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Deep-learning-assisted online surface roughness monitoring in ultraprecision fly cutting

Science China(Technological Sciences) 2024年第5期67卷 1482-1497页

作者： SHEHZAD Adeel RUI XiaoTing DING YuanYuan ZHANG JianShu CHANG Yu LU HanJing chen yiheng Institute of Launch Dynamics Nanjing University of Science and TechnologyNanjing210094China National Key Laboratory of Complex Multibody System Dynamics Nanjing210094China Automotive Engineering Centre University of Engineering and TechnologyLahore54890Pakistan School of Science Nanjing University of Science and TechnologyNanjing210094China College of Engineering Peking UniversityBeijing100871China

Surface roughness is one of the most critical attributes of machined components,especially those used in high-performance *** surface roughness monitoring offers advancements comparable to post-process inspection methods,reducing inspection time and costs and concurrently reducing the likelihood of ***,online monitoring approaches for surface roughness are constrained by several limitations,including the reliance on handcrafted feature extraction,which necessitates the involvement of human experts and entails time-consuming ***,the prediction models trained under one set of cutting conditions exhibit poor performance when applied to different experimental *** address these challenges,this work presents a novel deep-learning-assisted online surface roughness monitoring method for ultraprecision fly cutting of copper workpieces under different cutting *** acceleration signals were acquired during each cutting experiment to develop two datasets,and no handcrafted features were *** deep learning models were developed and evaluated using standard performance metrics.A convolutional neural network stacked on a long short-term memory network outperformed all other network models,yielding exceptional results,including a mean absolute percentage error as low as 1.51%and an R2value of 96.6%.Furthermore,the robustness of the proposed model was assessed via a validation cohort analysis using experimental data obtained using cutting parameters different from those previously *** performance of the model remained consistent and commendable under varied conditions,asserting its applicability in real-world scenarios.

关键词： online surface roughness monitoring UPFC deep learning CNN-LSTM vibration signal

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Tool-tip vibration prediction based on a novel convolutional enhanced transformer

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International Journal of Mechanical System Dynamics 2024年第1期4卷 34-47页

作者： Adeel Shehzad Xiaoting Rui Yuanyuan Ding Yu Chang Jianshu Zhang Hanjing Lu yiheng chen Institute of Launch Dynamics Nanjing University of Science&TechnologyNanjingChina Automotive Engineering Centre University of Engineering&TechnologyLahorePakistan School of Science Nanjing University of Science and TechnologyNanjingChina College of Engineering Peking UniversityBeijingChina

Superior surface finish remains a fundamental criterion in precision machining operations,and tool-tip vibration is an important factor that significantly influences the quality of the machined ***-based models heavily rely on assumptions for model simplification when applied to complex high-end ***,these assumptions may come at the cost of compromising the model's *** contrast,data-driven techniques have emerged as an attractive alternative for tasks such as prediction and complex system *** exploit the advantages of data-driven models,this study introduces a novel convolutional enhanced transformer model for tool-tip vibration prediction,referred to as *** effectiveness of this model is demonstrated through its successful application in ultra-precision fly-cutting(UPFC)*** distinct variants of the model,namely,guided and nonguided CeT-TV,were developed and rigorously tested on a data set custom-tailored for UPFC *** results reveal that the guided CeT-TV model exhibits outstanding performance,characterized by the lowest mean absolute error and root mean square error ***,the model demonstrates excellent agreement between the predicted values and the actual measurements,thus underlining its efficiency and potential for predicting the tool-tip vibration in the context of UPFC.

关键词： tool-tip vibration ultraprecision fly cutting data-driven modeling transformer

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基于AIS数据的长三角沿海地区船舶碳排放估算与分析

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环境科学学报 2024年第8期44卷 83-97页

作者：蔡欣宇陈焱明陈奕恒汪峰崔越尹昌贵河海大学地球科学与工程学院南京211100 河海大学江苏省水资源环境遥感监测评估工程研究中心南京211100 国家海洋信息中心天津300171 南京信息工程大学商学院南京210044 南京信息工程大学气候经济与低碳产业研究院南京210044

长三角地区涵盖上海、江苏、浙江和安徽,作为中国经济腾飞的关键推动力,在我国的经济繁荣中发挥着至关重要的作用.随着经济的快速发展,碳排放问题逐渐显现,其中,船舶碳排放成为环境挑战的一项重要议题.船舶自动识别系统(AIS)数据作为记... 详细信息

长三角地区涵盖上海、江苏、浙江和安徽,作为中国经济腾飞的关键推动力,在我国的经济繁荣中发挥着至关重要的作用.随着经济的快速发展,碳排放问题逐渐显现,其中,船舶碳排放成为环境挑战的一项重要议题.船舶自动识别系统(AIS)数据作为记录船舶活动的有力工具,提供了精确量化碳排放的手段.本文利用2016年AIS船舶数据,借助船舶交通排放评估模型(Steam)对长三角周边海域的全年船舶碳排放量进行精细估算,并从船舶类型、排放源、航行状态等时空角度对全年碳排放特征进行详尽分析.结果显示,2016年长三角沿海区域的二氧化碳总排放量估计为1258万t,其中,货船贡献了67%的碳排放,而巡航和低速巡航状态下的船舶碳排放量占长三角沿海区域水域碳总排放量的1/2以上.船舶碳排放的变化趋势与季节性、气候和社会等多种因素密切相关.由于春节期间贸易活动相对减少,航运需求下降,船舶运输量减少,因此,1—2月的碳排放量最低,大约分别为78万t和56万t.而9—11月气候适宜,航运需求增大,这几个月的船舶活动最为明显,其中,10月达到全年船舶碳排放的高峰,大约为145万t.长三角沿海区域碳排放量较高的主要区域大多位于港口地带,尤其是上海港、宁波舟山港及长江口区域的碳排放最为显著.本研究对长三角沿海区域船舶碳排放的规律进行了深入剖析,为加深对该问题的理解和采取有效措施应对船舶碳排放问题提供了有益的参考和指导.这项研究不仅为未来相关研究奠定了基础,还可用于与历史或未来的船舶排放数据进行比较,并为制定船舶排放监管行动提供支持.

关键词：船舶碳排放长三角沿海地区 AIS数据时空分析

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基于通信时延概率分布的虚拟编组技术研究

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应用技术学报 2024年第1期24卷 117-122页

作者：邹劲柏陈一衡许哲谱上海应用技术大学轨道交通学院上海201418

轨道交通车车通信作为列车虚拟编组系统中的关键环节,深刻影响着虚拟编组状态下列车间的协调运行。在分析通信时延概率分布特征的基础上,探讨了通信延误对列车虚拟编组的影响,为车车通信系统性能设计提供理论支撑。提出一种列车动力学模... 详细信息

轨道交通车车通信作为列车虚拟编组系统中的关键环节,深刻影响着虚拟编组状态下列车间的协调运行。在分析通信时延概率分布特征的基础上,探讨了通信延误对列车虚拟编组的影响,为车车通信系统性能设计提供理论支撑。提出一种列车动力学模型,利用模型预测控制(MPC)的方法实现多列车间的虚拟编组协调运行控制。通过该模型仿真实验分析不同概率分布情况下的通信时延对虚拟编组列车控制系统的影响。实验结果表明,较大的通信时延扰动将加剧虚拟编组系统的振荡,这些问题将给列车的平稳运行与节能带来挑战。

关键词：虚拟编组模型预测控制车车通信时延

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考虑电液伺服系统建模不确定性的一种自适应控制方法

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工程与试验 2024年第1期64卷 3-5页

作者：陈轶珩曲浩然贾小雪杨超张昭中国飞机强度研究所强度与结构完整性全国重点实验室陕西西安710065

电液伺服系统因具有功率重量比大、响应快、刚度大、维护成本低等优点,广泛应用于工业生产、航空航天、机械制造等领域,在飞行器结构静力/疲劳强度试验中发挥着重要作用。然而,电液伺服系统复杂的物理特性使得对其建立精确的动力学模型... 详细信息

电液伺服系统因具有功率重量比大、响应快、刚度大、维护成本低等优点,广泛应用于工业生产、航空航天、机械制造等领域,在飞行器结构静力/疲劳强度试验中发挥着重要作用。然而,电液伺服系统复杂的物理特性使得对其建立精确的动力学模型非常困难,这为控制器设计带来了很大挑战。本文考虑到电液伺服系统的建模不确定性,基于系统状态空间方程,利用反步法设计了一种自适应鲁棒控制器,在控制过程中系统模型不确定部分能够自适应估计和在线更新。最后,在搭建的仿真平台上进行了跟踪仿真试验,并与PID方法进行对比,验证了所提方法在控制过程中具有更快的响应速度和更高的控制精度。

关键词：电液伺服系统建模不确定性反步法自适应控制

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电液伺服系统一种动力学建模方法

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工程与试验 2024年第1期64卷 22-23,104页

作者：陈轶珩曲浩然贾小雪杨超张昭中国飞机强度研究所强度与结构完整性全国重点实验室陕西西安710065

电液伺服系统具有响应速度快、输出功率大、抗冲击性好等优点,广泛应用于飞行器结构强度试验中。然而,因特殊物理结构,电液伺服系统具有复杂的非线性、时变性和不确定性,这为其动力学建模和控制器设计带来了很大的挑战。本文通过分析系... 详细信息

电液伺服系统具有响应速度快、输出功率大、抗冲击性好等优点,广泛应用于飞行器结构强度试验中。然而,因特殊物理结构,电液伺服系统具有复杂的非线性、时变性和不确定性,这为其动力学建模和控制器设计带来了很大的挑战。本文通过分析系统各个部件的物理学特性和工作原理,分别建立了伺服阀流量方程、非对称液压缸流量方程和液压缸力平衡方程。经过一系列数学变化,将动力学方程进一步转化为系统状态空间方程,便于未来工作中对系统进行基于模型的控制器设计。最后,进行了系统仿真平台的搭建,并采用PID控制器进行跟踪控制仿真试验,验证了所提模型的有效性。

关键词：电液伺服系统动力学建模状态空间方程

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Hybrid multibody system method for the dynamic analysis of an ultra‐precision fly‐cutting machine tool

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International Journal of Mechanical System Dynamics 2022年第3期2卷 290-307页

作者： Hanjing Lu Xiaoting Rui Ziyao Ma Yuanyuan Ding yiheng chen Yu Chang Xuping Zhang College of Engineering Peking UniversityBeijingChina Institute of Launch Dynamics Nanjing University of Science&TechnologyNanjingChina Department of Engineering Aarhus UniversityAarhusDenmark School of Science Nanjing University of Science and TechnologyNanjingChina

The dynamics of an ultra‐precision machine tool determines the precision of the machined *** study aims to propose an effective method to model and analyze the dynamics of an ultra‐precision fly‐cutting machine ***,the dynamic model of the machine tool considering the deformations of the cutter head and the lathe head is ***,the mechanical elements are classified into M subsystems and F subsystems according to their properties and *** M‐subsystem equations are formulated using the transfer matrix method for multibody systems(MSTMM),and the F‐subsystem equations are analyzed using the finite element method and the Craig-Bampton reduction ***,all the subsystems are assembled by combining the restriction equations at connection points among the subsystems to obtain the overall transfer equation of the machine tool ***,the vibration characteristics of the machine tool are evaluated numerically and are validated *** proposed modeling and analysis method preserves the advantages of the MSTMM,such as high computational efficiency,low computational load,systematic reduction of the overall transfer equation,and generalization of its computational capability to general flexible‐body *** addition,this study provides theoretical insights and guidance for the design of ultra‐precision machine tools.

关键词： transfer matrix method for multibody systems finite element method Craig-Bampton reduction method ultra‐precision fly‐cutting machine tool

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The preservation effects of chitosan copolymers(gallic acid and protocatechuic acid)on sea bass(Lateolabrax japonicus)fillets

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Aquaculture and Fisheries 2023年第3期8卷 305-315页

作者： Jiali Liu Weiqing Lan Yi Wu Xiaohong Sun Jun Mei yiheng chen Jing Xie College of Food Science and Technology Shanghai Ocean UniversityShanghai201306China Shanghai Aquatic Products Processing and Storage Engineering Technology Research Center Shanghai201306China National Experimental Teaching Demonstration Center for Food Science and Engineering(Shanghai Ocean University) Shanghai201306China Laboratory of Quality&Safety Risk Assessment for Aquatic Products on Storage and Preservation(Shanghai) Ministry of AgricultureShanghai201306China

This study was aimed at preparing chitosan(CS)-phenolic acids copolymers to obtain better preservation effect in marine *** this work,CS was grafted onto phenolic acids such as gallic acid(GA)and protocatechuic acid(PA)by a carbodiimide coupling *** copolymers(CS-grafted-GA(CS-g-GA)and CS-grafted-PA(CS-g-PA))were further confirmed through physicochemical properties including ultraviolet-visible(UV-Vis)spectrophotography,fourier transform infrared(FTIR)spectrometry,differential scanning calorimetry(DSC)thermogram,rheological behaviour,scanning electron microscope(SEM)and antioxidant activity ***,the effects of copolymers on preservation of refrigerated sea bass(Lateolabrax japonicus)fillets were *** results showed that the CS-g-GA(110.82 mg GA/g)exhibited higher grafting rate than CS-g-PA(62.63 mg PA/g).According to the assessment of UV-Vis and FTIR spectrometry,both the GA and PA were grafted onto CS *** analysis demonstrated that the microstructure of copolymers became ***,both the CS-g-GA and CS-g-PA copolymers displayed superior thermal stability,rheological properties and antioxidant capacity than the pure ***,the copolymers also revealed a significantly stronger preservation effect on sea bass fillets including inhibiting microbial growth and delaying the deterioration of color,texture and sensory ***,CS-g-GA and CS-g-PA could be used as promising preservatives for seafood.

关键词： Sea bass fillets Chitosan Grafted Coating Carbodiimide coupling Antioxidant capacity

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SURFACE EFFECT ON NANOSIZED VOID GROWTH IN A RIGID-PERFECTLY PLASTIC MATERIAL

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Acta Mechanica Solida Sinica 2008年第1期21卷 9-14页

作者： Tong Hui yiheng chen School of Aerospace MOE Xi＇an Jiaotong University Xi＇an 710049 China

The influence of the surface effect on the nanosized spherical void growth in a rigidperfectly plastic material is analyzed and the mechanism of the nanosized void growth with high triaxiality is given. Based on the Rice and Tracey model for a macro void growth, the present model is proposed to account for the nanosized void growth under a uniform remote strain rate field with consideration on the surface effect. It is concluded that the surface effect yields an evident resistant influence on the nanosized void growth. That is, this influence decays as the void radius increases. With high triaxiality, the nanosized void growth is divided into two stages： the initial stage and the mature stage. At the first stage, the void grows slowly and the influence of surface effect is relatively weak, whereas at the second stage, the influence is significant and the void grows drastically.

关键词： nanosized void extended variational principle void growth surface effect high triaxiality

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CONSERVATION LAWS IN FINITE MICROCRACKING BRITTLE SOLIDS

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Acta Mechanica Solida Sinica 2005年第3期18卷 189-199页

作者： Wang Defa chen yiheng Fukui Takuo Department of Civil Engineering Xi＇an University of Technology Xi＇an 710048 China Department of Engineering Mechanics Xi＇an Jiaotong University Xi＇an 710049 China Department of Architecture and Civil Engineering Fukui University Fukui 910-8507 Japan

This paper addresses the conservation laws in finite brittle solids with microcracks. The discussion is limited to the 2-D cases. First, after considering the combination of the Pseudo-Traction Method and the indirect Boundary Element Method, a versatile method for solving multi-crack interacting problems in finite plane solids is proposed, by which the fracture parameters （SIF and path-independent integrals） can be calculated with a desirable accuracy. Second, with the aid of the method proposed, the roles the conservation laws play in the fracture analysis for finite microcracking solids are studied. It is concluded that the conservation laws do play important roles in not only the fracture analysis but also the analysis of damage and stability for the finite microcracking system. Finally, the physical interpretation of the M-integral is discussed further. An explicit relation between the M-integral and the crack face area, i.e., M = GS, has been discovered using the analytical method, which can shed some light on the Damage Mechanics issues from a different perspective.

关键词： conservation laws finite microcracking solids pseudo-traction method boundary element method stress intensity factors

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