Surface metrology algorithm testing system

This paper presents the development of a Web-based surface metrology algorithm testing system. The system includes surface analysis tools and a surface texture specimen database for parameter evaluation and algorithm verification. The system runs from a Website at the National Institute of Standards and Technology (NIST), USA. Manufacturers, instrument makers, and researchers have access via the Internet to standard data sets and analysis tools located on a NIST server. The system serves to validate the accuracy of algorithms as well as the calculation of surface parameters in industry. The System can be accessed through http://syseng.nist.gov/VSC/jsp.     

A framework for Internet-based surface texture analysis and information system

With the emergence of a global market and the recent trend of outsourcing, it is necessary for companies to have tools for remote access of data and an ability to analyze and troubleshoot manufacturing processes remotely. This need is addressed by developing an Internet-based surface texture analysis and information system, and a peer-to-peer data-sharing tool. These systems will help companies to diagnose problems related to surface texture in manufacturing process remotely. The development of the system has provided engineers from industry and academia a common framework for sharing, analyzing and storing surface texture data, analysis results, documents and reports. The system also provides a platform for quick deployment of solutions developed anywhere in the world. This paper presents the design, development and applications of a framework for surface texture analysis and information system.     

计算机辅助已加工表面质量分析系统

分析已加工表面质量的影响因素和变化规律 ,有助于在零件加工时 ,获得规定的表面质量要求。设计和开发计算机辅助已加工表面质量分析系统 ,可以快捷地检索到各种加工方法所能达到的表面粗糙度 ,工件表面加工硬化情况 ,以及调整与控制残余应力的措施     

A universal spline filter for surface metrology

In this study, a novel fractional spline filter is proposed for surface metrology. The filter combines arbitrary order fractional spline function with variational principle, and is endowed with an adjustability of transition characteristic. If the order is high enough, the fractional spline filter can obtain more step-edge-like cut-off characteristic of the low-pass filter, and it can also realize the transmission characteristic of the Gaussian filter with high accuracy if the order equals to two. In addition, if the approximation parameter is set to zero, this filter will be simplified to a form of ordinary spline filter. Therefore, this fractional spline filter is called the universal spline filter. In order to reduce the computation time, the universal spline filter is calculated by a fast Fourier transform (FFT) algorithm. Furthermore, for practical use, an improved method prior to the FFT algorithm is proposed to suppress the end effect. Finally, the efficiency of the whole algorithm in comparison with the ordinary spline filter is demonstrated by the experiments, and it is also shown that the universal spline filter is able to alleviate the end effect significantly.     

Inference engine for process diagnostics and functional correlation in surface metrology

The practice of surface metrology in the industry today has not advanced beyond simple parameter computation and tolerance verification. While surface texture measurements are intended to aid in process diagnostics or functional prediction, it is currently mostly used only as a go-no go gage for specification compliance. A primary reason for this is the lack of availability of tools and techniques for correlating surface texture parameters with functional measures. Current analysis systems are not geared towards analysis of multiple profiles or for correlating parameters with function. Thus, there is a need for the development of an advanced surface texture analysis system that can analyze multiple profiles and develop cause-effect models for process diagnostics and functional prediction. This paper presents the features of this analysis system and illustrates their use with a variety of case studies.     

High-order spline filter: Design and application to surface metrology

The differences between the transmission characteristics of the standard cubic spline filter and the Gaussian filter lead to different evaluation results even for the same profile. There is indeed an adverse impact on the comparison of measurement results and the applications of the related international standards. A novel high-order spline filter is proposed to resolve this practical problem of approximating the Gaussian filtering characteristic. The design of the new filter is based on an improved variational approach by adding the high order derivative terms to the bending energy part whose structural parameters are determined by the aid of the universal Taylor series, so as to realize the convergence to the function of the Gaussian filter. In addition, a cascade algorithm in terms of the low-order filters is also developed in order to ensure stable performance of the high-order filter. Its effectiveness and application were verified by the experiments.     

Scale independent surface characterisation: Geography meets precision surface metrology

The recently published standard ISO 25178-2 distinguishes between field parameters and feature parameters for surface texture characterisation, whereby the main difference between these two types is due to the fact that the parameters belonging to the first group are deduced from all points of a scale-limited surface, while the parameters belonging to the second group are deduced from only a subset of predefined topological surface features. As specified in ISO 25178-2, two prerequisites are indispensable for the determination of the feature parameters, viz., an adequate data structure for surface characterisation and a suitable formal method for surface generalisation, i.e. for the successive elimination of the less important surface features. Within ISO 25178-2 change trees are proposed for describing the surface topography, while Wolf pruning is suggested for surface simplification (cf. also ISO 16610-85). Apart from the techniques specified in ISO 25178-2 and ISO 16610-85, the present paper describes a second geometrical–topological approach for the characterisation and generalisation of surfaces that has its origin within the geosciences and is based on weighted surface networks and w-contractions. In addition, it is revealed how the two approaches, both of which have their foundations in graph theory, are interrelated to each other and how, from a historical point of view, the GIScience approach forms the basis of the one applied within surface metrology. Finally, some applications within precision engineering are described.     

Internet-based electronics manufacturing troubleshooting tool for surface mount PCB assembly

Increasing product complexity, decreasing component size, and using double-sided boards have made surface mount technology (SMT) based electronics manufacturing (EM) components more difficult to assemble. This has resulted in the economic troubleshooting of EM defects being one of the main problems facing all manufacturers. Although the authors have made significant improvements in the EM process, it has been shown that the implemented changes in the automated lines have not yet produced a high enough percentage of reliable finished products. The objective of this current development is to make a contribution towards these EM processes by creating an Internet-based intelligent system of circuit board defect detection so that EM process flaws that necessitate rework operations can be identified prior to manufacturing runs. With the development of this system, the need to rework the defective components will be minimized for any assembly line and assembly line process parameters, which cause some reliability problems (such as solder balls, insufficient solder at joints, burnt joint connections, bridged leads, voids, skewed leads, and unformed joints) will be troubleshot directly, and the rework will be greatly reduced from the EM assembly line. This paper reports the current development and its structure.     

基于声发射技术的微切削加工表面形貌监测

采用声发射技术对工件材料为A16061-T6的微切削表面轮廓进行了实时测量.采集监控微切削加工表面时产生的声发射均方根信号,并与表面轮廓仪测得的结果进行对比.研究表明,声发射均方根信号与微切削表面形貌很好的相对应,因此,声发射技术适于微切削表面形貌的监测.研究了切削用量(每齿进给量和主轴转速)与表面形貌之间的关系,微切削的每齿进给量对表面粗糙度影响较大.     

B样条滤波器建立表面轮廓中线的方法

根据离散B样条函数的Z域表达式，B样条空间中对信号的拟合和分解可以表示成FIR滤波器和IIR滤波器的滤波过程，再结合变分原则，构建了表面粗糙度测量中用于确定中线的B样条滤波器。将零相移滤波技术应用到B样条滤波器的实现中，得到了相应的差分方程。对一实际工件表面轮廓进行了实验，验证了该方法的可行性，该滤波器同样具有零相移的特性，与其它方法相比，其具有计算效率高的优点。     

Process mapping and functional correlation in surface metrology: a sheet metal case study

This paper presents a case study on process mapping and functional correlation in surface metrology. Stainless steel sheets are used for home and industrial applications in a variety of products. Visual characteristics form the dominant functional aspect in these sheets. Therefore, monitoring and controlling surface finish is critical. Because the process is in the development stage, there are no specifications for surface texture parameters. Therefore, quality control involves visual inspection by human inspectors. There is a need for mapping the process to develop a preliminary specification and researching tools for automating the process of quality assessment. While surface texture is traditionally measured only for tolerance compliance in most industrial situations, the case study developed in this paper captures the larger scope of surface texture measurement and analysis. Also, in developing the case study, novel techniques for functional correlation in surface metrology are explored .     

截面测量数据的曲面重构算法研究

自由曲面重构是逆向工程研究中的一个重要部分。利用传统蒙面法生成曲面存在控制顶点膨胀的问题，这里提出了一种新的截面测量数据的曲面重构算法。该算法在传统蒙面法的基础上．采用一组平行平面去截重构曲面，在一定精度要求下，合理选择尽量少的截面曲线，再对其运用蒙面操作，从而构造一张新曲面。应用实例表明算法稳定、可靠、高效。     

面铣刀铣削表面微观几何形貌仿真系统

以面铣刀为研究对象,结合刀具的进给方式,建立了刀具刃形的数学模型,提出了面铣削加工的仿真算法,并研究主轴转速、进给速度、刀盘直径、刀片边长、刀具刃数、吃刀量、刀片形状等参数对加工表面几何形貌的影响规律,发现铣削表面质量随刃数的增加越来越好。在同一种切削条件下,进给量越大,粗造度越大。通过开发的铣削表面几何形貌仿真系统,对铣削表面粗糙度的预测及表面质量的改善有着重要的指导意义。     

Design and validation of a grinding wheel optical scanner system to repeatedly measure and characterize wheel surface topography

This paper describes the design and validation of an upgraded grinding wheel scanner system that controls the position of a Nanovea CHR-150 Axial Chromatism sensor along the x- and y-directions of the wheel surface to measure and characterize wheel surface topography. The scanner features a novel homing system that enables the wheel to be removed from the scanner, used on a grinding machine and then re-mounted and re-homed so that the same location on the wheel surface can be repeatedly measured and monitored. The average standard deviation for homing was 27.6 μm and 19.3 μm in the x- and y-directions, respectively, which is more than adequate for typical area scans of 25 mm². After homing, the scanner was able to repeatedly measure features that were similar in size to an abrasive grain (∼200 μm diameter) with an average error of 9.3 μm and 5.9 μm in the x- and y-directions, respectively. The resulting topography measurements were compared with Scanning Electron Microscope images to demonstrate the accuracy of the scanner. A custom particle filter was developed to process the resulting data and a novel analysis technique involving the rate of change of measured area was proposed as a method for establishing the reference wheel surface from which desired wheel topography results can be reported such as the number of cutting edges, cutting edge width and cutting edge area as a function of radial depth.     

An improved decomposition algorithm of surface topography of machining

Abstract

In order to accurately decompose the surface morphology of machined surface and trace the potential errors of the machine, a comprehensive improved algorithm is proposed, which combines wavelet packet decomposition (WPD) and improved complete ensemble empirical modal decomposition of adaptive noise (Improve CEEMDAN). Firstly, the cost function is used to find the optimal wavelet packet base and the optimal decomposition tree is obtained. Secondly, under semi-hard threshold denoising, the wavelet coefficients obtained by the optimal decomposition tree can generate the denoised signal. Finally, the white noise is preprocessed to obtain the upper limit frequency and the band white noise, and the improvement of CEEMDAN is completed. The improved CEEMDAN is used to decompose the denoised signal to obtain a series of intrinsic mode functions (IMFs). The merit of this comprehensive improved algorithm is that it can improve the calculation efficiency and decomposition accuracy by adaptively finding the optimal wavelet packet base and adding band-limited white noise. Simulations and experiments results show the feasibility, effectiveness and higher accuracy of the comprehensive algorithm in decomposing surface topography.     

Design of an optical probe for testing surface roughness and micro-displacement

This paper presents a practical monitoring tool for measurements of surface roughness and micro-displacement. An optical probe of the methods based on light scattering for measuring surface roughness and optical triangulation for measuring micro-displacement is described. The proposed technique allows evaluation of surface roughness and micro-displacement of specimen by using just one device. The theoretical models of surface roughness and micro-displacement measurements have been established for the probe. The measuring principles applied in the design are described in detail and the validity of the design is demonstrated by experimental evaluations. The experimental results show that, for specimens with surface roughnesses R_a in the range from 0.005μm to 0.1 μm, micro-displacement measurements in the linear range of ± 300μm can be obtained.     

Ants colony algorithm approach for multi-objective optimisation of surface grinding operations

An ant colony based optimisation procedure has been developed to optimise grinding conditions, viz. wheel speed, workpiece speed, depth of dressing and lead of dressing, using a multi-objective function model with a weighted approach for the surface grinding process. The procedure evaluates the production cost and production rate for the optimum grinding condition, subjected to constraints such as thermal damage, wheel wear parameters, machine tool stiffness and surface finish. The results are compared with Genetic Algorithm (GA) and Quadratic Programming (QP) techniques.Nomenclature a _p down feed of grinding (mm/pass) - a _w total thickness of cut (mm) - A _o initial wear flat-area percentage (%) - b _e empty width of grinding (mm) - b _s width of wheel (mm) - b _w width of workpiece (mm) - B _k positive definite approximation of the Hessian - doc depth of dressing (mm) - c _d cost of dressing ($) - c _s cost of wheel per mm³ ($/mm³) - CT total production cost ($/pc) - CT ^* expected production cost limit ($/pc) - d _g grind size (mm) - D _e diameter of wheel (mm) - f _b cross feed rate (mm/pass) - G grinding ratio - k _a constant dependent on coolant and wheel grind type - k _u wear constant (mm^-1) - k _c cutting stiffness (N/mm) - k _m static machine stiffness (N/mm) - k _s wheel wear stiffness (N/mm) - L lead of dressing (mm/rev) - L _e empty length of grinding (mm) - L _w length of workpiece (mm) - M _c cost per hour labour and administration ($/h) - N _d total number of pieces to be grouped during the life of dressing (pc) - N _t batch size of workpieces (pc) - N _td total number of workpieces to be grouped during the life of dressing (pc) - P number of workpieces loaded on the table (pc) - R _a surface roughness (µm) - R _a* surface finish limit during rough grinding (µm) - R _c workpiece hardness (Rockwell hardness number) - R _em dynamic machine characteristics - S _d distance of wheel idling (mm) - S _p number of spark out grinding (pass) - t _sh time of adjusting machine tool (min) - t _i time of loading and unloading workpiece (min) - T _ave average chip thickness during grinding (µm) - U specific grinding energy (J/mm) - U ^* critical specific grinding energy (J/mm³) - V _r speed of wheel idling (mm/min) - V _s wheel speed (m/min) - V _w workpiece speed (m/min) - VOL wheel bond percentage (%) - WRP workpiece removal parameter (mm³/min-N) - WRP ^* workpiece removal parameter limit (mm³/min-N) - WWP wheel wear parameter (mm³/min-N) - W _i weighting factor, 0W _i1 (W ₁+W ₂+W ₃=1)     

Internet based software system for surface texture and form analysis

With the emergence of a global market and the recent trend of outsourcing, it has become increasingly necessary for companies to have remote access to data for process diagnostics and quality control. This paper presents an Internet based surface texture and form analysis system that will allow a user at one geographic location to upload surface profiles into a database that another user can later analyze. This system has all the features found on commercial instruments and also some special analysis tools such as wavelet analysis, valley removal algorithms etc. The capabilities include surface texture analysis with database support, straightness, flatness, roundness and cylindricity analysis.     

机载交联设备综合检测系统设计与实现

介绍了某型机载交联设备综合检测系统的功能。主要阐述了系统的设计与实现，最后讨论了操作系统及开发软件的选择。     

On-line surface roughness recognition system using artificial neural networks system in turning operations

In modern manufacturing environments, the quality assurance of machined parts has attracted great attention from manufacturers. The surface roughness of a workpiece is one of the most important factors to consider. The need for developing a surface recognition system that is able to replace stylus-style surface measuring systems has increased to improve the efficiency of production. In this research an on-line surface recognition system was developed based on artificial neural networks (OSRR-ANN) using a sensing technique to monitor the effect of vibration produced by the motions of the cutting tool and workpiece during the cutting process. Different combinations of cutting conditions were conducted to develop an OSRR system for a lathe. In order to determine the direction of the vibration which most significantly affects surface roughness, a triaxial accelerometer was employed. Three directional vibrations which were detected simultaneously by the accelerometer were analyzed using a statistical method. The radial direction vibration was found to be the most significant vibration in turning operations. The accuracy of the developed systems showed that the developed system could predict surface roughness efficiently. The developed system not only proposes a surface recognition system which is alternative to that using a traditional measurement instrument, but also provides an on-line surface recognition system for turning operations.