Smart manufacturing systems for Industry 4.0: Conceptual framework,scenarios, and future perspectives

Information and communication technology is undergoing rapid development, and many disruptive technologies, such as cloud computing, Internet of Things, big data, and artificial intelligence, have emerged. These technologies are permeating the manufacturing industry and enable the fusion of physical and virtual worlds through cyber-physical systems (CPS), which mark the advent of the fourth stage of industrial production (i.e., Industry 4.0). The widespread application of CPS in manufacturing environments renders manufacturing systems increasingly smart. To advance research on the implementation of Industry 4.0, this study examines smart manufacturing systems for Industry 4.0. First, a conceptual framework of smart manufacturing systems for Industry 4.0 is presented. Second, demonstrative scenarios that pertain to smart design, smart machining, smart control, smart monitoring, and smart scheduling, are presented. Key technologies and their possible applications to Industry 4.0 smart manufacturing systems are reviewed based on these demonstrative scenarios. Finally, challenges and future perspectives are identified and discussed.     

摩擦学设计主要是摩擦学系统的设计

在一般意义下的讨论了摩擦学设计,涉及 摩擦学设计的目标和特征。强调摩擦学设计不能仅仅被理解为理解为摩擦副的设计,更能被理解为摩擦,磨损或润滑的设计。介绍了国内在转子－轴承－密－齿轮系统、推力轴承系统、缸套－活塞－活塞环系统、主动磁轴承系统和摩擦学机敏材料系统设计方面所做的一些工作。国家自然科学基金委员会对这些 强有力的经费支持。     

A GENERIC MECHANICS OF CUTTING APPROACH TO PREDICTIVE TECHNOLOGICAL PERFORMANCE MODELING OF THE WIDE SPECTRUM OF MACHINING OPERATIONS

The need for quantitatively reliable predictive models for the many technological machining performance measures to optimize the economic performance of machining operations, and to design machine tools and cutting tools that enhance this economic performance, has been highlighted. Also highlighted is the formidable task of establishing the required quantitative technological performance data and equations, and the gap between theory and practice. The development and generic nature of the “unified or generalized mechanics of cutting approach” to technological performance prediction for the wide spectrum of machining operations is presented and discussed in this paper. Suggestions for overcoming some practical difficulties and extending the scope of this predictive modeling approach are also considered.     

New cylinder liner surfaces for low oil consumption

Anticipated emission legislation and reduced fuel consumption are the main driving forces when developing new engines. Optimization of the active surfaces in the piston system is one possible way to meet the above demands. In this study the effects of surface topography and texture direction of the ring/liner contact on oil film thickness and friction were simulated and experimentally tested. “Low wear” results from the experimental wear tests with “glide honed” smooth liner surfaces supported the “low friction” simulation results. In addition a new wear volume sensitive surface roughness parameter, R_ktot, based on the Abbot–Firestone bearing area curve was introduced.     

The stability of plastic deformation in tension

Different concepts of the term “stability” are discussed and the resulting stability conditions in tension are derived. Particular importance is given to the relation between stability and the type of heterogeneities that may occur in tensile specimens. It is shown that a general instantaneous criterion of stability, in terms of the deformation properties of the material, cannot be formulated. However, if finite deformations are considered it is possible to derive general necessary criteria, which depend, of course, on the definition of stability adopted.The results obtained can explain the experimental observations concerning the phenomenon of necking in tensile tests, particularly its “weak” relation to the point of maximum load.     

Crack propagation in non-proportionally scaled elastic structures

Scaling laws for load, stress, displacement and crack velocity are given for crack propagation in non-proportionally scaled elastic structures where the scaling factors for height, width, thickness and crack length can all be different. Problems are addressed where only one or two of the scaling factors are important, in contrast to geometrically similar scaling where all factors are equal. Examples discussed include pipelines and plate-like structures of ships or bridges. The conditions under which strength of materials design criteria, based on yielding, prove inadequate for such large structures are investigated. In addition, the validity of determining “brittle” fracture toughness by “equivalent energy” scaling procedures from small laboratory specimens is discussed.     

Methodology for teaching measuring systems

In this paper, a system approach to electrical measurement teaching is presented. This approach enables one to integrate different fields of measurements and different measurement courses. “Measuring Systems” is proposed as a main measurement course for students of Electronics Faculties. A multi-function laboratory stand for teaching measuring systems is proposed to train basic abilities in measuring system design. The stand consists of an IBM PC with an IEEE-488 (IEC-625) interface board, a bus tester, HP 33120A function generator, HP 34401A multimeter with IEEE-488 and RS-232 interface, and — optionally — a measurement plug-in card and a device with a VXI interface. Students are taught how to remote control, in a unifying way, various measuring devices with various interfaces, using simple IEEE-488 software and advanced software (LabWindows/CVI, HP VEE). The laboratory stand enables students to learn practical aspects of the design of measuring systems, teaching them the system approach to measurements.     

Specific Features of the Behavior of the Coercive Force in Low-Carbon Plastically Deformed Steels

The relationship between the coercive force in low-carbon steels under plastic extension and compression and the values of deformation and actual and residual stresses are studied. This relationship is investigated for both “ slow” loading (when an equilibrium deformation is attained for each load value) and “fast” loading (when such equilibrium is not attained). It is shown that (i) a comparatively small increase in the coercive force in a loaded condition is due only to an increase in the density of dislocations in the process of plastic extension; (ii) a significant steep increase in the coercive force accompanying removal of the load from a plastically stretched specimen is fully due to residual compression stresses; (iii) the values of the coercive force under “slow” and “fast” loading are significantly different in the region of small deformations less than 2.5%; (iv) these values are close to each other in the loaded state for all deformations up to 10%; (v) a relief of the compression stress that creates plastic deformations causes a steep decrease in the coercive force that is as large as its increase following relief of plastic extension; this is explained by the emergence of a significant residual tension stress. The obtained results are of importance for the use of the method based on measuring the coercive force to test steel structures under the conditions when plastic deformations develop.__________Translated from Defektoskopiya, Vol. 41, No. 5, 2005, pp. 24–38.Original Russian Text Copyright © 2005 by Kuleev, Tsar’kova, Nichipuruk.     

Inelastic buckling of columns : The effect of imperfections

In the design of columns of mild steel (idealized as an elastic-perfectly plastic material) it is usual to take account of the effect of possible initial crookedness by means of a “Perry” formula. In contrast, the design of columns of aluminium alloys (and other materials which cannot reasonably be idealized as perfectly plastic) is usually made by means of the “tangent modulus” formula, which is strictly relevant only to initially perfect columns. The paper proposes a way of supplementing this formula for initially imperfect columns, and a simple graphical procedure is devised to generate a family of “column curves” for different degrees of imperfection.It turns out that although the “column curve” based on the tangent-modulus formula is sensitive to the precise shape of the rising stress-strain curve, the curves for the imperfect columns are insensitive to this shape, except for stocky columns. This suggests, paradoxically, a possible design approach using a Perry formula for columns made of aluminium alloys.     

Strain-rate and inertia effects in the collapse of two types of energy-absorbing structure

The dynamic plastic collapse of energy-absorbing structures is more difficult to understand than the corresponding quasi-static collapse, on account of two effects which may be described as the “strain-rate factor” and the “inertia factor” respectively. The first of these is a material property whereby the yield stress is raised, while the second can affect the collapse mode, etc. It has recently been discovered [6,7]that structures whose load-deflection curve falls sharply after an initial “peak” are much more “velocity sensitive” than structures whose load-deflection curve is “flat-topped” (Fig. 1a); that is, when a given amount of energy is delivered by a moving mass, the final deflection depends more strongly on the impact velocity. In this paper we investigate strain-rate and inertia effects in these two types of structure by means of some simple experiments performed in a “drop hammer” testing machine, together with some simple analysis which enables us to give a satisfactory account of the experimental observations. The work is motivated partly by difficulties which occur in small-scale model testing of energy-absorbing structures, on account of the fact that the “strain-rate” and “inertia” factors not only scale differently in general, but also affect the two distinct types of structure differently.     

Analytical solution for interface stresses due to concentrated surface force

The two-dimensional analytical solution for interface stresses due to concentrated surface force has been deduced, by introducing infinite mirror points which are the images of the load point reflected by the interface and the free surface, and adopting the interchange law of differentiation. The analytical solution can be represented in terms of the summation of the “partial” Goursat's complex stress functions defined in the local coordinate systems with their origins placed at each of the mirror points. It is found that the “partial” stress functions corresponding to a higher order mirror point can be determined from those to the lower one. It is also found that the contribution of the “partial” stress functions to the stress field decreases with the increase of the corresponding mirror point order, therefore, only considering the stress functions corresponding to the first several order mirror points can give the accurate enough solution. Numerical examination by the use of boundary element method has also been carried out to verify the theoretical development.     

The alpha risk of the Taguchi method for STB type quality characteristic

One of the basic assumptions of experimental design is that the error variances are equal for all treatment combinations. On the contrary, one of the basic assumptions of Taguchi’s parameter design is that the error variances are not equal for the treatment combinations. Thus, the significant parameter levels are found by maximising the signal-to-noise ratio of the quality characteristic. In the analysis of variance (ANOVA) of the signal-to-noise ratio, the combination of column effects to better estimate error variance is referred to as pooling. Taguchi has suggested the strategy of “pooling-up”. When using the pooling-up strategy, there will be the tendency to make the alpha mistake more often. If the assumption of the former is true, then there is an alpha risk that judges some factor being significant when in fact it is not. The purpose of this paper is to investigate the alpha risk of the Taguchi method for the smaller-the-better (STB) type problem by simulation. The results show that the alpha risk is very high for several orthogonal arrays.     

Machine health management in smart factory: A review

In this paper, we present a review of machine health managements for the smart factory. As the Industry 4.0 leads current factory automation and intelligent machines, the machine health management for diagnostic and prognostic purposes are essential, and their importance is getting more significant for the realization of the smart factory in the Industry 4.0. After brief introductions to important concepts and definitions composing smart factory and Industry 4.0, the developments in maintenance strategies towards Prognostics and health management (PHM) of machines are summarized. The review of machine health managements is followed, classifying the references by the monitoring components, types of measurements, as well as PHM tools and algorithms. 94 existing articles are reviewed and summarized in this regard. The implementations of machine health managements within the smart factory are discussed in terms of data connectivity, communications, Cyber-physical system (CPS) and virtual factory, relating them to Internet of things (IoT), cloud computing, and big data management.     

网络化智能传感器通用开发平台的设计与实现

网络化智能传感器是当代传感器技术的重要发展方向。提出一种构造网络化智能传感器通用开发平台的新设计思想。该平台的硬件环境由 80 5 1单片机和 PC/ 10 4单板计算机共同构成 ;平台的支撑软件系统包括自行研制的嵌入式 L inux操作系统和基于 IEEE14 5 1标准的网络化智能传感器构件库 ;在支撑软件之上 ,构造面向开发的应用环境。在该设计思想的基础上 ,一个网络化智能传感器通用开发平台已经研究开发完成 ,并在该开发平台上实现了若干种网络传感器。该开发平台 ,可以提高网络化智能传感器的设计和开发效率 ,加快智能传感器普及应用。     

Tribology applications of surface reflectance analyzers: optical characterization of the head disk interface

In this paper, we will discuss Surface Reflectance Analyzers (SRA) and their applications in tribology. We will show how the SRA instrument can be used to locate and quantify tribological parameters, such as carbon wear and lubricant buildup, at the head/disk interface. This damage can be caused by a variety of head/disk interactions. In one case, we will demonstrate the importance of slider crown on tribological performance by quantitatively comparing the damage to the disk surface during continuous start–stop test in the laser texture zone. In another case we will demonstrate the importance of slider air bearing design in ramp load/unload tests by quantitatively comparing the amount of damage near the OD of the disk. Ramp load/unload damage manifests itself in various forms. In addition to local carbon wear and lubricant effects, there is also debris from the ramp wear and occasional “dings”. We will show how the SRA system can be used to distinguish and quantify these various types of damage.     

An international length comparison at an industrial level using a photoelectric incremental encoder as transfer standard

A Japanese–German interlaboratory comparison of length measurements was conducted. A photoelectric incremental encoder with a measurement length of 270 mm was used as transfer standard. An agreement of better than 27 nm over the entire length was ascertained, and the “short-range” deviations within a length interval of approximately 10 mm could be characterized with a standard deviation of σ=0.8 nm. The results attained are considered as consistent with the estimated uncertainties of measurement. Since the measurements performed are directly traceable to the SI unit of the “metre”, the comparison supports ideas currently being discussed by some National Metrology Institutes and dealing with the question of how foundations can be laid for a generally accepted application of this method of traceability.     

Analysing the vibrating conveyor

Several possible vibrating conveyor designs—the “sealskin” conveyor, the “jerk” conveyor, the conveyor with inclined motion and the conveyor with out-of-phase motion—are first discussed and their relative performances are compared. The most promising (and most widely employed) design, namely the conveyor with inclined motion, is then analysed in detail. The analysis is in all cases limited to conveyors with a horizontal track and with vertical track accelerations not exceeding g, the gravitational constant. Since the analytical performance prediction of the conveyor with sinusoidal motion is very difficult, an alternative type of motion having a triangular velocity profile is introduced. This allows analytical expressions for conveyor performance by simple methods to be derived. The results of this analysis are compared with the theoretical predictions for sinusoidal motion obtained by means of a simulation on the analogue computer. To simplify the presentation of the performance results, the design variables are reduced to two non-dimensional parameters, one for vertical acceleration and the other for horizontal sliding. The performance, too, is described by a non-dimensional parameter, so that the completely general performance maps presented for triangular and sinusoidal track velocity profiles need contain only three parameters.     

Walking aids for elderly people: a systematic overview

Reduction of falls of elderly people has been an active research area for many years.Falls of older people can be signicantly reduced through the smart use of technologies.Such technologies can help older people to regain mobility and reduce their reliance on community care services.Therefore,mobility aids,as one of the main components of these assistive technologies,are mainly discussed in this paper.Recent obstacle detection systems and mobility aids will be reviewed in this paper,where different features are explicitly addressed.     

Comparison of experimental and theoretical residual stresses in welds: The issue of gauge volume

Welding residual stresses have an effect on many aspects of the integrity of structures but are normally one of the largest unknown stresses. Residual stresses are difficult to measure and to estimate theoretically but are often significant when compared with the service stresses on which they superimpose. High tensile residual stresses can lead to loss of performance in corrosion, fatigue and fracture.In this research, measurement of residual stresses by the neutron diffraction technique is compared to an analysis of a sample geometry by theoretical finite-element procedures. The results indicate good qualitative agreement. One of the key issues in this comparison relates to what is termed “gauge volume” in the measurement technologies and what might be described as a “calculation volume” in theoretical approaches.     

Modelling of superplastic blow forming

Some metals and metallic alloys, when deformed in particular conditions, manifest exceptional ductility giving tensile elongations of up to 1000%. This behaviour, known as “superplasticity”, could undergo considerable development in sheet metal production. The aerospace industry has already taken the opportunity of producing complex-shaped objects in a limited number of mechanical operations. It makes use of superplastic characteristics to noticeably reduce the weight and cost entailed in manufacturing some components, including structural ones. To better take advantage of the superplastic characteristics of the material, it is necessary to control the temperature and the strain rate during the manufacturing process. Since the material undergoes significant elongation, it also, necessarily, undergoes extreme thinning. The latter can prove not to be uniformly distributed because of (i) the particular geometry of the manufactured product, (ii) the characteristics of the material used, (iii) the lubrification and (iv) the process parameters adopted. The design stage should take account of the real thickness distribution in order to avoid critical areas. At this stage, thus, it is necessary, not only to design the product, but also to design the process in order to establish the optimum production parameters and to foresee the real geometry of the product. Numerical modelling is used since “in the field” analysis could prove to be expensive, and, analytical modelling would be limited only to some forms and to the use of largely approximated assumptions. The finite element method can be considered to be the most dependable both for analysing complex geometries, and for taking into consideration all the phenomena involved in the manufacturing process. One of the most delicate operations in this method is sub-dividing the continuum into elements since this discretization can have an influence both on the reliability of the results, and on computational requirements. The objective of this paper is to verify the approximation of the results that can be obtained compared to the different options possible both in terms of element type and number. The production of an axisymmetric cup in commercial aluminium based alloy Al 7475 using blow forming technology was taken as a reference case. Comparison between the results of the different simulations showed a substantial equivalence and a good correspondence to the measured thickness values. Since the computational resources required are very different for the cases examined, it can be stated that the best solution is discretization of the start-off sheet with a row of 55 axisymmetrical four node elements.