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Deep Reinforcement Learning Model for Blood Bank Vehicle Routing Multi-Objective Optimization

Computers, Materials & Continua 2022年第2期70卷 3955-3967页

作者： Meteb M.Altaf Ahmed Samir Roshdy Hatoon S.AlSagri director of advanced manufacturing and industry 4.0 center King Abdul-Aziz City for Science and Technology RiyadhSaudi Arabia Data Science and AI Senior Manager Vodafone CairoEgypt Information System Department Al Imam Mohammad Ibn Saud Islamic UniversityRiyadhSaudi Arabia

The overall healthcare system has been prioritized within development top lists *** many national populations are aging,combined with the availability of sophisticated medical treatments,healthcare expenditures are rapidly *** banks are a major component of any healthcare system,which store and provide the blood products needed for organ transplants,emergency medical treatments,and routine *** delivery of blood products is vital,especially in emergency ***,blood delivery process parameters such as safety and speed have received attention in the literature,as well as other parameters such as delivery *** this paper,delivery time and cost are modeled mathematically and marked as objective functions requiring simultaneous optimization.A solution is proposed based on Deep Reinforcement Learning(DRL)to address the formulated delivery functions as Multi-objective Optimization Problems(MOPs).The basic concept of the solution is to decompose the MOP into a scalar optimization sub-problems set,where each one of these sub-problems is modeled as a separate Neural Network(NN).The overall model parameters for each sub-problem are optimized based on a neighborhood parameter transfer and DRL training *** optimization step for the subproblems is undertaken collaboratively to optimize the overall *** solutions can be directly obtained using the trained ***,the multi-objective blood bank delivery problem is addressed in this *** technical advantage of this approach is that once the trainedmodel is available,it can be scaled without the need formodel *** scoring can be obtained directly using a straightforward computation of the NN layers in a limited *** proposed technique provides a set of technical strength points such as the ability to generalize and solve rapidly compared to othermulti-objective *** model was trained and tested on 5 major hospi

关键词： Optimization blood bank deep neural network reinforcement learning blood centers multi-objective optimization

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Position-varying surface roughness prediction method considering compensated acceleration in milling of thin-walled workpiece

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Frontiers of Mechanical Engineering 2021年第4期16卷 855-867页

作者： Zequan YAO Chang FAN Zhao ZHANG Dinghua ZHANG Ming LUO Key Laboratory of High Performance manufacturing for Aero Engine(Ministry of industry and Information Technology) Northwestern Polytechnical UniversityXi'an 710072China Engineering Research center of advanced manufacturing Technology for Aero Engine(Ministry of Education) Northwestern Polytechnical UniversityXi'an 710072China

Machined surface roughness will affect parts?service ***,predicting it in the machining is important to avoid *** roughness will be affected by system position dependent vibration even under constant parameter with certain toolpath processing in the *** at surface roughness prediction in the machining process,this paper proposes a position-varying surface roughness prediction method based on compensated acceleration by using regression *** reduce the stochastic error of measuring the machined surface profile height,the surface area is repeatedly measured three times,and Pauta criterion is adopted to eliminate abnormal *** actual vibration state at any processing position is obtained through the single-point monitoring acceleration compensation *** acceleration features are extracted,and valley,which has the highest/^-square proving the effectiveness of the filtering features,is selected as the input of the prediction model by mutual information ***,by comparing the measured and predicted surface roughness curves,they have the same trends,with the average error of 16.28%and the minimum error of 0.16%.Moreover,the prediction curve matches and agrees well with the actual surface state,which verifies the accuracy and reliability of the model.

关键词： surface roughness prediction compensated acceleration milling thin-walled workpiece

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Three-dimensional modeling and reconstructive change of residual stress during machining process of milling, polishing, heat treatment, vibratory finishing, and shot peening of fan blade

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Advances in manufacturing 2021年第3期9卷 430-445页

作者： Ji-Yin Zhang Chang-Feng Yao Min-Chao Cui Liang Tan Yun-Qi Sun Key Laboratory of High Performance manufacturing for Aero Engine Northwestern Polytechnical UniversityMinistry of Industry and Information TechnologyXi’an710072People’s Republic of China Engineering Research center of advanced manufacturing Technology for Aero Engine Northwestern Polytechnical UniversityMinistry of EducationXi’an710072People’s Republic of China

Residual stress during the machining process has always been a research hotspot,especially for aero-engine *** three-dimensional modeling and reconstructive laws of residual stress among various processes in the machining process of the fan blade is studied in this *** fan blades of Ti-6Al-4V are targeted for milling,polishing,heat treatment,vibratory finishing,and shot *** surface and subsurface residual stress after each process is measured by the X-ray diffraction *** distribution of the surface and subsurface residual stress is *** Rational Taylor surface function and cosine decay function are used to fit the characteristic function of the residual stress distribution,and the empirical formula with high fitting accuracy is *** value and distribution of surface and subsurface residual stress vary greatly due to different processing *** reconstructive change of the surface and subsurface residual stress of the blade in each process intuitively shows the change of the residual stress between the processes,which has a high reference significance for the research on the residual stress of the blade processing and the optimization of the entire blade process.

关键词： Fan blade Machining process Surface residual stress Subsurface residual stress Three-dimensional modeling Reconstructive change

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Machinability ofγ-TiAl:A review

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Chinese Journal of Aeronautics 2023年第7期36卷 40-75页

作者： Ziwen XIA Chenwei SHAN Menghua ZHANG Minchao CUI Ming LUO Key Laboratory of High Performance manufacturing for Aero Engine Ministry of Industry and Information TechnologyNorthwestern Polytechnical UniversityXi’an 710072China Engineering Research center of advanced manufacturing Technology for Aero Engine Ministry of EducationNorthwestern Polytechnical UniversityXi’an 710072China State Key Laboratory of Cemented Carbide Zhuzhou 412000China

Owing to its outstanding mechanical properties,γ-TiAl is desirable materials for crossgeneration *** 70 years of exploration have made it into the initial ***,the intrinsic brittleness ofγ-TiAl is still a critical obstacle to its large-scale *** this context,researchers have made many attempts to study the machinability ofγ-*** present,existing relevant reviews have mostly discussed the processing methods ofγ-***,there is still a lack of a perspective on material properties to analyze the cutting ***,this paper provides the systematic review of such *** all,the developmental process,phase transformation,and microstructural evolution ofγ-TiAl are discussed,as well as its deformation mechanism at *** topics can provide a materials science foundation for the machining ofγ-*** then,the review focuses on the cutting mechanism and surface integrity ofγ-***,special attention is paid to the microscope deformation mechanism and surface defects evolution ofγ-TiAl during ***,the review indicates that the highperformance machining technology ofγ-TiAl faces challenges and proposes potential future research *** the difficulties during machiningγ-TiAl aero-engine components will accelerate the development of new aero-engines.

关键词： Cutting mechanism Deformation Machinability Surface integrity γ-TiAl

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advanced operation of heated fluidic resonators via mechanical and thermal loss reduction in vacuum

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Microsystems & Nanoengineering 2023年第5期9卷 255-262页

作者： Juhee Ko Bong Jae Lee Jungchul Lee Department of Mechanical Engineering Center for Extreme Thermal Physics and ManufacturingKorea Advanced Institute of Science and Technology(KAIST)34141 DaejeonKorea

For simultaneous and quantitative thermophysical measurements of ultrasmall liquid volumes,we have recently developed and reported heated fluidic resonators(HFRs).In this paper,we improve the precision of HFRs in a vacuum by significantly reducing the thermal loss around the sensing element.A vacuum chamber with optical,electrical,and microfluidic access is custom-built to decrease the convection loss by two orders of magnitude under 10-4 mbar *** a result,the measurement sensitivities for thermal conductivity and specific heat capacity are increased by 4.1 and 1.6 times,*** differentiating between deionized water(H2O)and heavy water(D2O)with similar thermophysical properties and~10%different mass densities,the signal-to-noise ratio(property differences over standard error)for H2O and D2O is increased by 9 and 5 times for thermal conductivity and specific heat capacity,respectively.

关键词： fluid operation vacuum

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Effect of ultrasonic impact treatment on the surface integrity of nickel alloy 718

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Advances in manufacturing 2021年第1期9卷 160-171页

作者： Zheng Zhou Chang-Feng Yao Yu Zhao Yang Wang Liang Tan Key Laboratory of High Performance manufacturing for Aero Engine Ministry of Industry and Information TechnologySchool of Mechanical EngineeringNorthwestern Polytechnical UniversityXi'an 710072People's Republic of China Engineering Research center of advanced manufacturing Technology for Aero Engine Ministry of EducationSchool of Mechanical EngineeringNorthwestern Polytechnical UniversityXi'an 710072People's Republic of China

Ultrasonic impact treatment(UIT)is a type of surface strengthening technology that can improve the fatigue properties of materials by improving the surface quality,residual stress,and other *** this study,the influence of ultrasonic impact parameters on the surface integrity of nickel alloy 718 was *** micro stress concentration caused by the surface morphology was also *** cosine and exponential decay functions were used to fit and characterize the distribution of residual stress and work hardening in the surface *** results showed that the feed rate had the greatest influence on surface roughness,stress concentration,and surface residual *** was not appropriate to evaluate the surface hardening effect only by the number of impacts per unit area,the ultrasonic impact parameters such as feed speed and pre extrusion depth should also be *** grain refinement was obvious after *** multiobjective optimization of machining parameters was performed with the objective of surface stress concentration and residual stress.A surface with a smaller surface stress concentration factor and larger compressive residual stress can be obtained simultaneously using medium linear velocity,medium pre extrusion depth,and smaller feed rate.

关键词： Nickel alloy 718 Ultrasonic impact Surface stress concentration Surface integrity Grain refinement

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Experimental study on surface integrity refactoring changes of Ti-17 under milling-ultrasonic rolling composite process

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Advances in manufacturing 2023年第3期11卷 492-508页

作者： Zheng Zhou Chang-Feng Yao Liang Tan Ya Zhang Yi Fan Key Laboratory of High Performance manufacturing for Aero Engine Ministry of Industry and Information TechnologySchool of Mechanical EngineeringNorthwestern Polytechnical UniversityXi'an 710072People's Republic of China Engineering Research center of advanced manufacturing Technology for Aero Engine Ministry of EducationSchool of Mechanical EngineeringNorthwestern Polytechnical UniversityXi'an 710072People's Republic of China

Ultrasonic rolling is an advanced non-cutting surface strengthening method that combines traditional rolling with ultrasonic *** this research,the experiment of orthogonal end milling-ultrasonic rolling composite process has been carried *** surface integrity refactoring changes and its mechanism of Ti-17 titanium alloy during the milling-ultrasonic rolling composite process has been studied and analyzed by the test and analysis of the surface geometric characteristics,residual stress,microhardness and microstructure before and after ultrasonic *** residual stress and microhardness gradient distribution were characterized by cosine decay function and exponential decay *** indicators of surface integrity were significantly improved after ultrasonic *** study demonstrates that the reduction effect of the surface roughness by ultrasonic rolling process is inversely proportional to the initial surface roughness *** ultrasonic rolling can only change the distribution form of the surface topography when the initial surface roughness is *** addition,the improvement effect of ultrasonic rolling on surface compressive residual stress and microhardness decreased with the increase of initial milled surface roughness and surface compressive residual stress due to the factors such as energy absorption efficiency and mechanical properties changes of surface materials.A better ultrasonic rolled surface can be obtained by controlling the roughness and residual compressive stress of the initial milling surface to a small level.

关键词： Ti-17 End milling Ultrasonic rolling Surface integrity Refactoring changes

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Geometric error measuring,modeling,and compensation for CNC machine tools:A review

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Chinese Journal of Aeronautics 2024年第2期37卷 163-198页

作者： Zhao ZHANG Feng JIANG Ming LUO Baohai WU Dinghua ZHANG Kai TANG Engineering Research center of advanced manufacturing Technology for Aero Engine(Northwestern Polytechnical University) Ministry of EducationXi’an 710072China Key Laboratory of High Performance manufacturing for Aero Engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an 710072China Department of Mechanical and Aerospace Engineering Hong Kong University of Science and TechnologyHong KongChina

Geometric error,mainly due to imperfect geometry and dimensions of machine components,is one of the major error sources of machine *** that geometric error has significant effects on the machining quality of manufactured parts,it has been a popular topic for academic and industrial research for many years.A great deal of research work has been carried out since the 1970s for solving the problem and improving the machining *** have studied how to measure,detect,model,identify,reduce,and compensate the geometric *** paper presents a thorough review of the latest research activities and gives an overview of the state of the art in understanding changes in machine tool performance due to geometric *** advances in measuring the geometrical errors of machine tools are summarized,and different kinds of error identification methods of translational axes and rotation axes are illustrated ***,volumetric geometric error modeling,tracing,and compensation techniques for five-axis machine tools are emphatically ***,research challenges in order to improve the volumetric accuracy of machine tools are also highlighted.

关键词： Error compensation Error identification Error measurement Error modeling Geometric error Machine tools

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Prediction model of surface integrity characteristics in ball end milling TC17 titanium alloy

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Advances in manufacturing 2023年第3期11卷 541-565页

作者： Xue-hong Shen Chang-Feng Yao Liang Tan Ding-Hua Zhang Key Laboratory of High Performance manufacturing for Aero Engine Ministry of Industry and Information TechnologySchool of Mechanical EngineeringNorthwestern Polytechnical UniversityXi'an 710072People's Republic of China Engineering Research center of advanced manufacturing Technology for Aero Engine Ministry of EducationSchool of Mechanical EngineeringNorthwestern Polytechnical UniversityXi'an 710072People's Republic of China

Surface integrity is important to improve the fatigue property of *** selection of the cutting parameters is extremely important in ensuring high surface *** this paper,ball end milling of TC17 alloy has been carried out utilizing response surface *** effects of cutting speed,feed per tooth,cutting depth,and cutting width on the surface integrity characteristics,including surface roughness(R_(a)),surface topography,residual stress,and microstructure were ***,predictive metamodels for surface roughness,residual stress,and microhardness as a function of milling parameters were *** to the experimental results obtained,the surface roughness increases with the increase of milling parameters,the(R_(a))values vary from 0.4μm to 1.2μm along the feed direction,which are much lower compared to that along the pick feed *** surface compressive residual stress increases with the increase of feed per tooth,cutting depth,and cutting width,while that decreases at high cutting *** depth of the compressive residual stress layer is mostly in the range of 25-40μ*** milled surface microhardness represents 6.4% compared with the initial state;the work-hardened layer depth is approximately 20μ***,plastic deformation and strain streamlines are observed within 3μm depth beneath the *** empirical model of surface integrity characteristics is developed using the results of ten experiments and validated by two extra *** prediction errors of the three surface integrity characteristics are within 27%;the empirical model of microhardness has the lowest prediction errors.

关键词： Prediction model Surface roughness(R_(a)) Residual stress Microhardness Microstructure

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Analytical model of cutting force in axial ultrasonic vibration-assisted milling in-situ TiB_(2)/7050Al PRMMCs

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Chinese Journal of Aeronautics 2021年第4期34卷 160-173页

作者： Xiaofen LIU Wenhu WANG Ruisong JIANG Yifeng XIONG Kunyang LIN Junchen LI Chenwei SHAN Key Laboratory of High Performance manufacturing for Aero Engine Ministry of Industry and Information TechnologySchool of Mechanical EngineeringNorthwestern Polytechnical UniversityXi'an 710072China Engineering Research center of advanced manufacturing Technology for Aero Engine Ministry of EducationSchool of Mechanical EngineeringNorthwestern Polytechnical UniversityXi'an 710072China School of Aeronautics and Astronautics Sichuan UniversityChengdu 610065China

Ultrasonic vibration-assisted milling has been widely applied in machining the difficultto-cut materials owing to the remarkable improvements in reducing the cutting ***,analytical models to reveal the mechanism and predict the cutting force of ultrasonic vibrationassisted milling metal matrix composites are still needed to be *** this paper,an analytical model of cutting force was established for ultrasonic vibration-assisted milling in-situ TiB_(2)/7050 Al metal matrix *** modeling,change of motion of the cutting tool,contact of toolchip-workpiece and acceleration of the chip caused by ultrasonic vibration was considered based on equivalent oblique cutting ***,material properties,tool geometry,cutting parameters and vibration parameters were taken into ***,the developed analytical force model was validated with and without ultrasonic vibration milling experiments on in-situ TiB_(2)/7050 Al metal matrix *** predicted cutting forces show to be consistent well with the measured cutting ***,the relative error of instantaneous maximum forces between the predicted and measured data is from 0.4%to 15.1%.The analytical model is significant for cutting force prediction not only in ultrasonic-vibration assisted milling but also in conventional milling in-situ TiB_(2)/7050 Al metal matrix composites,which was proved with general applicability.

关键词： Al-MMCs Analytical model Cutting force In-situ Milling TiB_(2)particles Ultrasonic vibration

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