial for advancing SiC materials in high-frequency and high-power devices. This study utilized a 1030 nm near-infrared femtosecond laser to anneal the 4H-SiC surface， analyzing the effects of various laser annealing parameters. We examined changes in surface morphology， element distribution， and bonding structure of the laser-annealed samples using scanning electron microscopy， X-ray photoelectron spectroscopy， confocal Raman spectroscopy， and other methods. The study revealed that improvements in electrical properties at the contact interface result from a disordered graphite structure and SiOx/Si structure with oxygen vacancies created by laser annealing. This structure reduces the interface Schottky barrier height， enhances conductivity， and shifts the Fermi level of the 4H-SiC surface， significantly boosting interface electrical properties. Femtosecond laser annealing reduced the SiC interface Schottky barrier from 1.43 eV to 0.69 eV and increased the carrier concentration from 5.40×1013 cm-3 to 1.77×1018 cm-3， presenting a novel method for optimizing SiC interface electrical properties with ultrafast laser annealing.关键词：femtosecond laser;Silicon Carbide;contact interface;Schottky barrier- 40
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发布时间：2024-11-20
Modern Applied Optics
- “在协作机器人领域，专家提出了一种集成于谐波减速器内部的扭矩传感器，通过有限元分析和响应面模型优化敏感栅结构，实现了高精度的负载扭矩感应，为机器人关节力控制和系统集成度提升提供了有效方案。”摘要：The article introduces an integrated torque sensor within a harmonic drive reducer to accurately measure joint output torque， enhancing intelligent control and integration of collaborative robots. Using finite element analysis， the relationship between strain on the harmonic drive reducer's flexible wheel surface and torque is examined. A response surface model based on this analysis determines optimal grid structure parameters for the sensor， ensuring the best linear response. The sensor is designed using the Wheatstone bridge principle. Calibration and testing show a sensitivity of 0.249 mV/N·m， a linearity of 0.999 74， and a hysteresis error of 2.19%. With load torque changes from 0 to 70 N·m， the root mean square error is between 0.89 N·m and 0.98 N·m； for sinusoidal changes between ±70 N·m， it's 0.96 N·m to 1.05 N·m. This sensor accurately detects torque magnitude， aiding joint force control in collaborative robots and enhancing system integration.关键词：torque sensor;harmonic reducer;finite element analysis;sensitive grid;response surface methodology
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发布时间：2024-11-20 - “在Mini/Micro LED巨量转移技术领域，专家提出了“永磁+电磁”磁场耦合的新型流磁巨量转移用定位磁针，优化设计后提升了自组装巨量转移技术的效率。”摘要：To improve the efficiency and yield of Mini/Micro LED mass transfer and self-assembly， a new positioning magnetic needle using a permanent magnet + electromagnetic magnetic field coupling is proposed. An electromagnetic bias coil is designed to precisely control the magnetic force on the needle's upper surface for accurate chip grasping. Magnetic circuit analysis establishes a mathematical model for the magnetic needle structure， identifying parameters affecting the magnetic flux density in the air gap. The finite element method optimizes these parameters， increasing the Bmax on the needle's upper surface from 57 mT to 68 mT， a 19.2% improvement， and enhancing the peak-to-valley variation rate δ from 50.8% to 70.5%. Based on these optimizations， a permanent magnet bias positioning magnetic needle device was developed. Tests show the optimized needle achieves a Bmax of 60 mT and a δ of 66.6%， efficiently securing thousands of chips per minute. This meets precise chip grasping requirements and enhances the yield of self-assembly mass transfer technology when combined with fluid.关键词：Mini/Micro LED;Mass Transfer（MT）;permanent magnet bias;positioning magnetic needle;Optimized design
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发布时间：2024-11-20 - “在永磁同步电机驱动系统领域，专家提出了一种改进的滑模控制策略，有效提升了系统稳定性和动态响应性能。”摘要：To enhance the speed control of permanent magnet synchronous motor （PMSM） drive systems， this paper introduces a new sliding mode control （NSMC） strategy with an improved exponential convergence law and an adaptive Lunberger observer. Firstly， to overcome the slow convergence of traditional exponential laws， a nonlinear adaptive function-based law is proposed， enabling faster convergence and reduced jitter for the NSMC strategy. This adaptive function also resolves the discontinuity issue of the convergence law's exponential term. Secondly， addressing the limitations of the traditional Lunberger observer， an adaptive version is developed to estimate and compensate system perturbations， offering quicker response without affecting steady-state performance， thus enhancing the system's disturbance resistance and speed tracking. Simulations and experiments demonstrate that for step speed commands at 500 r/min and 750 r/min， the system's settling times are 0.44 s and 0.71 s， respectively. When loads suddenly increase by 5， 10， and 20， the settling times are 1.16 s， 1.79 s， and 1.99 s. The proposed sliding mode control strategy significantly improves both dynamic and steady-state system performance.关键词：Permanent Magnet Synchronous Motor （PMSM）;sliding mode control;approach rate;Lunberger observer
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发布时间：2024-11-20
Micro/Nano Technology and Fine Mechanics
- “晶圆飞拍成像系统曝光控制新方法，提升成像质量，缩短参数调整时间。”摘要：The exposure control of wafer motion imaging systems greatly affects image quality. Traditional spatial domain-based algorithms are complex and overlook differences in die features， causing uneven exposure. To solve this， we propose a method using frequency domain evaluation through image partitioning. This method uses a block-based dual-threshold segmentation algorithm to adaptively segment image features. By combining high-pass filtering with a Gaussian pyramid algorithm， it efficiently extracts high-frequency information. A region-weighted evaluation function is crafted to evaluate uniform exposure effects. Furthermore， a decision tree-based search algorithm with variable steps is introduced to quickly find optimal exposure parameters. Experiments show this algorithm improves image quality by 1.34% and reduces exposure adjustment time by 61.3%， ensuring fast imaging quality in wafer motion imaging.关键词：exposure control;Frequency domain analysis;Image evaluation function;Variable step search;Decision tree
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发布时间：2024-11-20 - “在雷视监控设备测速领域，专家提出了一种影像优先与二维三维视图一体的多目标连续追踪测速方法，有效解决了视角导致的不同分辨率点云目标检测混淆问题，为提高测速准确性和实用性提供了解决方案。”摘要：This paper introduces an image-priority approach with integrated 2D-3D views for continuous multi-target tracking and speed estimation in camera-LiDAR surveillance systems. It addresses differences in acquisition frequency， resolution， and viewing angles between camera and LiDAR-based speed estimation tasks. Geometrically matched feature points are selected， and external parameters are computed using the Direct Linear Transformation method for online calibration between devices. A vision-guided， frustum-based spatial method combines 2D and 3D localization， uses high-resolution ground points to define area boundaries， and adapts clustering parameters in a 2D top-down view transformed from a 3D frustum perspective. This approach helps eliminate irrelevant points and address mixed-resolution point cloud detection due to varying viewing angles. The speed estimation process employs Kalman filtering and vehicle motion states， modeling speed estimation as observation equations using discrete synchronized frame point cloud data. The observation noise covariance matrix is calculated based on point cloud resolution， allowing continuous optimal estimation and reducing observation noise and asynchronous timing effects. Experiments on traffic scene datasets show that the method achieves an average absolute error of 0.276 4 m/s and a root mean square error of 0.325 1 m/s， with a maximum detection range of 103.211 m， demonstrating high accuracy and practicality.关键词：Intelligent transportation;Speed estimation;image frustum;data fusion;kalman filtering;object detection
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发布时间：2024-11-20 -
Rotating point cloud segmentation and reverse reconstruction based on computed tomography images AI导读
“在逆向工程领域，提出了一种基于主轴点云切片的分割方法，有效提高了模型重建质量，平均交并比达0.8797，为实际工程应用提供重要价值。”摘要：Computed tomography is a crucial non-destructive testing technique for acquiring point cloud data and reverse reconstructing workpieces with complex internal structures. Point cloud segmentation is vital in reverse engineering， as its accuracy affects the quality of the reconstructed model. To address reverse reconstruction needs， this paper introduces a slice segmentation method based on the principal axis for part segmentation， involving two stages： coarse and fine segmentation. Initially， parallel equidistant point cloud slices are generated along the principal axis， classified by calculating slice features. Similar slices are then merged and clustered for coarse segmentation results. These results serve as input for the fine segmentation stage， where sub point cloud features are calculated and classified. The sub point clouds are verified， merged， and under-segmented to achieve the final segmentation result. Subsequently， a geometry-topology tree structure is proposed for fast， accurate model reconstruction， representing the model unambiguously. The experimental results demonstrate that the proposed method achieves effective segmentation and high applicability， with an average IoU of 0.879 7. Additionally， the model reconstructed using a geometric-topological tree fully retains the object's main structural information， which is highly valuable for practical engineering applications.关键词：computed tomography;3D point cloud;part segmentation;reverse reconstruction- 28
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发布时间：2024-11-20 - “在遥感图像处理领域，专家基于Zernike多项式退化模型构建数据集，并提出降质图像质量增强算法，显著提升图像质量，满足工程应用时效性要求。”摘要：Traditional image processing algorithms lack stability， and deep learning algorithms fall short of engineering requirements for remote sensing due to insufficient training datasets and high computational demands. To tackle this， the paper integrates degradation modeling and image processing. It introduces a method for creating a remote sensing image enhancement dataset using a Zernike polynomial degradation model. Additionally， it designs an algorithm for enhancing degraded remote sensing images using a hybrid frequency-domain and spatial-domain attention mechanism. This algorithm employs a dual-domain selection module and a frequency feature residual module to improve the learning of high-frequency image textures and details in both domains. The hybrid attention mechanism further boosts feature extraction capabilities. The algorithm's performance was validated against five common methods using NIQE values， visualization effects， MTF curves， and inference efficiency. Results show that the proposed approach significantly reduces NIQE values and improves MTF curves， leading to clearer images and substantially enhancing degraded image quality. For images with a specific pixel size of 27 620×29 200， the algorithm processes them in just 27 s， compared to hours for traditional methods， thus meeting engineering timeliness requirements. This research offers a rapid and effective solution for addressing satellite imaging degradation.关键词：optical remote sensing images;image enhancement;deep learning;Zernike polynomial;image degradation model
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发布时间：2024-11-20
Information Sciences
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