最新刊期
- “在古铜镜X光图像融合领域，专家提出了一种新方法，有效保留纹饰细节和病害特征，为古铜镜保护提供新方案。”摘要：A fusion method was proposed to solve the problem that the single-energy X-ray cannot detect the complete decoration and disease information of the corroded ancient bronze mirror due to the uneven thickness of the mirror edge and the mirror center area. The method combined intuitionistic fuzzy set entropy measure and salient feature detection to fuse ancient bronze mirror X-ray images. Firstly， the effective guided filtering was introduced to enhance the contrast of the decorative structure of high-energy X-ray images. Secondly， a three-scale decomposition model was designed by using joint bilateral filtering and structure-texture decomposition strategy. The model extracted the energy layer， residual layer and detail layer information of different energy X-ray images. Then， the energy layer obtained the fused energy image through the
- “最新研究提出EDFDNet去雾网络，有效提升非均匀雾霾图像真实性和可见性。”摘要：Haze in natural environments is usually non-homogeneous and irregular， which has a large impact on computer vision tasks. Therefore， this paper proposes Enhanced-edge-feature Dual-branch Fusion Dehazing Network （EDFDNet）. In order to retain the realism of the image and at the same time effectively improve the visibility after dehazing in the case of severe blurring， the transmission graph fine branch is constructed， which is the premier branch of the network， and the U-shaped network hierarchical codec structure that fuses the discrete wavelet transform is used to extract the multi-scale fine feature information， and the mathematical method for the determination of the enhanced edge information is defined； the feature extraction branch tandemly connects the ResNet residual block and the Transformer combined with dual attention for parallel feature extraction module， which fuses the extracted local and global features， improves the network's ability to understand and process non-uniform haze images， and further restores the visibility of the images， and joins the above two branches into the backbone framework of Generative Adversarial Network （GAN）， and defines a mathematical method to strengthen the determination of edge information. GAN） backbone framework to form the defogging network EDFDNet.The results of the experiments show that the average PSNR and SSIM of this method on the outdoor synthetic dataset are improved by 1.2567 and 0.0308， respectively， compared with the optimal results of the current mainstream methods.Meanwhile， in the test on the real-world dataset， the PIQE， RI， and VI reach the optimal indexes of 21.471， 0.9711 and 0.9003.EDFDNet achieves good results in both realism enhancement and visibility restoration， and is suitable for dehazing real-world non-uniform haze images.关键词：real-world haze;non-homogeneous dehazing;feature fusion;edge feature enhancement;generative adversarial network69|98|0更新时间：2025-01-08
- “在生物细胞工程领域，研究人员设计了柔性并联压电定位台，实现细胞捕获、切割、分离及注射等操作，为细胞级操作提供解决方案。”摘要：In order to achieve cell-level operations such as cell capture， cutting， separation and injection， a flexible parallel piezoelectric positioning stage for biocellular engineering is designed， modeled， simulated and tested in this paper. The positioning stage consists of a moving platform， a base， a three-stage amplification mechanism and three piezoelectric actuators. The displacements generated by the piezoelectric actuators are amplified by the three-stage amplification mechanism， and the precise movement of the positioning stage is realized through feedback control， so as to achieve the target positioning effect. In the design process， the pseudo-rigid-body method combined with the flexible hinge stiffness calculation model is adopted to analyze the kinematic statics of the mechanism. The Lagrange equation is used to establish the dynamics model of the designed flexible parallel piezoelectric positioning stage using the lumped mass method. After determining the structural parameters， finite element analysis is carried out to verify the derived theoretical model， and the simulation results show that the error between the theoretical and simulation models is less than 10%， and the mechanism is able to achieve a large stroke as well as a higher frequency of motion. In addition， a prototype system for the flexible parallel piezoelectric positioning stage is also built and experimentally tested to evaluate its open and closed loop performance. The experimental results show that the designed positioning stage has a working stroke of 125μm×126μm， the natural frequencies in the X- and Y-direction are 128.9 Hz and 132.8 Hz， and the corresponding motion resolution are both better than 400 nm， respectively.关键词：Cell micromanipulation;piezoelectric actuators;flexible parallel mechanism;micro-positioning stage70|82|0更新时间：2025-01-08
- “在图像融合领域，研究者提出了一种低光增强和语义注入式多尺度红外与可见光图像融合方法，有效提升了低光环境下融合图像的质量，有助于提升高级视觉任务的性能。”摘要：Aiming at the problems of unclear texture details and poor visual perception due to neglecting illumination in infrared and visible image fusion under low-light conditions， a low-light enhancement and semantic injection multi-scale infrared and visible image fusion method is proposed. Firstly， a network suitable for low-light enhancement is designed to realize the enhancement of visible image in nighttime scenes by repeated iterations of residual models. Then， a feature extractor based on Nest architecture is used as the encoder and decoder of the network， in which the deep features can capture the complex structure and semantic information of the images， a semantic prior learning module is designed to further extract the semantic information of the deep infrared and visible images through cross-attention， and a semantic injection unit is adopted to inject the enhancement features into each scale step by step. Thirdly， a gradient enhancement branch is designed， where the mainstream features are firstly passed through the hybrid attention， and then the Sobel operator stream and Laplacian operator stream are divided from the mainstream as a way to enhance the gradient of the fused image. Finally， the features at each scale are reconstructed by dense connections between the same layers and jump connections between different layers in the decoder. Experimental results show that this method improves the visual information fidelity， mutual information， disparity correlation coefficient， and spatial frequency， on average， by 23.1%， 16.3%， 18%， and 39.8%， respectively， in comparison with the nine methods， which effectively enhances the quality of fused images in low-light environments， and helps to improve the performance of the advanced visual tasks.关键词：infrared and visible image fusion;multiscale fusion networks;low-light enhancement;cross-attention;semantic injection57|81|0更新时间：2025-01-08
- 摘要：In order to realize the detection and control of 3D printed pieces and improve their printing accuracy， the research of 3D reconstruction of 3D parts and position estimation is completed. The system is based on the peripheral scanning visual detection principle of binocular structured light， adopts binocular structured light illumination， and takes the peripheral scanning imaging mode of dual-color camera to realize image acquisition and visual calibration through the color and infrared scene at different positions， binocular vision and scattered structured light depth information， etc. It completes the image processing and analysis， such as image fusion， point cloud coloring， multi-frame point cloud alignment fusion， segmentation， etc.， so as to realize the reconstruction of object field Point cloud reconstruction. The camera position estimation scheme based on EPNP and ICP algorithms is adopted， and the EPNP algorithm completes the coarse alignment of the reconstructed object scene point cloud and single-view point cloud， while the ICP algorithm completes the fine alignment of the reconstructed object scene point cloud and single-view point cloud to obtain the position estimation of the target. The accuracy of 3D printed pieces’ 3D reconstruction is evaluated by calculating the chamfer distance between the scene point cloud and the standard point cloud， and the average accuracy is 0.675mm； the accuracy of position estimation is evaluated by the reprojection method， and the average accuracy is 1.669mm.Through the systematic research， a better evaluation method is provided for the printing inspection of 3D pieces， and a better reference is provided for the subsequent inspection and control of the accuracy of 3D pieces.关键词：Machine Visualization;3D reconstruction;position estimation;image processing;EPNP;ICP50|57|0更新时间：2025-01-08
- “在水下图像增强领域，研究人员提出了融合域迁移和注意力机制的模型，有效提升了图像质量，色彩恢复更自然，细节增强效果显著。”摘要：Due to the attenuation and scattering of light in an underwater environment， the images directly captured by imaging equipment suffer from significant quality degradation. Although learning-based underwater image enhancement methods improve the original image imaging quality to a certain extent， most of the existing methods use artificially synthesized or model-generated paired datasets for training. Meanwhile， there is a large domain difference between artificial or model-generated images and real underwater images in distribution， which leads to problems of excessive enhancement and no obvious removal of color shift in the enhancement results. Focus on these problems， an underwater image enhancement model that integrates domain transfer and attention mechanism has been proposed in this paper. First， an image generation network with domain transfer is designed， and combined with the physical imaging model and the water type classifier. In this way， the feature description mapping between images in different domains and scenarios could be learned， hence reducing the difference between the generated images and the real images. Furthermore， a multi-scale hybrid attention encoder-decoder network is designed. With the help of efficient feature connections and different attention fused structures， the image local details recovery ability of the model could be improved. Finally， a global domain association consistency loss function is proposed to better train the network model parameters and improve the quality of image enhancement by constructing content and structure consistent associations of the generated images at each stage of the domain transfer. The proposed model achieved accuracies of 3.1401， 0.6021 and 3.0768， 0.6124 for the UIQM and UCIQE metrics on the underwater real datasets UIEB and EUVP， respectively. The experiments show that the proposed model could effectively improve the color recovery ability of underwater images， and more details could be recovered.关键词：underwater image enhancement;domain transfer;generative adversarial networks;Attention enhancement77|94|0更新时间：2025-01-08
- “在伺服电机位置检测领域，专家提出了一种新方法，有效提升了测量精度，为该技术发展奠定了基础。”摘要：The stator slot of servo motor leads to the unequal amplitude of the output signal of TMR in two orthogonal positions. Unequal amplitude affects the measurement accuracy in the position detection theory of servo motor based on time-gate technology. Based on the structural characteristics of the motor stator， a servo motor position detection method is proposed， which can effectively improve the precision of the motor rotor position detection. One pair of sensing probes are placed symmetrically and orthogonally on both sides of the symmetry axis of the stator teeth to achieve equal output signal amplitude. The other pair of sensing probes are positioned symmetrically and orthogonally at intervals of （2n+1） λi/2 （n = 0， 1， 2， 3…） degree， which can reduce the influence of harmonic components of magnetic field generated by motor stator winding. Meanwhile， waveform reconstruction method is used to eliminate the corresponding i harmonic component. Based on the above method， the signal amplitude is equal and the phase is orthogonal， which can effectively improve the accuracy. Simulation results demonstrate the effectiveness of the sensor structure based on the new error compensation method. The experimental results show that compared with the single pair probe which only satisfies the space orthogonal condition， the amplitude of the signal output by symmetrical structure sensors after compensation is equal， and the third harmonic component is reduced by 73.8%， The accuracy has been improved by 6 times. This method illustrates the obvious advantage in the accuracy of the motor rotor position detection.关键词：servo motor;time grating;position detection;error compensation;waveform reconstruction53|59|0更新时间：2025-01-08
- 摘要：Telecentric imaging has the advantages of stable magnification， large depth of field and low distortion， which has attracted much attention in the field of three-dimensional precision measurement. However， due to manufacturing limitations， the aperture stop of a telecentric lens cannot be perfectly positioned at the focal plane， allowing light rays with slight angular deviations from the optical axis to enter， thereby introducing measurement errors. To address this issue， a telecentric 3D reconstruction model based on calibration parameter correction is proposed. The theoretical analysis of the causes of telecentric optical path non-ideality leads to the construction of a system calibration parameter model related to the imaging depth， which compensates for the measurement error caused by optical path non-ideality. Based on the calibration parameters of the focal plane， the mathematical polynomial expression between the radial distortion coefficient and the imaging depth is established based on the control variable method and the least squares fitting algorithm. A random sampling consistency algorithm is employed to filter out the phase noise， and the phase-depth mapping relationship is established based on the polynomial model. During the process of three-dimensional reconstruction， the radial aberration coefficients are corrected based on the depth information determined from the absolute phase， thereby achieving high precision in the reconstruction of the lateral size. In the calibration plate and standard ball experiments， the measurement error of the measured line segment was reduced from 28.8 μm to 4.8 μm， and the measurement error of the diameter of the standard ball was reduced from 35.2 μm to 8.1 μm， thereby verifying the feasibility and necessity of the proposed scheme. This method provides an effective parameter correction idea for the precise measurement of the telecentric optical path system， and enriches the telecentric three-dimensional measurement technology.关键词：telecentric imaging;three-dimensional imaging;precision measurement;stripe projection profilometry43|67|0更新时间：2025-01-08
- 摘要：In order to improve the detection performance and integration of TDLAS detection system， A TDLAS system based on a portable adjustable optical path length cylindrical mirror multi-pass cell was designed， which achieved the simulated optical path length of 14 m， 10.6 m， 9.2 m， 7.1 m and 5.8 m. To reduce the impact of noise generated during gas measurement in TDLAS system on detection accuracy and sensitivity， the Variational Mode Decomposition （VMD） wavelet denoising algorithm optimized by the Northern Goshawk Optimization （NGO） was proposed. The simulation results showed that compared with other algorithms， the NGO-VMD wavelet denoising algorithm could effectively reduce noise without causing signal distortion. The performance of the system was evaluated by testing CH4 using a DFB laser with the central wavelength of 1.653 μm based on direct absorption detection technology. The results showed that the signal-to-noise ratio of the detection signal was increased from 66 to 109， and the lower detection limit of the system was improved from 12.1 ppm to 7.28 ppm. Allan analysis of variance showed that the optimal detection sensitivity of the system was improved from 641 ppb to 526 ppb at the integration time of 263 s after optimization with the NGO-VMD wavelet algorithm. The finding provided a reference for improving the performance of TDLAS trace gas detection system.关键词：TDLAS;direct absorption;Adjustable optical path length;Northern Goshawk Optimization Algorithm;variational mode decomposition43|60|0更新时间：2025-01-08
- 摘要：In order to improve the accuracy and efficiency of defect detection in power equipments， a time-division infrared polarization imaging system is constructed， combining a long-wave infrared detector and a polarizer. For electric transmission lines， multi-channel image acquisition is realized by controlling the polarizer rotation. Then， the polarization images with different channel numbers and different polarization angle intervals are evaluated using three parameters， i.e. root mean square error （RMSE）， peak signal-to-noise ratio （PSNR） and mean structural similarity （MSSIM）， respectively. The experimental results show that as the number of channels increases from 3 to 18， the image quality is gradually improved， especially in the range of 4 to 9 channels， where the improvement of imaging quality is most significant. However， further increasing the number of channels does not have a significant effect on the image quality， which leads to redundant calculations； for 3-channel polarization images， small angular intervals are able to capture the detailed information of fine targets， while large angular intervals are able to effectively separate the target from the background and reduce the noise interference， which are both suitable for some specific application scenarios. The experimental results are instructive for the polarization channel selection strategy of infrared polarization imaging.关键词：Power Inspection;Long-wave infrared （LWIR）;Time-division infrared polarization imaging system;Polarization channel;Stokes vector50|65|0更新时间：2025-01-08
- “在机器人协同作业领域，专家提出了一种两步法手眼标定方法，显著提高了标定精度和三维拟合精度。”摘要：MethodThe method utilizes a commonly available standard ball as the calibration object， and constructs the solution equations according to the characteristic of the ball center coordinates being constant in the robot coordinate system by changing the attitude once and translating once in a special measurement way， and solves the direction and position matrices independently by associating the solution equations in different attitudes.ResultThe experimental results show that the standard deviations of the spherical center coordinates in the X and Y directions of the two-step method are 0.3249 mm and 0.2462 mm， respectively， which are 29.5% and 61.5% higher than those of the one-step method of 0.4608 mm and 0.6391 mm， respectively. In addition， in the sphere fitting experiments， the difference between the radius of the sphere fitted by the two-step method and the nominal radius of 14.996 mm is 0.019 mm， while that of the one-step method is 0.278 mm， which is a higher fitting accuracy of the two-step method.ConclusionThe two-step hand-eye calibration method proposed in this paper significantly improves the calibration accuracy and 3D fitting accuracy compared to the one-step method.ObjetiveIn order to improve the accuracy of hand-eye calibration in the cooperative operation between line laser profilers and robots， a calibration method based on the two-step method is proposed.关键词：hand-eye calibration;Line laser profiler;Calibration sphere;Homogeneous transformation matrix62|200|0更新时间：2025-01-08
- 摘要：Microfiber leather is a high-end composite material， and its defect detection is critical for ensuring product quality. To address the challenges posed by the multi-scale， diverse aspect ratios， and numerous small defects on the surface of microfiber leather， the MFL_YOLOv8 algorithm for surface defect detection was proposed in this study. The MFL_YOLOv8 algorithm first introduces the multi-scale feature extraction module DCNv3-LKA based on the Deformable Large Kernel Attention （DLKA） mechanism， to significantly enhances the backbone network's multi-scale feature extraction capabilities. Subsequently， the incorporation of a P2 feature map and a Dysample upsampling module in the feature pyramid network strengthens the network's ability to extract detail information from small targets. Finally， the Minimum Points Distance Intersection over Union （MPDIoU） is utilized to mitigate the inefficacy of the loss function on small targets during the initial stages of training， thus improving the detection performance for small targets. Experimental results on a self-constructed microfiber leather surface defect dataset demonstrate that the proposed algorithm achieved 92.47% of average detection precision and 92.40% of average detection recall， with improvements of 5.38% and 7.27% compared to YOLOv8n. Additionally， the algorithm attainsed a frame rate of 135.2 frames per second （FPS）， meeting the accuracy and real-time requirements for industrial applications.关键词：Microfiber leather;defect detection;DCNv3-LKA;MPDIoU53|113|0更新时间：2025-01-08
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Development of bi-directional high overload silicon-based differential pressure sensitive element AI导读
“在差压传感器领域，研究人员设计了梁-群岛错位膜结构差压敏感元件，有效提高了双向过载能力。”摘要：In order to improve the bidirectional overload capability of differential pressure sensors， a beam-archipelago dislocated membrane structure differential pressure sensitive element is designed in this paper. The sensitive element consists of a beam-archipelago silicon membrane structure bonded to a glass substrate. The beam structure reduces the stress concentration and the archipelago structure improves the structural rigidity； the glass substrate is designed with square grooves and circular through holes on the bonding surface， and the dislocation structure formed by the square grooves of the silicon membrane structure and the glass substrate further reduces the maximum stress. Firstly， the stress distribution， full scale output and maximum stress of the bi-directional high overload silicon-based differential pressure sensitive element were analyzed by finite element software. Secondly， the relationship between structural dimensions and burst pressure was analyzed， and the structural dimensions at maximum burst pressure were solved by dimensional optimization. Finally， a silicon-based differential pressure sensitive element with bi-directional high overload was fabricated by MEMS silicon process. The pressure test results show that the fabricated bi-directional high overload silicon-based differential pressure sensitive element has a burst pressure of 8.5 times scale， which is 30.7% higher overload capacity compared with the traditional C-type membrane structure differential pressure sensitive element （burst pressure 6.5 times scale）. The experimental results demonstrate that the beam-archipelago dislocation membrane structure can effectively improve the bidirectional overload capacity of the differential pressure sensitive element.关键词：MEMS;Differential pressure sensitive element;finite element;size optimization;Overload capacity44|57|0更新时间：2025-01-08 - “在精密测量领域，研究者设计了一种新型绝对式平面二维时栅位移传感器，通过多频磁场耦合技术，实现了无需上电找零的一体式二维绝对位移测量与定位，有效测量范围达147毫米乘147毫米，X、Y方向原始测量误差控制在20微米左右。”摘要：Aiming at the problem that incremental planar two-dimensional （2-D） time-grating displacement sensors need to be zeroed when they are powered up， an absolute planar 2-D time-grating displacement sensor based on multi-frequency magnetic field coupling is designed， which adopts time-driven excitation signals of different frequencies to reduce the power consumption of the sensor circuit and at the same time make the decoupling of signals in the X and Y directions and the 2-D absolute position solving simpler and more reliable. Firstly， a mathematical model of magnetic field distribution of the excitation coil is established， and the relationship between the width of the excitation coil and the height of the coupled air gap is analyzed according to the characteristics of the spatial magnetic field distribution； based on the incremental 2-D time-grating displacement sensor structure of the differential structure， an absolute planar 2-D time-grating measurement model of the opposite poles reciprocal structure is established， and a new scheme for the 2-D absolute position solution based on the look-up table method is proposed， which avoids the influence of the measurement error on the solution result in the practical application； the feasibility of this solution is verified by electromagnetic field simulation， and the optimal installation gap of the sensor is determined to be 0.8 mm； finally， the sensor prototype is fabricated， and the 2-D precision experimental platform is constructed for performance testing. The experimental results show that the sensor prototype in the effective measuring range of 147 mm x 147 mm， the original measurement errors in the X and Y directions are ±20.4 μm and ±21.1 μm， respectively， and it has the advantages of no need to find the zero point on power-on， which realizes the all-in-one 2-D absolute displacement measurement and positioning.关键词：multifrequency magnetic field;antipolar prime;absolute two-dimensional;time-grating displacement sensor138|130|0更新时间：2024-09-30
- “在雷视监控设备测速领域，研究者提出了一种影像优先与二三维视图一体的多目标连续追踪测速方法，有效解决了视角差异导致的点云目标检测混淆问题，提高了测速准确性和实用性。”摘要：To overcome the differences in acquisition frequency， resolution， and viewing angle between laser and camera-based speed estimation tasks in camera-LiDAR surveillance systems， this paper proposes an image-priority approach integrated with 2D-3D views for multi-target continuous tracking and speed estimation. Initially， geometrically matched feature points are uniformly selected from the scene， and the external parameters are computed using the Direct Linear Transformation method for online calibration between the LiDAR and the camera. Subsequently， a vision-guided frustum-based spatial approach for combined 2D-3D target localization is introduced. By leveraging high-resolution ground points to compute area boundaries， the method preliminarily removes background points and then adaptively calculates clustering parameters in a 2D top-down view transformed from the frustum's 3D perspective. Then， the 2D densest voxel guides the selection of the 3D initial seed point to complete clustering and localization， effectively eliminating irrelevant points and addressing the issue of mixed-resolution point cloud target detection caused by varying viewing angles. Finally， based on Kalman filtering and considering vehicle motion states， the speed estimation process is modeled as observation equations using discrete synchronized frame point cloud localization results. The observation noise covariance matrix is estimated based on point cloud resolution， enabling continuous optimal estimation of discrete speed measurements to mitigate the effects of observation noise and asynchronous timing between the two devices. Experimental results conducted on common traffic scene image and point cloud datasets demonstrate that the proposed method achieves an average absolute error of 0.2764 m/s and a root mean square error of 0.3251 m/s， with a maximum detection range of 103.211 m， indicating high accuracy and practicality.关键词：Intelligent transportation;Speed estimation;Frustum;data fusion;kalman filtering;object detection118|126|0更新时间：2024-09-12
- “在光电瞄准吊舱领域，专家定义了四个评价标准，对多国典型产品进行了对比分析，揭示了技术趋同化特点，为提升功能密度和技术水平提供参考。”摘要：The overseas turret-type electro optical （EO） targeting pods have been subdivided into different generations， therefore， the main technical characteristics of typical third-generation pods have been introduced. Four different evaluation criteria for measuring their integration degree have been defined： the ratio of the aperture of the optical aperture to the diameter of the turret， the cube of the aperture of the optical aperture to the weight of the system， the cube of the diameter of the pod to the weight of the system， and the ratio of the weight of the payload to the weight of the system， so as to achieve the quantitative evaluation of the functional density or technological level of the EO targeting pods of similar performances at the macroscopic level. The development status of typical equipment is introduced， focusing on the corporations of typical products such as the American MTS-B pod， Turkish ASELFLIR350 pod and the subsequent ASELFLIR400/500， Canadian MX-15D pod， French EUROFLIR410 pod and German ARGOS II HDT， etc.， and their respective technical styles， characteristics and core payloads are introduced. A forward design evaluation verifies the performance of MTS-B front telescope system and ASELFLIR350 turret's optical payload. Several assimilated technical features of modern EO targeting pods are summarized： the optical-mechanical architecture of multi-band common aperture catadiopatric main system + side-axis small aperture sub-systems is gaining consensus； the laser detection technology of multiple wavelengths is increasingly inclined to the direction of active optics； composite-axis control technology based on the combination of multi-axis， multi-frame platforms and fast steering mirrors （FSM） is gaining popularity； the enhancement of target detail areas is acquiring more attention， and multi-band image fusion information processing technology is becoming more and more important.关键词：EO targeting turret;multiband common optical aperture;front telescope system;Composite axis control;see spot165|971|0更新时间：2024-09-12
- 摘要：MethodThe influence of the adding electric field with parallel direction of the axis of the fiber on the dispersion， effective mode field area， and non-linearity coefficient is simulated by using the finite element method （FEM）， the evolution of optical pulse transmission in optical fiber is investigated， and the tunability of the axial electric field on the spectral width and coherence of the supercontinuum spectrum is analyzed.ResultThe results reveal that the spectral width and tunable range of the supercontinuum spectrum in the fiber with a filling factor of 0.6 is greater than that with other filling factors at the same pump. When injecting a pump pulse with a peak power of 5 kW， a pulse width of 100 fs， and a central wavelength of 3.5 μm into the fiber， the output supercontinuum spectral width reaches 2.2420 μm for an electric field strength of 40 × 108 V/m， an increase of 176.30 nm over that without the electric field. As the adding electric field causes the coherence factor of the supercontinuum to converge to 1 at longer wavelengths， it also contributes to the coherence of the supercontinuum.ConclusionMid-infrared supercontinuum light sources with continuously tunable spectral width can be obtained and have potential applications in fields such as sensing detection and biomedicine.ObjetiveIn order to make the spectral width of the mid-infrared supercontinuum spectrum continuously tunable， a chalcogenide photonic crystal fiber （PCF） with As2S3 matrix material and LiNbO3 crystal auxiliary rods， whose optical axis is running along the axial direction of the fiber， is proposed.关键词：photonic crystal fiber;supercontinuum;tunable spectrum;LiNbO3;As2S3103|75|0更新时间：2024-08-07
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High-precision adaptive fractional order sliding mode tracking control for piezoelectric platform AI导读
“在压电平台控制领域，研究者提出了自适应分数阶滑模跟踪控制方法，有效解决了迟滞问题，显著提升了指令跟踪精度。实验结果表明，该方法将跟踪误差降低了80%以上，平均误差降至0.41微米。”摘要：To realize the high-precision command tracking control of the piezoelectric platform， an adaptive fractional order sliding mode tracking control method is proposed in this paper to address the serious hysteresis problems. At first， the fractional order operator and adaptive law based on the Duhem model are introduced into the design of the sliding mode surface. It increases the degree of freedom variability of the sliding mode surface and achieves the adaptive adjustment of parameters. Next， an uncertainty and disturbance estimation technique is proposed to replace the traditional switching term of the sliding mode controller， which solves the chattering problem of the sliding mode controller and improves its robustness. Finally， the experimental results of the command tracking control of the piezoelectric platform show that compared with traditional PID and sliding mode control method， the tracking error of the adaptive fractional order sliding mode controller has decreased by more than 80%， and the root mean square tracking error of the piezoelectric platform based on adaptive fractional order sliding mode controller is reduced to 0.41μm under the reference command signal at 50 Hz. Therefore， the adaptive fractional order sliding mode controller has more superior tracking performance.关键词：Piezoelectric platform;Hysteresis nonlinear;Adaptive control;fractional order;sliding mode control101|181|0更新时间：2024-07-15 - “在协作机器人精准力控领域，研究人员利用谐波减速器柔轮变形研制了一种原位集成转矩传感器，并提出了基于傅里叶级数模型的剩余纹波补偿方法以提高测量精度。通过分析柔轮底部应变规律，设计了应变敏感栅结构，并建立纹波与波发生器角度之间的傅里叶级数模型进行补偿。测试结果表明，该补偿方法能有效降低剩余纹波对传感器输出的干扰，为关节转矩精准测量的实现提供了解决方案。”摘要：In order to achieve precise force control of collaborative robot， an in-situ integrated torque sensor is developed by using the deformation of the flexspline of the harmonic reducer.. Proposed a residual ripples compensation method based on Fourier series model to improve measurement accuracy. Firstly， the strain law at the bottom of the flexspline was analyzed， and the sensitive grid structure of the strain gauge was designed based on the principle of sinusoidal superposition； Then the Fourier series model between the remain ripples and the angle of the wave generator was established to compensate the residual ripple； Finally， a test platform is developed for loading test， the results show that the output errors of the self-made torque sensor and the standard torque sensor are 0.988% and 0.253% when the instantaneous excitation and step load are applied under the static state of the wave generator； Under the rotating state of the wave generator， three kinds of loads， i.e. step change， sinusoidal change and man-made collision in the process of sinusoidal change， are applied. The output errors between the self-made torque sensor and the standard torque sensor are 3.822%， 4.247% and 4.456%. The compensation method proposed in this paper can effectively reduce the interference of residual ripple on the sensor output， which is conducive to the realization of accurate measurement of joint torque.关键词：torque sensor;harmonic reducer;Fourier series;error compensation119|259|0更新时间：2024-05-30
- “一项关于水下导航的研究取得了重要进展。该研究提出了一种利用偏振分布模式获取水下载体航姿信息的方法，为水下导航提供了新的解决方案。研究团队通过在载体上安装鱼眼镜头与偏振相机，拍摄水下天空图像，得到偏振角分布模式。利用小孔成像模型，对相机参数进行标定，对偏振角分布模式进行畸变校正，进而得到太阳子午线特征区域。通过Canny算子和霍夫直线检测算法，计算出太阳子午线与水下载体体轴的夹角，从而得到航向角。为减小测量误差，研究团队还建立了光入射角与偏振角误差的函数关系，进行误差补偿。此外，利用灰度阈值检测算法筛选出图像中的天顶点坐标，进而计算载体的横滚角和俯仰角。实验结果表明，该方法得到的航向角平均绝对误差为0.5303°，横滚角和俯仰角在[-50°, 50°]范围内的平均绝对误差分别为0.7544°和0.6213°，满足水下导航的精度需求。这一研究为水下导航技术的发展提供了新的思路和方法，有望为水下机器人等水下载体的自主导航和智能控制提供有力支持。”摘要：This paper proposes a method to observe the celestial polarization pattern and the coordinate of zenith through Snell’s window， which consequently yields the navigation information of the carrier， i.e.， yaw angle， roll angle， and pitch angle. A fish-eye lens and an imaging polarimeter are installed on the carrier to capture the sky and obtain the celestial polarization pattern. First， a pinhole imaging model is established to obtain both the internal and external parameter matrices of the camera and the distortion coefficients of the lens. A distortion correction is applied to the polarization pattern to obtain the solar meridian characteristic region. A Canny operator is used to detect the edge of the characteristic region， after which a Hough line detection algorithm is used to calculate the angle between the solar meridian and the carrier’s axis， yielding the Yaw angle. Second， the relationship between incidence angles and the error of polarization angle is abstracted as a function through experiments. Error compensation based on the function is performed to reduce the measurement error of the polarization angle caused by changes in the incident light polarization state of the fish-eye lens， hence improving the accuracy of measuring the angle between the solar meridian and the carrier axis. Third， the grayscale threshold detection algorithm is used to calculate the coordinates of the zenith in the image， and therefore the roll and pitch angles of the carrier. The accuracy of the algorithm is verified through experiments. Lastly， an experimental platform is constructed to simulate an underwater environment. Results show that the mean absolute error of the yaw angle calculated by this method is 0.5303°. Within the range of ［-50°， 50°］， the mean absolute error of the roll angle and pitch angle are 0.7544° and 0.6213°， respectively， which meets the accuracy requirements of underwater navigation.关键词：Underwater navigation;Snell window;Polarization distribution;image processing143|187|0更新时间：2024-05-06
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