支持STEP-NC和ISO6983双重标准的开放式数控系统原型设计

采用"PC+运动控制卡"开放式数控系统模式,通过分析STEP-NC的数据模型特点,利用VC++、OpenGL图形库等工具,开发出支持STEP-NC和ISO6983双重标准的开放式数控系统原型。加工实例表明:该系统不但具备传统数控系统G代码解释功能,而且具有对STEP-NC向G代码数据转换功能,为CAD/CAM/CNC一体化奠定了基础。     

OPEN ARCHITECTURE CNC SYSTEM HITCNC AND KEY TECHNOLOGY

Aiming at the characteristics of modularity and reconfigurable in open architecture com-puter numerical control (CNC) system,the open architecture CNC system,Harbin Institute of Tech-nology computer numerical control (HITCNC),is researched and manufactured based on the interface standards. The system’s external interfaces are coincident with the corresponding international stan-dards,and the internal interfaces follow the open modular architecture controller (OMAC) agreement. In the research and manufacturing process,object-oriented technology is used to ensure the openness of the HITCNC,and static programming is applied in the CNC system according to the idea of modu-larization disassembly. The HITCNC also actualizes real-time and unreal-time modules adopting real-time dynamical linked library (RTDLL) and component object model (COM). Finite state ma-chine (FSM) is adopted to do dynamically modeling of HITCNC. The complete separation between the software and the hardware is achieved in the HITCNC by applying the SoftSERCANS technique. The application of the above key techniques decreases the programming workload greatly,and uses software programs replacing hardware functions,which offers plenty technique ensures for the open-ness of HITCNC. Finally,based on the HITCNC,a three-dimensional milling system is established. On the system,series experiments are done to validate the expandability and interchangeability of HITCNC. The results of the experiments show that the established open architecture CNC system HITCNC is correct and feasible,and has good openness.     

一种基于硬件在环的可重构数控系统验证方法

作为一种开放式控制器,可重构数控(Computer numerical control,CNC)系统充分利用先进的控制技术、硬件产品等有利资源,提高系统功能的自适应性与快速响应能力。针对可重构CNC系统的验证过程复杂、硬件环境依赖性强等特点,采用硬件在环的设计方法,由仿真系统模拟数控机床的加工制造过程。给出面向可重构CNC系统的硬件在环仿真环境设计方法:采用现场总线连接数控系统与仿真环境,满足实时性、动态性等测试要求;建立机床驱动设备的仿真功能单元,完成数控加工指令的控制操作;实现数控机床的加工过程仿真,采用图形方式显示工件的切削成形过程。结合S曲线插补算法以及三轴数控铣床的仿真实例,对可重构CNC系统的加工控制过程进行测试,并且与实际加工样件进行对比分析,说明硬件在环技术在可重构CNC系统测试过程中的可行性与有效性。     

基于RT-Linux的开放式数控系统的开发研究

操作系统的选择直接关系到开放式数控系统的开发难度和能否可靠地实现实时控制。文中在分析RT—Linux的特点和实时性基础上，选择RT—Linux和PC104总线计算机作为数控系统的软硬件开发平台，并从满足数控系统实时性要求的条件出发，提出了一种开放式数控系统的软硬件结构和基于共享内存方法的模块间实时通信机制。     

Windows平台下的软件化数控系统研究

首先对Windows的实时性能进行了分析,并通过实验对Windows下常用定时方法的实时性进行了考核。结果表明,内核模式下中断定时具有极强的实时性,借助于驱动程序开发工具开发出满足数控系统要求的实时模块是完全可能的。提出了基于Windows纯软件开放式数控系统的解决方案及软、硬件结构。开发出软件化数控系统实验平台,并在工作台上完成了高精度X-Y工作台圆运动实验。实验结果表明该平台不仅能完成运动控制系统的基本任务功能,且圆轮廓误差不超过±5μm,达到中档数控系统精度水平,并能通过改变控制策略和添加误差补偿环节进一步提高轮廓精度,实现了Windows下开发纯软件数控系统的目的。     

An interpolation method for the open CNC system based on EPM

A typical open computer numerical control (CNC) system should own the capability of being redeveloped easily and effectively, and any improvements of interpolation algorithm or machining technique could be put into practice by users conveniently. However, this is not always available in the current open CNC systems. To solve this problem, an interpolation method based on external profile mode (EPM) is introduced to improve the universality and the performance of an open CNC system in this paper. The method is realized with a rough interpolation in the PC host and a fine interpolation in the slave motion controller. With this method, various interpolation algorithms can be easily realized in the rough interpolation when machining complex contours. Meanwhile, the machining parameters during each interpolation cycle can be wholly determined by the host, so a real-time adjustment of machining parameters can be accomplished during the interpolation. The working principal of EPM is presented in this paper, and the realization of interpolation algorithms with the proposed method is described. A look-ahead algorithm for determining the machining parameters of each segment is implemented based on the length of segments in the rough interpolation. An acceleration/deceleration strategy with confined jounce is proposed in the look-ahead algorithm. The experimental results of specific profile interpolation show that the interpolation method based on EPM can make the open CNC system more universality and high performance.     

开放型CNC系统模块化的设计

基于模块化设计思想,建立计算机数控系统软、硬件的功能模块研制模式及原型系统。借助于计算机众多的最新成果,探讨以通用模块方式柔性组合为开放型 Ｃ Ｎ Ｃ 系统的实现方法,以 寻求解决计算机 集成制造系统中的一项关键技术。     

基于RTAI的嵌入式Linux水射流数控系统设计

通过分析磨料水射流数控系统的功能需求,提出并设计一种基于实时应用接口(Time Application Interface,RTAI)的嵌入式Linux水射流数控系统.通过RTAI加载实时内核,使得系统具有很好的开放性、分布性和实时性.     

基于USB通讯的PC-ARM9数控系统设计

设计一种基于USB通讯的PC-ARM9数控系统,采用"上位机+下位机"结构模式。PC机作为上位机负责G代码文件的生成和管理、G代码译码、界面的搭建等任务;以"ARM+CPLD+FPGA"构建的运动控制器作为下位机,负责粗精插补和开关量I/O管理等任务。重点介绍了系统的硬件架构和软件流程。     

A software oriented CNC system based on Linux/RTLinux

The software-oriented CNC is one of the ideal solutions for open architecture CNC. However, its implementation is a difficult task, especially the guarantee of system’s real-time performance. In this paper, a software oriented CNC system named Lin-soft CNC, whose operating system (OS) is Linux with its real-time extension - RTLinux - was proposed and depicted. The proposed system consists of four layers: the GUI, non-real-time layer, real-time layer and driver layer. Both the system and subsystem layout are detailed, along with the relevant implementation detail, such as the hierarchy design and the data communication between layers. Furthermore, the real-time layer has been identified as the kernel of the system, in which a simple and effective strategy - rational design of data buffer and high precision period of the real-time thread - is adopted to guarantee the real-time performance. At last, the prototype controller and test results are present.     

一种基于数字孪生的重型数控机床碰撞检测方法

目前数控机床碰撞检测通常利用系统的仿真功能对加工G代码进行检测,仅考虑数控机床加工过程中加工轨迹上刀具与理想状况下的工作台、夹具之间是否有干涉现象,难以满足开放式重型数控机床动态的加工环境、装夹方式以及刀具尺寸变化等实际情况。将数字孪生引入重型数控机床碰撞检测,构建了感知-演化预测-反馈的碰撞检测框架,即通过构建数控机床的数字孪生体,动态感知工件、夹具、刀具等加工要素,并感知数据驱动孪生模型演化,从而预测数控机床加工过程中潜在的干涉现象,提高了机床加工效率,避免加工过程的潜在危害。将所提方法应用于重型数控龙门镗铣机床ZK5520的碰撞检测,证明了其有效性与可行性。     

基于ASP模式的数控手工编程示教学习系统

通过对一种基于AsP(Application Service Provider)模式的在线互动式数控手工编程示教学习系统的设计和对其若干关键技术与功能(如数控加工工艺知识的抽取、表示与存取方法,数控加工工艺知识库,常见G指令和M指令数据库及其帮助查询,指令代码联想及纠错,在线互动式数控练习系统以及数控编程实例集等)的开发实现,为数控编程学习者提供一个Web风格的、具有良好人机界面的启发式数控手工编程环境、学习和练习系统,使其能便捷地学习、掌握数控编程及数控加工相关的知识.     

数控教学系统研究与开发

介绍了一套多媒体数控教学系统软件。该系统具有操作面板，可以对NC代码进行编辑、检验，还具备插补仿真、简单G指令仿真等基本数控原理仿真功能，而且可以实现加工预览。     

基于DSP的数控插补平台研究

介绍了一种基于DSP的数控插补平台。该平台由上位机以及基于DSP和FPGA的运动控制器组成。上位机进行G代码的解析处理,通过ISA接口传输给DSP,在DSP中完成多轴运动控制,包括插补预处理、多轴插补运算、伺服控制、数据采集和实时轮廓误差的计算等。插补算法中,采用前瞻控制和柔性的加减速控制,实现了多段直线或圆弧的连续插补控制。由于DSP运算速度快,插补周期可以达到1ms以内,因此,该平台可达到很高的插补精度。实验验证表明,该平台运行稳定,功能完备,同时具有较高的轮廓精度,适合各种插补算法的研究。     

复合加工中心开放式数控系统设计与应用

复合加工机床是世界机床的发展方向，针对这种先进的数控机床开发出了与其相适应的数控系统。采用Turbo PMAC运动控制卡作为下位机，PC平台和Win2000操作系统作为上位机的结构，组建双CPU开放式数控系统。在开放式软件设计中，采用COM（Component Object Model）技术实现软件的插件化，为软件功能的扩展奠定了基础，便于系统的维护和升级。将该开放式数控系统应用于工程实际中，验证了系统的开放性与实用性。     

Time synchronization of hierarchical real-time networked CNC system based on ethernet/internet

With the development of Ethernet/Internet, using Ethernet/Internet technology to implement the communication of computer numerical control (CNC) system is a new research field of networked CNC system. To support the synchronization control of the CNC system based on Ethernet/Internet, a time synchronization solution for the hierarchical real-time networked CNC system based on Ethernet/Internet is designed in this paper. To evaluate the performance, some experiments were conducted and the results were analyzed. The results show that the field level time synchronization based on the hard real-time Ethernet time synchronization protocol IEEE 1588 meets the requirement of the hard real-time tasks, and the time synchronization between the NC server and the NC core computer based on global positioning system (GPS) and network time protocol (NTP) also meets the requirement of the soft real-time tasks. The results testify that the time synchronization solution based on Ethernet/Internet for the CNC system is realizable.     

数控技术发展状况及策略综述

对于数控系统而言,一方面由于传统数控系统的各个模块相互耦合,使得结构变更和功能扩展异常困难;另一方面由于数控系统结构的开放程度低,其研发过程无法充分利用先进的电子信息技术,极大降低了数控系统的研发效率,同时基于小团队的数控系统研发不能充分调动社会的有效资源和积极性,包括工艺过程实现在内的各模块难以全面细致,使得开发的高端数控并不高端。我国数控行业的发展很大程度上受限于数控系统自身的封闭性,数控系统的不开放以及制造工艺流程未体现等问题成为目前制约我国数控行业发展的主要瓶颈。随着先进计算机和电子信息技术的发展,充分利用组件式软件技术、通过互联网手段把全社会乃至全球的资源集中起来,有效发挥掌握工艺经验的一线人员等社会资源参与开发和甄别成为可能。为此分析我国数控行业和技术的发展状况,提出基于大数据的组件式数控平台体系结构,提出创建数控APP,营造中国数控发展大舞台,突破我国数控发展瓶颈的策略。     

Key Technology of Embedded System Implementation for Software-based CNC System

The software-based computer numerical control(CNC)system includes three types of tasks: periodic real-time tasks,aperiodic real-time tasks,and non-real-time tasks.The tasks are characterized by concurrency,hybridization,and correlation,which make system implementation difficult.The conventional scheduling algorithm can not meet the demands of system implementation in the software-based CNC system completely.The uncertainty factors when running real-time tasks affect control performance by degrading manufacturing accuracy as a result of system resource and processor use restrictions.To address the technical difficulty of embedded system implementation,a novel fuzzy feedback scheduling algorithm based on output jitter of key real-time tasks for a software-based CNC system is proposed.Time characteristics,such as sampling jitter,input-output jitter,and non-schedulability are discussed,followed by quantification through simulations of the impact of time characteristics on manufacturing accuracy.On the basis of this research,the scheduler architecture is designed,and then the algorithm table is calculated.When the system resource changes,the key periodic real-time tasks meet their deadlines by means of dynamically adjusting the task period.The simulated results show that the machining precision rises by an order of magnitude for the proposed scheduler in resource-constrained software-based CNC systems.Moreover,unlike conventional feedback scheduling methods,the algorithm in this paper does not rely on the availability of task execution times and is easy to implement while incurring only a small overhead.     

基于Windows多线程数控文件传输系统

利用多线程技术和Win32串行通信原理,实现了计算机与数控机床之间数控文件的传输。利用Windows多任务属性,实现了一机程控多台NC机床。该系统能够实时、高效、准确地传输数控文件,并具有代码传输可控化、可视化及操作灵活等特点。