最新刊期
卷 32 ， 期 11 ， 2024
- “在提高激光跟踪仪坐标测量精度领域，专家建立了几何结构误差模型，通过标定和修正方法，成功将测量误差从13 μm/m减小到4 μm/m以内，显著提升了测量精度。”摘要：To enhance the coordinate measurement accuracy of laser trackers, we analyzed the geometric errors of the device and studied calibration and correction methods for transit offset error, transit tilt error, laser offset error, and laser tilt error. First, geometric error models were established using geometric analysis methods. A calibration device for geometric error parameters was constructed based on a telecentric measurement system, test rods and a PSD device. This setup allows for rapid, automatic high-precision calibration and compensation of geometric errors. Subsequently, the geometric errors measured by the calibration experiment were incorporated into the error compensation models, and the scale bar length measured by the laser tracker was compared with its standard length. Experimental results indicate that after geometric error correction, the coordinate measurement error of the laser tracker can be reduced from 13 μm/m to less than 4 μm/m, improving measurement accuracy by approximately 9 μm/m. These findings confirm the validity of the geometric error calibration and correction methods, demonstrating that coordinate measurement accuracy of laser trackers can be significantly enhanced using these methods.关键词：laser tracker;Geometric errors;error calibration;error correction;least square method
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发布时间：2024-07-10 - “在高精度平面干涉仪系统评价领域，研究人员通过仿真分析与实验结合，探究了噪声对仪器传递函数测试结果的影响，并提出了优化方案。实验结果验证了优化方案能有效降低噪声干扰，提高测试精度。”摘要：In the evaluation of high-precision flat interferometer systems, the Instrument Transfer Function (ITF) has become an essential index for assessing interferometer performance. It accurately characterizes the resolution capability of optical systems in measuring profiles at different spatial frequencies. However, strict experimental environment requirements and interference system noise can significantly distort ITF test results. To accurately characterize interferometer performance, this paper combines simulation analysis with practical experiments, introducing simulated interferograms into varying levels of Gaussian random noise. We explore the impact of noise on ITF test results, propose the ITFRMS value as an evaluation index for measurement error, and analyze the noise tolerance of the interferometer system. Several ITF test optimization methods are presented based on this evaluation index. An experimental system is built for analysis and validation. The final results indicate that in the unoptimized ITF testing process, the ITFRMS value of the interferometer system is 0.111 2. After optimization, with the same noise level, ITFRMS values reduce to 0.069 3, 0.036 7, and 0.057 9, respectively. These results demonstrate the feasibility of the proposed optimization scheme, effectively suppressing noise interference during ITF testing of the interferometer system.关键词：Interferometry technology;Fizeau interferometer;Instrument transfer function;Noise tolerance
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发布时间：2024-07-10 - “最新研究进展显示，通过集成微透镜提高InP基InGaAs单光子红外探测器的光能利用效率，成功设计并验证了磷化镓和硅材料的方形孔径微透镜阵列，为探测器灵敏度提升提供了有效解决方案。”摘要：The integrated application of microlens and detector chip can improve the efficiency of light energy utilization of the detector and thus increase the sensitivity of the detector. For two kinds of InP-based InGaAs single-photon infrared detectors， two kinds of square aperture microlens arrays with materials of GaP and Si are designed respectively. The design process of the structural parameters of the microlens arrays is introduced and the design points of each step are analyzed. The structural parameters of the designed microlens arrays are simulated and calibrated by ray tracing software， which determines that the two microlens arrays meet the design requirements. The morphology of the two fabricated microlens arrays was examined using a step meter and a confocal microscope. The curvature deviations of the two microlens arrays were calculated to be 1.38% and 3.44%， respectively. The focal lengths of two microlens arrays in air at 1.064 μm wavelength were tested experimentally， and the focal deviations of 5.69% and 2.76% were obtained in comparison with the simulated results. By analyzing the manufacturing process of microlenses， the two deviations meet the application requirements.关键词：microlens array;photodetector;light energy utilization;rectangular aperture
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发布时间：2024-07-10 - “最新研究突破：自由运动线虫双光路观测系统成功实现细胞级成像，为线虫行为运动数据采集提供新方案。”摘要：To overcome challenges related to a limited field of view and susceptibility to environmental factors impacting data accuracy, we have developed a free-moving Caenorhabditis elegans (C. elegans) dual-optical observation system. This system integrates both a microscopy imaging module and a large-field-of-view imaging module, allowing for the simultaneous capture of C. elegans microscope images and Petri dish images. By incorporating a switchable fluorescence module, the system meets the requirements for capturing C. elegans fluorescence images. Additionally, the system includes an XYZ three-axis platform to prevent vibration-triggered escape responses from C. elegans. We utilized this system to conduct imaging experiments on USAF1951 resolution plates and various C. elegans strains. The experimental results demonstrated exceptional microscopy imaging resolution of less than 2.19 mm, vividly displaying C. elegans' organs, tissues, and cell boundaries in bright-field microscopy images, along with clear imaging of various fluorescent protein distributions. The large-field-of-view module, featuring uniform illumination and a morphological algorithm, enables the collection of behavior and motion data from the C. elegans population. In summary, this system fulfills various C. elegans tracking requirements, exhibits significant stability and data accuracy, enhances the flexibility of C. elegans experiments, and lays a foundation for integrating C. elegans tracking data across different scales.关键词：microscopy imaging;daul-optical path imaging;C. elegans;C. elegans observing system
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发布时间：2024-07-10 - “在惯性空间观测领域，专家提出了一种TDI相机长弧段星源主动扫描设计方法，有效扩大观测范围和成像信噪比。通过构建映射函数和建立扫描成像模型，实现了动态星源无拖尾高信噪比成像。实验结果验证了该方法的有效性，为惯性空间观测提供了新的解决方案。”摘要：To effectively enhance the bandwidth range and imaging signal-to-noise ratio for inertial space observation, we propose a design method for the active scanning of long arc star sources using TDI cameras, based on the mapping function of star magnitude and optical multi-parameters. First, we construct a mapping function between TDI optical parameters and the limit detection star magnitude, grounded in the blackbody radiation energy density formula. Next, employing homogeneous coordinate transformation and the Euler axis optimal path planning method, we establish an imaging model for dynamic star source scanning with continuous compensation of inertial space satellites and payload. This achieves high signal-to-noise ratio imaging of dynamic star sources without tailing. Finally, leveraging the theory of parallel experiments, we build an experimental system consisting of a TDI camera and a dynamic star source simulator, conducting scanning imaging experiments and error analysis. Experimental results indicate that when the Euler angular rate of the body coordinate system relative to the inertial coordinate system is 8.5 (°)/s, the integration series is 96, the row frequency of the TDI camera is 1 kHz, and the imaging duration is 10 s, the imaging signal-to-noise ratio of the star map reaches a maximum of 7.325, and the solid angle of the scanning area is 5.423 2. The active scanning of long arc star sources by the inertial space TDI camera can achieve high signal-to-noise ratio imaging of star sources and significantly expand the observation range of imaging.关键词：space remote sensing;TDI camera;signal-to-noise ratio;long arc segment;Euler axis;active scanning
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发布时间：2024-07-10
Modern Applied Optics
- “最新研究进展：基于电化学传感原理和微流控技术，成功研发出一种能连续监测血液pH和PCO2的芯片，为血液透析患者提供连续在线检测，降低死亡率。”摘要：For continuous assessment of the acid-base balance in the blood of hemodialysis patients and reducing mortality risk, this work proposes a chip for continuous monitoring of pH and PCO2 in blood, utilizing electrochemical sensing and microfluidic technology. The chip combines pH and PCO2 detection via a pH electrode and a carbonate ion-selective electrode, sharing a common reference electrode. The microfluidic test chamber ensures continuous blood flow and accurate detection by preventing air interference. The chip's pH detection performance was tested using Tris-HCl solutions ranging from pH 6.00 to 9.00, showing a detection sensitivity of 61.2 mV/pH with a standard deviation under 0.01 (n=10) for continuous detection of the same sample. The reproducibility test showed average relative errors of 0.46% (n=6), ensuring accurate detection of sample solutions within the pH 6.00-9.00 range. The sensor was tested in both blood gas control solutions and blood samples. In blood gas control solutions, the absolute errors for pH and PCO2 detection were under 0.04 and 2.30 mmHg, with average relative errors of 0.23% and 1.94%, respectively. In blood samples, the absolute errors for pH and PCO2 detection were under 0.05 and 3.50 mmHg, with average relative errors of 0.36% and 2.60%, respectively. Compared to commercial blood gas analyzers, the chip's small size allows it to connect to the hemodialysis pipeline, enabling continuous online detection of pH and PCO2 in blood.关键词：microfluidic technology;hemodialysis;acid-base balance;electrochemical sensor;continuous blood monitoring
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发布时间：2024-07-10 - “最新研究突破：微型超声电机实现小空间大驱动力，结构紧凑，性能优越，为精密驱动领域提供创新解决方案。”摘要：To meet the application requirements of narrow spaces, low voltage, and high driving force, a multi-legged linear miniature ultrasonic motor based on a single bending vibration mode was proposed. Firstly, the stator structure was designed according to the driving principle of the ultrasonic motor. Using the finite element software ANSYS Workbench, a dynamic simulation model of the stator was established, followed by structural optimization and dynamic analysis. The final dimensions of the stator were determined to be 8 mm×1 mm×0.6 mm, with measured resonant frequency errors of 6.99% and 5.46%, respectively. Finally, a nonlinear simulation contact model between the stator and mover of the motor was created to verify the feasibility of the bidirectional drive of the ultrasonic motor. A driving performance test device for the micro linear ultrasonic motor was constructed. The measured results indicated that with a driving voltage of 60 Vpp, the maximum no-load speed was 53.3 mm/s, the maximum load was 43.3 mN, and the thrust-to-weight ratio was 280. Experimental results demonstrate that the micro ultrasonic motor has a viable principle, a simple and compact structure, and good output performance, suggesting broad application prospects in precision drive fields such as optical systems, precision positioning systems, and mobile terminals.关键词：micro ultrasonic motor;standing wave;dynamic simulation;vibration characteristics
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发布时间：2024-07-10 - “在压电微定位平台精度提升领域，专家建立了反映压电陶瓷作动器频率依赖迟滞非线性特性的Hammerstein模型，采用基于卡尔曼滤波的预测控制，有效提高控制精度。”摘要：To mitigate the influence of hysteresis and nonlinearity in piezoelectric ceramics on the accuracy of piezoelectric micropositioning platforms, the Hammerstein model is employed to describe the frequency-dependent hysteretic nonlinearity of piezoelectric ceramic actuators. This model comprises an asymmetric Bouc-Wen model and a dynamic linear model to represent static hysteresis nonlinearity and frequency-dependent dynamic properties, respectively. Recognizing that the hysteresis compensator cannot entirely eliminate such issues and there is noise interference in experimental equipment, predictive control based on a Kalman filter is used to enhance the control accuracy of the piezoelectric micropositioning platform. Model predictive control addresses model uncertainties like inverse compensation errors and modeling errors, while the Kalman filter estimates the state of the system. Experimental results indicate that the relative tracking error of the proposed controller is less than 0.68% for sine wave signals and less than 0.70% for triangular wave signals. By incorporating Kalman filter-based predictive control alongside hysteresis compensation, the micropositioning platform effectively achieves high-precision tracking.关键词：model predictive control;Kalman filter;piezoelectric actuator;hammerstein model
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发布时间：2024-07-10 - “在微流道设计领域取得新进展，研究人员设计并制备了大尺寸仿猪笼草口缘区结构的半圆管型微流道，通过实验分析验证了其单向铺展性，为微流道参数设计提供基础指导。”摘要：Addressing the challenge of uni-directional fluid flow without power input in a semi-circular tubular microchannel, a large-scale model inspired by the Nepenthes alata peristome was designed and fabricated, with a scale of 100 μm. The mechanism behind the uni-directional liquid spreading was examined, leading to the design of a semi-circular tube structure featuring the Nepenthes alata peristome surface. A digital light processing 3D printer using a photocuring method was employed to create the workpiece. Experimental studies were conducted to observe the uni-directional spreading of liquid within this large-scale semi-circular tubular microchannel. By calculating the range, various structural parameters' influence on the liquid's uni-directional spreading performance was quantified. Results indicate that the semi-circular tubular microchannel, characterized by factors such as the ellipse's semi-major axis of 570 μm, microcavity wedge of 30°, microchannel width of 320 μm, structural length of 360 μm, stretching length of 200 μm, and curvature of 2, showed superior uni-directional spreading performance. The influence of each factor on the spreading coefficient, ranked from smallest to largest, was stretching length, structure length, microcavity wedge, semi-major axis of the ellipse, microchannel width, and curvature. These findings offer essential guidance for the design parameters of large-size semi-circular tubular microchannels with a Nepenthes alata peristome structure and also confirm the feasibility of using conventional 3D printing technology to create microchannels with uni-directional fluid spreading.关键词：microchannels;3D printing;Nepenthes alata peristome;uni-directional spreading performance;open semi-circular tubular
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发布时间：2024-07-10
Micro/Nano Technology and Fine Mechanics
- “在自动化检测领域，研究者设计了基于机器视觉的蜗杆缺陷采集系统，改进YOLOv7算法，引入数据增广、注意力机制和SIOU损失函数，显著提升了检测精度，为蜗杆表面缺陷自动化检测提供了高效解决方案。”摘要：To tackle the challenges of reliance on manual inspection, low detection efficiency, and high costs in detecting surface defects on worm gear teeth, automated methods utilizing machine vision were researched. A defect collection system was designed to capture worm gear defects, and data augmentation strategies were introduced to handle varying defect occurrence rates. Enhancements were made to the YOLOv7 algorithm. Firstly, to address the differences in defect size distribution, a progressive feature pyramid was incorporated to reconstruct the neck network, improving the model's multi-scale feature fusion capability. Secondly, an attention mechanism was added to minimize interference from non-defective areas and bolster the model's focus on defects. Lastly, the regression loss function was modified to SIOU, and orientation consideration was included during network training to boost detection accuracy. Ablation experiments demonstrated the effectiveness of these improvements. With a 20.7% reduction in parameter count, experimental results show that the proposed algorithm achieves a 3.3 percentage point increase in accuracy compared to the YOLOv7 algorithm. Additionally, when compared to other algorithms like YOLOR and YOLOv5m, this algorithm provides optimal detection performance, effectively meeting the requirement for automated detection of surface defects in worm gears.关键词：machine vision;Surface defect detection;YOLOv7;feature pyramid
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发布时间：2024-07-10 - “在点云测量领域，研究者提出了多层级过滤网络MulFNet，有效解决了低重叠率点云匹配失真的问题，为提高测量精度提供了新方案。”摘要：Aiming at the problem of matching distortion caused by structural occlusion， field of view constraints， and stitching errors during point cloud reconstructed， a multi-level filter network （MulFNet） is proposed to achieve single-shot scanning point clouds for low-overlap registration. Firstly， the multi-level features of the point clouds are extracted through the feature pyramid coding network to obtain semantic information at different scales， and the attention module and the location module are embedded to enhance the feature significance； secondly， the multi-level features are filtered based on the multi-scale consistency voting mechanism， outliers are screened out and prominent features of the point clouds are retained to obtain the initial correspondence； and finally， the initial corresponding nodes are adaptively grouped based on the geometric relationships， and weighted estimation conversion is performed from local to global to obtain a prediction matrix based on the multi-level filtering. The experimental results show that the MulFNet is better than the popular networks such as FCGF and PREDATOR on the standard 3DMatch. The registration accuracy of the MulFNet on the scanning dataset with an average overlap rate of 10% is 40.9% and 85.4% higher than the ICP and the GeoTransformer， respectively. It is verified that the proposed network can effectively solve the problem of low-overlap point cloud matching distortion.关键词：point cloud registration;matching distortion;low-overlap point cloud;multi-level filter;partial measurement
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发布时间：2024-07-10 -
Establishment and optimization of aerial multispectral field straw mulch quantity inversion model AI导读
“在农业可持续发展领域，专家通过无人机搭载多光谱相机，利用机器学习算法和优化算法，建立了玉米秸秆覆盖量反演模型，为保护性耕作秸秆还田量检测提供科学参考。”摘要：Conservation tillage is a crucial method for the sustainable development of agricultural arable land and has been adopted worldwide. The quantity of straw mulch is determined not just by its presence but by its amount, serving as a key indicator for detecting straw return to the field. In this study, aerial remote sensing data from the spring and autumn seasons were captured using a UAV equipped with a multi-spectral camera, while the corn straw mulch quantity was measured simultaneously. Spectral reflectance was first extracted, and spectral indices were constructed from the remote sensing data. The correlation coefficient method was then used to identify the band variables and spectral variables sensitive to the straw mulch quantity, which served as model input variables. Subsequently, machine learning algorithms such as support vector machine (SVM), random forest (RF), BP neural network (BPNN), and extreme learning machine (ELM) were employed to establish the inversion model for straw mulch quantity. The accuracy of these models was compared across different time periods and study areas. To address the significant impact of model parameters on predictive performance, genetic algorithm (GA) and particle swarm optimization (PSO) were introduced, culminating in the proposed genetic-particle swarm optimization hybrid algorithm (GA-PSO). This hybrid approach leveraged their complementary strengths to enhance model performance and complete the estimation of straw coverage in the region. The results indicated that the RF algorithm optimized by GA-PSO achieved the best inversion effect for corn straw mulch quantity, with an R² value of 0.74. Comparative analysis of different data sets consistently reflected the straw mulch quantity in the region accurately. The accuracy of estimating the corn straw mulch quantity in the field reached 91.36%, demonstrating that result estimation can be effectively achieved through model optimization. This study provides a scientific reference for detecting straw return in conservation tillage and offers a reliable model inversion method for estimating straw mulch quantity in other crops.关键词：multi-spectral image;machine learning;Straw mulch quantity;UAVs;genetic algorithm;particle swarm algorithm- 49
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发布时间：2024-07-10 - “在提高粘连导电粒子检测精度和稳定性领域，研究者基于圆卷积神经网络提出了一种新方法，通过修改采样策略和增加注意力机制，显著提升了检测效果，满足了工业生产需求。”摘要：To enhance the accuracy and stability of conductive particle detection and to meet actual production demands, a multi-particle detection method based on a simplified deformable convolutional (circular convolutional) neural network is proposed. First, an appropriate model and network are chosen based on the characteristics of the detection task and target. Then, a deformable convolution sampling strategy is introduced and modified to restrict the sampling point offset, with added size control parameters. A circular convolution, more suitable for particle detection, replaces some convolutional layers of the original network. Additionally, an attention mechanism is introduced to calculate self-attention through label graphs, which serve as weight modification loss functions and label graphs. Finally, a comprehensive evaluation algorithm for the accuracy and stability of repeatability and reproducibility indicators is proposed. The results show that the repeatability and reproducibility indicators of our method are 0.809 2 and 0.705 1, respectively, outperforming existing mainstream methods by 4.52% and 1.74%. The accuracy and recall rates are 0.712 8 and 0.697 4, respectively, with an overall accuracy of 0.834 1, surpassing existing methods by 1.68%. Compared to existing mainstream methods, our approach significantly improves the particle detection performance under adhesion interference, meeting industrial requirements for accuracy, stability, and real-time processing.关键词：machine vision;deep learning;neural network;conductive particle detection;circular convolution
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发布时间：2024-07-10
Information Sciences
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