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Optimization of Cutting Parameters for Trade-off Among Carbon Emissions, Surface Roughness, and Processing Time

Chinese Journal of Mechanical Engineering 2019年第6期32卷 124-141页

作者： Zhipeng Jiang Dong Gao Yong Lu Xianli Liu School of Mechatronics Engineering Harbin Institute of TechnologyHarbin 150001China State Engineering Laboratory of High Efficiency Cutting and Tool Harbin University of Science and TechnologyHarbin 150080China

As the manufacturing industry is facing increasingly serious environmental problems, because of which carbon tax policies are being implemented, choosing the optimum cutting parameters during the machining process is crucial for automobile panel dies in order to achieve synergistic minimization of the environment impact, product quality, and processing efficiency. This paper presents a processing task-based evaluation method to optimize the cutting parameters, considering the trade-off among carbon emissions, surface roughness, and processing time. Three objective models and their relationships with the cutting parameters were obtained through input–output, response surface, and theoretical analyses, respectively. Examples of cylindrical turning were applied to achieve a central composite design(CCD), and relative validation experiments were applied to evaluate the proposed method. The experiments were conducted on the CAK50135 di lathe cutting of AISI 1045 steel, and NSGA-Ⅱ was used to obtain the Pareto fronts of the three objectives. Based on the TOPSIS method, the Pareto solution set was ranked to find the optimal solution to evaluate and select the optimal cutting parameters. An S/N ratio analysis and contour plots were applied to analyze the influence of each decision variable on the optimization objective. Finally, the changing rules of a single factor for each objective were analyzed. The results demonstrate that the proposed method is effective in finding the trade-off among the three objectives and obtaining reasonable application ranges of the cutting parameters from Pareto fronts.

关键词： Automobile panel dies Carbon emission Parameter optimization Multi-objective optimization NSGA-Ⅱ

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Bayesian history Matching for Forward Model-Driven Structural Health Monitoring 36th

Bayesian History Matching for Forward Model-Driven Structura...

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36th International Modal Analysis Conference and Exposition (IMAC) on Structural Dynamics

作者： Gardner, P. Lord, C. Barthorpe, R. J. Univ Sheffield Dept Mech Engn Dynam Res Grp Sheffield S Yorkshire England

ISBN: (纸本)9783319747934;9783319747927

Computer models are widely utilised in many structural dynamics applications, however their use depends on calibration to observational data. A complexity in calibrating a computer model is that even when the 'true' input parameters to the model are known, there may be model discrepancy caused by the simplification or absence of certain physics. As a consequence the calibration technique employed must incorporate a mechanism for dealing with model discrepancy. Bayesian history matching is a process of using observed data in order to identify and discard areas of the computer model's parameter space that will result in outputs that are unlikely given the observational data. This is performed using an implausibility metric that encompasses uncertainties associated with observational measurements and model discrepancy. The method employs this metric to identify a non-implausible space (i.e., parameter combinations that are likely to have produced the observed outputs). A maximum a posterior (MAP) approach can be used to obtain the calibrated computer model outputs from the non-implausible space. Model discrepancy between the calibrated computer model and observational data can then be inferred using a Gaussian process (GP) regression model. This paper applies Bayesian history matching in order to calibrate a computer model for forward model-driven structural health monitoring (SHM). Quantitative metrics are used to compare experimental and predictive damage features from the combined Bayesian history matching and GP approach.

关键词： history matching Calibration Model discrepancy Emulator Gaussian processes

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An Online Calibration Method for Microsoft HoloLens

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IEEE ACCESS 2019年 7卷 101795-101803页

作者： Guo, Na Wang, Tianmiao Yang, Biao Hu, Lei Liu, Hongsheng Wang, Yuhan Beihang Univ Sch Mech Engn & Automat Beijing 100083 Peoples R China Beihang Univ Beijing Adv Innovat Ctr Biomed Engn Beijing 100183 Peoples R China

An optical see-through (OST) head-mounted display (HMD) is an appropriate option for an image-guided surgical navigation system (IGS) based on augmented reality (AR). However, the calibration of OST-HMDs has been challenging, since the augmented results can only be observed by the users wearing it. In this paper, we proposed an online calibration method based on the single-point active alignment method (SPAAM) for a HoloLens using a virtual tracking system. The transformation matrices between the world coordinates and the virtual holographic coordinates are calculated using a linear model and decomposed by the singular value decomposition (SVD) algorithm. The surgical workspace is analyzed, and there are nine sampling points for the offline calibration: eight at the vertices and one at the center of a cube of the workspace. 20 groups of data at each sampling point are collected. Five alignments should be implanted in the online calibration. The transformation matrices are compensated for the offset of every use of a HoloLens. To assess the accuracy of the calibration method, in accordance with the RANSAC algorithm, eight groups of additional data at random non-sampling locations are collected. Three different users that are familiar with the calibration procedures performed the calibration. The average distance error of our calibration was below 6 mm, and the rotation error was up to 5 degrees. It is a user-friendly, simple method for the online calibration of OST-HMDs.

关键词： Optical see-through augmented reality HMD calibration

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Unsupervised Anomaly Localization Using Variational Auto-Encoders 22nd

Unsupervised Anomaly Localization Using Variational Auto-Enc...

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10th International Workshop on Machine Learning in Medical Imaging (MLMI) / 22nd International Conference on Medical Image Computing and Computer-Assisted Intervention (MICCAI)

作者： Zimmerer, David Isensee, Fabian Petersen, Jens Kohl, Simon Maier-Hein, Klaus German Canc Res Ctr Heidelberg Germany

ISBN: (纸本)9783030322519;9783030322502

An assumption-free automatic check of medical images for potentially overseen anomalies would be a valuable assistance for a radiologist. Deep learning and especially Variational Auto-Encoders (VAEs) have shown great potential in the unsupervised learning of data distributions. In principle, this allows for such a check and even the localization of parts in the image that are most suspicious. Currently, however, the reconstruction-based localization by design requires adjusting the model architecture to the specific problem looked at during evaluation. This contradicts the principle of building assumption-free models. We propose complementing the localization part with a term derived from the Kullback-Leibler (KL)-divergence. For validation, we perform a series of experiments on FashionMNIST as well as on a medical task including >1000 healthy and >250 brain tumor patients. Results show that the proposed formalism outperforms the state of the art VAE-based localization of anomalies across many hyperparameter settings and also shows a competitive max performance.

关键词： Anomaly localization Anomaly detection

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Image reconstruction through dynamic scattering media based on deep learning

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OPTICS EXPRESS 2019年第11期27卷 16032-16046页

作者： Sun, Yiwei Shi, Jianhong Sun, Lei Fan, Jianping Zeng, Guihua Shanghai Jiao Tong Univ Ctr Quantum Sensing & Informat Proc State Key Lab Adv Opt Commun Syst & Networks Shanghai 200240 Peoples R China Univ N Carolina Dept Comp Sci Charlotte NC 28223 USA

Under complex scattering conditions;it is very difficult to capture clear object images hidden behind the media by modelling the inverse problem. With regard to dynamic scattering media;the challenge increases. For solving the inverse problem, we propose a new class-specific image reconstruction algorithm. The method based on deep learning classifies blurred scattering images according to scattering conditions and then recovers to clear images hidden behind the media. The deep learning network is used to learn the mapping relationship between the object and the scattering image rather than characterizing the scattering media explicitly or parametrically. 25000 scattering images are obtained under five sets of dynamic scattering condition to verity the feasibility of the proposed method. In addition, the generalizability of the method has been verified successfully. Compared with common CNN method, it's confirmed that our algorithm has better performance in reconstructing higher-quality images. Furthermore, for a given scattering image with unknown scattering condition, the closest scattering condition information can be given by classification network, and then the corresponding clear image is restored by reconstruction network. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

关键词： Digital micromirror devices Image quality Imaging systems Medical imaging Multiple scattering Scattering media

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Effect of the loading sequence of CeO2 and Pd over Al2O3 on the catalytic performance of Pd-only close-coupled catalysts

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MOLECULAR CATALYSIS 2020年 482卷

作者： Sun, Min Hu, Wei Yuan, Shandong Zhang, Hailong Cheng, Tianqiong Wang, Jianli Chen, Yaoqiang Sichuan Univ Coll Chem Chengdu 610064 Peoples R China Sichuan Univ Coll Chem Engn Chengdu 610064 Sichuan Peoples R China Sichuan Univ Inst New Energy & Low Carbon Technol Chengdu 610064 Sichuan Peoples R China

The Pd-only close-coupled catalysts of the different loading sequence of CeO2 and Pd over Al2O3 were prepared using consecutive wetness impregnation method. Differences in structural, surface properties and catalytic performance, together with the thermal aging behaviors of catalyst at 1000 degrees C were investigated systematically by XRD, TPR, XPS, ICP, CO adsorption and TEM. Consequently, the Ce/Pd/Al catalysts loaded Ce after Pd over the alumina show superior structural properties before and after aging treatment, suggesting the Ce/Pd/Al catalysts possess better thermal resistance than Pd/Ce/Al catalysts loaded Pd after Ce. Moreover, the aged Ce/Pd/Al catalysts possess stronger reducible probed by TPR, and HRTEM and CO adsorption show smaller particles size of Pd and higher palladium dispersion. As a result, for Ce/Pd/Al catalysts, more palladium sites play a role as active site, which promotes low temperature conversion of pollutants effectively. The catalytic performance of the catalysts is forcefully subject to palladium dispersion and reduction property, especially for NO conversion, and the light-off temperature of NO over aged Ce/Pd/Al is 27 degrees C lower than aged Pd/Ce/Al. The results have demonstrated that novel loading sequence is beneficial to catalytic activity which is maintained even after aging treatment. (C) 2017 Elsevier B.V. All rights reserved.

关键词： Loading sequence Pd-only close-coupled catalysts Palladium dispersion Thermal stability Catalytic performance

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Partial Observer Decision Process Model for Crane-Robot Action

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SCIENTIFIC programMING 2020年第0期2020卷 14-14页

作者： Khan, Asif Li, Jian Ping Haq, Amin ul Nazir, Shah Ahmad, Naeem Varish, Naushad Malik, Asad Patel, Sarosh H. UESTC Sch Comp Sci & Engn Chengdu 611731 Peoples R China Univ Sawabi Dept Comp Sci Swabi Kpk Pakistan Madanapalle Inst Technol & Sci Sch Comp Applicat Madanapalle India KL Univ Koneru Lakshmaiah Educ Fdn Comp Sci & Engn Guntur Andhra Pradesh India Southwest Jiaotong Univ Sch Informat Sci & Technol Chengdu 611756 Peoples R China Univ Bridgeport Sch Engn Dept Comp Sci & Engn Interdisciplinary Robot Intelligent Sensing & Con Bridgeport CT USA

The most common use of robots is to effectively decrease the human's effort with desirable output. In the human-robot interaction, it is essential for both parties to predict subsequent actions based on their present actions so as to well complete the cooperative work. A lot of effort has been devoted in order to attain cooperative work between human and robot precisely. In case of decision making , it is observed from the previous studies that short-term or midterm forecasting have long time horizon to adjust and react. To address this problem, we suggested a new vision-based interaction model. The suggested model reduces the error amplification problem by applying the prior inputs through their features, which are repossessed by a deep belief network (DBN) though Boltzmann machine (BM) mechanism. Additionally, we present a mechanism to decide the possible outcome (accept or reject). The said mechanism evaluates the model on several datasets. Hence, the systems would be able to capture the related information using the motion of the objects. And it updates this information for verification, tracking, acquisition, and extractions of images in order to adapt the situation. Furthermore, we have suggested an intelligent purifier filter (IPF) and learning algorithm based on vision theories in order to make the proposed approach stronger. Experiments show the higher performance of the proposed model compared to the state-of-the-art methods.

关键词： Decision making

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An Optimal Feed Interpolator Based on G^2 Continuous Bézier Curves for high-Speed Machining of Linear Tool Path

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Chinese Journal of Mechanical Engineering 2019年第3期32卷 109-118页

作者： Yongqiao Jin Sheng Zhao Yuhan Wang Shanghai Spaceflight Precision Machinery Institute Shanghai 201600China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

A numerical control (NC) tool path of digital CAD model is widely generated as a set of short line segments in machining. However, there are three shortcomings in the linear tool path, such as discontinuities of tangency and curvature, huge number of line segments, and short lengths of line segments. These disadvantages hinder the development of high speed machining. To smooth the linear tool path and improve machining efficiency of short line segments, this paper presents an optimal feed interpolator based on G^2 continuous Bézier curves for the linear tool path. First, the areas suitable for fitting are screened out based on the geometric characteristics of continuous short segments (CSSs). CSSs in every area are compressed and fitted into a G^2 Continuous Bézier curve by using the least square method. Then a series of cubic Bézier curves are generated. However, the junction between adjacent Bézier curves is only G^0 continuous. By adjusting the control points and inserting Bézier transition curves between adjacent Bézier curves, the G^2 continuous tool path is constructed. The fitting error is estimated by the second-order Taylor formula. Without iteration, the fitting algorithm can be implemented in real-time environment. Second, the optimal feed interpolator considering the comprehensive constraints (such as the chord error constraint, the maximum normal acceleration, servo capacity of each axis, etc.) is proposed. Simulation and experiment are conducted. The results shows that the proposed method can generate smooth path, decrease the amount of segments and reduce machining time for machining of linear tool path. The proposed research provides an effective method for high-speed machining of complex 2-D/3-D profiles described by short line segments.

关键词： G^2 continuous path Least square method high-speed machining Continuous short segments Optimal feed interpolator Data compression

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Intensity-based 2D-3D registration for an ACL reconstruction navigation system

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INTERNATIONAL JOURNAL OF MEDICAL ROBotICS AND COMPUTER ASSISTED SURGERY 2019年第4期15卷 e2008-e2008页

作者： Guo, Na Yang, Biao Ji, Xuquan Wang, Yuhan Hu, Lei Wang, Tianmiao Beihang Univ Sch Mech Engn & Automat Beijing Peoples R China Beihang Univ Beijing Adv Innovat Ctr Biomed Engn Beijing Peoples R China

To improve the positioning accuracy of tunnels for anterior cruciate ligament (ACL) reconstruction, we proposed an intensity-based 2D-3D registration method for an ACL reconstruction navigation system. Methods for digitally reconstructed radiograph (DRR) generation, similarity measurement, and optimization are crucial to 2D-3D registration. We evaluated the accuracy, success rate, and processing time of different methods: (a) ray-casting and splating were compared for DRR generation;(b) normalized mutual information (NMI), Mattes mutual information (MMI), and Spearman's rank correlation coefficient (SRC) were assessed for similarity between registrations;and (c) gradient descent (GD) and downhill simplex (DS) were compared for optimization. The combination of splating, SRC, and GD provided the best composite performance and was applied in an augmented reality (AR) ACL reconstruction navigation system. The accuracy of the navigation system could fulfill the clinical needs of ACL reconstruction, with an end pose error of 2.50 mm and an angle error of 2.74 degrees.

关键词： ACL reconstruction intensity-based 2D-3D registration surgical navigation system

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Photocatalytic degradation of acetochlor by α-Fe2O3 nanoparticles with different morphologies in aqueous solution system

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OPTIK 2019年 178卷 36-44页

作者： Fu, Yong Li, Yan Hu, Jianshe Li, Song Qin, Gaowu Northeastern Univ Ctr Mol Sci & Engn Coll Sci Shenyang 110819 Liaoning Peoples R China Northeastern Univ Key Lab Anisotropy & Texture Mat Minist Educ Shenyang 110819 Liaoning Peoples R China

Photocatalytic degradation technology is an important and promising method for complete elimination of toxic organics. In this study, the photocatalytic degradation of acetochlor using alpha-Fe2O3 nanoparticles under H2O2/UV system was studied with UV-Vis spectrophotometer and GC MS. The degradation rate was investigated on the effects of alpha-Fe2O3 morphology and dosage, initial acetochlor concentration, solution pH, and H2O2 dosage. The results showed that photo catalytic degradation efficiency could reach 91% by alpha-Fe2O3 with 200 mg/L hollow morphology at an initial acetochlor concentration, pH value, and H2O2 dosage of 50 mg/L, 7 and 40 mu L, respectively. The photocatalytic reaction mechanism and degradation process of acetochlor by alpha-Fe2O3 were investigated and the degradation pathway of acetochlor was proposed. The oxidative attack involves N-C bond connecting the aromatic ring with side chain, the nitrogen-containing side chain, chlorinated aliphatic to produce 1-methyl-3-wing-benzene, allyl-methyl-amine and 1-chloro-2-ethoxy-ethane. These intermediate products could be further oxidized to NO3-, CO2 and H2O. These findings provide new insights for the photocatalytic degradation of organic pollutants in the using alpha-Fe2O3 nanoparticles to achieve pollutant degradation.

关键词： alpha-Fe2O3 Photocatalytic degradation Acetochlor

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