Development of an In-Situ Laser Machining System Using a Three-Dimensional Galvanometer Scanner

In this study, a three-dimensional (3D) in-situ laser machining system integrating laser measurement and machining was built using a 3D galvanometer scanner equipped with a side-axis industrial camera. A line structured light measurement model based on a galvanometer scanner was proposed to obtain the 3D information of the workpiece. A height calibration method was proposed to further ensure measurement accuracy, so as to achieve accurate laser focusing. In-situ machining software was developed to realize time-saving and labor-saving 3D laser processing. The feasibility and practicability of this in-situ laser machining system were verified using specific cases. In comparison with the conventional line structured light measurement method, the proposed methods do not require light plane calibration, and do not need additional motion axes for 3D reconstruction;thus they provide technical and cost advantages. The insitu laser machining system realizes a simple operation process by integrating measurement and machining,which greatly reduces labor and time costs.

Phase Error Compensation of Three-Dimensional Reconstruction Combined with Hilbert Transform

Nonlinear response is an important factor affecting the accuracy of three-dimensional image measurement based on the fringe structured light method.A phase compensation algorithm combined with a Hilbert transform is proposed to reduce the phase error caused by the nonlinear response of a digital projector in the three-dimensional measurement system of fringe structured light.According to the analysis of the influence of Gamma distortion on the phase calculation,the algorithm establishes the relationship model between phase error and harmonic coefficient,introduces phase shift to the signal,and keeps the signal amplitude constant while filtering out the DC component.The phase error is converted to the transform domain,and compared with the numeric value in the space domain.The algorithm is combined with a spiral phase function to optimize the Hilbert transform,so as to eliminate external noise,enhance the image quality,and get an accurate phase value.Experimental results show that the proposed method can effectively improve the accuracy and speed of phase measurement.By performing phase error compensation for free-form surface objects,the phase error is reduced by about 26%,and about 27%of the image reconstruction time is saved,which further demonstrates the feasibility and effectiveness of the method.

Generative deep-learning-embedded asynchronous structured light for three-dimensional imaging

Three-dimensional(3D)imaging with structured light is crucial in diverse scenarios,ranging from intelligent manufacturing and medicine to entertainment.However,current structured light methods rely on projector-camera synchronization,limiting the use of affordable imaging devices and their consumer applications.In this work,we introduce an asynchronous structured light imaging approach based on generative deep neural networks to relax the synchronization constraint,accomplishing the challenges of fringe pattern aliasing,without relying on any a priori constraint of the projection system.To overcome this need,we propose a generative deep neural network with U-Net-like encoder-decoder architecture to learn the underlying fringe features directly by exploring the intrinsic prior principles in the fringe pattern aliasing.We train within an adversarial learning framework and supervise the network training via a statisticsinformed loss function.We demonstrate that by evaluating the performance on fields of intensity,phase,and 3D reconstruction.It is shown that the trained network can separate aliased fringe patterns for producing comparable results with the synchronous one:the absolute error is no greater than 8μm,and the standard deviation does not exceed 3μm.Evaluation results on multiple objects and pattern types show it could be generalized for any asynchronous structured light scene.

Calibration for 3D Structured Light Measurement

A calibration procedure was developed for three-dimensional(3D) binocular structured light measurement systems. In virtue of a specially designed pattern, matching points in stereo images are extracted. And then sufficient 3D space points are obtained through pairs of images with the intrinsic and extrinsic parameters of each camera estimated prior and consequently some lights are calibrated by means of multi point fitting. Finally, a mathematical model is applied to interpolate and approximate all dynamic scanning lights based on geometry. The process of calibration method is successfully used in the binocular 3D measurement system based on structured lights and the 3D reconstruction results are satisfying.

Soft pneumatic actuators by digital light processing combined with injection-assisted post-curing

The soft robotics display huge advantages over their rigid counterparts when interacting with living organisms and fragile objects.As one of the most efficient actuators toward soft robotics,the soft pneumatic actuator(SPA)can produce large,complex responses with utilizing pressure as the only input source.In this work,a new approach that combines digital light processing(DLP)and injection-assisted post-curing is proposed to create SPAs that can realize different functionalities.To enable this,we develop a new class of photo-cross linked elastomers with tunable mechanical properties,good stretchability,and rapid curing speed.By carefully designing the geometry of the cavities embedded in the actuators,the resulting actuators can realize contracting,expanding,flapping,and twisting motions.In addition,we successfully fabricate a soft self-sensing bending actuator by injecting conductive liquids into the three-dimensional(3D)printed actuator,demonstrating that the present method has the potential to be used to manufacture intelligent soft robotic systems.

基于服装个性化智能定制的三维人体测量系统物-像结构算法的研究

目前,我国基于服装个性化智能量身定制的理念日趋完善。但是,在消费者目标尺寸自动获取方面仍然缺乏实用的设备和技术,成为了大多数企业个性化智能定制发展的一个瓶颈,其根本原因是缺少实用性强的个性化智能定制系统。人体动态测量与其他工业产品精密测量相比具有自身独有的特殊性和困难。在探讨了现有的光学类基于个性化智能定制系统的现状的前提下,针对目前存在的激光三维人体扫描测量系统普遍存在硬件设备庞大、结构复杂的问题,对文中提出的基于个性化智能定制系统进行了原理设计,建立了系统的物-像结构算法的数学模型。该算法采用了扫描单元旋转的测量方式,使系统能够在垂直方向上获得较大的测量范围,目的是使系统采用较小的硬件获取满意的三维人体空间坐标,有利于节省竖直空间、减小体积。该算法已成功应用于基于服装个性化智能定制系统。为了验证本算法的精度,设计了与法国力克系统的三维人台对比扫描实验,实验数据验证了本系统结构算法的精度、工程实用性和可靠性。

林区机载LiDAR点云的多分辨率层次布料模拟滤波

针对现有机载LiDAR(light detection and ranging)点云滤波方法在地形起伏剧烈的林区适用性不足的问题,提出一种多分辨率层次布料模拟滤波方法。首先,通过多尺度形态学开运算选择大量种子地面点;然后,基于种子地面点,使用布料模拟法由低至高逐层构建参考地形,以快速获取高分辨率参考地形;最后,基于点至参考地形的高差区分地面点和非地面点。利用国际摄影测量和遥感学会提供的数据集和参考方法,评估该方法性能。利用在中国、美国多个代表性林区的点云数据,评估该方法的可推广性。结果表明,该方法的Kappa系数和运行时间是83.72%和34.11 s,精度和效率较经典布料模拟滤波方法提高10.49%和52.17%。相比8种参考方法,该方法能够获得更高精度,并且具有稳定的可推广性。

Superior performance in visible-light-driven hydrogen evolution reaction of three-dimensionally ordered macroporous SrTiO_(3) decorated with Zn_(x)Cd_(1−x)S

It is of broad interest to develop emerging photocatalysts with excellent light-harvesting capacity and high charge carrier separation efficiency for visible light photocatalytic hydrogen evolution reaction.However,achieving satisfying hydrogen evolution efficiency under noble metal-free conditions remains challenging.In this study,we demonstrate the fabrication of three-dimensionally ordered macroporous SrTiO_(3)decorated with Zn_(x)Cd_(1−x)S nanoparticles for hydrogen production under visible light irradiation(λ>420 nm).Synergetic enhancement of photocatalytic activity is achieved by the slow photon effect and improved separation efficiency of photogenerated charge carriers.The obtained composites could afford very high hydrogen production efficiencies up to 19.67 mmol·g^(−1)·h^(−1),with an apparent quantum efficiency of 35.9%at 420 nm,which is 4.2 and 23.9 times higher than those of pure Zn_(0.5)Cd_(0.5)S(4.67 mmol·g^(−1)·h^(−1))and CdS(0.82 mmol·g^(−1)·h^(−1)),respectively.In particular,under Pt-free conditions,an attractive hydrogen production rate(3.23 mmol·g^(−1)·h^(−1))was achieved,providing a low-cost and high-efficiency strategy to produce hydrogen from water splitting.Moreover,the composites showed excellent stability,and no obvious loss in activity was observed after five cycling tests.

基于机器学习的服装店照明环境指标对氛围感知影响的研究

研究个性化服装店的照明环境与氛围感知的影响规律,并根据不同服装风格提出相应的照明环境优化建议。本文以四种服装风格下的665家服装店作为研究对象,通过主客观调研收集数据,运用方差法、CRITIC赋权等方法对数据进行处理与分析,利用XGBoost归回算法建立照明环境氛围感知预测模型,采用SHAP法解释照明环境指标对氛围感知的贡献程度、相关性及影响规律。可以通过舒适性、活泼性和超然性三个氛围感知维度来评价服装店的照明环境所营造出的氛围感。水平照度是影响舒适性的关键变量,并与之呈负相关;重点照明系数是影响活泼性的关键变量,并与之呈正相关;色温是影响超然性的关键变量,并与之呈正相关。

3D虚拟仿真技术在服装设计中的应用

文章主要探讨了3D虚拟仿真技术在服装设计中的应用。首先介绍了研究的背景、目的和意义,接着概述了服装设计的定义、特点和传统方法。然后详细介绍了3D虚拟仿真技术原理,包括3D建模技术、材质与纹理映射技术以及光照与渲染技术。接着研究了3D虚拟仿真技术在服装设计中的应用,包括在服装设计流程、服装样衣设计和服装配饰设计中的具体应用。

Three-dimensional Flower-like Rutile TiO2 Microsphere Composed of Nanorods： a Potential Material as Light Scattering Layer for DSSCs

The low spectrum utilization and the recombination of photo-generated electrons are the main challengesfor improving the performance of dye sensitized solar cells（DSSCs）. In this article, a three-dimensional flower-likeruffle titanittm dioxide（TDF-TiO2） was successfully synthesized via a simple sol-thermal process. X-Ray diffractionpatterns（XRD） and scan electron microscopy（SEM） images exhibit that the TDF-TiO2 are the futile TiO2 microspherecomposed of lots of regular cuboid nanorods. Applying this TDF-TiO2 as light scattering layer on the photoanode ofDSSCs, the devices present an excellent photovoltage performance, yielding a power conversion efficiency（PCE） of7.69%, which can be mainly attributed to the enhanced light utilization and the reduced recombination of pho-to-generated electrons upon a combined analysis of electrochemical impedance spectroscopy（EIS）, open-circuit vol-tage decay（OCVD）, and intensity-modulated photocurrent spectroscopy and intensity-modulated photo voltage spec-troscopy（IMPS/1MVS）, etc. As a conclusion, TDF-TiO2 is a potential material as light scattering layer and opticaltransition medium to improve the performance of DSSCs, and this work further demonstrated that regulating themorphology and particle size of TiO2 is an efficient approach for enhancing the performance of DSSCs by optimizingthe utilization of light and the transporting behaviors of photo-generated electrons.

轻资产运营模式下财务风险控制研究——以服装企业M公司为例

轻资产运营是一种相对于传统商业模式的创新模式,可以使企业以较低的资本投入实现较高的资本收益。但采用轻资产运营模式的企业有时并不能取得预期效果,在运营过程中可能存在着一些问题,如因质量问题而影响品牌形象、融资方面存在困境、存货和应收账款周转率下降等一系列财务风险。文章以服装行业中最先实施轻资产运营模式的M公司为例,分析其在轻资产运营模式下产生的一些问题,并提出防范风险的措施和建议。

自发光高可视警示服的可视性能评价

为评价自发光警示服的可视性能,采用稀土发光材料、反光材料、发光二极管(light emitting diode, LED)灯带及电激发光(electro luminescent, EL)冷光线制备了2款具有光致发光与电致发光特性的自发光高可视警示服试样。通过可视时间与可视距离测试,对试样的可视性能进行评价。结果表明:时间及距离在很大程度上影响可视性能,相较于距离,时间对可视性能的影响更大,第一代高可视警示服的可视时间与可视效果相关度更高,第二代高可视警示服的发光性能更稳定。

纺织品抗紫外辐射的特征参量与测量

探讨了纺织品的防紫外特性及其测试方法，研究了布料抗紫外能力与各种因素之间的关系．结合大气的紫外特性、皮肤对紫外辐射的生理反应和相应的测试方法，提出了表征布料防紫外性能的特征参量。

轻薄型牛仔布的开发

对新型纺织纤维用于轻薄型牛仔布的设计试织进行了探讨,并对其织物进行性能测试分析,结果表明轻薄型牛仔布体现出了牛仔轻盈、柔软、随意的织物风格和特征。

丝绸表面光老化实验研究

为使可见光区分波段的纺织品老化实验能够进行,研制了一种纺织品分波段光老化实验仪器,并使用该仪器进行了丝绸的可见光区分波段光老化实验,得到一批实验数据。通过对六组未染色的丝绸进行光老化实验数据进行的分析,发现了在可见光区段中,存在几个光老化比较弱的波段,并且找到了丝绸表面光老化现象与受照射光强、波长和照射时间影响的规律。对丝绸表面光老化的情况与光照时的环境温度和湿度之间的关系有了初步的认识,实验结果可为今后纺织类博物馆展览光源的制造和选择提供参考。

光湿复合老化对消防服用织物性能的影响

为进一步探讨多种环境因素对消防服用织物性能的影响,设计光湿复合老化实验,测试织物的表面色差、物理机械性能以及TPP值。结果表明:织物表面色彩随着光照时间的延长而加深;润湿程度越大,色差值也越大(P<0.05);光照时间越长,织物的撕破强力越小(P<0.001),光照60 min后PBI织物的干强保持率最高,约65%,而国产芳纶的仅为50%左右,纬向干强已低于标准值;光老化对断裂强力影响不显著;随着润湿程度的增加,织物的机械强力显著减小(P<0.01),饱和润湿状态下撕破强力减小率最大为55.14%;织物经光湿复合老化后热防护性能反而变好。

LED光环境及服装色彩对消费者行为影响分析

LED光源具有高显色性、高发光效率、寿命长、节能环保等优秀的性能,目前很多服装店已经采用LED进行照明。但服装店在选择照明方式上出现很多问题,比如灯光不能再现服装的真实原貌,消费者的氛围感知不强,消费者购买欲望差。以可调LED光源为基础,针对服装店室内照明场合,分别采用普通照明方式、重点照明方式、局部照明方式和混合照明方式,设计了四种不同物理参量的光环境,借助心理物理实验的语意差别量表法,使用了36组词对组成了主观评价问卷调查表,采用22名观察者模拟消费者(11名男性和11名女性),对相应的四种照明环境的五种颜色服装(黑色、蓝色的男装以及白色、红色和黄色的女装)进行喜好度、吸引度、舒适度和色彩真实度的主观评价。运用差异系数检验了主观评价数据的稳定性与准确性,确定了数据真实有效。采用主成分分析方法,评估了相应的照明方式效果,得到了评价服装店照明环境氛围的基本维度为活泼性(liveness)、舒适度(coziness)和商业性(commercial),通过单因素方差分析方法进一步判断得到活泼性为服装店最重要的基本维度。另外,分析了在四种LED照明光环境下,服装颜色对观察者颜色感知的影响。研究结果表明:在服装店中,普通照明方式由于与传统光源的照明效果相似,消费者的各项评价指标普遍较低,因此普通照明方式不应在服装店中单独使用;对于黑色、蓝色的男装和红色的女装,混合照明方式比其他照明方式更适合,产生的照明效果更能吸引消费者的注意;对于黄色的女装,采用局部照明方式的效果更受消费者喜爱,但是消费者对照明环境采用局部照明方式下的蓝色男装的评价指标很低,所以对于服装店的蓝色服装应该避开使用局部照明方式;对于白色的女装,利用重点照明方式,更能吸引消费者的注意。

基于CPLD的高效冷光源驱动器的设计

利用PIC16F单片机和CPLD技术产生SPWM信号,该信号是一个等幅不等宽的高频脉冲。该SPWM信号经过半桥电路,然后再经过体积小、质量轻的LC滤波器后得到一个850 Hz、110 V的低频大功率信号,以驱动发光布冷光源工作。通过调整半桥电路的输入电平和负载参数使半桥电路工作在能充分导通和截止的工作状态,设计的驱动器工作效率较高,接近90%。

防弹衣的服用发展趋势

目前,防弹衣作为一种重要的防护装备,虽然其防弹性能已经得到了较大的提高,但其对使用者的活动和穿着舒适性有较大的限制和影响。因此,对防弹衣减重和舒适性的研究相当迫切。本文对国内外的防弹衣研究进展情况进行了介绍,并对防弹衣减重及舒适性发展的研究和未来趋势进行了探讨。