数控图形仿真的设计与实现

数控仿真是代替传统试切来验证加工程序的重要手段。首先介绍了三维图形几何仿真数学模型,根据数控ANC_45M加工中心的图形仿真需求,对图形仿真器数学建模、图形裁减和三维图形层次感等问题进行了研究与设计,并在加工中心的控制系统中用C语言实现。最后用加工程序进行验证,结果表明采用层次感的图形显示方法,对表达图形的真实感有所改善,图形仿真器完全能够满足数控程序调试的需要。     

三维虚拟加工环境及其关键技术的研究

在分析虚拟制造特点的基础上,提出了三维可视化虚拟加工环境的系统结构,介绍了支持三维建模仿真的组件设计、基于装配模型的三维实体建模方法、NC代码解析器的设计方案以及基于毛坯表面三角片离散化的加工过程仿真算法,并开发了虚拟加工环境原型系统,该系统能够实时地反映零件虚拟原型的加工成形过程仿真,并进行可加工性分析。     

基于Web的铣削过程颤振稳定域远程仿真系统研究

文章在分析数控加工铣削过程颤振稳定域仿真技术,介绍MATLABWebServer应用程序体系结构与开发原理的基础上,研究开发了基于Web的数控加工铣削过程颤振稳定域远程仿真系统;该系统实现了MATLAB语言与HTML语言的结合应用,为数控加工过程切削参数的合理、有效地选择提供了一种网络化远程仿真工具和方法,整个系统的主要功能在实际数控加工中得到了相应的验证。     

基于Java及PS/2协议的数控仿真平台

数控加工技术是机械类工科大学生必备的专业技能之一,但由于资源的缺乏及安全的考虑,受培训者实际动手操作的机会有限,教学效果不佳.数控仿真很好地解决了上述问题.文中以数控车床为主要研究对象,给出了切削加工的简单运动学模型和力学模型及Java语言的程序实现,取得了具有真实感的仿真效果.同时基于PS/2协议开发了数控车床的仿真面板,并实现仿真程序与仿真面板的连接.开发出跨平台（cross platform）、即插即用（plug and play）具有真实感的数控车床仿真教学平台.     

Parsec: a parallel simulation environment for complex systems

Design and development costs for extremely large systems could be significantly reduced if only there were efficient techniques for evaluating design alternatives and predicting their impact on overall system performance metrics. Due to the systems' analytical intractability, simulation is the most common performance evaluation technique for such systems. However, the long execution times needed for sequential simulation models often hampers evaluation. The slow speeds of sequential model execution have led to growing interest in the use of parallel execution for simulating large-scale systems. Widespread use of parallel simulation, however; has been significantly hindered by a lack of tools for integrating parallel model execution into the overall framework of system simulation. Another drawback to widespread use of simulations is the cost of model design and maintenance. The simulation environment the authors developed at UCLA attempts to address some of these issues. It consists of three primary components: a parallel simulation language called Parsec (parallel simulation environment for complex systems), its GUI, called Pave, and the portable runtime system that implements the simulation algorithms     

数控加工仿真系统的研究与应用

介绍数控加工仿真系统的整体设计,提出格栅voxel三维实体建模方法,刀具扫描体的生成算法,实现了刀具切削工件过程的动态仿真,并对碰撞检查算法进行了初步的研究.基于以上方法,建立了蓝天数控系统的加工仿真系统,在加工前对加工程序进行验证,在加工时对刀具轨迹的执行、工件的切削过程等进行实时监控.     

遗忘因子法参数辨识及其在Matlab中仿真实现

介绍了基于MATLAB／Simulink的使用遗忘因子法进行参数辨识的设计与仿真方法。首先简述参数辨识的概念和遗忘因子法的基本原理，然后介绍如何采用Simulink建立系统的仿真对象模型和运用MATLAB6．5的M语言编写遗忘因子递推算法，最后结合实例给出相应的仿真结果和分析。本文的仿真方法克服了传统编程语言仿真时繁杂、难度高、周期长的缺点。     

基于MATLAB的最小二乘法参数辨识与仿真

本文介绍了基于MATLAB/Simulink的使用最小二乘法进行参数辨识的设计与仿真方法.首先简述参数辨识的概念和最小二乘法的基本原理,然后介绍如何采用Simulink建立系统的仿真对象模型和运用MATLAB的M语言编写最小二乘递推算法,最后结合实例给出相应的仿真结果和分析.本文的仿真方法克服了传统编程语言仿真时繁杂、难度高、周期长的缺点.     

激光切割图形显示和校验研究

研究了激光切割图形显示和校验方法。编程人员通过图形显示，将所编辑的NC代码映射为直观的图形，并与用户要求的零件轮廓比较，从而纠正编程错误及工艺不合理，通过图形校验功能可以自动求出零件轮廓是否经过了顶针保护区，在避开顶外保护区的情况下，可以在编程人员的授权下自动修改NC代码，全部软件用C语言开发，已成功地用于激光切割系统中。     

iCoSim-FMS: An intelligent co-simulator for the adaptive control of complex flexible manufacturing systems

We describe an intelligent co-simulator for real time production control of a complex flexible manufacturing system (CFMS) having machine and tool flexibility. The manufacturing processes associated with the CFMS are complicated with each operation being possibly done by several machining centers. The co-simulator design approach is built upon the theory of dynamic meta-model based supervisory control with the cooperation of its own embedded intelligent blocks. The system is implemented by coupling of the centralized simulation controller (CSC) and real-time simulator for enforcing dynamic strategies of shop floor control. The posteriori adaptive co-simulator is equipped with a concurrent bilateral mechanism for simulation optimization based on appropriate control rules enhancing performance criteria simulation efficiency. A working intelligent adaptive controller prototype (iCoSim-FMS) has been developed to validate the proposed approach and compare its performance with well known FMS heuristic methods.     

策略可扩展的ACD模块的设计与实现

ACD（自动呼叫分配）作为呼叫中心的组成部分,实现了坐席路由功能。传统的A03均采用了固定路由策略的设计方式,使得用户在使用时不能自主添加新的策略。为了增加整个呼叫中心系统的可用性,基于动态链接技术以及程序模块化设计方法提出了一种有别于传统ACD的体系结构,并以此为基础实现了一套A03系统“KACD”。通过系统仿真试验,证明了在该系统中,用户能够在不丧失系统性能的前提下自主设计并添加坐席路由策略。     

Designing and evaluating a wizarded uncertainty-adaptive spoken dialogue tutoring system

We describe the design and evaluation of two different dynamic student uncertainty adaptations in wizarded versions of a spoken dialogue tutoring system. The two adaptive systems adapt to each student turn based on its uncertainty, after an unseen human “wizard” performs speech recognition and natural language understanding and annotates the turn for uncertainty. The design of our two uncertainty adaptations is based on a hypothesis in the literature that uncertainty is an “opportunity to learn”; both adaptations use additional substantive content to respond to uncertain turns, but the two adaptations vary in the complexity of these responses. The evaluation of our two uncertainty adaptations represents one of the first controlled experiments to investigate whether substantive dynamic responses to student affect can significantly improve performance in computer tutors. To our knowledge we are the first study to show that dynamically responding to uncertainty can significantly improve learning during computer tutoring. We also highlight our ongoing evaluation of our uncertainty-adaptive systems with respect to other important performance metrics, and we discuss how our corpus can be used by the wider computer speech and language community as a linguistic resource supporting further research on effective affect-adaptive spoken dialogue systems in general.     

BFPC龙门框架组件拓扑优化及性能分析

为探索提高机床基础件静、动态性能和轻质性的新方法,首先,以某加工中心框架组件为原型,初步设计玄武岩纤维树脂混凝土(Blasalt Fiber Reinforced Concrete,BFPC)龙门框架组件,分析典型工况下该框架组件的受力情况,并对原型龙门框架组件的静态、模态和谐响应进行仿真分析和计算。然后,对BFPC龙门框架组件进行拓扑优化设计,根据拓扑优化设计结果和BFPC龙门框架组件的制造工艺性,重构BFPC龙门框架组件结构。最后,对优化后的BFPC龙门框架组件的静、动态性能和轻质性进行仿真分析和计算,再与原型的相应性能进行对比分析。结果表明,拓扑优化设计后的BFPC龙门框架组件在静、动态性能和轻质性方面都明显优于原型龙门框架组件。     

HLA仿真系统中Lookahead的分析与动态调整策略

在HLA仿真系统中，Lookahead是影响系统性能的重要参量，对Lookahead的管理也是实现邦元程序的重要内容。采用时间分段的方式重新定义HLA仿真系统中的Lookahead，很好地解决了仿真运行中时戳增量改变较大的问题。在此基础上提出的Lookahead动态调整算法考虑了邦元程序对要接收事件的经验值，可以有效提高系统运行性能，协助邦元程序设计。     

The role of simulation in design of FMSs

The present work discusses the fundamental structure of simulation models (components, relations, terms, etc…); their basic elements, the programming language, and model structure and requirements. The study aims to define the role of simulation in design of a dynamic system such as FMS.

A simulation study is carried out to demonstrate the application of simulation models. The system to be examined is a planned PMColl. The major task was to evaluate design issues such as the effect of priority rules for job sequencing, the determination of the number of pallets limit, and better conveyor speed.     

Modeling and real-time simulation architectures for virtual prototyping of off-road vehicles

Virtual Reality-based simulation technology has evolved as a useful design and analysis tool at an early stage in the design for evaluating performance of human-operated agricultural and construction machinery. Detecting anomalies in the design prior to building physical prototypes and expensive testing leads to significant cost savings. The efficacy of such simulation technology depends on how realistically the simulation mimics the real-life operation of the machinery. It is therefore necessary to achieve ‘real-time’ dynamic simulation of such machines with operator-in-the-loop functionality. Such simulation often leads to intensive computational burdens. A distributed architecture was developed for off-road vehicle dynamic models and 3D graphics visualization to distribute the overall computational load of the system across multiple computational platforms. Multi-rate model simulation was also used to simulate various system dynamics with different integration time steps, so that the computational power can be distributed more intelligently. This architecture consisted of three major components: a dynamic model simulator, a virtual reality simulator for 3D graphics, and an interface to the controller and input hardware devices. Several off-road vehicle dynamics models were developed with varying degrees of fidelity, as well as automatic guidance controller models and a controller area network interface to embedded controllers and user input devices. The simulation architecture reduced the computational load to an individual machine and increased the real-time simulation capability with complex off-road vehicle system models and controllers. This architecture provides an environment to test virtual prototypes of the vehicle systems in real-time and the opportunity to test the functionality of newly developed controller software and hardware.     

Model continuity in the design of dynamic distributed real-time systems

Model continuity refers to the ability to transition as much as possible a model specification through the stages of a development process. In this paper, the authors show how a modeling and simulation environment, based on the discrete event system specification formalism, can support model continuity in the design of dynamic distributed real-time systems. In designing such systems, the authors restrict such continuity to the models that implement the system's real-time control and dynamic reconfiguration. The proposed methodology supports systematic modeling of dynamic systems and adopts simulation-based tests for distributed real-time software. Model continuity is emphasized during the entire process of software development $the control models of a dynamic distributed real-time system can be designed, analyzed, and tested by simulation methods, and then smoothly transitioned from simulation to distributed execution. A dynamic team formation distributed robotic system is presented as an example to show how model continuity methodology effectively manages the complexity of developing and testing the control software for this system.     

Solution of scheduling problems of job-shop type FMS with alternative machine tools

FMS is now expected as one of the measures to cope with the recent requirements for the production. To elevate the performance of the FMS, it is necessary to establish its design methodology by which the flexibility and compatibility of the system functions can be determined. In this regard, one of the most important technical subjects is how to solve problems arising from machine breakdown to ensure optimum use of the system performance.

This paper deals with a scheduling problem of a job-shop type FMS with machine breakdown, taking into account alternative machine tools for each machining process of parts. The problem is solved by a discrete event simulation using SLAM II simulation language. Performance of the system is measured in terms of the machine utilization, mean flow time, total production, number of workpieces in-progress, and makespan.