A Systematic Review of Computer Vision Techniques for Quality Control in End-of-Line Visual Inspection of Antenna Parts

The rapid evolution of wireless communication technologies has underscored the critical role of antennas in ensuring seamless connectivity.Antenna defects,ranging from manufacturing imperfections to environmental wear,pose significant challenges to the reliability and performance of communication systems.This review paper navigates the landscape of antenna defect detection,emphasizing the need for a nuanced understanding of various defect types and the associated challenges in visual detection.This review paper serves as a valuable resource for researchers,engineers,and practitioners engaged in the design and maintenance of communication systems.The insights presented here pave the way for enhanced reliability in antenna systems through targeted defect detection measures.In this study,a comprehensive literature analysis on computer vision algorithms that are employed in end-of-line visual inspection of antenna parts is presented.The PRISMA principles will be followed throughout the review,and its goals are to provide a summary of recent research,identify relevant computer vision techniques,and evaluate how effective these techniques are in discovering defects during inspections.It contains articles from scholarly journals as well as papers presented at conferences up until June 2023.This research utilized search phrases that were relevant,and papers were chosen based on whether or not they met certain inclusion and exclusion criteria.In this study,several different computer vision approaches,such as feature extraction and defect classification,are broken down and analyzed.Additionally,their applicability and performance are discussed.The review highlights the significance of utilizing a wide variety of datasets and measurement criteria.The findings of this study add to the existing body of knowledge and point researchers in the direction of promising new areas of investigation,such as real-time inspection systems and multispectral imaging.This review,on its whole,offers a complete study of computer vision approaches for quality control in antenna parts.It does so by providing helpful insights and drawing attention to areas that require additional exploration.

Relative Varying Dynamics Based Whole Cutting Process Optimization for Thin‑walled Parts

Thin-walled parts are typically difficult-to-cut components due to the complex dynamics in cutting process.The dynamics is variant for part during machining,but invariant for machine tool.The variation of the relative dynamics results in the difference of cutting stage division and cutting parameter selection.This paper develops a novel method for whole cutting process optimization based on the relative varying dynamic characteristic of machining system.A new strategy to distinguish cutting stages depending on the dominated dynamics during machining process is proposed,and a thickness-dependent model to predict the dynamics of part is developed.Optimal cutting parameters change with stages,which can be divided by the critical thickness of part.Based on the dynamics comparison between machine tool and thickness-varying part,the critical thicknesses are predicted by an iterative algorithm.The proposed method is validated by the machining of three benchmarks.Good agreements have been obtained between prediction and experimental results in terms of stages identification,meanwhile,the optimized parameters perform well during the whole cutting process.

Joint optimization of maintenance inspection and spare provisioning for aircraft deteriorating parts

With the wide application of condition based maintenance(CBM) in aircraft maintenance practice, the joint optimization of maintenance and inventory management, which can take full advantage of CBM and reduce the aircraft operational cost, is receiving increasing attention. In order to optimize the inspection interval, maintenance decision and spare provisioning together for aircraft deteriorating parts, firstly, a joint inventory management strategy is presented, then, a joint optimization of maintenance inspection and spare provisioning for aircraft parts subject to the Wiener degradation process is proposed based on the strategy.Secondly, a combination of the genetic algorithm(GA) and the Monte Carol method is developed to minimize the total cost rate.Finally, a case study is conducted and the proposed joint optimization model is compared with the existing optimization model and the airline real case. The results demonstrate that the proposed model is more beneficial and effective. In addition, the sensitivity analysis of the proposed model shows that the lead time has higher influence on the optimal results than the urgent order cost and the corrective maintenance cost, which is consistent with the actual situation of aircraft maintenance practices and inventory management.

Program Design of Graphic Realism Displaying System Based on DXF Lathe Turning Rotational Parts

For virtually realizing the graphic realism display of DXF machine parts, in AutoCAD2007 graphic drawing environment, an interactive experimental method was taken to realize the display of graphic in DXF, which was taken as the data-exchanged interface and source. Based on depth analysis of DXF data structure, take one drawing of DXF lathe turning rotational part asthe test piece. By VC＋＋6.0 programming, part＇s geometry information could be obtained. Through data processing, 3D data of the test piece could be generated, which is based on 2D data of DXF test piece. Then, OpenGL graphic processing technologies （light, material, texture, map, et al.） were applied on the 3D display of test piece from DXF files or program modules. Finally based on the test report, results of the system functions were shared to prove the realization of system design, and the feasibility of algorithms used. In the developed software, Machine Designers could get a full view of machine parts, and do some proper modifications. The study content and results of our work have some theory and practical significance on the application of program design in the practical projects.

Grinding/Cutting Technology and Equipment of Multi-scale Casting Parts

Multi-scale casting parts are important components of high-end equipment used in the aerospace,automobile manufacturing,shipbuilding,and other industries.Residual features such as parting lines and pouring risers that inevitably appear during the casting process are random in size,morphology,and distribution.The traditional manual processing method has disadvantages such as low efficiency,high labor intensity,and harsh working environment.Existing machine tool and serial robot grinding/cutting equipment do not easily achieve high-quality and high-efficiency removal of residual features due to poor dexterity and low stiffness,respectively.To address these problems,a five-degree-of-freedom(5-DoF)hybrid grinding/cutting robot with high dexterity and high stiffness is proposed.Based on it,three types of grinding/cutting equipment combined with offline programming,master-slave control,and other technologies are developed to remove the residual features of small,medium,and large casting parts.Finally,the advantages of teleoperation processing and other solutions are elaborated,and the difficulties and challenges are discussed.This paper reviews the grinding/cutting technology and equipment of casting parts and provides a reference for the research on the processing of multi-scale casting parts.

FRACTURE LIMIT LOAD OF CONE SHAPE PART IN DRAWING PROCESS

The deformation characters and load status of the blank＇s potential fracture zone are analyzed at the moment when blank is approaching to punch comer in drawing process of cone shape part. Based on tension instability theory, the formula for calculating fracture limit load of cone shape part in drawing process is derived. Also, the formula is analyzed and verified by experiment.

Characteristics of a Short-Term and Imminent Earthquake Precursor Field in the Northern Part of North China and Numerical Simulation of Source Process

According to studies of more than 20 earthquakes with MS≥5.0 in North China, seven features of the short-term and imminent earthquake precursors have been summarized in this paper. At the same time, taking the short-term and imminent earthquake stage as the physical process of a source’s medium softening and fault creep, we calculated temporal variation of mean stress, maximum shear stress, body strain, and pore pressure in some certain points (supposed stations) in the source area and its adjacent area by using an anisotropic and nonlinear source model and a finite element method. According to an analysis of these theoretical curves, we conclude that the short-term and imminent earthquake precursors have such characteristics as complex shapes, exponential growth of the precursor number with tune, and precursors’ migration from the outside area to the source area, which to a certain extent reveal the cause of the characteristics of the short-term and imminent earthquake precursor field.

基于PartMaker的车铣复合加工技术

车铣复合加工在现代数控加工技术中,发挥着日益重要的作用。针对典型结构件,研究了基于PartMaker的车铣复合加工技术。以典型的轴类零件为例,首先,选择加工机床,进行工艺设计;然后,利用PartMaker软件,编制数控程序并进行后置处理,生成机床加工程序,利用VERICUT软件构建了加工仿真模型,并对机床程序进行了仿真加工;最后,通过实际加工得到了合格的零件,验证了加工方法的可行性。

Application of ~1H NMR-based metabolomics for discrimination of different parts and development of a new processing workflow for Cistanche deserticola

Cistanche deserticola(CD) is one of the two authoritative source plants of Cistanches Herba, a well-known medicinal plant. Herein,~1H NMR spectroscopy was employed to characterize the chemical profile and to distinguish the different parts, as well as to propose a new processing workflow for CD.Signal assignment was achieved by multiple one and two dimensional NMR spectroscopic techniques in combination with available databases and authentic compounds. The upper parts of the plant were distinguished from the lower parts by combining ~1H NMR spectroscopic dataset with multivariate statistical analysis. A new processing method that hyphenated steaming with freeze-drying, was demonstrated to be superior to either steaming coupled with oven-drying or direct freeze-drying via holistic ~1H NMR-based metabolomic characterization. Phenylethanoid glycosides, mainly echinacoside and acteoside, were screened out and confirmed as the chemical markers responsible for exhibiting the superiority of the new processing workflow, whereas serial primary metabolites, especially carbohydrates and tricarboxylic acid cycle metabolites, were found as the primary molecules governing the discrimination between the upper and lower parts of the plant. Collectively,~1H NMR spectroscopy was demonstrated as a versatile analytical tool to characterize the chemical profile and to guide the indepth exploitation of CD by providing comprehensive qualitative and quantitative information.

Assessing Strategy of Power Transformers Insulation State Based on Part-division and Entropy Method

Failure mechanisms of power transformers are complex and uncertain; it is difficult to determine index weights of insulation state. Therefore, it is a challenge to acquire an accurate assessment of insulation state of power transformers. In this paper, an assessing strategy for transformer insulation is proposed base on part-division of transformer and a comprehensive weight determination method. An index system of transformer is established on the basis of part-division of transformer. Each index’s weight is consisted of two parts, the constant weight and the variable weight, which are determined by improved analytic hierarchy process (AHP) and entropy method respectively. Af- ter categorizing insulation state into four levels and standardizing assessing indexes, a Cauchy membership function is forged, and a fuzzy algorithm is employed to simulate the uncertainty of the insulation state. Finally, a confidence criterion is employed to perform part-division based condition assessment of transformer. Case studies reveal that the proposed assessing strategy method is effective, convenient, and practical; with the new strategy, potential failures of transformers can be forecasted and insulation state of transformer parts can also be as- sessed. Furthermore, the assessing results can be used to guide condition-based maintenance.

基于机器视觉的飞机故障检查系统

针对当前飞机维修检查工作以人工目视检查为主、效率低且存在人为因素影响的情况,设计一套基于图像识别与机器深度学习的飞机部件表面无损检测系统。收集并整理了某航空公司一线飞机维修员拍摄的飞机机身及发动机部件图片,对图片集进行预处理,包括通道提取、Sobel滤波处理及二值化;最后用Blob分析对处理后的图像进行特征提取与系统分析。系统运行速度快、准确率高且可连续自动识别图像。利用机器视觉技术对飞机部件表面进行无损检测不仅可以提高生产效率,同时可以去除人为因素对航空器飞行安全的影响,使得飞机的飞行安全得到进一步提升。实践证明,该系统性能稳定可靠,具有极高的推广应用价值。

盖板件高效铣削表面粗糙度预测与工艺参数优化

为了保证7075铝合金盖板件铣削表面质量和提高铣削加工效率,进行工艺参数优化,通过响应曲面法(RSM)构建铣削加工表面粗糙度预测模型,分析铣削工艺参数对表面粗糙度的影响规律。基于表面粗糙度预测模型建立高效铣削工艺参数优化目标方程,采用改进的粒子群算法(PSO)对目标方程进行优化,运用优化后的工艺参数对某盖板件进行铣削加工。试验结果表明:采用优化后的工艺参数进行盖板件铣削加工可以满足表面粗糙度要求,验证了预测模型的准确性和改进PSO方法的可行性。

差厚板U形件工艺孔成形性能仿真

以冷冲压差厚板U形件作为研究对象,通过有限元仿真分析了工艺孔的位置、数量、尺寸以及形状对成形性能的影响.结果表明,差厚板在薄区侧壁处开孔时有利于减少侧壁的残余应力;差厚板的回弹与工艺孔在板件中的位置分布关系不大,与工艺孔的数量、半径及形状有关.从成形性能和回弹影响角度考虑,工艺孔优先选差厚板U形件端部的厚区与过渡区区域,如果必须在侧壁开孔,优选侧壁薄区区域.在相邻区域,工艺孔的数量尽量不超过2个,工艺孔尺寸小一些更合适,工艺孔形状沿轧制方向距离越小越合适.

采用差分进化算法的复杂轴零件工艺路线优化

针对某复杂轴工艺路线编制不合理导致加工效率低的问题,从现有工艺路线优化方案出发,将加工特征以加工精度为加工元节点进行详细划分,构架合理加工元编码,以生产实际中装夹为依据,对工艺约束关系分组分析,获得更优的约束矩阵表达。利用差分进化算法,以机床、刀具及装夹更换最少为目标函数,合理设计差分变异、交叉及序列有效性校验与调整算法。通过对比表明,优化方案相较于优化前方案以及工艺约束不分组方案,刀具、装夹更换次数均有减少。

基于人工鱼群-遗传算法的多品种小批量零件数控加工工艺优化研究

基于多品种小批量零件加工成本高的问题,基于人工鱼群-遗传算法(AFSA-GA)构建了数控机床能耗模型,以实现零件加工能耗下降。首先,将数控机床功率划分为各工序功率模型,基于功率模型与工作时间关系得出机床运转能耗模型,结合产品表面粗糙度模型,对各工序能耗模型及整体粗糙度进行归一化处理,形成整体能耗模型;其次,以能耗及粗糙度为目标函数,建立AFSA-GA算法,通过对各工序能耗求解得出最适当的机床功率及其所对应的能耗和表面粗糙度;最后,针对所获得的最优功率,进行优化结果的验证,为五轴机床的实际加工提供解决方案。

难变形金属小模数齿形件电流辅助分形旋压成形工艺优化

目的针对30CrMnSiA合金结构钢小模数齿形件电流辅助分形旋压成形工艺,探究工艺参数对小模数齿形件成形质量的影响规律,分析工艺参数间的相关性,获得优化后的工艺参数组合。方法选取小模数齿形件齿廓偏差、齿距偏差、轮齿饱和度为成形质量响应指标,以电流密度、占空比以及旋轮进给速度为影响因素,设计响应面试验方案;根据有限元模拟结果建立成形质量回归预测模型,分析电流密度、占空比以及旋轮进给速度对小模数齿形件成形质量的影响规律,计算获得最优的参数组合并进行试验验证。结果电流密度、脉冲占空比、旋轮进给速度对小模数齿形件成形质量有显著影响,成形质量随着电流密度与占空比的升高而升高,随旋轮进给速度的升高而先升高后降低;且电流密度与旋轮进给速度、脉冲占空比与旋轮进给速度在对轮齿饱和度的影响上有一定的交互性;通过建立的回归模型预测得到的优化工艺参数如下:电流密度为17.5 A/mm2、脉冲占空比为40%、旋轮进给速度为0.6 mm/min。结论回归模型预测值与试验值的相对误差小于8%,说明所构建的成形质量回归预测模型是准确的,利用优化后的参数可制备出成形质量良好的小模数齿形件。

叶轮零件增减材复合加工工艺规划及虚拟仿真加工研究

针对叶轮零件结构复杂、加工难度大等问题,对其结构及工艺特点进行分析,制定增减材复合加工工艺规划,并基于NX软件设计增材和减材加工的刀具轨迹,最后通过在VERICUT中构建的虚拟仿真系统对加工过程进行仿真,验证增减材复合加工工艺及NC程序的正确性。虚拟仿真加工结果表明,该方法可为复杂零件高效、高质量加工提供一种新的思路和参考。

基于直驱机床的航空整体叶轮加工效率优化方法研究

为解决航空叶轮在复杂五轴联动加工过程中的效率和精度控制难题,本文基于直驱机床围绕加工参数对表面粗糙度和加工时间的影响进行了深入分析。首先通过与传统机床进行加工对比,证明了直驱机床的精度与速度方面的优势;其次针对原点坐标的研究揭示了原点位置对加工效率的影响,尤其是当原点接近A、C轴中心时,加工效率显著提高;最后通过正交试验法研究了转速、每齿进给量、切宽这3个关键因素,并发现每齿进给量是影响表面粗糙度的主导因素,其次是切宽,而转速的影响较小。在保证粗糙度小于1.6μm的前提下,以转速20000 r/mim、每齿进给量0.03 mm、切宽0.6 mm的参数组合获得最优结果。基于优化的工艺参数不仅提升了加工效率,节约了43.3%的加工时间,还确保了加工质量,为航空叶轮的精密加工提供了重要的技术参考,同时为基于直驱机床的复杂零件高效加工提供实践指导和理论依据。

车用铸铁零配件切削液的开发、应用及维护研究

文章针对铸铁内燃机等汽车零配件单机加工和集中供液加工的不同需求,采用石蜡基或环烷基基础油与乳化剂、防锈剂、油性剂等不同功能添加剂进行复配,通过一系列试验优化,研发了具有优异防锈性的铸铁单机用切削液及兼具防锈性和润滑性的集中供液切削液。开发产品不含亚硝酸钠、壬基酚等物质,符合GB/T 32812环保要求,并获得较广泛工业应用。同时文章根据应用情况,提出了切削液维护指标建议及异常排查处理建议。