基于MAS的加工中心协同开发系统框架及建模

构建具有一定智能响应特征的加工中心协同开发系统对于缩短产品开发周期具有重要作用。为实现加工中心分布式协同设计软件系统的构造,通过分析系统开发需求,利用目前分布式智能软件系统研究的主流技术——MAS（Multi-Agent System）技术建立了系统的框架。针对系统拟实现的总任务,将系统分为不同的功能模块,并构造具有不同功能的Agents组织,描述了系统的开发框架和网络体系结构,对Agents之间的交互进行定义,最后利用统一建模语言（UML）对系统进行建模。加工中心协同开发系统框架和模型的建立为真正实现具有完善功能的软件系统奠定了坚实的基础,可在很大程度上避免软件开发的失败。     

基于正交试验的加工过程伺服系统参数优选

针对加工过程伺服系统参数优选问题,提出一种基于正交试验的伺服系统参数优选方法。在分析、建立加工过程模型的基础上,选取伺服系统参数优选正交试验的因素与水平、指标,进而搭建伺服系统仿真平台并进行仿真试验,通过数据分析、参数优选得到伺服系统的最优参数,以改善系统动态性能和稳定性能。结果表明:对于n=600 r/min、Kn=1 mm/(V·s)、Ks=1670 N/mm2、Ke=2 mm、p=1的加工系统,其伺服系统的最优参数是指数m=0.6、阻尼系数ζ=0.8、自然频率ωn=30 rad/s。     

Wear mechanisms of PcBN tools when machining AISI 316L

This paper investigates the machinability of AISI 316L stainless steel without and with NMI treatment, when machined with three different PcBN tool grades: low cBN content (50% vol.), medium (65% vol.) and high (90% vol.). The NMI treatment consisted of resulfurized and Ca-treated steels with two different Si/Al ratio. The tool materials were evaluated in terms of tool life, showing the best performance for the medium cBN content grade. Results showed that the crater wear has a more significant effect on the tool performance than the standard wear criteria of maximum flank wear. The worn tools were examined using scanning electron microscopy (SEM), focused ion beam (FIB) and transmission electron microscopy (TEM). In most cases, the crater exhibited three distinct regions from the edge to the end of the contact zone: the plateau, middle crater, and the upper region. Plateau and crater region displayed tool protective layer (TPL), consisting mostly of Al, Si, Mg and Ca-oxides; and some dimples in the tool from preferential wear of cBN grains. In the upper region of the best performing material, a ~1.5 μm thick TPL of mostly MnCr₂O₄ spinel was found, a result of the transfer of Mn- and Cr-rich oxide NMIs found in this material or oxidation of workpiece material, during the machining process.     

An experimental study of tool wear and cutting force variation in the end milling of Inconel 718 with coated carbide inserts

Inconel 718 is a difficult-to-cut nickel-based superalloy commonly used in aerospace industry. This paper presents an experimental study of the tool wear propagation and cutting force variations in the end milling of Inconel 718 with coated carbide inserts. The experimental results showed that significant flank wear was the predominant failure mode affecting the tool life. The tool flank wear propagation in the up milling operations was more rapid than that in the down milling operations. The cutting force variation along with the tool wear propagation was also analysed. While the thermal effects could be a significant cause for the peak force variation within a single cutting pass, the tool wear propagation was believed to be responsible for the gradual increase of the mean peak force in successive cutting passes.     

机械加工中假废品的研究

通过实例分析，给出快速判定易产生假废品的范围的办法，与传统的方法比，节省了检查人员与工人的时间，提高了劳动效率。具有操作简梗、切实可靠等特点.     

可转位刀片三维断屑槽CAT/CAD/CAM系统

给出了一个可转位刀片三维断屑槽测量、设计与制造的CAT／CAD／CAM系统，并对该开发系统各部分结构和功能进行了简介。     

Adaptive interpolation scheme for NURBS curves with the integration of machining dynamics

This paper develops a comprehensive interpolation scheme for non-uniform rational B-spline (NURBS) curves, which does not only simultaneously meet the requirements of both constant feedrate and chord accuracy, but also real-time integrates machining dynamics in the interpolation stage. Although the existing work in this regard has realized the importance to simultaneously consider chord error and machining dynamics, none has really incorporated these in one complete interpolation scheme. In this paper, machining dynamics is considered for three aspects: sharp corners or feedrate sensitive corners on the curves, components with high frequencies or frequencies matching machine natural ones and high jerks. A look-ahead module was developed for detecting and adaptively adjusting the feedrate at the sharp corners. By Fast Fourier Transform (FFT) analysis with a moving window in the interpolation stage identified were some special frequency components such as those containing high frequencies or with frequencies matching machine natural ones. Then, the notch filtering or time spacing method was used to eliminate these components. To more completely reduce feedrate and acceleration fluctuations, the jerk-limited algorithm was also developed. Finally, the interpolated feedrate was further smoothened with B-spline fitting method and the NURBS curves were re-interpolated with the smoothened feedrate. During the interpolation, the chord error was repeatedly checked and confined in the prescribed tolerance. Two NURBS curves were used as examples to test the feasibility of the developed interpolation scheme.     

Machining accuracy for shearing process of thin-sheet metals—Development of initial tool position adjustment system

In the shearing process, clearance has a significant effect on machining accuracy. However, the relationship between uneven clearance caused by misalignment of tool position and machining accuracy remains unclear. This is attributed to the fact that, previously, the effect was small because the thickness of the workpiece was not so thin, and a method for precisely measuring and adjusting the tool position had not been established. Therefore, in the present study, a new method of adjusting the initial tool position is developed. In addition, punching experiments are conducted under the condition that the initial tool position is adjusted to an accuracy of 2 μm or better, and the effects of clearance on machining accuracy, shape of cross-section, and diameter of hole, are investigated in three types of materials. From these results, the importance of adjusting the initial tool position is clarified.     

Numeripath CNC-800M系统编程技巧探讨

基于Numeripath CNC-800M系统的特性和被加工机件的结构特点，探讨了使用该系统编程的一些工艺处理方法和技巧。     

Fuzzy adaptive networks in machining process modeling: surface roughness prediction for turning operations

Due to the complexity of the machine tool structure and the cutting process, the dynamics of machining processes are still not completely understood. This is especially true due to the demand of high-speed machining to increase productivity. In order to model and control these complex processes, new approaches, which can represent complex phenomenon combined with learning ability, are needed. The combined neural–fuzzy approach appears to be ideally suited for this purpose. In this paper, the recently developed fuzzy adaptive network (FAN) is used to model surface roughness in turning operations. The FAN network has both the learning ability of neural network and linguistic representation of complex, not well-understood, vague phenomenon. Furthermore, it can continuously improve the initially obtained rough model based on the daily operating data. To illustrate this approach, a model representing the influences of machining parameters on surface roughness is established and then the model is verified by the use of the results of pilot experiments. Finally, a comparison with the results based on statistical regression is provided.