Mechanistic modelling of the milling process using complex tool geometry

Mechanistic models of the milling process must calculate the chip geometry and the cutter edge contact length in order to predict milling forces accurately. This task becomes increasingly difficult for the machining of three dimensional parts using complex tool geometry, such as bull nose cutters. In this paper, a mechanistic model of the milling process based on an adaptive and local depth buffer of the computer graphics card is compared to a traditional simulation method. Results are compared using a 3-axis wedge shaped cut – a tool path with a known chip geometry – in order to accommodate the traditional method. Effects of cutter nose radius on the cutting and edge forces are considered. It is verified that there is little difference (1.4% at most) in the predicted force values of the two methods, thereby validating the adaptive depth buffer approach. The numerical simulations are also verified using experimental cutting tests of aluminium, and found to agree closely (within 12%).     

Manufacturing message specification (MMS) based open manufacturing system

Manufacturing equipment should be integrated to construct a computer integrated manufacturing (CIM) environment, but several economical and technological difficulties may surface when heterogeneous systems are integrated into each other. Manufacturing message specification (MMS) can be effective in such case, but the problem is that MMS-related products are comparatively expensive and most existing manufacturing equipment does not support MMS. This study focused on developing a gateway suitable to a non-MMS-compatible CNC machine-tool, and on implementing an open system interconnection (OSI) upper layer on TCP/IP. The development system was applied to a cell controller by means of heterogeneous equipment under the CIM environment and to evaluate its interoperability and portability.     

航空产品工艺过程管理系统研究

针对航空产品工艺过程管理复杂、信息共享困难的难题,通过对其工艺过程中信息传递过程、工艺业务流程的深入分析,从制造过程全局的角度出发,提出工艺过程管理体系.通过对物料清单数据、业务流程的统一组织管理,打通制约工艺工作的瓶颈,缩短产品流转过程,提高生产效率,实现产品快速生产.     

面向工艺设计的制造过程建模

基于工艺设计对产品制造成本、质量和效率的重要影响,提出了一种基于工艺设计的制造过程建模方法,以通过对过程模型的仿真,预测、分析和优化工艺设计效果。基于对制造过程的特征分析,采用面向对象的方法,首先将制造过程定义为一组成对象,并划分为制造活动、过程控制和制造资源3类成分对象,建立了制造过程类结构模型和动态过程模型。分别定义了工序类、制造资源类和过程控制类的类结构模型,以及各类对象的方法和属性。基于这些模型开发了一种计算机辅助工艺设计系统,可快速、自动地构建工艺设计定义的制造过程模型,并对过程参数（成本、时间）、切削加工、工件物流进行计算和仿真。     

A specification language for planning and fault recovery in manufacturing systems

This paper presents the syntax and semantics of a component-oriented rule-based language for specifying the formal models of manufacturing systems. A model captures the state of a component of the system in a set of first-order logic predicates, and it captures the semantics of the operations performed by this component in a set of rules that determine the preconditions and postconditions of an operation. The models are then used to plan the sequence of operations of each class of jobs to be manufactured by these systems. A plan-oriented fault detection and correction strategy is proposed. This strategy can automatically handle any combination of faults that may occur when monitoring the operations of manufacturing systems. A fault-tree is consulted prior to executing the scheduled operations of a plan, and the faults that affect the execution of these operations are handled subsequently. Resuming the original cyclic schedule is attempted, whenever feasible. As a proof of concept, a prototype implementation of both the main constructs of the component-oriented rule-based language and the planning and fault-recovery algorithms presented in this paper have been completed. This prototype is implemented on a Unix-based system in the Ada programming language. The specification of a manufacturing system is first expressed in the proposed language. These statements are then translated into Ada code. This code is next compiled by a Verdix Ada compiler and is executed in order to create and populate the model data structure of the system. A detailed plan of execution and a set of fault-recovery plans may then be derived for a job to be manufactured on this system.     

业务过程执行语言流程语义标注方法研究

为提高工作流模型在分布式执行过程中的自动化程度.解决语义异构问题,提出了一种基于本体的业务过程执行语言语义标注方法,构建了业务工程执行语言流程树和Web本体描述语言领域本体树.针对业务工程执行语言流程中的每个概念,分别从三个角度计算其与Web本体描述语言领域本体中所有概念之问的语义相似度,并选取与该概念复合相似度最大的概念建立映射关系.通过语义消歧过程.消除业务工程执行语言流程中存在的语义异构,并生成语义消歧树,进而基于一系列映射规则,将语义消歧树转化为Web服务本体描述语言描述的语义工作流模型.最后给出应用实例,并采用F1-measure对所提出的语义消歧方法进行评估.     

基于装配工艺规程的产品虚拟装配技术

描述了VPD环境下的产品装配模型，建立了产品装配模型的数据结构，定义了产品装配模型系统的结构组成及模块功能；参照加工工艺规程，提出了虚拟产品装配工艺规程的概念；结合挤塑模和轻型客车的虚拟装配、活塞连杆机构及发动机的运动过程，实现了基于真实动画感的VPD环境下的产品虚拟装配及虚拟工作过程仿真。     

Review of research in tooling technology,process modelling and process planning part I: Tooling and process modelling

This review contains an assessment of research in the areas of tooling technology and management and process modelling. The assessment was performed as part of a recent travel study to several university research centres. Research in tooling technology was found to be fragmented and inadequate. Additional work is needed in integrated tooling technology concepts and in tool management. Extensive research work is reported in process modelling for product development, whilst detailed process models are frequently constructed on an ad-hoc basis without any formal analysis regarding data requirements and knowledge representation.     

一种大型结构件的制作工艺

近年来,国家生态环境部下发了《钢铁企业超低排放改造工作方案》,要求加快推进钢铁行业超低排放改造,从根本上扭转钢铁行业高能耗、高污染的形象,在提升行业高质量发展的同时为员工创造良好的工作环境,有效保障员工的职业健康安全,提升周边环境的空气质量.国内冶金行业多家知名单位正在进行超低排放改造项目的立项和实施验收,大型冶金起重...     

Workpiece modelling for computer-aided process planning

Different concepts can be applied for representation of workpiece data for CAPP. Instead of waiting for future standards, a practical method is required, which can be used for actual workpieces or those that have been designed in the past by using already existing CAD systems. Therefore, for developing the CAPP system an approach has been chosen which consists of (1) a structure and geometry recognition of the workpiece and (2) an editor for technological data.This paper shows the main characteristics of a workpiece model which can be used for process planning. The results of an analysis of workpieces in industry give an overview of the topological relationships between geometrical elements which is an essential part of workpiece modelling for future design and planning systems. Also, a link between the workpiece model and the CAPP system is presented and briefly discussed.     

制造企业工艺知识Web检索技术研究

从制造业信息化发展与工艺知识结合点考虑,简要介绍知识管理在企业工艺方面的应用,并基于工艺知识的特征建立了工艺知识的检索模型.     

柔性结构滚筒的制造工艺

分析了柔性结构滚筒的特点,介绍了设计制造的要点、制作流程,用工程实例具体说明注意事项,对生产实践具有一定的参考意义。     

Fuzzy process capability plots for families of one-sided specification limits

Process capability indices (PCIs) have been popularly used in the manufacturing industry for measuring process potential and performance. When our data are imprecise, classical PCIs are improper. In this paper, a graphical approach has been presented for monitoring whether or not our process is capable by using the process capability plots for two families of the one-sided PCIs based on fuzzy data. The presented methodology takes into consideration the certain degree of imprecision on the sample data and leads to the three-decision rule that has been presented on the process capability plot. Also, the advantages of this method in comparison to the fuzzy hypothesis test have been discussed. Two real examples have been presented to demonstrate this approach.     

整车验证模型五轴数控加工编程工艺规范研究

探讨了整车验证模型五轴数控加工工艺要点;基于先进CAM软件对整车验证模型五轴数控加工刀具路径编程工艺进行研究;提出了对该模型的五轴数控加工编程工艺规范化思路以及具体实施方案;基于Power MILL系统、易语言编程系统开发了整车验证模型五轴数控加工编程工艺模版库、刀具库和机床库。     

服务交互过程模型的业务流程执行语言描述方法

为了解决目前各种流程建模技术与建模语言之间差异所造成的服务交互过程模型集成和交互的困难,更好地实现以数据为中心的体系结构开发策略,提出了一种指挥自动化系统体系结构服务视图的业务流程执行语言建模的实现方法。该方法依据国际国防企业体系结构规范的建模基础,构建了C4ISR体系结构服务视图的元模型;以模型驱动体系结构思想为基础,基于元对象设施的四层元建模架构,研究了指挥自动化系统体系结构服务视图元模型到业务流程执行语言的转换方法;基于建模原语—模式方法研究了指挥自动化系统体系结构服务视图中主要服务交互模式到业务流程执行语言描述的映射规则。     

拟实制造的机械加工过程仿真

叙述了拟实制造技术的含义、构成及发展情况,分析了在拟实制造中占有重要地位的机械加工过程仿真。提出了机械加工过程仿真的系统结构,发展现状与存在的问题,最后讨论了车削加工过程进行仿真及其实现的可能性。     

分布虚拟制造中的加工过程仿真

简述了分布虚拟制造的内涵和机加工过程仿真的内容。指出了目前分布虚拟制造加工过程仿真在几何仿真、物理仿和数据通信与传输中存在的问题,并对其中关键技术提出了研究对策。     

生产型虚拟制造系统过程模型的Z规范技术

为解决虚拟制造系统间过程信息的集成与共享,提出了一种基于虚拟制造过程元模型和形式化Z语言工具的过程模型规范研究方法.元模型以活动和连接弧为核心,关联制造过程中的产品、资源、转移条件和相关数据,并根据制造过程特点设计了三种标志节点、七种任务节点和两类连接弧.过程要素的Z规范描述保证了数据语义的准确性和无二义性.通过对典型的车间生产和装配过程进行建模,验证了元模型的有效性.     

Mathematical modelling of burr height of the drilling process using a statistical-based multi-gene genetic programming approach

Drilling is one of the important machining processes performed extensively in production industry. Literature emphasises that the output process parameters such as burr height, surface roughness, strength, etc. are related to and can be improved by the appropriate settings of the input process parameters. Recently, researchers have applied well-known computational intelligence methods such as regression analysis, artificial neural networks (ANNs), support vector regression (SVR), etc. in the prediction of performance characteristics of the drilling process. Alternatively, an evolutionary approach of multi-gene genetic programming (MGGP) that evolves the model structure and its coefficients automatically can be applied. Despite of being widely applied, MGGP has the limitation for producing models that over-fit on the testing data. One of the reasons attributed for this behaviour is the over-size of the evolved models. Therefore, a statistical-based MGGP (S-MGGP) approach is proposed and applied to the burr height data obtained from the drilling of AISI 316L stainless steel. In this proposed approach, Bayesian information criterion is embedded in its paradigm, which punishes the fitness of larger size models. The performance of S-MGGP and ANN models is found to be better than those of the standardised MGGP and SVR. Further, the parametric and sensitivity analysis conducted validates the robustness of our proposed model and is proved to capture the dynamics of the drilling phenomenon by unveiling dominant input process parameters and the hidden non-linear relationships.     

The process modelling of epoxy dispensing for microchip encapsulation using fuzzy linear regression with fuzzy intervals

Epoxy dispensing is a popular way to perform microchip encapsulation for chip-on-board (COB) packages. However, the determination of the proper process parameters setting for a satisfactory encapsulation quality is difficult due to the complex behaviour of the encapsulant during the dispensing process and the inherent fuzziness of epoxy dispensing systems. Sometimes, the observed values from the process may be irregular. In conventional regression models, deviations between the observed values and the estimated values are supposed to have a probability distribution. However, when data is scattered, the obtained regression model has too wide of a possibility range. These deviations in processes such as epoxy dispensing can be regarded as system fuzziness that can be dealt with satisfactorily using a fuzzy regression method. In this paper, the fuzzy linear regression concept with fuzzy intervals and its application to the process modelling of epoxy dispensing for microchip encapsulation are described. Two fuzzy regression models, expressing the correlation between various process parameters and the two quality characteristics, respectively, were developed. Validation experiments were performed to demonstrate the effectiveness of the method for process modelling.